A&P 2 module 7

A&P 2 Module 7 Complete Solutions 2023 The urinary system has ____ kidneys, _____ ureters, and _____ bladder. Ans- two, two, one Describe the shape, weight and location of the adult kidney. Ans- An adult kidney is bean-shaped, about the size of a can of soup and weighs about 5 ounces. The right kidney lies slightly lower than the left because of the liver's location just above it. Both kidneys are mostly protected by the rib cage because of their location between the T-12 and L-3 vertebra. The ____glands are located on top of each kidney. Ans- Adrenal glands Describe the three layers of protective tissue that surround the kidney. Ans- The kidney surface is protected by three layers of specialized tissue. The renal capsule is a tough fibrous outer skin of the kidney which protects it from injury and infection. Outside of the renal capsule is a fatty layer that protects the kidney from trauma called the adipose capsule. The outer renal fascia is dense fibrous connective tissue which keeps the kidney in place inside the abdominal cavity. A vertical cross section shows what three regions inside the kidney? Ans- the cortex, the medulla, and the pelvis The _____ is a continuous outer region with several cortical columns. Ans- Renal cortex The renal medulla is divided into sections called _____. Ans- Pyramids Describe the renal pelvis. Ans- The renal pelvis constitutes a funnel-shaped tube that connects to the ureter as it leaves the hilus. Trace the flow of blood through the vessels of the kidney from renal artery into the glomerulus and back to the renal vein. Ans- (1) Renal artery, (2) Segmental artery, (3) Lobar artery, (4) Interlobar artery, (5) Arcuate artery, (6) Interlobular artery, (7) Afferent arteriole, (8) Glomerular capillaries, (9) Efferent arteriole, (10) Peritubular or Vasa recta capillaries, (11) Interlobular vein, (12) Arcuate vein, (13) Interlobar vein, (14) Renal vein Input from the _______ adjusts the diameter of the renal arteries thereby regulating renal blood flow. Ans- sympathetic nervous system Urine is carried from the kidneys to the bladder by thin muscular tubes called ____. Ans- ureters ______are sphincters located where the ureters enter the bladder. Ans- Ureterovesical valves Describe the three layers of the ureter wall. Ans- The inner lining, made of transitional epithelium, is continuous with the kidney's lining. The middle layer is two sheets of muscle, one longitudinal and the other circular. The outer adventitia layer is fibrous connective tissue. Describe the urinary bladder. Compare male and female locations. Ans- The urinary bladder is the hollow, muscular, elastic pouch that receives, and stores urine excreted by the kidneys before disposal through the urethra. In males, the base of the bladder lies in front of the rectum and just behind the pubic symphysis. In females, the bladder sits below the uterus and in front of the vagina, so the maximum capacity of the bladder is lower in females than in males. Both ureters open into the bladder via the _____. Ans- ureteral orifices Describe the three layers of the bladder. Ans- The outer adventitia is fibrous connective tissue, the middle layer is a muscular layer known as the detrusor muscle with inner and outer longitudinal layers and middle circular layer, the inner mucosal layer is composed of transitional epithelium. Transitional epithelium cells are specialized to enable cellular expansion to absorb fluid. Describe the bladder when it is full and when it is empty. Ans- The bladder is very elastic, collapsing into it a pyramidal shape when empty. As it is filled by urine, the bladder swells and becomes pear-shaped, rising in the abdominal cavity. Describe the two sphincters of the bladder. Ans- The involuntary-controlled internal urethral sphincter is located near the bladder and keeps the urethra closed to prevent urine from leaving the bladder. The voluntary-controlled external urethral sphincter, composed of skeletal muscle, surrounds the urethra as it passes through the pelvic floor. Discuss the differences between the male and female urethra. Ans- In males and females, the length and functions of the urethra differ. The female urethra is shorter and only carries urine while the male urethra is about 5 times longer and carries both urine and semen from the body. What are the three regions of the male urethra? Ans- The prostatic urethra which runs within the prostate gland, the membranous urethra which runs within the urogenital diaphragm and the spongy (penile) urethra. What is a nephron? Ans- The basic structural and functional unit of a kidney. The function of the nephron is to control the concentration of water and soluble materials by filtering the blood, reabsorbing needed materials and excreting the rest as urine. Each nephron consists of: Ans- Two parts: the glomerular capsule (renal corpuscle) and the renal tubule. The renal tubule is made of: Ans- Three parts: the proximal convoluted tubule (PCT), the loop of Henle, and the distal convoluted tubule (DCT). Describe the structure of the renal corpuscle. Ans- The renal corpuscle is composed of the glomerulus, a network of tiny blood capillaries surrounded by the glomerular (Bowman's) capsule, a double-walled simple squamous epithelial cup (Figure 10). The glomerular capillaries are extremely porous. The capillary endothelium has fenestrations (pores) which allow certain substances to leave the capillaries. What causes water and solutes to leave the glomerulus? Ans- The afferent arteriole, which is fed by the interlobular artery, is much larger in diameter than the efferent arteriole. The difference in diameter causes an extremely high blood pressure in the glomerular capillaries, forcing water and solutes out of the blood, thus making filtration possible. Water and solutes leave the glomerulus, enter the glomerular capsule, and subsequently flow into the renal tubule. Once water and solutes leave the blood and enter the glomerular capsule it is called ____. Ans- filtrate ________are found in the cortex region of the kidney, except for a portion of their loop of Henle which extends into the medulla. ______pass deeply into the medulla because of their location and their longer loops of Henle. Ans- Cortical nephrons; juxtamedullary nephrons Describe the proximal convoluted tubule Ans- The first section of the tubule is a coiled proximal convoluted tubule which is specialized to reabsorb water and many solutes from the glomerular filtrate into the low-pressure peritubular capillaries which surround the renal tubule as well as secrete certain unwanted substances. Describe the loop of Henle. Ans- The second section is the hairpin loop of Henle. Initially the loop of Henle has the descending limb followed by the ascending limb. The descending limb allows water loss and the ascending limb allows salt (NaCl) loss. Describe the distal convoluted tubule. Ans- The last part of the tubule is the highly coiled distal convoluted tubule which allows for hormonally controlled reabsorption of water and solutes. Mostly the distal convoluted tubule is responsible for the secretion of unwanted substances. What are the three types of capillaries associated with nephrons and their function? Ans- The glomerular capillaries, the peritubular capillaries and the vasa recta. The glomerular capillaries (glomerulus) are highly coiled capillary beds formed from the afferent arteriole, leaving as the efferent arteriole. The peritubular capillaries closely follow the renal tubules and drain into the interlobular vein. the vasa recta which follow the loops of Henle in the juxtamedullary nephrons of the medulla. Describe the process of micturition. Ans- Micturition is the act of emptying the bladder. As urine accumulates, the rugae flatten and the wall of the bladder thins as it stretches, allowing the bladder to store larger amounts of urine without a significant rise in internal pressure. The urge to urinate usually starts when about 200 ml of urine has accumulated, causing distension of the bladder walls which initiates a visceral reflex arc. This causes the detrusor muscle to contract and the internal sphincter to relax forcing stored urine through the internal sphincter into the upper part of the urethra. A person can consciously resist this initial urge to urinate because the external sphincter is voluntarily controlled. As the bladder continues to fill, the desire to urinate becomes stronger. Eventually, if the amount of urine reaches 100% of the bladder's capacity, the voluntary sphincter opens, and micturition occurs involuntarily. What is incontinence? Ans- Incontinence is the inability to control micturition voluntarily. What is urinary retention? Ans- The inability to expel stored urine How many times a day does the kidney filter through the blood plasma? Ans- The kidneys filter the entire blood plasma volume about 60 times each day About how many gallons are filtered vs. excreted as urine? Ans- About 47 gallons of glomerular filtrate containing the water, nutrients, and essential ions are removed daily from the blood plasma. By the time filtrate enters the collecting ducts, it contains about only 0.5 gallons of urine, with the other 99% being returned to the blood. What are the three steps of urine formation? Ans- For the body to filter the entire blood and then retain the important elements, three processes must take place: filtration, reabsorption and secretion. What is Blood hydrostatic pressure (HP)? Ans- It is the amount of pressure found inside the blood in the capillaries, driving fluids out of the glomerular capillar