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Cleaning out the Wrk
Urinary System
Question | Answer |
---|---|
Function Of Urinary System | Regulates blood volume and composition. Regulates blood pressure , Aids the metabolism (Vitamin D). |
Describe First Function of Regulating blood volume and composition | removes wastes(thus making urine) and excess water, and by excreting specific wastes (such as H ions lowering PH) |
Describe the Second Function Regulating blood pressure | through the release of renin and the action of nephron |
Describe the third function: Aids in metabolism | by making new glucose (gluconeogensis), stimulating production of RBC, and converting D3 made by the skin into the hormone calcitrol. |
How much blood does the kidneys receive per minute | 1200ml |
What type of organ is the kidney based on its location? | Retroperitoneal organ. Hidden behind the abdominal wall. |
The hilus contains? | Indented regions of the kidney where the Renal artery and vein as well as the ureters. |
Function of Ureters | carry the waste filled urine made by the kidneys down to the next stop, the urinary bladder. |
Function of the Renal Capsule | innermost layer of smooth, fibrous, and transparent layer prevents infections from reaching the kidney. |
Adipose capsule | middle, fatty layer of the kidney. Protective and anchor kidney in place. |
Renal fascia | the outermost layer of dense irregular connective tissue. Protective and anchor kidney in place |
Renal Pyramids | located inside the kidney. Pyramid shaped structures. |
Renal Columns | located inside the kidney the pyramids are columns of tissues. |
Renal Cortex | the outer cortex of the kidney |
Renal medulla | inner medulla of the kidney. |
How many sphincters does the urethra have? | Two. Internal and external urethral sphincter. Internal is involuntary, and external is voluntary. |
Name the organs in the urinary system | kidneys, ureters, urinary blader, and urethra. |
Trace the blood through the nephron. | Blood enters the glomerulus through an afferent arteriole, flows through the fenestrated capillaries of the glomerulus, and then exits through a smaller efferent arteriole. |
Nephron function and location | located in the cortex and medulla.where urine is made. function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine. |
Juxtaglomerular apparatus (JGA) | smooth muscle cells that wrap around the afferent arteriole and the distal convoluted tubule. Help regulate blood sugar. Hormone renin is also released from these special cells to regulate BP. |
What does Renin do and how? | Renin regulates BP. Does this by converting angiotensinogen into angiotensin I, which then turns into angiotensin II in the lungs. Angiotensin II raises BP. Also simulates the release of aldosterone which causing reabsorption of Na ions. |
Aldosterone function and where it is produced. | Hormone released from adrenal glands. Its function is to increase the retention of sodium and water and to increase the excretion of potassium by the kidneys. |
Antidiuretic (ADH) | prevents water loss in urine. ADH is a hormone that is produced in a part of the brain called the hypothalamus. It is then stored and released from the pituitary gland, a small gland at the base of the brain. |
Major parts of the nephron | renal corpuscle and Renal Tubule. |
Renal Corpuscle | where the fluid is filtered. Made of Bowmans capsule or glomerular capsule and the glomerulus. |
Renal Tubule | Proximal convoluted tubule or PCt, the loop of Henle, the distal convoluted tubule or DCT and finally the collecting ducts. |
Filtration | process of selectively removing, or filtering, materials out of a solution, and it happens in the glomerulus, producing a protein free fluid, filtrate, that is somewhat similar to blood plasma. |
Glomerular capsule | Glomerulus lies in here. This capsule is made of simple squamous epithelium which makes up the parietal epithelium. The visceral epithelium consists of cells called podocytes, which have numerous small "feet" called pedicels. |
Pedicels | numerous small feet of the podocyte cells. help keep the proteins from entering the filtrate. |
Normal glomerular filtration rate (GFR) | 125ml a minute. This is possible due to the enormous filtration surface per kidney. 180L per day. |
Peritubular capillaries | peritubular capillaries are tiny blood vessels that travel alongside nephrons allowing reabsorption and secretion between blood and the inner lumen of the nephron. |
How many liters of urine do we excrete each day? | 1-2L |
How much fluid is reabsorbed a day? | 178-179L |
True or False PCT contain microvilli? | True. Increases surface area for reabsorption. |
What type of cells make up the proximal convoluted tubule? | simple cuboidal cells |
countercurrent mechanism | the flow of the filtrate through the tubes passes in the opposite direction from the flow of the blood, despite both starting at the glomerulus in the Bowman's capsule. |
countercurrent mechanism cont. | the filtrate goes directly from the glomerulus to the pct and loop of henle and then to the dct. Capillaries go from the glomerulus skip over to the dct, and then move backward to the loop of henle and PCT. |
Secretion | is the release by active transport of substances into the filtrate. Secretion plays a major role in the blance of ions in the blood. Example: Excess K can cause cardiac arrest, so the level can be lowered by secreting it into the collecting duct. |
Example of Secretion | When blood gets to acidic, H ions are secreted into the PCT and the collecting duct, thus raising the ph to normal. |
What is the capacity of the urinary bladder? | 750ml. |
micturition | aka urination. Sensory neurons(stretch receptors in urinary bladder) send a message to the brain that makes us consciously perceive a full bladder and a desire to urinate, or void ones bladder. |
micturition reflex | a reflex action (parasympathetic nerve impulse) located in the sacral region of the spinal cord that causes the urinary bladder walls to contract and the internal urethral sphincter to relax. |
Roger is hit in the lower back by an errant baseball. What protects his kidneys from this mechanical trauma | The lower part of his rib cage and the perirenal fat capsule protect his kidney from the biow |
From inside to outside, list the three layers of supportive tissue that surround each kidney. Where is the parietal peritoneum in relation to these layers. | The layers of supportive tissue around each kidney are the fibrous capsule, the perirenal fat capsule and the renal fascia. |
The lumen of the ureter is continuous with a space inside the kidney. This space has branching extensions. What are the names of this space and its extensions. | The renal pelvis, which has extensions called calyces, is continuos with ureter. |
Name the tubular components of a nephron in the order that filtrate passes through them. | Filtrate is formed in the glomerular capsule and then passes through the proximal convoluted tuble (PCT), the descending and ascending limbs of the loops of Henle (thin-Thick), and the distal convoluted tubule (DCT). |
what are the structural differences between juxtamedullary and cortical nephrons? | The structural differences are: Juxtamedullary nephrons supply vasa recta, while efferent arterioles of cortical nephrons supply peritublar capillaries. |
what type of capillaries are the glomerular capillaries? What is their function? | The glomerular capillaries are fenestrated capillaries. Their function is to filter large amounts of plasma into the glomerular capsule. |
vasa recta | bundles of stragiht vessels that extend deep into the medulla paralleling the longest loops of henle. Pay an important role in forming concentrated urine. |
Extrinsic and intrinsic controls of GFR Serve two different purposes. What are they? | |
Describe two main ways in which angiotensin II increases blood pressure and volume. | |
In what part of the nephron does the majority of reabsorption occur? | The majority of reabsorption occurs in the PCT |
How are primary and secondary active transport processes different? | Primary active transports, the energy for the process is providied directly by the cleavage of ATP. In secondary active transport, the energy for the process is provided by the Na concentration gradient. |
How does the movement of Na drive the reabsorption of water and solutes? | The reabsorption of Na by primary active transport, in turn, drives reabsoprtion of amino acids and glucose by secondary active transport. It also drives passive reabsorption of choloride, and reabsorption of water by osmosis. |
List several substance that are secreted into the kidney tubules. | H, K, NH, Creatinine, urea, and uric acid. |
Describe the special characteristics of the descending and ascending loops of Henle that cause the formation of the medullary osmotic gradient. | The decending limb of the loop of Henle is permeable to water and impermeable to NaCl. The ascending limb is impermeable to water and permeable to NaCl |
Under what conditions is ADH released formt the posterior pituitary? What effect does ADH have on the collecting duct | ADH is released from the posterior pituitary in response to hyperosmotic extracellular fluid. ADH causes insertion of aquaporinins into the luminal membrane of the principal cells of the collecting ducts. |
Three nitrogenous wastes in urine | urea, uric acid, creatinine. |
Path of blood flow through renal blood vessels | Aorta, Renal Artery, Segmental artery, Interlobar artery, arcuate artery, cortical radiate artery, Afferent arteriole, Glomerulus, Efferent arteriole, pertibular capillaries and vasa recta, cortical radiate vein, arcuate vein, interlobarvein, renal vein, |
Nerve supply of the kidneys & ureters | renal plexus |
Urine | typically clear, yellow, aromatic, and slightly acidic. Specific gravity ranges from 1.001 to 1.035. 95% water, solutes include nitrogenous wastes and various ions |
Substances not usually found in urine | glucose, proteins, erythrocytes, leukocytes, hemoglobin, and bile pigments. |
Daily urinary volume is typically ___ | 1.5-1.8L |
Kidney has three distinct regions | renal cortex, renal medulla, renal, pelvis. |
Glomerulus | cluster of capillaries. Part of a nephron. Located inside the glomerular capsule |
Through these slits, filtrate enters the capsular space inside teh glomerular capsule. | filtration slits on the glomerular capsule visceral layer. |
Describe the Wall of the PCT | cubodial epithelial cells with large mitochondria, and their luminal surfaces bear dense microvilli. Increases teh surface area and capacity for reabsorbing water and solutes from the filtrate and secreting substances into it. |