Composition and Function of Blood
The blood volume of an adult correlates with his or her fat-free body mass and amounts to ca. 4-4.5 L in women 9 and 4.5-5 L in men of 70 kg BW table . The functions of blood include the transport of various molecules O2, CO2, nutrients, metabolites, vitamins, electrolytes, etc. , heat regulation of body temperature and transmission of signals hormones as well as buffering and immune defense. The blood consists of a fluid plasma formed elements Red blood cells RBCs transport O2 and play an...
Smooth Muscle
Smooth muscle SmM consists of multiple layers of spindle-shaped cells. It is involved in the function of many organs stomach, intestine, gall bladder, urinary bladder, uterus, bronchi, eyes, etc. and the blood vessels, where it plays an important role in circulatory control. SmM contains a special type of F-actin-tropomyosin and myosin II filaments p. 60 , but lacks troponin and myofibrils. Furthermore, it has no distinct tubular system and no sarcomeres nonstriated . It is therefore called...
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Tubuloglomerular Feedback, Renin-Angiotensin System The juxtaglomerular apparatus JGA consists of a juxtaglomerular cells of the afferent arteriole including renin-containing and sympathetically innervated granulated cells and efferent arteriole, b macula densa cells of the thick ascending limb of the loop of Henle and c juxtaglomerular mesangial cells polkissen, A of a given nephron A . JGA functions 1 local transmission of tubuloglomerular feedback TGF at its own nephron via angiotensin II...
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Carbohydrate Metabolism and Pancreatic Hormones Glucose is the central energy carrier of the human metabolism. The brain and red blood cells are fully glucose-dependent. The plasma glucose concentration blood sugar level is determined by the level of glucose production and consumption. The following terms are important for proper understanding of carbohydrate metabolism A, C 1.Glycolysis generally refers to the anaerobic conversion of glucose to lactate p.72 . This occurs in the red blood...
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concentration will not yet drop to the resting value, and residual Ca2 will accumulate. As a result, the more recent rise in Ca2 i builds on the former one. Ca2 i rises to a higher level after the second stimulus than after the first, and also releases more transmitters. Hence, the first stimulus facilitates the response to the second stimulus. Muscle strength increases at high stimulus frequencies for similar reasons Among the many substances that act as excitatory transmitters are...
Organization of the Autonomic Nervous System
In the somatic nervous system, nerve fibers extend to and from the skeletal muscles, skin and sense organs. They usually emit impulses in response to stimuli from the outside environment, as in the withdrawal reflex p. 320 . Much somatic nervous activity occurs consciously and under voluntary control. In contrast, the autonomic nervous system ANS is mainly concerned with regulation of circulation and internal organs. It responds to changing outside conditions by triggering ortho-static...
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Digestion and Absorption of Carbohydrates and Protein Carbohydrates provide half to two-thirds of the energy requirement p. 226 . At least 50 of dietary carbohydrates consist of starch amylose and amylopectin , a polysaccharide other important dietary carbohydrates are cane sugar saccharose sucrose and milk sugar lactose . Carbohydrate digestion starts in the mouth A1 and p. 236 . Ptyalin, an a-amylase found in saliva, breaks starches down into oligosaccharides maltose, maltotriose, a limit...
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Anterolateral spinothalamic pathway C violet . Afferent signals from nocisensors, thermosensors and the second part of pressure and touch afferent neurons are already relayed partly via interneurons at various levels of the spinal cord. The secondary neurons cross to the opposite side at the corresponding segment of the spinal cord, form the lateral and ventral spinothalamic tract in the anterolateral funiculus, and project to the thalamus. Descending tracts from the cortex can inhibit the flow...
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Concentration of bile salts in plasma Concentration of bile salts in plasma E. Micelle-mediated dissolution of cholesterol in the bile
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Calcium, particularly ionized calcium Ca2 , plays a central role in the regulation of numerous cell functions pp.36, 62ff., 192, 276 . Calcium accounts for 2 of the body weight. Ca. 99 of the calcium occurs in bone while 1 is dissolved in body fluids. The total calcium conc. in serum is normally 2.1-2.6 mmol L. Ca. 50 of it is free Ca2 1.1-1.3 mmol L while ca. 10 is bound in complexes and 40 is bound to proteins mainly albumin p. 178 . Calcium protein binding increases as the pH of the blood...
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Androgen-related disorders of female sex differentiation Sexual Response, Intercourse and Fertilization Sexual response in the male A1 . impulses from tactile receptors on the skin in the genital region especially the glans penis and other parts of the body erogenous areas are transmitted to the erection center in the sacral spinal cord S2-S4 , which conducts them to parasympathetic neurons of the pelvic splanchnic nerves, thereby triggering sexual arousal. Sexual arousal is decisively...
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Androgens male sex hormones are steroid hormones with 19 C atoms. This group includes potent hormones like testosterone T and 5a-dihydrotestosterone DHT and less potent 17-ketosteroids 17-KS such as DHEA p. 294 . In males, up to 95 of testosterone is synthesized by the testes A2 and 5 by the adrenal cortex Al . The ovaries and adrenal cortex synthesize testosterone in females. The plasma testosterone conc. in males is about 15 times higher than in females, but decreases with age. Up to 98 of...
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Parvalbumin, a protein that occurs in the cy-tosol of fast-twitch muscle fibers type F p. 58 , accelerates muscle relaxation after short contractions by binding cytosolic Ca2 in exchange for Mg2 . Parvalbumin's binding affinity for Ca2 is higher than that of troponin, but lower than that of SR's Ca2 -ATPase. t therefore functions as a slow Ca2 buffer. The course of the filament sliding cycle as described above mainly applies to isotonic contractions, that is, to contractions where muscle...
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The central nervous system contains around 1011 nerve cells and 10 times as many glia cells such as oligodendrocytes, astrocytes, ependy-mal cells, and microglia A . Oligodendrocytes ODC form the myelin sheath that surrounds axons of the CNS A . Astrocytes AC are responsible for extracellular K and H homeostasis in the CNS. Neurons release K in response to high-frequency stimulation B . Astrocytes prevent an increase in the interstitial K concentration and thus an undesirable depolarization of...
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The length L and force F or tension of a 0 muscle are closely related C, E . The total force of a muscle is the sum of its active force and its extension force at rest, as was ex-c plained above. Since the active force is deter-m mined by the magnitude of all potential actinia myosin interactions, it varies in accordance Z with the initial sarcomere length C, D . Skeletal muscle can develop maximum active isometric force Fo from its resting length Lmax sarcomere length ca. 2 to 2.2 m C . When...
Motor Endplate
The transmission of stimuli from a motor axon to a skeletal muscle fiber occurs at the motor end-plate, MEP A , a type of chemical synapse p.50ff. . The transmitter involved is acetylcholine ACh, cf. p. 82 , which binds to the N nicotinergic -cholinoceptors of the sub-synaptic muscle membrane A3 . N-cholino-ceptors are ionotropic, that is, they also function as ion channels A4 . The N-cholinocep-tor of the MEP type NM has 5 subunits 2a, 113, 1Y, 16 , each of which contains 4 membrane-spanning...
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Somatovisceral sensibility is the collective term for all sensory input from receptors or sensors of the body as opposed to the sensory organs of the head . It includes the areas of proprioception p. 316 , nociception p. 318 , and skin or surface sensitivity. The sense of touch taction is essential for perception ofform, shape, and spatial nature of objects stereognosis . Tactile sensors are located predominantly in the palm, especially in the fingertips, and in the tongue and oral cavity....
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Adrenal Cortex and Glucocorticoid Synthesis The mineralocortico stero ids aldosterone, corticosterone and 11-desoxycorticosterone pp. 182ff. and 294 are synthesized in the glomerular zone of the adrenal cortex A1 , whereas the glucocortico stero ids cortisol hydrocortisone and cortisone p. 294, small quantities are synthesized in the fascicular zone A2 . Androgens are synthesized in the reticular zone of the adrenal cortex A3 . One of the androgens is dehydroepian-drosterone DHEA , which is...
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Several coagulation factors are involved in the clotting process. Except for Ca2 , they are proteins formed in the liver B and Table . Factors labeled with a K in the table as well as protein C and protein S, see below are produced with vitamin K, an essential cofactor in posttranslational -y-carboxylation of glutamate residues of the factors. These -y-carboxy-glutamyl groups are chelators of Ca2 . They are required for Ca2 -mediated complex formation of factors on the surface of phospholipid...
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and glycogenesis and suppresses those involved in gluconeogenesis. Insulin also increases the number of GLUT-4 uniporters in skeletal myocytes. All these actions serve to lower the plasma glucose concentration which increases after food ingestion . About two-thirds of the glucose absorbed by the intestines after a meal postprandial is temporarily stored and kept ready for mobilization via glucagon during the interdigestive phase. This provides a relatively constant supply of glucose for the...
Flow Properties of Blood
The viscosity n of blood is higher than that of plasma due to its erythrocyte RBC content. Viscosity n 1 fluidity shearing force x shearing action y Pa s . The viscosity of blood rises with increasing hematocrit and decreasing flow velocity. Erythrocytes lack the major organelles and, therefore, are highly de-formable. Because of the low viscosity of their contents, the liquid film-like characteristics of their membrane, and their high surface volume ratio, the blood behaves more like an...
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Pain is an unpleasant sensory experience associated with discomfort. It is protective insofar as it signals that the body is being threatened by an injury noxa . Nociception is the perception of noxae via nocisensors, neural conduction and central processing. The pain that is ultimately felt is a subjective experience. Pain can also occur without stimulation of nocisensors, and excitation of nocisensors does not always evoke pain. All body tissues except the brain and liver contain sensors for...
Pco2
Respiratory alkalosis is usually caused by hyperventilation due to anxiety or high altitude oxygen deficit ventilation p. 136 , resulting in a fall in plasma Pco2. This leads to a slight decrease in HCO3 Act since a small portion of the HCO3- is converted to CO2 H HCO3- CO2 H2O the HCO3- required for this reaction is supplied by H ions from NBB's buffering NBB-H NBB- H . This is also the reason forthe additional drop in HCO3 Act when respiratory compensation of non-respiratory acidosis occurs...
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The neuroepithelium of the olfactory region contains ca. 107 primary olfactory sensor cells A1 which are bipolar neurons. Their dendrites branch to form 5-20 mucus-covered cilia, whereas the axons extend centrally in bundles called fila olfactoria A1,2 . Olfactory neurons are replenished by basal cell division in 30-60-day cycles. Free nerve endings trigeminal nerve in the nasal mucosa also react to certain aggressive odors e.g., acid or ammonia vapors . Olfactory sensors. Odorant molecules Mr...
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I B. Impairment of alveolar gas exchange Normal alveolar ventilation and perfusion I B. Impairment of alveolar gas exchange Normal alveolar ventilation and perfusion Pulmonary Blood Flow, Ventilation-Perfusion Ratio Neglecting the slight amount of blood that reaches the lungs via the bronchial arteries, the mean pulmonary perfusion Q , or blood flow to the lungs, is equal to the cardiac output CO 5-6 L min . The pulmonary arterial pressure is about 25 mmHg in systole and 8 mmHg in diastole,...
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Consciousness. Selective attention, abstract thinking, the ability to verbalize experiences, the capacity to plan activities based on experience, self-awareness and the concept of values are some of the many characteristics of consciousness. Consciousness enables us to deal with difficult environmental conditions adaptation . Little is known about the brain activity associated with consciousness and controlled attention LCCS, see below , but we do know that subcortical activation systems such...
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, C. Secondary active vitamin absorption -,
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taken up by endocytosis into erythroblasts and cells of the liver, placenta, etc. with the aid of transferrin receptors. Once iron has been released to the target cells, apotransferrin again becomes available for uptake of iron from the intestine and macrophages see below . Iron storage and recycling A3 . Ferritin, one of the chief forms in which iron is stored in the body, occurs mainly in the intestinal mucosa, liver, bone marrow, red blood cells, and plasma. It contains binding pockets for...
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Proprioception is the mechanism by which we sense the strength that our muscles develop as well as the position and movement of our body and limbs. The vestibular organ p. 342 and cutaneous mechanosensors p. 314 assist the propriosensors in muscle spindles, joints and tendons. Sensors of Golgi tendon organs are located near muscle-tendon junctions. Muscle spindles A1 contain intensity P and differential D sensors for monitoring of joint position and movement. The velocity of position change is...
Hormones and Reproduction
Unlike unicellular organisms, multicellular organisms have numerous specialized groups of cells and organs, the many different functions of which must be expediently integrated and coordinated see also p. 2 . In mammals, the nervous system and endocrine system are chiefly responsible for control and integration, while the immune system serves as an information system for corporal immune defense p.94ff. . These systems communicate by way of electrical and or chemical signals A . Nerve impulses...
Physical Fitness and Training
The physical exercise capacity can be measured using simple yet standardized techniques of ergometry. This may be desirable in athletes, for example, to assess the results of training, or in patients undergoing rehabilitation therapy. Ergometry assesses the effects of exercise on physio.logical parameters such as O2 consumption VO2 , respiration rate, heart rate p. 74 , and the plasma lactate concentration A . The measured physical power performance is expressed in watts W or W kg body weight...
From the Preface to the Third Edition
The first German edition of this book was already in press when, on November 2nd, 1979, Agamennon Despopoulos and his wife, Sarah Jones-Despopoulos put to sea from Bizerta, Tunisia. Their intention was to cross the Atlantic in their sailing boat. This was the last that was ever heard of them and we have had to abandon all hope of seeing them again. Without the creative enthusiasm of Aga-mennon Despopoulos, it is doubtful whether this book would have been possible without his personal support it...
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Anatomy. The terminal end of the gastrointestinal tract includes the large intestine cecum and colon, ca. 1.3 m in length and rectum. The large intestinal mucosa has characteristic pits crypts , most of which are lined with mucus-forming cells goblet cells . Some of the surface cells are equipped with a brush border membrane and reabsorb ions and water. The large intestine has two main functions 1 It serves as a reservoir for the intestinal contents cecum, ascending colon, rectum . 2 It absorbs...
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The posterior funiculus-lemniscus system C, green is the principal route by which the somatosensory cortex S1 postcentral gyrus receives sensory input from skin sensors and propriosensors. Messages from the skin su- 5 perficial sensibility and locomotor system c proprioceptive sensibility reach the spinal m cord via the dorsal roots. Part of these primarily 2 afferent fibers project in tracts of the posterior funiculus without synapses to the posterior funicular nuclei of the caudal medulla...
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0.1 1 10 Rate of pressure change mm s 20 40 80 200 400 Vibration frequency Hz After Zimmermann amp Schmidt D. PD proprioception Response to velocity and angle of joint flexion text on next page 0 5 10 15 After Boyd amp Roberts Time s
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i B. Enterohepatic circulation of bile salts . Bile salt pool 2-4g circulates 6-10 times a day Bile salt pool 2-4g circulates 6-10 times a day
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Excretory Liver Function Bilirubin The liver detoxifies and excretes many mostly lipophilic substances, which are either generated during metabolism e.g., bilirubin or steroid hormones or come from the intestinal tract e.g., the antibiotic chloramphenicol . However, this requires prior biotransformation of the substances. In the first step of the process, reactive OH, NH2 or COOH groups are enzymatically added e.g., by monooxy-genases to the hydrophobic substances. In the second step, the...
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tracts from the entire cortex and use glutamate as their transmitter D . Once activated, neurons of the striatum release an inhibitory transmitter GABA and a co-transmitter either substance P SP or enkephalin Enk., D p. 55 . The principal output of the basal ganglia runs through the pars reticularis of the substantia nigra SNr and the pars interna of the globus pallidus GPi , both ofwhich are inhibited by SP GABAergic neurons of the stri-atum D . Both SNr and GPi inhibit by GABA the...
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Diving creates a problem for respiration due to the lack of normal ambient air supply and to higher the outside pressures exerted on the body. The total pressure on the body underwater is equal to the water pressure 98 kPa or 735 mmHg for each 10 m of water plus the atmospheric pressure at the water surface. A snorkel can be used when diving just below the water surface A , but it increases dead space pp.114 and 120 , making it harder to breathe. The additional pressure load from the water on...
Co2 Dissociation Curve
The total carbon dioxide concentration chemically bound CO2 dissolved CO2 of mixed venous blood is about 24-25 mmol L that of arterial blood is roughly 22-23 mmol L. Nearly 90 of this is present as HCO3- A, right panel, and table on p. 124 . The partial pressure of CO2 Pco2 is the chief factor that determines the CO2 content of blood. The CO2 dissociation curve illustrates how the total CO2 concentration depends on PCO2 A . The concentration of dissolved CO2, CO2 , in plasma is directly...
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The arcuate arteries A1 pass between the renal cortex and medulla. They branch towards the cortex into the interlobular arteries A2 from which the afferent arterioles or vasa af-ferentia arise A3 . Unlike other organs, the kidney has two successive capillary networks that are connected with each other by an efferent arteriole or vas efferens A, B . Pressure in the first network of glomerular capillaries p. 148 is a relatively high B and p. 152 and is regulated by adjusting the width of...
Mechanics of Breathing
Pressure differences between the alveoli and the environment are the driving forces for the exchange of gases that occurs during ventilation. Alveolar pressure Pa intrapulmonary pressure B must be lower than the barometric pressure Pb during inspiration breathing in , and higher during expiration breathing out . If Pb is defined as zero, the alveolar pressure is negative during inspiration and positive during expiration B . These pressure differences are created through coordinated movement of...
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H ions are buffered by filtered HPO42-. Non-reabsorbed phosphate 5-20 of the filtered quantity, p. 178 is therefore loaded with H ions, about half of it in the proximal tubule pH 7.4 ca. 6.6 , and the rest in the collecting duct pH 6.6 4.5 C1 . When acidosis occurs, increased quantities of phosphate are mobilized from the bone and excreted. The resulting increase in H excretion precedes the increased NH4 production associated with acidosis see below . Excretion of ammonium ions NH4 NH3 H ,...
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I E. Nitric oxide NO as a transmitter substance In the hypothalamus, 1 humoral signals from the periphery e.g., from circulating cortisol can be converted to efferent neuronal signals, and 2 afferent neuronal signals can be converted to endocrine messengers neurosecretion . The first case is possible because the hypothalamus is situated near circumventricular organs like the or-ganum vasculosum laminae terminalis OVLT , sub-fornical organ, the median eminence of the hypothalamus, and the...
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Placenta. The maternal placenta acts as the gut absorption of nutrients , kidneys removal of waste products and lungs of the fetus uptake of O2 and elimination of CO2 . Although the fetal O2-hemoglobin dissociation curve is shifted to the left compared to that of adults p. 129 C , only 60 0.6 of placental hemoglobin is saturated with O2 A . Fetal blood is distributed according to need. Inactive or hardly active organs receive little blood. The fetal cardiac output from both ventricles is about...
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Food provides necessary nutrients, but also contains inert and harmful substances. The body can usually sort out these substances already at the time of intake, either based on their smell or taste or, if already eaten, with the help of specific digestive enzymes and intestinal absorptive mechanisms e.g., D-glucose and L-amino acids are absorbed, but L-glucose and D-amino acids are not . Similar distinctions are made in hepatic excretion bile stools useful bile salts are almost completely...
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vides an additional driving force for water reabsorption. The more water filtered at the glomerulus, the higher this oncotic pressure. Thus, the reabsorption of water at the proximal tubule is, to a certain extent, adjusted in accordance with the GFR glomerulotubular balance . Because the descending limb of the loop of Henle has aquaporins AQP1 that make it permeable to water, the urine in it is largely in osmotic balance with the hypertonic inter-stitium, the content of which becomes...
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Coronary arteries. The blood flow to the myocardium is supplied by the two coronary arteries that arise from the aortic root. The right coronary artery approx. 1 7th of the blood usually supplies the greater portion of the right ventricle, while the left coronary artery 6 7th of the blood supplies the left ventricle A . The contribution of both arteries to blood flow in the septum and posterior wall of the left ventricle varies. Coronary blood flow Qcor is phasic, i.e., the amount of blood in...
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where C is the concentration of the substrate in question, Jmax is its maximum transport rate, and Km is the substrate concentration that produces one-halfJmax p.383 . Cytosis is a completely different type of active transport involving the formation of membrane-bound vesicles with a diameter of 50-400 nm. Vesicles are either pinched off from the plasma membrane exocytosis or incorporated into it by invagination endocyto- sis in conjunction with the expenditure of ATP. In cytosis, the uptake...
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After Porter and Franzini-Armstrong After Porter and Franzini-Armstrong i B. Ca2 as mediator between electrical stimulus and contraction i B. Ca2 as mediator between electrical stimulus and contraction Actin-myosinII binding I Strong I Weak Strong Actin-myosinII binding I Strong I Weak Strong 2 Work phase 3 Resting phase ca. 90 of time other 2 Work phase 3 Resting phase ca. 90 of time other Contraction cycle C and D . Each of the two myosin heads M of a myosin- molecule bind one ATP molecule...