Osseous Tissue and pH Balance
The urinary, respiratory, and skeletal systems cooperate to maintain the body's acid-base balance. If the pH of the blood drops below 7.35, a state of acidosis exists and triggers corrective mechanisms in these three organ systems. The role of the skeleton is to release calcium phosphate. As a base, calcium phosphate helps to prevent the blood pH from dropping lower. Patients with chronic kidney disease may have impaired hydrogen ion excretion in the urine. Their pH stabilizes at a level below...
Membrane Transport
When you have completed this section, you should be able to explain what is meant by a selectively permeable membrane describe the various mechanisms for transporting material through the plasma membrane and define osmolarity and tonicity and explain their importance. The plasma membrane is both a barrier and gateway between the cytoplasm and extracellular fluid ECF . It is selectively permeable it allows some things through, such as nutrients and wastes, but usually prevents other things, such...
Interactions Between the LYMPHATIC and IMMUNE SYSTEMS and Other Organ Systems
indicates ways in which these systems affect other organ systems indicates ways in which other organ systems affect these systems Lymphatic system drains excess tissue fluid and removes cellular debris and pathogens. Immune system provides defense against pathogens and immune surveillance against cancer. Skin provides mechanical and chemical barriers to pathogens has antigen-presenting cells in epidermis and dermis and is a common site of inflammation Lymphocytes and macrophages arise from bone...
Blood Chemistry and the Respiratory Rhythm
When you have completed this section, you should be able to explain how blood gases affect the respiratory centers of the brain and explain how the respiratory centers homeostatically control blood gases and pH. The most potent stimulus for breathing is the pH of the body fluids, followed by Pco2 and, least significant, Po2. These conditions are monitored by chemoreceptors in two general locations peripheral chemoreceptors located outside the central nervous system CNS and central...
Insight 195 Clinical Application
and stroke volume rise, cardiac output rises, which compensates for the increased venous return. A sustained program of exercise causes hypertrophy of the ventricles, which increases their stroke volume. As explained earlier, this allows the heart to beat more slowly and still maintain a normal resting cardiac output. Endurance athletes commonly have resting heart rates as low as 40 to 60 bpm, but because of the higher stroke volume, their resting cardiac output is about the same as that of an...
Testing Your Comprehension 1
Identify which anatomical plane sagittal, frontal, or transverse is the only one that could not show a both the brain and tongue, b both eyes, c both the hypogastric and gluteal regions, d both kidneys, e both the sternum and vertebral column, and f both the heart and uterus. 2. Laypeople often misunderstand anatomical terminology. What do you think people really mean when they say they have planter's warts 3. Name one structure or anatomical feature that could be found in each of the following...
Neural Coding
The nervous system must interpret and pass along both quantitative and qualitative information about its environment whether a light is dim or bright, red or green whether a taste is mild or intense, salty or sour whether a sound is loud or soft, high-pitched or low. Considering the complexity of information to be communicated about conditions in and around the body, it is a marvel that it can be done in the form of something as simple as action potentials particularly since all the action...
The Refractory Period
During an action potential and for a few milliseconds after, it is difficult or impossible to stimulate that region of a neuron to fire again. This period of resistance to restimulation is called the refractory period. It is divided into two phases an absolute refractory period in which no stimulus of any strength will trigger a new action potential, and then a relative refractory period in which it is possible to trigger a new action potential, but only with an unusually strong stimulus fig....
Structure of the Skin and Subcutaneous Tissue
When you have completed this section, you should be able to describe the histological structure of the epidermis, dermis, and subcutaneous tissue and discuss the skin's color and markings. The skin, or integument, is the body's largest organ fig. 6.1 . In adults, it covers an area of 1.5 to 2.0 m2 and accounts for about 15 of the body weight. It consists of two layers 1 a stratified squamous epithelium called the epidermis and 2 a deeper connective tissue layer called the dermis. Below the skin...
Interactions Between the RESPIRATORY SYSTEM and Other Organ Systems
indicates ways in which this system affects other systems indicates ways in which other systems affect this one The respiratory system serves all other systems by supplying O2, removing CO2, and maintaining acid-base balance Nasal guard hairs reduce inhalation of dust and other foreign matter Thoracic cage protects lungs movement of ribs produces pressure changes that ventilate lungs Skeletal muscles ventilate lungs, control position of larynx during swallowing, control vocal cords during...
Smell
The receptor cells for smell olfaction form a patch of epithelium, the olfactory mucosa, in the roof of the nasal cavity fig. 16.6 . This location places the olfactory cells close to the brain, but it is poorly ventilated forcible sniffing is often needed to identify an odor or locate its source. Nevertheless, the sense of smell is highly sensitive. We can detect odor concentrations as low as a few parts per trillion. Most people can distinguish 2,000 to 4,000 odors, and some can distinguish up...
Bone Contamination
When Marie and Pierre Curie and Henri Becquerel received their 1903 Nobel Prize for the discovery of radioactivity see insight 2.1, p. 58 , radiation captured the public's imagination. Not for several decades did anyone realize its dangers. For example, watch factories employed women to paint glow-in-the-dark numbers on watch and clock dials with radium paint. The women moistened their paint brushes with their tongues to keep them finely pointed and ingested radium in the process. The radium...
Connective Tissue
When you have completed this section, you should be able to describe the properties that most connective tissues have in common discuss the types of cells found in connective tissue explain what the matrix of a connective tissue is and describe its components name 10 types of connective tissue, describe their cellular components and matrix, and explain what distinguishes them from each other and visually recognize each connective tissue type from specimens or photographs.
Higher Brain Functions
When you have completed this section, you should be able to list the types of brain waves and discuss their relationship to sleep and other mental states explain how the brain controls the skeletal muscles identify the parts of the cerebrum that receive and interpret somatic sensory signals identify the parts of the cerebrum that receive and interpret signals from the special senses describe the locations and functions of the language centers discuss the brain regions involved in memory and...
Mechanics of Ventilation
When you have completed this section, you should be able to explain how pressure gradients cause air to flow into and out of the lungs explain how the respiratory muscles produce these pressure gradients explain the relevance of pulmonary compliance and elasticity to ventilation explain why the alveoli do not collapse when one exhales and define various measurements of pulmonary function. Saladin Anatomy amp 22. The Respiratory System Text Physiology The Unity of Form and Function, Third...
Inspiration
Pulmonary ventilation is achieved by rhythmically changing the pressure in the thoracic cavity. Air flows into the lungs when thoracic pressure falls below atmospheric pressure, then it's forced out when thoracic pressure rises above atmospheric pressure. The diaphragm does most of the work. It is dome-shaped at rest, but when stimulated by the phrenic nerves, it tenses and flattens somewhat, dropping about 1.5 cm in quiet respiration and as much as 7 cm in deep breathing. This enlarges the...
Diuretics
Diuretics are chemicals that increase urine volume. They are used for treating hypertension and congestive heart failure because they reduce the body's fluid volume and blood pressure. Diuretics work by one of two mechanisms increasing glomerular filtration or reducing tubular reabsorption. For example, caffeine, in the former category, dilates the afferent arteriole and increases GFR. Alcohol, in the latter category, inhibits ADH secretion. Also in the latter category are many osmotic...
The ReninAngiotensin Mechanism
When blood pressure drops, the sympathetic nerves also stimulate the juxtaglomerular cells to secrete the enzyme renin REE-nin . Renin acts on a plasma protein, angiotensinogen, to remove a fragment called angiotensin I, a chain of 10 amino acids. In the lungs and kidneys, angiotensin-converting enzyme ACE removes two more Saladin Anatomy amp I 23. The Urinary System I Text I I The McGraw-Hill Physiology The Unity of Companies, 2003 Form and Function, Third Edition Figure 23.12 Negative...
Urinary Tract Infections
Infection of the urinary bladder is called cystitis.30 It is especially common in females because bacteria such as Escherichia coli can travel easily from the perineum up the short urethra. Because of this risk, young girls should be taught never to wipe the anus in a forward direction. If cystitis is untreated, bacteria can spread up the ureters and cause pyelitis,31 infection of the renal pelvis. If it reaches the renal cortex and nephrons, it is called pyelonephritis. Kidney infections can...
Testing Your Recall Ruv
1 ._are not used as fuel and are required in relatively small quantities. 2. The only significant digestible polysaccharide in the diet is 3. Which of the following stores the greatest amount of energy for the smallest amount of space in the body 4. The lipoproteins that remove cholesterol from the tissues are 5. Proteins serve all of the following functions except to act as e. structural support for cells. 6. The primary function of B-complex vitamins is to act as a. structural components of...
RNA Structure and Function
DNA directs the synthesis of proteins by means of its smaller cousins, the ribonucleic acids RNAs . There are three types of RNA messenger RNA mRNA , ribosomal RNA rRNA , and transfer RNA tRNA . Their individual roles are described shortly. For now we consider what they have in common and how they differ from DNA table 4.1 . The most significant difference is that RNA is much smaller, ranging from about 70 to 90 bases in tRNA to slightly over 10,000 bases in the largest mRNA. DNA, by contrast,...
Mineral Resorption
Mineral resorption is the process of dissolving bone. It releases minerals into the blood and makes them available 26 calc stone ulus little for other uses. Resorption is carried out by osteoclasts. Hydrogen pumps in the ruffled border of the osteoclast secrete hydrogen ions into the extracellular fluid, and chloride ions follow by electrical attraction. The space between the osteoclast and the bone thus becomes filled with concentrated hydrochloric acid with a pH of about 4. The acid dissolves...
A
Central incisor-Lateral incisor Canine Figure 25.5 The Dentition and Ages at Which the Teeth Erupt. a Permanent teeth b deciduous baby teeth. Which teeth are absent from a 3-year-old child Figure 25.6 Permanent and Deciduous Teeth in a Child's Skull. This dissection shows erupted deciduous teeth and, below them and marked with asterisks, the permanent teeth waiting to erupt. Figure 25.6 Permanent and Deciduous Teeth in a Child's Skull. This dissection shows erupted deciduous teeth and, below...
Hormone Nomenclature
Many hormones are denoted by standard abbreviations which are used repeatedly in this chapter. These abbreviations are listed alphabetically in table 17.2 so that you can use this as a convenient reference while you work through the chapter. This is by no means a complete list. It does not include hormones that have no abbreviation, such as estrogen and insulin, and it omits hormones that are not discussed much in this chapter. Synonyms used by many authors are indicated in parentheses, but the...
Steroids and Thyroid Hormone
The hydrophilic steroid and thyroid hormones easily penetrate the phospholipid plasma membrane of a target cell and enter the cytoplasm. Steroids enter the nucleus and bind to a receptor associated with the DNA. The receptor has three functional regions that explain its action on the DNA one that binds the hormone, one that binds to an acceptor site on the chromatin, and one that activates DNA transcription at that site. Transcription produces new mRNA that leads to the synthesis of proteins,...
Interactions Between the ENDOCRINE SYSTEM and Other Organ Systems
indicates ways in which this system affects other systems indicates ways in which other systems affect this one Growth hormone, insulin-like growth factors, insulin, thyroid hormone, and glucocorticoids affect the development and metabolism of most tissues Sex hormones affect skin pigmentation, development of body hair and apocrine glands, and subcutaneous fat deposition Skin carries out a step in calcitriol vitamin D synthesis Parathyroid hormone, calcitonin, calcitriol, growth hormone,...
Testing Your Comprehension Fge
1. A woman in labor is often told to push. In doing so, is she consciously contracting her uterus to expel the baby Justify your answer based on the muscular composition of the uterus. 2. A major tenet of the cell theory is that all bodily structure and function is based on cells. The structural properties of bone, cartilage, and tendons, however, are due more to their extracellular material than to their cells. Is this an exception to the cell theory Why or why not 3. When cartilage is...
Blood
Blood table 5.8 is a fluid connective tissue that travels through tubular vessels. Its primary function is to transport cells and dissolved matter from place to place. Blood consists of a ground substance called plasma and of cells and cell fragments collectively called formed elements. Eryth-rocytes22 eh-RITH -ro-sites , or red blood cells, are the most abundant formed elements. In stained blood films, they look like pink discs with a thin, pale center. They have no nuclei. Erythrocytes...
Info Wip
Figure 14.23 The Primary Motor Cortex precentral gyrus . a Location, superior view. b Motor homunculus, drawn so that body parts are in proportion to the amount of primary motor cortex dedicated to their control. Saladin Anatomy amp I 14. The Brain and Cranial I Text I The McGraw-Hill Physiology The Unity of Nerves Companies, 2003 Form and Function, Third Edition ,7-' Vestibular V 'i pathways Rubrospinal tract relatively insignificant in humans Rubrospinal tract relatively insignificant in...
Blood Flow Heart Sounds and the Cardiac Cycle
When you have completed this section, you should be able to explain how pressure and resistance determine the flow of a fluid explain what causes the sounds of the heartbeat describe in detail one complete cycle of heart contraction and relaxation and relate the events of the cardiac cycle to the volume of blood entering and leaving the heart. A cardiac cycle consists of one complete contraction and relaxation of all four heart chambers. We will examine these events in detail to see how they...
Testing Your Comprehension Obl
1. Anti-D antibodies of an Rh woman sometimes cross the placenta and hemolyze the RBCs of an Rh fetus see p. 697 . Yet the anti-B antibodies of a type A mother seldom affect the RBCs of a type B fetus. Explain this difference based on your knowledge of the five immunoglobulin classes. 2. In treating a woman for malignancy in the right breast, the surgeon removes some of her axillary lymph nodes. Following surgery, the patient experiences edema of her right arm. Explain why. 3. A girl with a...
Table 2013 The Hepatic Portal System continued
4. The hepatic portal vein is formed by convergence of the splenic and superior mesenteric veins. It travels about 8 cm up and to the right and then enters the inferior surface of the liver. Near this point it receives the cystic vein from the gallbladder. In the liver, the hepatic portal vein ultimately leads to the innumerable microscopic hepatic sinusoids. Blood from the sinusoids empties into the hepatic veins described earlier. Circulation within the liver is described in more detail in...
Testing Your Comprehension Pqe
1. Why would the supercoiled, condensed form of chromosomes seen in metaphase not be suitable for the Gt phase of the cell cycle Why would the finely dispersed chromatin of the G1 phase not be suitable for mitosis 2. Suppose the DNA double helix had a backbone of alternating nitrogenous bases and phosphates, with the deoxyribose components facing each other across the middle of the helix. Why couldn't such a molecule function as a genetic code 3. Given the information in this chapter, present...
Think About It Uyc
A third-degree burn may be surrounded by painful areas of first- and second-degree burns, but the region of the third-degree burn is painless. Explain the reason for this lack of pain. Saladin Anatomy amp 6. The Integumentary Text The McGraw-Hill Physiology The Unity of System Companies, 2003 The two most urgent considerations in treating a burn patient are fluid replacement and infection control. A patient can lose several liters of water, electrolytes, and protein each day from the burned...
The Functions of Muscles
A muscle is an organ specialized to produce movement of a body part. Its cells convert the chemical energy of ATP into the mechanical energy of motion and exert a useful pull on another tissue. More specifically, muscle contraction serves the following overlapping functions Movement. Most obviously, the muscles enable us to move from place to place and to move individual body parts. Muscular contractions also move body contents in the course of respiration, circulation, digestion, defecation,...
Disturbances of Thermoregulation
Chapter 21 described the mechanism of fever and its importance in combating infection. Fever is a normal protective mechanism that should be allowed to run its course if it is not excessively high. A body temperature above 42 to 43 C 108 -110 F , however, can be very dangerous. The high temperature elevates the metabolic rate, and the body generates heat faster than its heat-losing Chapter 26 Nutrition and Metabolism 1011 mechanisms can disperse it see fig. 1.14 . Thus the metabolic rate...
Filtration Pressure
Glomerular filtration follows the same principles that govern filtration in other blood capillaries see pp. 761-762 , but there are significant differences in the magnitude of the forces involved The blood hydrostatic pressure BHP is much higher here than elsewhere about 60 mmHg compared with 10 to 15 mmHg in most other capillaries. This results from the fact that the afferent arteriole is substantially Saladin Anatomy amp Physiology The Unity of Form and Function, Third Edition 888 Part Four...
Think About It Xfw
How is smooth muscle contraction affected by the drugs called calcium channel blockers see p. 101 Smooth muscle has no troponin. Calcium binds instead to a similar protein called calmodulin13 cal-MOD-you-lin , associated with the thick filaments. Calmodulin then activates an enzyme called myosin light-chain kinase, which transfers a phosphate group from ATP to the head of the myosin. This activates the myosin ATPase and enables it to bind to actin, but in order to execute a power stroke, the...
Hormone Chemistry
Most hormones fall into three chemical classes steroids, peptides, and monoamines table 17.6 . 1. Steroid hormones are derived from cholesterol. They include sex steroids produced by the testes and ovaries such as estrogens, progesterone, and testosterone and corticosteroids produced by the adrenal gland such as cortisol, corticosterone, aldosterone, and DHEA . Calcitriol, the calcium-regulating hormone, is not a steroid but is derived from one and has the same hydrophobic character and mode of...
Insight 194 Clinical Application
Congestive heart failure CHF results from the failure of either ventricle to eject blood effectively. It is usually due to a heart weakened by myocardial infarction, chronic hypertension, valvular insufficiency, or congenital defects in cardiac structure. If the left ventricle fails, blood backs up into the lungs and causes pulmonary edema fluid in the lungs , shortness of breath, and a sense of suffocation. If the right ventricle fails, blood backs up into the venae cavae and causes systemic,...
The Neural Components
The neural components are the retina and optic nerve. The retina forms from a cup-shaped outgrowth of the dien-cephalon see chapter 14 it is actually a part of the Saladin Anatomy amp I 16. Sense Organs I Text I The McGraw-Hill Physiology The Unity of Companies, 2003 Form and Function, Third Edition brain the only part that can be viewed without dissection. It is a thin transparent membrane attached at only two points the optic disc, where the optic nerve leaves the rear fundus of the eye, and...
A 1
abdominal cavity The body cavity between the diaphragm and pelvic brim. fig. A.7 abduction ab-DUC-shun Movement of a body part away from the median plane, as in raising an arm away from the side of the body. fig. 9.10 absorption 1. Process in which a chemical passes through a membrane or tissue surface and becomes incorporated into a body fluid or tissue. 2. Any process in which one substance passes into another and becomes a part of it. Compare adsorption. acetate The ionized form of acetic...
Heart Sounds
As we follow events through the cardiac cycle, we will note the occurrence of heart sounds. Listening to sounds made by the body is called auscultation AWS-cul-TAY-shun . Each cardiac cycle generates two or three sounds that are audible with a stethoscope. The first and second heart sounds, symbolized S1 and S2, are often described as a lubb-dupp S1 is louder and longer and S2 a little softer and sharper. In children and adolescents, it is normal to hear a third heart sound S3 . This is rarely...
Hypothalamic and Cerebral Control
Both lobes of the pituitary gland are strongly subject to control by the brain. As we have seen, the anterior lobe is regulated by releasing and inhibiting hormones from the hypothalamus. Thus, the brain can monitor conditions within and outside of the body and stimulate or inhibit the release of anterior lobe hormones appropriately. For example, in cold weather, the hypothalamus stimulates the pituitary to secrete thyroid-stimulating hormone, which indirectly helps generate body heat in times...
Testing Your Recall Yqr
1. The cardiac conduction system includes all of the following except 2. To get from the right atrium to the right ventricle, blood flows through 3. Assume that one ventricle of a child's heart has an EDV of 90 mL, an ESV of 60 mL, and a cardiac output of 2.55 L min. What are the child's stroke volume SV , ejection fraction EF , and heart rate HR a. SV 60 mL EF 33 HR 85 bpm b. SV 30 mL EF 60 HR 75 bpm c. SV 150 mL EF 67 HR 42 bpm d. SV 30 mL EF 33 HR 85 bpm e. There is not enough information to...
Keloids
In some people, especially dark-skinned adults, healing skin wounds exhibit excessive fibrosis, producing raised, shiny scars called keloids fig. 5.35 . Keloids extend beyond the boundaries of the original wound and tend to return even if they are surgically removed. Keloids may result from the excessive secretion of a fibroblast-stimulating growth factor by macrophages and platelets. They occur most often on the upper trunk and earlobes. Some tribespeople practice scarification-scratching or...
True or False Lmi
Determine which five of the following statements are false, and briefly explain why. 1. After ovulation, a follicle begins to move down the uterine tube to the uterus. 2. Human chorionic gonadotropin is secreted by the granulosa cells of the follicle. 3. An oocyte never completes meiosis II unless it is fertilized. 4. A slim girl who is active in dance and gymnastics is likely to begin menstruating at a later age than an overweight inactive girl. 5. There are more future egg cells in the ovary...
Organization of the Chromatin
A human cell usually has 46 molecules of DNA with an average length of 44 mm total slightly over 2 m . Each molecule is 2 nm in diameter. To put this in perspective, if a DNA molecule were the thickness of a telephone pole 20 cm, or 8 in. , it would reach about 4,400 km 2,700 mi into space far higher than the orbits of satellites and space shuttles. Imagine trying to make a pole 20 cm thick and 4,400 km long without breaking it The problem for a cell is even greater. It has 46 DNA molecules...
Equilibrium Projection Pathways
Hair cells of the macula sacculi, macula utriculi, and semicircular ducts synapse at their bases with sensory fibers of the vestibular nerve. This nerve joins the cochlear nerve to form the vestibulocochlear nerve VIII . Most fibers from the vestibular apparatus terminate in the vestibular nucleus of the pons, while others project to the cerebellum. Fibers from the vestibular nucleus project caudally to the cervical spinal cord, and from there, fibers lead to the brainstem nuclei for the...
Predigested Protein and Athletic Performance
Some bodybuilders and other power athletes take powdered or liquid amino acid mixtures predigested protein in the belief that simple amino acids are absorbed more easily and rapidly or that they somehow contribute more to muscle building. Such beliefs are unfounded. Dietary proteins are rapidly digested and absorbed, and there is no added benefit to taking predigested protein. Amino acid Chapter 26 Nutrition and Metabolism 993 supplements have not been shown to increase muscle mass, strength,...