Systemic Anatomy and Physiology | My Assignment Tutor

1U3198414Systemic Anatomy and Physiology- Case Study 1Endocrine system1. Hypothyroidism (underactive thyroid hormone) is the condition that might be responsible for Janelle’sdifficulty losing weight. If Thyrohyoid glands are not active, they will not produce sufficient Thyrohyoidhormones to burn kept fat (1).2. The pituitary glands produce the thyroid-stimulating hormone, thyrotropin, which control thyroid’sfunctions. The release of TSH is under the control of the thyrotropin-releasing hormone, secreted bythe hypothalamus (2).Two classifications of hormones:a. Amino acids derivative hormones, including thyroid hormones and catecholamines.b. Lipid derivative hormones, including eicosanoids and steroid hormones.Digestive system3. The small intestine is adapted to absorb the nutrients from the food and drinks that Spencer hasingested due to the egg is primarily made of protein and fats. Bacon is combined of fats and orangejuice contains carbohydrates.Adaptations of the small intestine for absorption. (2)i. The mucosa of the small intestine has numerous circular folds called plicae circularis / valvulaeconniventes, which emerge to form villi and microvilli. Together with Plicae circularis, the villi andits microvilli provide a larger surface area for uptake of nutrients.ii. The small intestine is long enough, nearly 700 cm, to provide enough time for digestion andabsorption.iii. Its smooth muscle tissue permits peristalsis to force food along the small intestine.iv. The structure also has digestive enzymes, which are produced in the pancreas, apart from bileoriginating from the gallbladder, to dissociate lipids, proteins, and carbohydrates.4. Elimination of stools from the body requires the work of defecation reflex. It is of two types:i). Inherent excretion reflex; when stool enters the rectum, stimulus and receptors cause rectal walls toexpand. Afferents transduce defecation information to the myenteric plexus, while efferents signal thesmooth muscles. Effectors cause the smooth muscles to expand to allow feces to move out of the colon.In response, weak nerve responses to peristalsis force stool from the colon and loosen the internal analsphincter(2).ii). parasympathetic defecation reflex: it is controlled by stimulus, receptors, afferents, efferents,effectors, and nerve responses. The stimulus and receptors cause rectal expansion, while afferents andefferents act as sensory fibers (3). Effectors are responsible for contracting or expanding in response tothe defecation reflex to allow feces to move along the rectum. Strong nerve responses to peristalsis forcestool from the rectum and trigger relaxation of the internal anal sphincter.2iii). The pudendal nerve can also trigger voluntary impairment of the external anal sphincter.The onset of defecation reflex allows an individual to either defecate immediately or after a while. Latedefecation is aided by the sphincter muscles in the anus, which trigger backward movement of stool.When the stool moves backward, an individual’s urge to defecate decreases (2).5. The small intestine produces cholecystokinin, which impairs gastric emptying, resulting in hungersuppression. The hormone causes the gall bladder to contract apart from triggering relaxation of theSphincter of Oddi. As a result, bile is delivered to the duodenum. Bile contains salts which assistemulsification of fats as well as digestion and absorption. Cholecystokinin also triggers the release ofdigestive enzymes in the pancreas to assist the break down of proteins, fats, and carbohydrates (2).Urinary System6. Stewart’s water intake explains his lightheadedness, since he did not take an enough amount ofwater he would have been dehydrated. Insufficient fluids cause the volume of the blood todecrease. (4). The blood pressure drops, and the brain does not receive enough supply of blood. Thiseffect will cause lightheadedness (3).7. The renin-angiotensin system would be activated, which increases thirst as a path of increasing bloodvolume. Antidiuretic hormone (ADH) originating from the posterior pituitary glands triggers thekidneys to take water from urine. This fluid dilutes the body plasma. The primary hormone limitingthe production of renal renin is the atrial peptide hormone. It also inhibits the release of aldosteronehormone, hindering the absorption of sodium. This inhibition also causes more sodium to be lost inthe distal convoluted tubule as well as the collecting duct, leading low blood pressure and volume.A decrease in the volume of blood triggers the production of enzyme renin, which transformsangiotensinogen to angiotensin 1. Enzyme ACE which the lungs secrete catalyzes angiotensin 1 toangiotensin 2. This final product triggers the adrenal glands to produce the aldosterone hormone forthe uptake of water and sodium in the renal tubules. Potassium is excreted as well. Both aldosteroneand angiotensin 2 hormones maintain blood pressure and volume (2).8. Two mechanisms that contribute to autoregulation include the myogenic response of preglomerulararterioles and tubule-glomerular feedback.• A slower glomerular filtration rate will prevent the removal of metabolic waste from thebloodstream.• Extremely higher glomerular filtration rate will impair the Myogenic mechanism, whichcontrols the absorption of salt and water in the renal tubules.In the tubule-glomerular feedback mechanism, fluid flow rate affects the concentration of sodiumchloride, which reaches the macula densa. The process is also dependent on the glomerular capillarypressure and GFR (2).3References1. Disa P. Endocrine System Physiology [Internet]. Lecture given in Unit 6529 Systemic Anatomyand Physiology, lecture, week 1; 2020; University of Canberra. PowerPoint slides. Availablefrom Tortora GJ, Derrickson BH. Principles of anatomy and physiology. John Wiley & Sons; 2020December 17. Available from Martin K. Urinary System Physiology [Internet]. Lecture given in Unit 6529 Systemic Anatomyand Physiology, lecture, week 2; 2020; University of Canberra. PowerPoint slides. Availablefrom Disa P. Homeostasis. [Internet]. Lecture given in Unit 6529 Systemic Anatomy and Physiology,lecture, week 1; 2020; University of Canberra. PowerPoint slides. Availablefrom


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