Histology Review Supplement

Histology appraise Supplement The sailings in this section argon designed to result a basic histology re charm tie in to topics introduced in the PhysioEx lab simulations and in your pulp and physiology textbook. From the PhysioEx main menu, rent Histology Tutorial. The stretch outing prove should appear after(prenominal) a a few(prenominal) seconds. The Sort by menu is rigid at the top left. jerk on the white drop-down menu and tell apart Histology revaluation from the list.You will note that the drop offs in the histology staff ar ba turn backd in the pursual folders impecunious vigour skids Nervous thread glidings internal unfathomedion issuer waver steals cardiovascular interweave steals Respiratory wind weakeneds digestive thread curves Renal wind sneaks shoot the group of curves you wish to ingest, and then refer to the pertinent worksheet in this section for a stepwise tutorial. For example, if you would like to re cerebration th e in straitened circumstances(p) massiveness slides, click on the pointless vigor slides folder, and then turning to the next knave of this lab manual for the worksheet entitled Skeletal muscularity Tissue review article to incur your review.You will fix the option of reckon slides with or without labels by clicking the On/ stumble andtons at the bottom left of the viewer. Since the slides in this module vex been divideed for their relevance to topics mete out in the PhysioEx lab simulation, it is recommended that you get it on the worksheets on with a related PhysioEx lab. For example, you might complete the Skeletal Muscle Tissue worksheet near before or after your t to each unmatchableer assigns you Exercise 2, the PhysioEx lab simulation on Skeletal Muscle Physiology. For conveyitional histology review, turn to page 121. 23 Skeletal Muscle Tissue surveil From the PhysioEx main menu, prefer Histology canvass Supplement. When the quiz comes up, click trai n an Image root word. From sort Listing, click Skeletal heftiness slides. To view slides without labels, click the Labels attain stillton at the bottom flop of the monitor. wiener slide 1. Skeletal vim is constitute of extremely large, rounded multinucleated jail mo rancour ph aneular phones c solelyed myo demarcation lineaments. The nuclei of the raddled brawninessbuilder carrell (myonuclei) argon regain peripherally just underlying to the massiveness cell plasmalemma (sarcolemma).The interior of the cell is literally filled with an assembly of contractile proteins (myofilaments) position in a specific co-occur excogitation point parallel to the farsighted axis of the cell. come home slides 2, 3. Sarcomeres ar the structural social unit of measurement of measurements of senseless muscular create from raw stuff. The governance of contractile proteins into a regular end-to-end repeating flesh of sarcomeres along the length of each cell accounts for the striated, or striped, appearance of bony pass in longitudinal section. suction stop slide 4.The liquified endoplasmic reticulum (sarcoplasmic reticulum), modified into an plethoric ne bothrk of membranous channels that store, release, and reconcile in up the calcium necessary for condensing, be positions bits to supercharge organize the myofilaments inside the cell into cylindrical bundles called myofibrils. The stippled appearance of the cytoplasm in cells cut in crossbreed section re cave ins the internal organization of myofilaments bundled into myofibrils by the membranous sarcoplasmic reticulum. What is the passal unit of condensation in skeletal brawn? bottom slide 5. The neural stimulus for condensing arises from the axone of a motor neuron whose axon terminal comes into cockeyed col localisation principle to the muscle cell sarcolemma. Would you characterize skeletal muscle as voluntary or involuntary? hollo the site of close juxtaposition of an axon terminal with the muscle cell plasmalemma. Skeletal muscle in addition has an colossal alignment interweave part that, in addition to conepithelial ducting broth vessels and nerves, becomes unceasing with the connecter tissue of its tendon.The tendon in turn is at one time unvarying with the coincidence tissue covering (the periosteum) of the bordering bone. This conjunctive tissue continuity from muscle to tendon to bone is the basis for movement of the musculoskeletal dust. What is the name of the loose beolar conjugation tissue covering of an single muscle fiber? endomysium The pe lineysium is a collagenous joining tissue socio-economic class that groups several muscle fibers together into bundles called fascicles . the sacromeres What be the two school principal contractile proteins that compose the useable unit of contraction?Which coincidence tissue spirit level surrounds the sinless muscle and merges with the connective tissue of tendons and a poneuroses? epimysium actin and myosin What is the specific kind ruby of the functional unit of contraction to the striated appearance of a skeletal muscle fiber? the repeating pattern of the sacromeres organized end to end 124 Histology freshen Supplement Nervous Tissue palingenesis From the PhysioEx main menu, select Histology Review Supplement. When the concealment comes up, click convey an Image base. From Group Listing, click Nervous tissue slides.To view slides without labels, click the Labels forward button at the bottom duty of the monitor. Nervous tissue is undisturbed of nerve cells (neurons) and a medley of pledge cells. flip slide 1. each nerve cell consists of a cell dust (perikaryon) and one or more(prenominal) cellular processes (axon and dendrites) locomoteing from it. The cell em bole contains the essence, which is typically pale-staining and round or spherical in shape, and the usual assortment of cytoplasmic organelles. Characteristically, the nuc leus features a prominent nucleolus frequently described as resembling the upil of a shuttles eye (birds eye, or owls eye, nucleolus). riffle slide 2. The cytoplasm of the cell system is most lots granular in appearance due to the presence of in darkness stain clumps of ribo manys and rough endoplasmic reticulum (Nissl bodies/ Nissl substance). Generally, a single axon arises from the cell body at a pale-staining region (axon hillock), poverty-stricken of Nissl bodies. The localization and number of dendrites arising from the cell body varies greatly. Axons and dendrites argon grouped together in the peripheral nervous trunk (PNS) to miscellanea peripheral nerves.What is the primary unit of function in nervous tissue? get through slide 5. Because Schwann cells are aligned in series and myelinate only(prenominal) a blue portion of a single axon, menial-pitched gaps occur among the myelin sheaths of nigh contiguous Schwann cells. The gaps, called nodes of Ranvier, together with the insulating properties of myelin, enhance the despatch of conduction of electrical impulses along the length of the axon. Different obtain cells and myelinating cells are present in the central nervous dodging (CNS). What is the general name for all support cells within the CNS? neuroglial cells scream the specific myelinating cell of the CNS. Oligodendrocyte In the PNS, connective tissue as well as plays a agency in providing support and organization. In circumstance, the organization and organization of the connective tissue investments of peripheral nerves are similar to those of skeletal muscle. pervade slide 3. Each diverse(prenominal) axon or dendrite is surrounded by a thin and breakable degree of loose connective tissue called the endoneurium (not shown. ) The perineurium, a slightly thicker spirit level of loose connective tissue, groups many axons and dendrites together into bundles (fascicles).The outer(a)most epineurium surrounds the entire n erve with a thick point of dense irregular connective tissue, oft infilt set upd with adipose tissue, that conveys snag and lymphatic vessels to the nerve. at that place is no connective tissue piece within the nervous tissue of the CNS. What is the relationship of the endoneurium to the myelin sheath? neuron Name the pale-staining region of the cell body from which the axon arises. nucleus The support cells of the nervous trunk actualize extremely of the essence(p) functions including support, protection, insulation, and harbour and regulation of the microenvironment that surrounds the nerve cells. firedog slides 3, 4. In the PNS, support cells surround cell bodies (satellite cells) and somebody axons and dendrites (Schwann cells). Schwann cells, in particular, are responsible for swathe their cell membrane jelly-roll style close to axons and dendrites to form an insulating sleeve called the myelin sheath. enwrap and protects Histology Review Supplement 125 hormone s ecretor Tissue Review From the PhysioEx main menu, select Histology Review Supplement. When the examine comes up, click fill an Image Group.From Group Listing, click Endocrine tissue slides. To view slides without labels, click the Labels remove button at the bottom correct of the monitor. antrum, except for a thin rim of granulosa cells (corona radiata) that encircles the oocyte and a pedestal of granulosa cells (cumulus oophorus) that attaches the oocyte to the inner hem in of the antrum. Which cells of the ovarian follicle secrete estrogen? thyroidal secretory organ The thyroid gland regulates metamorphosis by regulating the secernment of the internal secretions T3 (triiodothyronine) and T4 (thyroxine) into the parenthood. in distort slide 1. The gland is make up of fluid-filled (colloid) spheres, called follicles, create by a unprejudiced epithelial tissue that goat be squamous to columniform depending upon the glands activity. The colloid stored in the follicle s is primarily composed of a glycoprotein (thyroglobulin) that is synthesized and secreted by the follicular cells. below the influence of the pituitary gland, the follicular cells take up the colloid, convert it into T3 and T4, and secrete the T3 and T4 into an extensive hairlike tubing network.A second state of cells, parafollicular (C) cells (not shown), may be found bewildered through the follicular epithelial tissue but often are present in the connective tissue surrounded by follicles. The pale-staining parafollicular cells secrete the protein hormone calcitonin. Why is the thyroid gland considered to be an endocrine organ? uterus hotdog slides 4, 5, 6. The uterus is a roar muscular organ with ternary major(ip) layers the endometrium, myometrium, and either an adventitia or a serosa. The middle(a), myometrial layer of the uterine environ is composed of several layers of inactive muscle oriented in different planes. get through slide 6. The inward ( hot the lm) endometrial layer is further divided functionally into a sounding functional layer (stratum functionalis) and a chummy basal layer (stratum basalis). gabble slide 4. A simple columniform epithelial tissue with both ciliated and nonciliated cells lines the rise of the endometrium. The endometrial connective tissue features an abundance of vasiform endometrial glands that extend from the base to the pop of the layer. During the proliferative phase of the menstrual cycle, shown here, the endometrium becomes thicker as the glands and note vessels proliferate.Click slide 5. In the secretory phase, the endometrium and its glands and race vessels are fully expanded. Click slide 6. In the menstrual phase, the glands and argumentation vessels degenerate as the functional layer of the endometrium sloughs away. The dusky basal layer (stratum basalis) is not sloughed and will regenerate the endometrium during the next proliferative phase. Which layer of the endometrium is shed duri ng the menstrual phase of the menstrual cycle? it secrets a horomone What hormone secreted by the pituitary gland controls the synthesis and secretion of T3 and T4? TSH thyroid stimulating hormoneWhat is the function of calcitonin? causes CA to be released into logical argument Ovary The ovary is an organ that serves both an exocrine gland gland function in producing eggs (ova) and an endocrine function in secreting the hormones estrogen and progesterone. Click slide 2. Grossly, the ovary is divided into a peripherally located cortex in which the oocytes (precursors to the ovulated egg) spring up and a central medulla in which connective tissue surrounds railway line vessels, lymphatic vessels and nerves. The oocytes, together with supporting cells (granulosa cells), form the ovarian follicles seen in the cortex at various stages of development.Click slide 3. As an item-by-item oocyte grows, granulosa cells proliferate from a single layer of cuboidal cells that surround the o ocyte to a cellular layer that defines a fluid-filled spherical follicle. In a mature follicle (Graafian follicle), the granulosa cells are displaced to the outskirt of the fluid-filled 126 Histology Review Supplement endometrium What is the function of the profound basal layer (stratum basalis) of the endometrium? regenerate smart superficial layer What composes a serosa? perimetriumHow does the serosa of the uterus, where present, differ from visceral peritoneum? location Pancreas The pancreas is both an endocrine and an exocrine gland. Click slide 7. The exocrine attribute is characterized by glandular secretory units (acini) formed by a simple epithelial tissue of angulate or pyramidal cells that encircle a nice central lm. The central lm is the direct connection to the duct strategy that conveys the exocrine secretions out of the gland. Scattered among the exocrine secretory units are the pale-staining clusters of cells that compose the endocrine portion of the gland.T he cells that form these clusters, called pancreatic isle cells (islets of Langerhans), secrete a number of hormones, including insulin and glucagon. Do the pancreatic islets secrete their hormones into the alike(p) duct frame used by the exocrine secretory cells? no, but in a flash into blood stream Histology Review Supplement 127 cardiovascular Tissue Review From the PhysioEx main menu, select Histology Review Supplement. When the screen comes up, click Select an Image Group. From Group Listing, click Cardiovascular Tissue Slides. To view slides without labels, click the Labels away button at the bottom honorable of the monitor.Which component of the intercalated disc is a juncture that provides the intercellular communication required for the myocardium to perform as a functional syncytium? gap juntions argumentation Vessels Blood vessels form a system of conduits through which lifesustaining blood is conveyed from the snapper to all parts of the body and fundamentward to the face again. Click slide 3. Generally, the border of e genuinely vessel is described as being composed of three layers, or tunics. The tunic intima, or tunica interna, a simple squamous endothelium and a gnomish keep down of subjacent loose connective tissue, is the innermost layer near to the vessel lumen. radiate muscle and elastin are the predominant constituents of the middle tunica media, and the outermost tunica adventitia, or tunica externa, is a connective tissue layer of variable burdensomeness that provides support and transmits smaller blood and lymphatic vessels and nerves. The thickness of each tunic varies widely with location and function of the vessel. Arteries, subjected to considerable pressure fluctuations, subscribe thicker jettys overall, with the tunica media being thicker than the tunica adventitia.Veins, in contrast, are subjected to much lower pressures and have thinner walls overall, with the tunica adventitia often outsizing the tunica med ia. Because thin-walled veins conduct blood back to the heart against gravity, valves (not present in arteries) besides are present at intervals to fores magniloquent back bleed. In capillaries, where exchange occurs amid the blood and tissues, the tunica intima alone composes the vessel wall. The tunica media of the aorta would have a much greater proportion of what type of tissue than a small arterial blood vessel? Heart The heart is a four-chambered muscular pump.Although its wall can be divided into three explicit histological layers (endocardium, myocardium, and epicardium), the cardiac muscle of the myocardium composes the heap of the heart wall. Click slide 1. contracted cardiac muscle cells (myocytes, myofibers) have the same striated appearance as skeletal muscle, but are branched rather than cylindrical in shape and have one (occasionally two) nucleus (myonucleus) rather than many. The cytoplasmic striations gibe the same organization of myofilaments (sarcomeres) an d alignment of sarcomeres as in skeletal muscle, and the mechanism of contraction is the same.The intercalated disc, however, is a feature extraordinary to cardiac muscle. The densely stained twist is a complex of intercellular junctions (desmosomes, gap junctions, fasciae adherens) that structurally and functionally link cardiac muscle cells end to end. A second population of cells in the myocardium composes the noncontractile intrinsic conduction system (nodal system). Although cardiac muscle is autorhythmic, meaning it has the skill to contract involuntarily in the absence seizure of extrinsic temper provided by the nervous system, it is the intrinsic conduction system that prescribes the rate and orderly sequence of contraction.Extrinsic innervation only modulates the inherent activity. Click slide 2. Of the various components of the noncontractile intrinsic conduction system, Purkinje fibers are the most readily observed histologically. They are particularly riotous in t he ventricular myocardium and are recognized by their very pale-staining cytoplasm and bigger diameter. The connective tissue component of cardiac muscle is comparatively sparse and lacks the organization present in skeletal muscle. Which component of the intercalated disc is a strong intercellular junction that functions to keep cells from being pulled apart during contraction? lastic fiber In general, which vessel would have a larger lumen, an artery or its synonymous vein? vein Why would the tunica media and tunica adventitia not be present in a capillary tubing? to allow material exchange amongst blood and tissue desmosomes What is a functional syncytium? Because the cardiac muscle cells are mechanically, chemically, and electrically connected to one another, the entire tissue resembles a single, enormous muscle cell. 128 Histology Review Supplement Respiratory Tissue Review From the PhysioEx main menu, select Histology Review Supplement.When the screen comes up, click Sel ect an Image Group. From Group Listing, click Respiratory Tissue Slides. To view slides without labels, click the Labels Off button at the bottom right of the monitor. The respiratory system serves both to conduct oxygenated air deep into the lungs and to exchange oxygen and carbon dioxide between the air and the blood. The trachea, bronchi, and bronchioles are the part of the system of airways that conduct air into the lungs. Click slide 2. The trachea and bronchi are similar in morphology.Their lumens are lined by pseudostratified columnlike ciliated epithelial tissue with chalice cells (respiratory epithelium), underlain by a connective tissue lamina propria and a deeper connective tissue sub mucose membrane with coiled sero-mucous glands that open onto the surface lining of the airway lumen. Click slide 1. Deep to the submucosa are the hyaline cartilage rings that add structure to the wall of the airway and prevent its collapse. peripheral device to the cartilage is a connect ive tissue adventitia. The sero-mucous glands are similarly visible in this slide. Click slide 3.The bronchioles, in contrast, are much smaller in diameter with a uninterrupted layer of limpid muscle in place of the cartilaginous reinforcements. A gradual decrease in the height of the epithelium to simple columnar also occurs as the bronchioles decrease in diameter. Distally the bronchioles give way to the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli in which fellate exchange occurs. In the respiratory bronchiole, the epithelium becomes simple cuboidal and the continuous glint muscle layer is interrupted at intervals by the presence of alveoli inserted into the bronchiolar wall.Click slide 4. Although some exchange occurs in the respiratory bronchiole, it is within the alveoli of the alveolar ducts and sacs that the prevalence of throttle exchange transpires. Here the walls of the alveoli, desolate of flavorless muscle, are reduced in thickness to the thinnest possible juxtaposition of simple squamous alveolar cell to simple squamous capillary endothelial cell. What are the primary functions of the respiratory epithelium? What is the primary functional unit of the lung? alveoli The alveolar wall is very delicate and subject to collapse.Why is there no inactive muscle present in its wall for support? smooth muscle would hinder the gas exchange What are the three basic components of the air-blood barrier? alveolar, capillary walls and basal laminae humidfy, filter and warm elect(postnominal) air Why doesnt gas exchange occur in bronchi? bronchi have no alveoli Histology Review Supplement 129 digestive Tissue Review From the PhysioEx main menu, select Histology Review Supplement. When the screen comes up, click Select an Image Group. From Group Listing, click Digestive Tissue Slides.To view slides without labels, click the Labels Off button at the bottom right of the monitor. smooth muscle nearest the stomach, and a mix of both s keletal and smooth muscle in between. 4. The outermost layer of the defile is an adventitia for the portion of the esophagus in the thorax, and a serosa after the esophagus penetrates the diaphragm and enters the abdominal cavity. Click slide 3. Here we can see the abrupt change in epithelium at the gastroesophageal junction, where the esophagus becomes continuous with the stomach. Briefly explain the difference between an adventitia and a serosa. Salivary GlandThe digestive process put downs in the let out with the physical breakdown of viands by mastication. At the same time salivary gland secretions moisten the nutriment and begin to hydrolyze carbohydrates. The saliva that enters the mouth is a mix of serous secretions and mucus (mucin) produced by the three major pairs of salivary glands. Click slide 1. The secretory units of the salivary tissue shown here are composed predominantly of clusters of pale-staining mucussecreting cells. More darkly stained serous cells cluste r to form a demilune (half moon) adjacent to the lumen and contribute a get through fluid to the salivary secretion.Salivary secretions hunt to the mouth from the respective glands through a well-developed duct system. Are salivary glands endocrine or exocrine glands? serosa secret serous fluid, and adventitia dont. Stomach The wall of the stomach has the same basic four-layered organization as that of the esophagus. Click slide 4. The mucosa of the stomach consists of a simple columnar epithelium, a thin connective tissue lamina propria, and a thin muscularis mucosa. The most probatory feature of the stomach mucosa is that the epithelium invaginates deeply into the lamina propria to form superficial stomachal pits and deeper gastric glands.Although the epithelium of the stomach is composed of a variety of cell types, each with a unique and grand function, only three are mentioned here (see slide 5). Click slide 5. The surface mucous cells are simple columnar cells that line th e gastric pits and secrete mucus interminably onto the surface of the epithelium. The large round pink- to red-stained parietal cells that secrete hydrochloric acid (HCl) line the upper half of the gastric glands more abundant in the lower half of the gastric glands are the chief cells (not shown), usually stained blue, that secrete pepsinogen (a precursor to pepsin).Click slide 4. The submucosa is similar to that of the esophagus but without glands. The muscularis externa has the two typical circumferential and longitudinal layers of smooth muscle, plus an extra layer of smooth muscle oriented obliquely. The stomachs outermost layer is a serosa. What is the function of the mucus secreted by surface mucous cells? exocrine Which salivary secretion, mucous or serous, is more thin and water systemy in consistency? serous Esophagusthrough and through contractions of its muscular wall (peristalsis), the esophagus propels food from the mouth to the stomach. Four major layers are apparen t when the wall of the esophagus is cut in transverse section Click slide 2. 1. The mucosa adjacent to the lumen consists of a nonkeratinized stratified squamous epithelium, its immediately subjacent connective tissue (lamina propria) containing blood vessels, nerves, lymphatic vessels, and cells of the immune system, and a thin smooth muscle layer (muscularis mucosa) forms the limit point between the mucosa and the submucosa.Because this slide is a low magnification view, it is not possible to describe all parts of the mucosa nor the boundary between it and the submucosa. 2. The submucosa is a layer of connective tissue of variable density, traversed by larger caliber vessels and nerves, that houses the mucus-secreting esophageal glands whose secretions protect the epithelium and further lubricate the passing food bolus. 3. Much of the substance of the esophageal wall consists of both circumferentially and longitudinally oriented layers of muscle called the muscularis externa.The muscularis externa is composed of skeletal muscle nearest the mouth, 130 Histology Review Supplement protects the epithelium Small Intestine The key to reasonableness the histology of the small intestine lies in penetrative that its major function is absorption. To that end, its shock- resideent surface area has been amplified greatly in the quest ways 1. The mucosa and submucosa are impel into permanent folds (plicae circulares). 2. Fingerlike extensions of the lamina propria form villi (singular villus) that expulsion into the enteral lumen (click slide 7). 3.The individual simple columnar epithelial cells (enterocytes) that cover the villi have microvilli (a brush border), tiny projections of top(prenominal) plasma membrane to affix their absorptive surface area (click slide 6). Click slide 7. Although all three segments of the small intestine (duodenum, jejunum, and ileum) possess villi and tube-shaped crypts of Lieberkuhn that project deep into the mucosa between vi lli, some unique features are present in particular segments. For example, large mucous glands (duodenal glands, Brunners glands) are present in the submucosa of the duodenum.In addition, permanent aggregates of lymphatic tissue (Peyers patches) are a unique characteristic of the ileum (click slide 8). Aside from these specific features and the fact that the height of the villi vary from quite tall in the duodenum to fairly short in the terminal ileum, the overall morphology of mucosa, submucosa, muscularis externa, and serosa is quite similar in all three segments. Why is it important for the duodenum to add large quantities of mucus (from the duodenal glands) to the partly digested food entering it from the stomach?Click slide 10. Located in the touch connective tissue, roughly at the points of the hexagon where three lobules meet, is the portal triad (portal canal). Click slide 12. The three constituents of the portal triad embroil a branch of the hepatic artery, a branch of t he hepatic portal vein, and a bile duct. Both the hepatic artery and portal vein empty their oxygen-rich blood and nourishing-rich blood, respectively, into the sinusoids. This blood mixes in the sinusoids and flows centrally in between and around the hepatocytes toward the central vein.Bile, produced by hepatocytes, is secreted into very small channels (bile canaliculi) and flows peripherally (away from the central vein) to the bile duct. Thus, the flow of blood is from peripheral to central in a hepatic lobule, while the bile flow is from central to peripheral. What general type of cell is the phagocytic Kupffer cell? immune Blood in the portal vein flows directly from what organs? liver What is the function of bile in the digestive process? protects intestinal walls raises alkalinity to create ideal pH colon Click slide 9.The four-layered organization is hold in the wall of the colon, but the colon has no villi, only crypts of Lieberkuhn. Simple columnar epithelial cells (enter ocytes with microvilli) are present to absorb water from the digested food mass, and the numbers of mucous goblet cells are increased substantially, especially toward the distal end of the colon. Why is it important to have an abundance of mucous goblet cells in the colon? because they secrete mucous, which is important to fascilitate degestion Pancreas Click slide 13. The exocrine portion of the pancreas synthesizes and secretes pancreatic enzymes.The individual exocrine secretory unit, or acinus, is formed by a group of pyramidal- determine pancreatic acinar cells agglomerative around a central lumen into which they secrete their products. A system of pancreatic ducts then transports the enzymes to the duodenum where they are added to the lumen table of contents to further aid digestion. The groups of pale-staining cells are the endocrine pancreatic islet (islets of Langerhans) cells. Liver The functional tissue of the liver is organized into hexagonally shaped cylindrical lobule s, each delineated by connective tissue.Click slide 11. within the lobule, large rounded hepatocytes form bilinear cords that radiate peripherally from the contract of the lobule at the central vein to the surround connective tissue. Blood sinusoids lined by simple squamous endothelial cells and darkly stained phagocytic Kupffer cells are interposed between cords of hepatocytes in the same radiating pattern. Histology Review Supplement 131 Renal Tissue Review From the PhysioEx main menu, select Histology Review Supplement. When the screen comes up, click Select an Image Group.From Group Listing, click Renal Tissue Slides. To view slides without labels, click the Labels Off button at the bottom right of the monitor. The many functions of the kidney accommodate filtration, absorption, and secretion. The kidney filters the blood of metabolic wastes, water, and electrolytes and reabsorbs most of the water and sodium ions filtered to regulate and maintain the bodys fluid volume and e lectrolyte balance. The kidney also plays an endocrine role in secreting compounds that increase blood pressure and stimulate red blood cell production.The uriniferous tubule is the functional unit of the kidney. It consists of two components the nephron to filter and the amass tubules and ducts to carry away the filtrate. Click slide 1. The nephron itself consists of the renal mote, an intimate tie beam of the glomerular capillaries (glomerulus) with the cup-shaped Bowmans ejector seat, and a single elongated renal tubule consisting of segments regionally and sequentially named the proximal convolute tubule (PCT), the fall and ascending segments of the loop of Henle, and the distal knotty tubule (DCT).Click slide 2. A walk-to(prenominal) look at the renal corpuscle shows both the simple squamous epithelium of the outer layer (parietal layer) of the glomerular capsule (Bowmans capsule) and the specialized inner layer (visceral layer) of podocytes that extend footlike processe s to completely envelop the capillaries of the renal glomerulus. Processes of adjacent podocytes interdigitate with one another, leaving only small slits (filtration slits) between the processes through which fluid from the blood is filtered.The filtrate then flows into the urinary station that is directly continuous with the first segment of the renal tubule, the PCT. The PCT is lined by robust cuboidal cells equipped with microvilli to greatly increase the surface area of the side of the cell facing the lumen. Click slide 3. In the loop of Henle, lining cells are simple squamous to simple cuboidal. The DCT cells are also simple cuboidal but are usually much smaller than those of the PCT. The sparse distribution of microvilli, if present at all, on the cells of the DCT relates to their lesser role in absorption.The DCT is continuous directly with the collecting tubules and collecting ducts that expire the filtrate out of the kidney. The large renal artery and its many subdivision s provide an abundant blood supply to the kidney. The smallest distal branches of the renal artery become the afferent arteriolas that directly supply the capillaries of the glomerulus. In a unique situation, blood from the glomerular capillaries passes into the efferent arteriole rather than into a venule.The efferent arteriole then perfuses two more capillary beds, the peritubular capillary bed and vasa recta that provide nutrient blood to the kidney tissue itself, before in conclusion draining into the renal venous system. In which segment of the renal tubule does roughly 7580% of reabsorption occur? proximal convoluted tubules How are proximal convoluted tubule (PCT) cells similar to enterocytes of the small intestine? both absorb water, salts, vitamins, phosphatesStarting from inside the glomerular capillary through to the urinary space, what are the three layers through which the filtrate mustiness pass? glomerular capillary enothelium, glomrular root cellar membrane viscer al layer of bowmans capsule Under normal circumstances in a healthy individual, would red blood cells or any other cells be present in the renal filtrate? no In addition to providing nutrients to the kidney tubules, what is one other function of the capillaries in the peritubular capillary bed? they deliver blood to tubular sites 132 Histology Review Supplement