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Define integumentary organ system. Distinguish between serous and mucous membranes. List six functions of skin. Distinguish between the epidermis and the dermis. Describe the subcutaneous layer. Explain what happens to epidermal cells as they undergo keratinization. Describe the function of melanocytes. Describe the structure of the dermis. Review the functions of dermal nervous tissue. Explain the functions of the subcutaneous layer. Distinguish between a...

Blood Platelets

Platelets (plat'letz), or thrombocytes, are not complete cells. They arise from very large cells in the red bone marrow, called megakaryocytes, that fragment a little like a shattered plate, releasing small sections of cytoplasm platelets into the circulation. The larger fragments of the megakaryocytes shrink and become platelets as they pass through the blood vessels of the lungs. Each platelet lacks a nucleus and is less than half the size of a red blood cell. It is capable of ameboid...

Special Senses page 463

Special senses are those whose receptors occur in relatively large, complex sensory organs of the head. (1) Olfactory receptors are chemoreceptors that chemicals dissolved in liquid stimulate. (2) Olfactory receptors function together with taste receptors and aid in food selection. (1) The olfactory organs consist of receptors and supporting cells in the nasal cavity. (2) Olfactory receptors are neurons with cilia that sense lipid-soluble chemicals. (1) Nerve impulses travel from the olfactory...

Spinal Nerves

Thirty-one pairs of spinal nerves originate from the spinal cord. They are mixed nerves, and they provide two-way communication between the spinal cord and parts of the upper and lower limbs, neck, and trunk. Spinal nerves are not named individually but are grouped by the level from which they arise, with each nerve numbered in sequence (fig. 11.30). Thus, there are eight pairs of cervical nerves (numbered C1 to C8), twelve pairs of thoracic nerves (numbered T1 to T12), five pairs of lumbar...

Nerve Fiber Classification

Like nerve fibers, nerves that conduct impulses into the brain or spinal cord are called sensory nerves, and those that carry impulses to muscles or glands are termed motor nerves. Most nerves, however, include both sensory and motor fibers, and they are called mixed nerves. Nerves originating from the brain that communicate with other body parts are called cranial nerves, whereas those originating from the spinal cord that communicate with other body parts are called spinal nerves. The nerve...

Genetic Heterogeneity

The same phenotype may result from the actions of different genes, a phenomenon called genetic heterogeneity. For example, nearly 200 forms of hereditary deafness are known, each due to impaired actions of a different gene. The eleven types of clotting disorders reflect the many protein factors and enzymes that control this process. Any of several genes may also cause cleft palate, albinism, diabetes insipidus, colon cancer, and breast cancer. 99 Distinguish between penetrance and expressivity....

Parasympathetic Division

The preganglionic fibers of the parasympathetic division (craniosacral division) arise from neurons in the mid-brain, pons, and medulla oblongata of the brain stem and from the sacral region of the spinal cord (fig. 11.40). From there, they lead outward on cranial or sacral nerves to ganglia located near or within various organs (terminal ganglia). The short postganglionic fibers continue from the ganglia to specific muscles or glands within these organs (fig. 11.41). Parasympathetic...

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Anterior Hormones Target Organs

Hormones released from the hypothalamus, the corresponding hormones released from the anterior lobe of the pituitary gland, and their target organs. Thyroid-stimulating hormone, also called thyrotropin, is a glycoprotein. It controls secretion of certain hormones from the thyroid gland. TSH can also stimulate growth of the gland, and abnormally high TSH levels may lead to an enlarged thyroid gland, or goiter. The hypothalamus partially regulates TSH secretion by producing thyrotropin-releasing...

Types of Sleep

The two types of normal sleep are slow wave and rapid eye movement (REM). Slow-wave sleep (also called non-REM sleep) occurs when a person is very tired, and it reflects decreasing activity of the reticular formation. It is restful, dreamless, and accompanied by reduced blood Inability to sleep, emotional instability, hallucinations, stupor, coma, death within thirteen months of onset around age fifty, both slow-wave and REM sleep abolished. Abnormal REM sleep causes extreme daytime sleepiness,...

Brain Waves

Brain waves are recordings of fluctuating electrical changes in the brain. To obtain such a recording, electrodes are positioned on the surface of a surgically exposed brain (an electrocorticogram, ECoG) or on the outer surface of the head (an electroencephalogram, EEG). These electrodes detect electrical changes in the extracellular fluid of the brain in response to changes in potential among large groups of neurons. The resulting signals from the electrodes are amplified and recorded. Brain...

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Opsinization Phagocytosis Figure Simple

Monoclonal antibodies are produced by a type of artificial cell combination called a hybridoma. It consists of a cancer cell (the flat blue cell) fused with a B cell (the round green cell). The cancer cell contributes rapid and continuous division the B cell secretes a single antibody type (7,000x). slowly releasing viral antigens after an initial infection. This constantly stimulates memory B cells, which present the antigens to T cells, maintaining immunity. As a result of a primary immune...

Life Span Changes

Tracking the changes that are part of normal aging of the cardiovascular system is difficult because of the high incidence of disease affecting the heart and blood vessels, which increases exponentially with age. For example, 60 of men over age sixty have at least one narrowed coronary artery the same is true for women over age eighty. Signs of cardiovascular disease may appear long before symptoms arise. Autopsies of soldiers killed in the Korean and Vietnam wars, for example, reveal...

Reproductive System

Hormones are carried in the bloodstream. Some hormones directly affect the heart and blood vessels. Blood pressure is important in normal function of the sex organs. The Online Learning Center is your link to electronic learning resources that will help you review and understand the chapter content. Visit the Student OLC on your text website at http www.mhhe.com shier Here is your chance to show how much you really know. Match figure labels to the corresponding structures and check your...

Transport

Two organ systems transport substances throughout the internal environment. The cardiovascular (kahr3de-o-vas< ku-lur) system (fig. 1.14) includes the heart, arteries, capillaries, veins, and blood. The heart is a muscular pump that helps force blood through the blood vessels. Blood transports gases, nutrients, hormones, and wastes. It carries oxygen from the lungs and nutrients from the digestive organs to all body cells, where these substances are used in metabolic processes. Blood also...

Carbohydrates

Carbohydrates (karbo-hi'dratz) provide much of the energy that cells require. They also supply materials to build certain cell structures, and they often are stored as reserve energy supplies. Carbohydrates are water-soluble molecules that contain atoms of carbon, hydrogen, and oxygen. These molecules usually have twice as many hydrogen as oxygen atoms, the same ratio of hydrogen to oxygen as in water molecules (H2O). This ratio is easy to see in the molecular formulas of the carbohydrates...

Adipose Tissue

Adipose tissue (adi-pos tishou), or fat, is another form of connective tissue. Certain cells within connective tissue (adipocytes) store fat in droplets within their cytoplasm. At first, these cells resemble fibroblasts, but as they accumulate fat, they enlarge, and their nuclei are pushed to one side (fig. 5.19). When adipocytes become so abundant that they crowd out other cell types, they form adipose tissue. This tissue lies beneath the skin, in spaces between muscles, around the kidneys,...

Your Link to Media Support

The Online Learning Center is your link to electronic learning resources that will help you review and understand the chapter content. Visit the Student OLC on your text website at http www.mhhe.com shier Test your mental powers with the labeling exercises. Evaluate your success by scoring the results. If you find yourself scrambling for help, take advantage of the online tutorial service. Ask the content expert for help with those hard-to-grasp concepts. Animation Activities Lab Exercises...

Hypertension continued

Hours with no lasting effects, but may be a warning of an impending, more serious stroke. Treatment of hypertension varies and may include exercising regularly, controlling weight, reducing stress, and limiting the diet to foods that are low in sodium. Drugs, such as diuretics and or inhibitors of sympathetic nerve activity, may help control blood pressure. Diuretics increase urinary excretion of sodium and water, reducing the volume of body fluids. Sympathetic inhibitors block the synthesis of...

Posterior Group

The gluteus maximus (gloo'te-us mak'si-mus) is the largest muscle in the body and covers a large part of each buttock. It connects the ilium, sacrum, and coccyx to the femur by fascia of the thigh and extends the thigh. The gluteus maximus helps to straighten the lower limb at the hip when a person walks, runs, or climbs. It is also used to raise the body from a sitting position (fig. 9.36). The gluteus medius (gloo'te-us me'de-us) is partly covered by the gluteus maximus. Its fibers extend...

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Anterior Pituitary Gland Slide 100x

Hypothalamic control of the peripheral endocrine glands may utilize as many as three types of hormones, with multiple negative feedback controls, indicated by 0. U Where is the pituitary gland located List the hormones that the anterior and posterior lobes of the pituitary gland secrete. Explain how the hypothalamus controls the actions of the pituitary gland. The anterior lobe of the pituitary gland is enclosed in a dense capsule of collagenous connective tissue and largely consists of...

Absorption in the Small Intestine

Because villi greatly increase the surface area of the intestinal mucosa, the small intestine is the most important absorbing organ of the alimentary canal. In fact, the small intestine is so effective in absorbing digestive products, water, and electrolytes, that very little absorbable material reaches its distal end. Carbohydrate digestion begins in the mouth with the activity of salivary amylase and is completed in the small intestine by enzymes from the intestinal mucosa and pancreas. The...

Cancer Pain and Chronic Pain

One of the shortcomings of modern medicine is that many patients suffering from the pain of advanced, untreatable cancer do not receive adequate medication to ease their final days. Studies show that 50 of people with cancer are in pain at the time of their diagnosis, and 90 of those in advanced stages are in pain. Doctors are beginning to advocate pain relief for all people with cancer who require it, not only for humanitarian reasons but for clinical ones. Studies on rats with lung cancer...

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Cortisol and aldosterone are steroids with similar molecular structures. Cortisol and aldosterone are steroids with similar molecular structures. 2. It promotes the release of fatty acids from adipose tissue, increasing the use of fatty acids as an energy source and decreasing the use of glucose as an energy source. 3. It stimulates liver cells to synthesize glucose from noncarbohydrates (gluconeogenesis), such as circulating amino acids and glycerol, thus increasing blood glucose...

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Possible to make unlimited amounts of pure proteins just as the AIDS epidemic was making it essential to find a purer source of biochemicals than cadavers Interferon was the first cytokine to be tested on a large scale. Although it did not live up to early expectations of being a wonder drug, it does treat a dozen or so conditions, including a type of leukemia, multiple sclerosis, hepatitis, and genital warts. In another cytokine-based cancer treatment, certain T cells are removed from tumor...

Stereoscopic Vision

Stereoscopic vision (stereopsis) simultaneously perceives distance, depth, height, and width of objects. Such vision is possible because the pupils are 6-7 centimeters apart. Consequently, objects that are close (less than 20 feet away) produce slightly different retinal images. That is, the right eye sees a little more of one side of an object, while the left eye sees a little more of the other side. These two images are somehow superimposed and interpreted by the visual cortex of the brain....

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Weating is a highly effective mechanism for cooling the body. Becoming drenched with sweat following heavy exertion or an intense workout can feel good. But for people with hyperhidrosis, sweating is profuse, uncontrollable, unpredictable, and acutely embarrassing. Sweat consists of water released from about glands in the skin, in response to stimulation by the nervous system. About 2 million of these glands are in the hands, which explains why our palms become sweaty when we are nervous. For...

OG Reconnect to chapter 3 Active Transport page

When a muscle fiber is at rest, the tropomyosin-troponin complexes block the binding sites on the actin molecules and thus prevent the formation of linkages with myosin cross-bridges (fig 9.11a). As the concentration of calcium ions in the cytosol rises, however, the calcium ions bind to the troponin, changing its shape (conformation) and altering the position of the tropomyosin. The movement of the tropomyosin molecules exposes the binding sites In an autoimmune disorder, the immune system...

Functions of the Cerebrum

Sensory Input Left Parietal Lobe

The cerebrum provides higher brain functions interpreting impulses from sense organs, initiating voluntary muscular movements, storing information as memory, and retrieving this information in reasoning. The cerebrum is also the seat of intelligence and personality. The regions of the cerebral cortex that perform specific functions have been located using a variety of techniques. Persons who have suffered brain disease or injury, such as Karen Ann Quinlan and Phineas Gage, or have had portions...

Factors that Influence Arterial Blood Pressure

Arterial pressure depends on a variety of factors. These include heart action, blood volume, resistance to flow, and blood viscosity (fig. 15.35). In addition to producing blood pressure by forcing blood into the arteries, heart action determines how much blood enters the arterial system with each ventricular contraction. The volume of blood discharged from the ventricle with each contraction is called the stroke volume and equals about 70 milliliters in an average-weight

Catabolism

Physiological processes that break down larger molecules into smaller ones constitute catabolism. An example of catabolism is hydrolysis (hi-drol'i-sis), which can decompose carbohydrates, lipids, and proteins. A water molecule is used to split these substances into two parts. The hydrolysis of a disaccharide, for instance, results in two monosaccharide molecules (see fig. 4.1 read from right to left). In this case, the bond between the simple sugars breaks, and the water molecule supplies a...

Unit Four

Artery Contraction

Tissues in affected regions typically become edematous and painful. Heredity, pregnancy, obesity, and standing for long periods raise the risk of developing varicose veins. Elevating the legs above the level of the heart or putting on support hosiery before arising in the morning can relieve discomfort. In travenous injection of a substance that destroys veins (a sclerosing agent) or surgical removal of the affected veins may be necessary. tissues in affected regions typically become edematous...

Laboratory Tests of Clinical Importance

Values increase in multiple myeloma and decrease with proteinuria and as a result of severe burns. Albumin-globulin ratio, or A G ratio (serum) Ratio of albumin to globulin is lowered in kidney diseases and malnutrition. Values increase in severe liver disease, pneumonia, shock, and congestive heart failure. Values increase in acute pancreatitis, intestinal obstructions, and mumps. They decrease in chronic pancreatitis, cirrhosis of the liver, and toxemia of pregnancy. Values increase in...

Elastic Connective Tissue

Hermaphrodite Humans Pictures Medical

Elastic connective tissue mainly consists of yellow, elastic fibers in parallel strands or in branching networks. Between these fibers are collagenous fibers and fibro-blasts. This tissue is found in the attachments between vertebrae of the spinal column (ligamenta flava). It is also in the layers within the walls of certain hollow internal organs, including the larger arteries, some portions of the heart, and the larger airways, where it imparts an elastic quality (fig. 5.22). O Differentiate...

General Characteristics

Reflexes in which sensory signals originate from receptors within the viscera and the skin regulate autonomic activities. Afferent nerve fibers transmit these signals to nerve centers within the brain or spinal cord. In response, motor impulses travel out from these centers on efferent nerve fibers within cranial and spinal nerves.

Peripheral Nervous system

The peripheral nervous system (PNS) consists of the nerves that branch from the central nervous system (CNS), connecting it to other body parts. The PNS includes the cranial nerves that arise from the brain and the spinal nerves that arise from the spinal cord. The peripheral nervous system can also be subdivided into somatic and autonomic nervous systems. Generally, the somatic nervous system consists of the cranial and spinal nerve fibers that connect the CNS to the skin and skeletal muscles,...

Peripheral Nervous System page 426

The peripheral nervous system consists of cranial and spinal nerves that branch out from the brain and spinal cord to all body parts. It can be subdivided into somatic and autonomic portions. 1. Structure of peripheral nerves a. A nerve consists of a bundle of nerve fibers surrounded by connective tissues. b. The connective tissues form an outer epineurium, a perineurium enclosing bundles of nerve fibers, and an endoneurium surrounding each fiber. a. Nerves are cordlike bundles of nerve fibers....

Critical Thinking Questions

They include the external oblique, internal oblique, transversus abdominis, and rectus abdominis. a. These muscles form the floor of the pelvic cavity and fill the space of the pubic arch. b. They include the levator ani, coccygeus, superficial transversus perinei, bulbospongiosus, ischiocavernosus, and sphincter urethrae. 10. Muscles that move the thigh a. These muscles are attached to the femur and to some part of the pelvic girdle. b. They include the psoas major, iliacus, gluteus...

Prenatal Tests

Several types of tests performed on pregnant women can identify increased risk of carrying a fetus with a chromosomal problem or actually detect the abnormal chromosomes (fig. 24.15) A blood test performed during the fifteenth week of pregnancy detects levels of maternal serum markers (specifically, alpha fetoprotein, a form of estrogen, and human chorionic gonadotropin) that can indicate the underdeveloped liver that is a symptom of certain trisomies, including Down syndrome. Often called the...

Functions of Bile Salts

Bile salts aid digestive enzymes and enhance absorption of fatty acids and certain fat-soluble vitamins. Molecules of fats clump into fat globules. Bile salts affect fat globules much like a soap or detergent would, reducing surface tension and breaking fat globules into smaller droplets. This action is called emulsification. Monoglyc-erides that form from the action of pancreatic lipase on triglyceride molecules aid emulsification. This emulsifi-cation greatly increases the total surface area...

Application

Hepatitis is an inflammation of the liver caused by viral infection, or, more rarely, from reaction to a drug, alcoholism, or autoimmunity. There are several types of hepatitis. Liver inflammation Causes Distinct Symptoms Hepatitis A is one of the least severe forms of this common illness. For the first few days, symptoms include mild headache, low fever, fatigue, lack of appetite, nausea and vomiting, and sometimes stiff joints. By the end of the first week, more distinctive symptoms arise,...

Facilitated Diffusion

Most sugars and amino acids are insoluble in lipids, and they are too large to pass through cell membrane pores. Facilitated diffusion includes not only protein channels, but also certain proteins that function as carriers to bring such molecules across the cell membrane. In the facilitated diffusion of glucose, for example, glucose combines with a protein carrier molecule at the surface of the membrane. This union of glucose and carrier molecule changes the shape of the carrier that moves...

Thigh Adductors

The pectineus (pek-tin'e-us) muscle runs from the spine of the pubis to the femur. It adducts and flexes the thigh (fig. 9.35). The adductor longus (ah-duk'tor long'gus) is a long, triangular muscle that runs from the pubic bone to the femur. It adducts the thigh and assists in flexing and rotating it laterally (fig. 9.35). The adductor magnus (ah-duk'tor mag'nus) is the largest adductor of the thigh. It is a triangular muscle that connects the ischium to the femur. It adducts the thigh and...

Auditory Tube

An auditory tube (eustachian tube) connects each middle ear to the throat. This tube allows air to pass between the tympanic cavity and the outside of the body by way of the throat (nasopharynx) and mouth. It helps maintain equal air pressure on both sides of the eardrum, which is necessary for normal hearing (see fig. 12.11). The function of the auditory tube becomes noticeable during rapid change in altitude. As a person moves from a high altitude to a lower one, the air pressure on the...

Specific Defenses Immunity page 661

Before birth, body cells inventory self proteins and other large molecules. b. After inventory, lymphocytes develop receptors that allow them to differentiate between nonself (foreign) and self antigens. c. Nonself antigens combine with T cell and B cell surface receptors and stimulate these cells to cause an immune reaction. d. Haptens are small molecules that can combine with larger ones, becoming antigenic. a. Lymphocytes originate in red bone marrow and are released into the blood before...

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Otic Vessels

The abdominal area may be subdivided into four quadrants. orbital (orcbi-tal) eye cavity otic (ocfcik) ear palmar (pahlcmar) palm of the hand patellar (pah-telcar) front of the knee pectoral (pekctor-al) chest pedal (pedcal) foot pelvic (pelcvik) pelvis perineal (perci-necal) region between the anus and the external reproductive organs (perineum) plantar (planctar) sole of the foot popliteal (popSli-tecal) area behind the knee sacral (sackral) posterior region between the hipbones sternal...

Blood Plasma

Plasma is the clear, straw-colored, liquid portion of the blood in which the cells and platelets are suspended. It is approximately 92 water and contains a complex The young woman had noticed symptoms for several months before she finally went to the doctor. At first it was just fatigue and headaches, which she attributed to studying for final exams. She had frequent colds and bouts of fever, chills, and sweats that she thought were just minor infections. When she developed several bruises and...

Lire 1815

Vitamin C is chemically similar to some 6-carbon monosaccharides. deficiency of folacin leads to megaloblastic anemia, which is characterized by a reduced number of normal red blood cells and the presence of large, nucleated red cells. Folacin deficiency has been linked to neural tube defects, in which the tube that becomes the central nervous system in a fetus fails to close entirely. Neural tube defects include spina bifida and anencephaly. Taking synthetic folacin supplements just before and...

Neuropeptides

Neurons in the brain or spinal cord synthesize neuropeptides. These peptides act as neurotransmitters or as neuromodulators substances that alter a neuron's response to a neurotransmitter or block the release of a neurotransmitter. Among the neuropeptides are the enkephalins that occur throughout the brain and spinal cord. Each enkephalin molecule is a chain of five amino acids. Synthesis of enkephalins increases during periods of painful stress, and they bind to the same receptors in the brain...

White Blood Cell Counts

The procedure used to count white blood cells is similar to that used for counting red blood cells. However, before a white blood cell count is made, the red blood cells in the blood sample are destroyed so they will not be mistaken for white blood cells. Normally, a cubic millimeter of blood includes 5,000 to 10,000 white blood cells. The total number and percentages of different white blood cell types are of clinical interest. A rise in the number of circulating white blood cells may indicate...

Cardiac Cycle

During a cardiac cycle, the pressure within the chambers rises and falls. When the atria contract (atrial systole), the ventricles relax (ventricular diastole). When the ventricles contract (ventricular systole), the atria are relaxed (atrial diastole). Then the atria and ventricles both relax for a brief interval (fig. 15.15). Pressure in the ventricles is low early in diastole, and the pressure difference between atria and ventricles causes the A-V valves to open and the ventricles to fill....

Clinical Application

Bile Duct Small Intestines

Kennedy's beautiful bronze complexion may have resulted not from sunbathing, but from a disorder of the adrenal glands. When he ran for the presidency in 1960, Kennedy knew he had Addison disease, but his staff kept his secret, for fear it would affect his career. Kennedy had almost no adrenal tissue, but was able to function by receiving mineralocorti-coids and glucocorticoids, the standard treatment. In Addison disease, the adrenal cortex does not secrete hormones sufficiently due to...

Penetrance and Expressivity

Most disease-causing allele combinations are completely penetrant, which means that everyone who inherits it has some symptoms. A genotype is incompletely penetrant if some individuals do not express the phenotype. Polydactyly, having extra fingers or toes, is incompletely penetrant (see fig. 7.48). Some people who inherit the dominant allele have more than five digits on a hand or foot, yet others who are known to have the allele (because they have an affected parent and child) have the normal...

Reconnect to chapter 11 Sympathetic Division page 438

What Hormone Stimulates Adrenal Medulla

H Describe the location and structure of the adrenal glands. 9 Name the hormones the adrenal medulla secretes. 9 What general effects do hormones secreted by the adrenal medulla produce Q What usually stimulates release of hormones from the adrenal medulla (a) An adrenal gland consists of an outer cortex and an inner medulla. (b) The cortex has three layers, or zones, of cells. (a) An adrenal gland consists of an outer cortex and an inner medulla. (b) The cortex has three layers, or zones, of...

Inorganic Salts

Inorganic salts are abundant in body fluids. They are the sources of many necessary ions, including ions of sodium (Na+), chloride (Cl-), potassium (K+), calcium (Ca+2), magnesium (Mg+2), phosphate (PO4-2), carbonate (CO3-2), bicarbonate (HCO3-), and sulfate (SO4-2). These ions play important roles in metabolic processes, helping to maintain proper water concentrations in body fluids, pH, blood clotting, bone development, energy transfer within cells, and muscle and nerve functions. These...

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Daughters of women who took the drug DES (diethyl-stilbestrol) while pregnant with them may develop a benign condition called adenosis. It arises when secretory columnar epithelium, resembling normal cells of the uterine lining, grow in the wrong place in the vagina, up near the cervix. It is a little as if the lining of the mouth were to grow onto the face. Adenosis may produce a slight vaginal discharge. It is detected with a procedure called the Pap (Papanicolaou) smear test. A doctor or...

Thymus

The thymus (thi'mus) gland is a soft, bilobed structure enclosed in a connective tissue capsule (fig. 16.12). It is located within the mediastinum, anterior to the aortic arch and posterior to the upper part of the body of the sternum, and extends from the root of the neck to the pericardium. The thymus varies in size from person to person, and it is usually larger during infancy and early childhood. After puberty, the thymus shrinks, and in an adult, it may be quite small. In elderly persons,...

JF Venules and Veins

Venules (ven' lz) are the microscopic vessels that continue from the capillaries and merge to form veins. The veins, which carry blood back to the atria, follow pathways that roughly parallel those of the arteries. The walls of veins are similar to those of arteries in that they are composed of three distinct layers. However, the middle layer of the venous wall is poorly developed. Consequently, veins have thinner walls that contain less smooth muscle and less elastic tissue than those of...

Taste Receptors

Each taste bud includes a group of modified epithelial cells, which are the taste cells (gustatory cells) that function as receptors. Each of our 10,000 taste buds houses 50 to 150 taste cells. The taste bud also includes epithelial supporting cells. The entire structure is somewhat spherical, with an opening, the taste pore, on its free surface. Tiny projections (microvilli), called taste hairs, protrude from the outer ends of the taste cells and jut out through the taste pore. These taste...

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(a) Microtubules help maintain the shape of a cell by forming an internal scaffolding, or cytoskeleton, beneath the cell membrane and within the cytoplasm. (b) A falsely colored electron micrograph of cells showing the cytoskeleton (250x micrograph enlarged to 750x). This is the condition of diffusional equilibrium (di-fuczhun-ul e3kwi-lib< ie-um). At diffusional equilibrium, although random movements continue, there is no further net movement, and the concentration of a substance will be...

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Ischiofemoral Ligament Coronal Section

(a) Ligaments hold together the articulating surfaces of the shoulder. (b) The glenoid labrum is a ligament composed of fibrocartilage. the lesser tubercle and the anatomical neck of the humerus. 3. Transverse humeral ligament. This ligament consists of a narrow sheet of connective tissue fibers that runs between the lesser and the greater tubercles of the humerus. Together with the intertubercular groove of the humerus, the ligament forms a canal (retinaculum) through which the long head of...

Line

Kolvoord The Image Works F1.1 Andreas Vesalius, 2nd book, De Humani Corporis Fabrica,1543 F1.3 The McGraw-Hill Companies Carol D. Jacobson Ph.D., Dept. of Veterinary Anatomy, Iowa State University F1A Alexander Tsiaras Photo Researchers F1B Lutheran Hospital Peter Arnold F1C SPL Photo Researchers Fl.19a(1) Patrick J. Lynch Photo Researchers F1.19b(1) Biophoto Associates Photo Researchers F1.19c(1) A. Glauberman Photo Researchers. Opener Leonard Lessin Peter...

Functions of the Large Intestine

Unlike the small intestine, which secretes digestive enzymes and absorbs the products of digestion, the large intestine has little or no digestive function. However, the mucous membrane that forms the inner lining of the large intestine contains many tubular glands. Structurally, these glands are similar to those of the small intestine, but they are composed almost entirely of goblet cells. Consequently, mucus is the only significant secretion of this portion of the alimentary canal (fig....

Veins from the Head Neck and Brain

Cervical Blood Vessels

The external jugular (jug'u-lar) veins drain blood from the face, scalp, and superficial regions of the neck. These vessels descend on either side of the neck, passing over the sternocleidomastoid muscles and beneath the platysma. They empty into the right and eft subclavian veins in the base of the neck (fig. 15.54). The internal jugular veins, which are somewhat larger than the external jugular veins, arise from numerous veins and venous sinuses of the brain and from deep veins in various...

Wwt

The developing placenta, composed of chorionic and endometrial capillaries, as it appears during the seventh week of development. because during it, the embryo implants within the uterine wall, and all the essential external and internal body parts form. Disturbances to development during the embryonic stage can cause major malformations or malfunctions. This is why early prenatal care is very important. Factors that cause congenital malformations by affecting an embryo during its period of...

Online Learning Center wwwmhhecomshier

The OLC offers an extensive array of learning and teaching tools. The site includes quizzes for each chapter, links to websites related to each chapter, supplemental reading lists, clinical applications, interactive activities, art labeling exercises, and case studies. Students can click on a diagram of the human body and get case studies related to the regions they select. Instructor resources at the site include lecture outlines, supplemental reading lists, technology resources, clinical...

Lifespan Changes

The redundancies and overlap of function built into our nervous systems ensure that we can perceive and interact with the environment for many decades. In a sense, aging of this organ system actually begins before birth, as apo-ptosis, a form of programmed cell death, occurs in the brain, essentially carving out the structures that will remain. This normal dying off of neurons continues throughout life. When brain apoptosis fails, disease results. The brains of individuals who die of...

Innervation of the Tube

Branches of the sympathetic and parasympathetic divisions of the autonomic nervous system extensively innervate the alimentary canal. These nerve fibers, mainly associated with the tube's muscular layer, maintain muscle tone and regulate the strength, rate, and velocity of muscular contractions. Many of the postganglionic fibers are organized into a network or plexus of neurons within the wall of the canal (see figure 17.3). The submucosal plexus is important in controlling secretions by the...

C7 C8 T1

Typically, these efferent fibers lead to ganglia outside the central nervous system. The impulses they carry are integrated within the ganglia and are relayed to various organs (muscles or glands) that respond by contracting, secreting, or being inhibited. The integrative function of the ganglia provides the autonomic nervous system with some degree of independence from the brain and spinal cord, and the visceral efferent nerve fibers associated with these ganglia comprise the autonomic nervous...

Brain Development

The basic structure of the brain reflects the way it forms during early (embryonic) development. It begins as the neural tube that gives rise to the central nervous system. The portion that becomes the brain has three major cavities, or vesicles, at one end the forebrain (prosen-cephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon) (fig. 11.14). Later, the forebrain divides into anterior and posterior portions (telencephalon and diencephalon, respectively), and the hindbrain...

Aneuploidy

Cells missing a chromosome or having an extra one are aneuploid. A normal chromosome number is termed eu-ploid. Symptoms that result from aneuploidy depend upon which chromosome is missing or extra. Autosomal aneuploidy often results in mental retardation, possibly because so many genes affect brain function. Sex chromosome aneuploidy is less severe. Extra genetic material is apparently less dangerous than missing material, and this is why most children born with the wrong number of chromosomes...

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Blood Vessel Blood Cycle

Major events in the female ovarian and menstrual cycles. Follicular development parallels FSH concentration. Ovulation is preceded and triggered by the LH surge. characteristics may change. The breasts, vagina, uterus, and uterine tubes may shrink, and the pubic and axillary hair may thin. The epithelial linings associated with urinary and reproductive organs may thin. There may be increased loss of bone matrix (osteoporosis) and thinning of the skin. Because the pituitary secretions of FSH and...

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Ike many things in life, individual muscles aren't appreciated until we see what happens whan trey cfo rot work. For children with Hfoebius syndroms, abserce of tre sixth and seventh cranial reives, whch cany impulses from tre brain to the musclas of tre rase, taads to an l re first signs or Utoebius syndrome are typcally difficulty sixk-ing, excessive drooling, and sometimes crossed eyes. The chid has difficulty swallowing ard chokes easily, cannot move the tongue well, and s very sensitive to...

Cervical Plexuses

The cervical plexuses lie deep in the neck on either side. They are formed by the anterior branches of the first four cervical nerves. Fibers from these plexuses supply the muscles and skin of the neck. In addition, fibers from the third, fourth, and fifth cervical nerves pass into the right and left phrenic (fren'ik) nerves, which conduct motor impulses to the muscle fibers of the diaphragm. The thirty-one pairs of spinal nerves are grouped according to the level from which they arise and are...

Rcg

Vaccine, 670, 676 cancer, 1000 edible, 670 Vagina, 37, 336, 337, 899, 904, 905-6, 908t, 913, 920 fibrous layer of, 906 HIV transport across lining of, 92, 93 mucosal layer of, 906 muscular layer of, 906 Vaginal orifice, 899, 906, 906, 958 Vaginal process, 883 Vaginal vein, 637 Vaginitis, 931 Vagotomy, 448 Vagus nerve (X), 429, 431, 432, 433t, 440, 444, 467, 597, 704, 706, 803, 1023 Valium, 384t, 387 Valvotomy, 639 van Leeuwenhoek, Anton, 888 Variable expressivity, 986 Varicocele, 931 Varicose...

Review Exercises

Distinguish between chemistry and biochemistry. 3. Explain the relationship between elements and atoms. 5. List the four most abundant elements in the human body. 6. Describe the major parts of an atom. 7. Distinguish between protons and neutrons. 8. Explain why a complete atom is electrically neutral. 9. Distinguish between atomic number and atomic weight. 12. Describe how electrons are arranged within atoms. 13. Explain why some atoms are chemically inert. 14. Distinguish between an ionic...

Pons Transmit Impulses

The pons appears as a rounded bulge on the underside of the brain stem where it separates the midbrain from the medulla oblongata (see fig. 11.20). The dorsal portion of the pons largely consists of longitudinal nerve fibers, which relay impulses to and from the medulla oblongata and the cerebrum. Its ventral portion contains large bundles of transverse nerve fibers, which transmit impulses from the cerebrum to centers within the cerebellum. Several nuclei of the pons relay sensory impulses...

Rsl

In semen, sperm swim in a straight line (a), but as they are activated by biochemicals normally found in the woman's body, their trajectories widen (b). The sperm in (c) are in the mucus of a woman's cervix, and the sperm in (d) are attempting to penetrate the structures surrounding an egg cell. glands is expelled first. This is followed by the release of fluid from the prostate gland, the passage of the sperm cells, and finally, the ejection of fluid from the...

Introduction page

When a patient arrives at a hospital with an unknown injury, medical staff must rapidly apply their knowledge of human anatomy and physiology to correctly diagnose the problem. 2. Early interest in the human body probably developed as people became concerned about injuries and illnesses. Changes in lifestyle, from hunter-gatherer to farmer to city dweller, were reflected in types of illnesses. 3. Early doctors began to learn how certain herbs and potions affected body functions. 4. The idea...

Gastric Absorption

Gastric enzymes begin breaking down proteins, but the stomach wall is not well-adapted to absorb digestive The food at the barbecue was so terrific that Perry W. didn't notice how much he was consuming two burgers, three hot dogs, beans in a spicy sauce, loads of chips, several beers, and ice cream for dessert. Later, he paid for it, as a feeling of fullness became abdominal pain, then heartburn, as stomach contents backed up into his esophagus. Perry found relief with an over-the-counter...

What Blood Vessel Empties Into The Interlobular Artery Is Called

Generalized Structure Blood Vessels

(a) Transverse section through the posterior abdominal cavity including the kidneys, which are located behind the parietal peritoneum. Adipose and other connective tissues surround and support the kidneys. (b) Sagittal section through the posterior abdominal cavity showing the kidney. About two in every ten patients with renal failure can use a procedure that can be done at home called continuous ambulatory peritoneal dialysis instead of hemodialysis. The patient infuses a solution into the...

Basal Nuclei

The basal nuclei (basal ganglia) are masses of gray matter located deep within the cerebral hemispheres. They are called the caudate nucleus, the putamen, and the globus pallidus, and they develop from the anterior portion of the forebrain (fig. 11.19). The neuron cell bodies that the basal nuclei contain relay motor impulses originating in the cerebral cortex and passing into the brain stem and spinal cord. The basal nuclei produce most of the inhibitory neurotrans-mitter dopamine. Impulses...

Ff Sense of Sight

Utricle And Saccule Electron Microscope

A number of accessory organs assist the visual receptors, which are in the eyes. These include the eyelids and lacrimal apparatus that help protect the eyes and a set of extrinsic muscles that move them. The macula responds to changes in position of the head. (a) Macula with the head in an upright position. (b) Macula with the head bent forward. The macula responds to changes in position of the head. (a) Macula with the head in an upright position. (b) Macula with the head bent forward....

Simple Squamous Epithelium

Simple squamous epithelium consists of a single layer of thin, flattened cells. These cells fit tightly together, somewhat like floor tiles, and their nuclei are usually broad and thin (fig. 5.1). Substances pass rather easily through simple squa-mous epithelium, which is common at sites of diffusion and filtration. For instance, simple squamous epithelium lines the air sacs (alveoli) of the lungs where oxygen and carbon dioxide are exchanged. It also forms the walls of capillaries, lines the...

Sex Hormones

Cells in the inner zone (zona reticularis) of the adrenal cortex produce sex hormones. These hormones are male (adrenal androgens), but some of them are converted Helps regulate the concentration of extracellular electrolytes by conserving sodium ions and excreting potassium ions Electrolyte concentrations in body fluids and renin-angiotensin mechanism Decreases protein synthesis, increases fatty acid release, and stimulates glucose synthesis from noncarbohydrates CRH from the hypothalamus and...

Bone

Bone (osseous tissue) is the most rigid connective tissue. Its hardness is largely due to mineral salts, such as calcium phosphate and calcium carbonate, in its matrix. This intercellular material also contains a great amount of collagen, whose fibers flexibly reinforce the mineral components of bone. Bone internally supports body structures. It protects vital structures in the cranial and thoracic cavities and is an attachment for muscles. Bone also contains red marrow, which forms blood...

Characteristics of Red Blood Cells

Red blood cells, or erythrocytes (e-rith'ro-sitz), are tiny, approximately 7.5 im in diameter. They are biconcave disks which means that they are thin near their centers and thicker around their rims (fig. 14.4). This special shape is an adaptation for the red blood cell's function of transporting gases it increases the surface area through which gases can diffuse. The shape also places the cell membrane closer to oxygen-carrying hemoglobin molecules within the cell. Because of its shape, a red...

Static Equilibrium

Medial Geniculate Body

The organs of static equilibrium are located within the vestibule, a bony chamber between the semicircular canals and the cochlea. More specifically, the membranous labyrinth inside the vestibule consists of two expanded chambers a utricle and a saccule. The larger utricle communicates with the saccule and the membranous portions of the semicircular canals the sac-cule, in turn, communicates with the cochlear duct (fig. 12.18). The utricle and saccule each has a small patch of hair cells and...

Clinical Applications

I.1 Ultrasonography and Magnetic Resonance Imaging 2.1 Radioactive Isotopes Reveal Physiology 42 2.2 Ionizing Radiation A Legacy of the Cold War 46 2.3 CT Scanning and PET Imaging 58 3.1 Faulty Ion Channels Cause Disease 70 3.2 The Blood-Brain Barrier 73 3.3 Disease at the Organelle Level 80 3.4 Cloning 102 4.1 Overriding a Block in Glycolysis 117 4.2 DNA Makes History 126 4.3 Gene Amplification 132 4.4 Phenylketonuria 136 5.1 Abnormalities of Collagen 153 5.2 Tissue Engineering 162 6.1 Skin...

Plantar Flexors

The gastrocnemius (gastrok-ne'me-us) on the back of the leg forms part of the calf. It arises by two heads from the femur. The distal end of this muscle joins the strong cal-caneal tendon (Achilles tendon), which descends to the heel and attaches to the calcaneus. The gastrocnemius is a powerful plantar flexor of the foot that aids in pushing the body forward when a person walks or runs. It also flexes the leg at the knee (figs. 9.40 and 9.41). Strenuous athletic activity may partially or...

Synaptic Potentials

Neuron Mcgraw Hilll Anatomy

Synaptic potentials are graded and can depolarize or hy-perpolarize the receiving cell membrane. For example, if a neurotransmitter binds to a postsynaptic receptor and opens sodium ion channels, the ions diffuse inward, depolarizing the membrane, possibly triggering an action potential. This type of membrane change is called an excitatory postsynaptic potential (EPSP), and it lasts for about 15 milliseconds. If a different neurotransmitter binds other receptors and increases membrane...

Chapter Summary

Chemistry deals with the composition of substances and changes in their composition. Biochemistry is the chemistry of living things. Matter is anything that has weight and takes up space. a. Naturally occurring matter on earth is composed of ninety-two elements. b. Elements occur most frequently in chemical combinations called compounds. c. Elements are composed of atoms. d. Atoms of different elements vary in size, weight, and ways of interacting. a. An atom consists of electrons surrounding a...

Visceral Pain

Visceral Pain Pathway

As a rule, pain receptors are the only receptors in viscera whose stimulation produces sensations. Pain receptors in these organs respond differently to stimulation than those associated with surface tissues. For example, localized damage to intestinal tissue during surgical procedures may not elicit any pain sensations, even in a conscious person. However, when visceral tissues are subjected to more widespread stimulation, as when intestinal tissues are stretched or when the smooth muscles in...

Two Approaches to Gene Therapy

Gene Therapy Side Effects

There are two basic types of gene therapy. Heritable gene therapy, also known as germline gene therapy, introduces the genetic change into a sperm, egg, or fertilized egg, which corrects each cell of the resulting individual. The change is repeated in the person's gametes and can be passed to the next generation. Heritable gene therapy is considered to be impractical and unethical in humans and will likely never be done, at least with government

Muscles that Move the

Muscles That Move The Pectoral Girdle

The arm is one of the more freely movable parts of the body because muscles connect the humerus to regions of the pectoral girdle, ribs, and vertebral column. These muscles can be grouped according to their primary actions flexion, extension, abduction, and rotation (figs. 9.27, 9.28, 9.29 reference plates 62, 63, 64 table 9.7).

Blood Vessel Summary

The cardiovascular system provides oxygen and nutrients to tissues and removes wastes. 1. Size and location of the heart a. The heart is about 14 centimeters long and 9 centimeters wide. b. It is located within the mediastinum and rests on the diaphragm. a. A layered pericardium encloses the heart. b. The pericardial cavity is a space between the visceral and parietal layers of the pericardium. a. The wall of the heart has three layers. b. These layers include an epicardium, a myocardium, and...

Pancreatic Juice

Blood Vessels Pancreas

Pancreatic juice contains enzymes that digest carbohydrates, fats, proteins, and nucleic acids. The carbohydrate-digesting enzyme, pancreatic amylase, splits molecules of starch or glycogen into double sugars (disaccharides). The fat-digesting enzyme, pancreatic lipase, breaks triglyceride molecules into fatty acids and monoglyc-erides. (A monoglyceride molecule consists of one fatty acid bound to glycerol.) The protein-splitting (proteolytic) enzymes are trypsin, chymotrypsin, and...

Central Venous Pressure

Because all the veins, except those of the pulmonary circuit, drain into the right atrium, the pressure within this heart chamber is called central venous pressure. This pressure is of special interest because it affects the pressure within the peripheral veins. For example, if the heart is beating weakly, the central venous pressure increases, and blood backs up in the venous network, raising its pressure too. However, if the heart is beating forcefully, the central venous pressure and the...

Control of Cell Division

Turtle Salivary Gland

How often a cell divides is strictly controlled and varies with cell type. Skin cells, blood-forming cells, and cells that line the intestine, for example, divide often and continually. In contrast, cells of the liver divide a specific number of times and then cease they are alive and specialized, but no longer divide. If, however, injury or sur gery removes some liver cells, the remaining cells may be stimulated to divide again, regenerating the organ. Some cells, such as certain nerve cells,...

Lumbosacral Plexuses

The lumbosacral (lumbo-sa'kral) plexuses are formed by the last thoracic nerve and the lumbar, sacral, and coc-cygeal nerves. These networks of nerve fibers extend from the lumbar region of the back into the pelvic cavity, giving rise to a number of motor and sensory fibers associated with the lower abdominal wall, external genitalia, buttocks, thighs, legs, and feet. The major branches of these plexuses include the following (fig. 11.35) 1. The obturator nerves supply the adductor muscles of...

Muscles of the Abdominal Wall

The walls of the chest and pelvic regions are supported directly by bone, but those of the abdomen are not. Instead, the anterior and lateral walls of the abdomen are composed of layers of broad, flattened muscles. These muscles connect the rib cage and vertebral column to the pelvic girdle. A band of tough connective tissue, called the linea alba, extends from the xiphoid process of the sternum to the symphysis pubis. It is an attachment for some of the abdominal wall muscles. Contraction of...