End of semester Short Responses PDF

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1. Draw a median section of the brain (showing the brain stem) and correctly label the following 10 major structures: [5 marks] 1. Cerebral Hemisphere 2. Corpus callosum 3. Diencephalon 4. Midbrain 5. Pons 6. Cerebellum 7. Medulla Oblongata 8. Pyramids 9. Fourth Ventricle 10. Transverse cerebral fissure 2. Draw a cross sectional view of the spinal cord from the thoracic region (and its closely associated peripheral nervous system components). Correctly label on your diagram the following 10 major structures: [5 marks] 1. Ventral horn of the grey matter 2. Lateral horn of grey matter 3. Dorsal horn of the grey matter 4. Dorsal root 5. Dorsal root ganglion 6. Ventral root 7. Spinal nerve 8. Dorsal ramus 9. Ventral Ramus 10. Ventral median fissure 3. In regards to the sympathetic nervous system, write short definitions for each of the following: (a) Postganglionic fibre [1 mark] Postganglionic fibers are unmyelinated fibers from the ganglion to the effector organ in the ANS  (b) Sympathetic chain [1 mark] Sympathetic chain is the pair of bilateral ganglionated longitudinal cords on either side of the vertebral column (sympathetic nervous system) (c) Collateral ganglion [1 mark] Collateral ganglion are any of several ganglia in the mesenteric nervous plexuses near the abdominal aorta and include the celiac and mesenteric ganglia (sympathetic nervous system) (d) Adrenal medulla [1 mark] The adrenal medulla (of the adrenal gland) is a specialized sympathetic ganglion that controls the hormones that initiate the flight or fight response (maintaining homeostasis). (e) Hypothalamus [1 mark] The hypothalamus is an integrator for autonomic functions, receiving ANS regulatory input from the limbic system for excitatory action

4. List and describe the 5 steps involved in the cardiac conduction cycle of the heart (5 marks). 1. sinoatrial node (SA - pacemaker cells): Initiation of the heartbeat 2. SA node signal travels to the atrioventricular (AV) node (AV node slows down the activation allowing time for atria to contract) 3. From the AV node the signal travels along the bundle branches 4. From the AV bundle the signal travels to the ventricles via the Purkinje fibres 5. Purkinje fibres spread signal to allow for rapid contraction of ventricle 5. (a) List the THREE (3) basic layers of the arterial and venous wall. (1.5 marks) The innermost layer is called the tunica intima. The muscular middle layer is called the tunica media, and the outermost layer is called the tunica adventitia. (b) Which of these layers is responsible for changing vessel diameter? (0.5 marks) Tunica media is responsible for vasodilation (c) Describe the differences in the gross anatomy of veins and arteries. (3 marks) The artery has a thicker wall, a thicker tunica media, a narrower lumen than the similarly sized vein, and thickened elastic membranes not present in the vein. The vein, by contrast, has a thicker tunica externa, a wider lumen, and valves 6. (a) Trace the route of inhaled air from the external nares to the alveolus, naming all of the structures through which the air passes. [4.5 marks] 1. external nares 2. nasal cavity 3. nasopharynx 4. oropharynx 5. laryngopharynx 6. larynx 7. trachea 8. bronchi 9. bronchioles 10. terminal bronchioles 11. alveoli (b) In this route, where does air enter the respiratory zone. [0.5 marks] The bronchioles 7. List THREE (3) key accessory organs of the digestive system. Give a key function that contributes to the digestive process for EACH, and describe where they are connected to the gastrointestinal tract (5 marks) salivary glands: Its enzymes, salivary amylase and lipase, begin the digestion of carbohydrates and fats. They are scattered within the mucosa of the tongue, palate, lips, and cheeks. pancreas: Most digestive enzymes that operate within the small intestine are secreted by the pancreas. The main pancreatic duct joins the bile duct to form the hepatopancreatic ampulla and empties into the duodenum at the major duodenal papilla. liver: The liver is the largest gland in the body, performs over 500 functions. Its digestive function is to produce bile (stored in the gallbladder, breaks up fatty nutrients) and secreted into the duodenum.

8. Compare and contrast the structure and function of the small intestine and the large intestine (5 marks). Small Intestine 1. Villi are present. 2. Important role in digestion - absorbs the nutrients from digested food. 3. It has 3 parts (duodenum, jejunum and ileum). 4. Narrow (4cm) but very long (~5m) 5. Internal surface of small intestine has circular folds, also called as 'plicae circulares'. Large intestine 1. Villi are absent. 2. No role in digestion, but it takes part in absorption of water and electrolytes and in production of vitamins. 3. It has 5 parts (cecum, appendix, colon, rectum, and anal canal) 4. Wider diameter (~4-6 cm) and length (~1.5 m.) 5. Circular folds are absent, no plicae circulares Explain the mechanisms for movement of air into and out of the lungs during quiet breathing. In your answer, identify the muscles involved in inhalation and exhalation. Contraction of the external intercostals causes the ribs to elevate, enlarging the thoracic cavity. This causes the lungs to expand and increase in volume. Because of the increase in volume the pressure in the lungs decreases to below barometric air pressure, according to Boyle's Law. This causes the air to flow into the lungs. During passive expiration, the external intercostals relax, once again decreasing the volume of the thoracic cavity and lungs. This results in an increase in pressure inside the lungs to above barometric air pressure and air flows out for the lungs until the pressure inside the lungs and the barometric air pressure equilibrate. Bucket to pump movement: The ribs start slanting downwards, then the diaphragm or external intercostals raise the lower parts of the ribs so that they are more horizontal. This increases the diameter of the thoracic cavity, allowing the lungs to further expand.

9. a) Trace the path urine takes in the urinary system, listing the structure and the function of each major organ. (4.5 marks) s Kidneys maintain the purity and chemical constancy of the blood and the other extracellular body fluids. The ureter carries urine from the kidney to the urinary bladder. The Urinary bladder is a muscular sac that stores urine, allowing urination to be infrequent and controlled. The urethra carries urine from the urinary bladder to the outside of the body. b) How is backflow of urine from the urinary bladder prevented? (0.5 marks) Backflow is prevented by the oblique angle at which the ureter enters the urinary bladder

10. Draw a diagram of the major components of the female reproductive system. On your diagram, Label 10 significant structures. (Each correctly labelled structure is worth half a mark). (5 m)...