Urinary System Flashcards
Functions of the urinary system:
- Rids body of waste products
- Maintains appropriate fluid volume (by regulating amount of water excreted in the urine)
- Maintains normal pH of the blood
- Secretes erythropoietin
- Secretes rennin
What controls red blood cell production?
What helps maintain normal blood pressure?
- erythropoietin
- rennin
What does the urinary system consist of? (4)
- Kidneys
- Ureters
- Urinary bladder
- Urethra
What produces urine?
Kidneys
What transport the urine away from kidneys to the urinary bladder?
Ureters
What stores urine until it is excreted from the body?
Urinary bladder
What is the tubular structure that carries urine from urinary bladder to the outside of the body?
Urethra
Primary organs of the urinary system. Filter the blood, remove wastes, and excrete the wastes in the urine. Bean-shaped.
Kidneys
Where are the kidneys located?
What organ displaces the right kidney slightly lower than the left?
- Between T-12 and L-3 vertebrae
- Liver
What is the connective tissue that holds the kidney in place?
Renal fascia
Thick layer of adipose tissue that surrounds each kidney.
Perirenal fat
Tough, fibrous connective tissue. Encases each kidney. Provides support for the soft tissue inside.
Renal capsule
Indentation in kidney. Where ureter and renal vein leave the kidney. Where renal artery enters the kidney. What is this?
This also leads to a large cavity within the kidney called what?
- Hilum
- renal sinus
What is the outer reddish region of the kidney?
What is the inner, reddish-brown region of the kidney that consists of a series of renal pyramids?
- Renal cortex
- Renal medulla
Appears striated and contain straight tubular structures and blood vessels. Wide bases of pyramids are adjacent to the cortex.
Renal pyramids
Pointed ends of the pyramids. Directed toward center of kidney.
Renal papillae
Formed by portions of the renal cortex. Extend into spaces between adjacent pyramids.
Renal columns
Central region of kidney. Continuous with ureter. Consists of a large cavity that collects urine as it is produced.
Renal pelvis
Cuplike projections of the renal pelvis.
What are he two calyx?
Calyces
- Minor calyx
- Major calyx
What surrounds the renal papillae of each pyramid and collects urine from that pyramid?
What is made up of several minor calyces and urine flows up into the renal pelvis from these and then flows into the ureter?
- Minor calyx
- Major calyx
Functional unit of the kidney. Each kidney contains over a million of these. Located in the cortex and medulla of kidney.
Nephrons
What are cluster of capillaries?
What is the double-layered epithelial cup that surrounds the glomerulus?
- Glomerulus
- Glomerular capsule (also known as Bowman’s capsule
Blood enters the glomerulus through what?
Blood is filtered in glomerulus, filtrate enters what?
Blood leaves glomerulus through what?
- afferent arteriole
- glomerular capsule (Bowman’s capsule)
- efferent arteriole
What carries fluid away from Bowman’s capsule?
What two things are highly coiled?
What makes a U-turn. ascends back toward the cortex?
- Renal tubule
- Proximal and Distal convoluted tubule
- Nephron loop (Henle’s loop)
Urine passes from nephrons into where? Flows from here into minor calyces.
Collecting Ducts
Macula densa monitors sodium chloride concentration in urine which also influences this… In afferent arteriole, these cells produce renin. What is this?
Macula densa and juxtaglomerular cells make up what?
- juxtaglomerular cells
- juxtaglomerular apparatus
Blood flow through kidney at approximate rate of how much?
1200 mL/min (about 1/4 of the cardiac output)
Transport urine from renal pelvis to urinary bladder. Descend from renal pelvis. Enter urinary bladder on the posterior inferior surface.
Ureters
What is the outer layer of ureter that consists of fibrous connective tissue?
What is the middle layer of ureter consisting of smooth muscle?
What is the inner layer?
- Fibrous coat
- Muscular layer
- Mucosa
What layer of ureter uses peristalsis to propel urine through the ureter?
What layer of ureter secretes mucus to coat and protect surface of the cells?
- Muscular layer
- Mucosa
Located in pelvic cavity. Temporary storage reservoir for urine. Size and shape varies with amount of urine it contains and pressure from surrounding organs.
Urinary bladder
What is the layer of urinary bladder that consists of mucous membrane that has rugae?
What is the layer of the urinary bladder that consists of connective tissue with elastic fibers?
What is the layer of the urinary bladder that is composed of smooth muscle interwoven in all directions and is also called the detrusor muscle?
- Mucosa
- Submucosa
- Muscularis
Folds that occur when bladder is empty–allow bladder to expand as it fills
Rugae
A contraction expels urine from bladder. Happen in muscularis.
detrusor muscle
Formed by three openings in the floow of the urinary bladder. What is this?
What are the small flaps of mucosa that cover openings?
What is the band of the detrusor muscle that encircles this opening and forms the internal urethral sphincter?
- trigone
- two openings from ureters
- third opening from urethra
Thin-walled tube. Conveys urine from urinary bladder to outside of body. What is this?
What are the 2 sphincters of this that control flow of urine?
- Urethra
- Internal and external sphincters
What surrounds urethra where it laves the urinary bladder. Consists of smooth (involuntary) muscle?
What encircles urethra where i passes through the pelvic floor and consists of skeletal (voluntary) muscle?
- Internal urethral sphincter
- External urethral sphincter
Opens to outside just anterior to vaginal opening.
External urethral orifice
Males urethra is much longer than women’s. Theirs transports both urine and semen.
Parts of the male urethra:
What is the part that passes through the prostate gland?
What is the short region that penetrates pelvic floor and enters penis?
What is the longest region?
- Prostatic urethra
- Membranous urethra
- Spongy urethra
Urine carries wastes, excess water, and excess electrolytes.
What are three things involved in the formation of urine?
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
Blood plasma move across filtration membrane in the renal corpuscle. Enters glomerular capsule. What is this?
What consists of capillary endothelium of the glomerulus and endothelium of the capsule. Acts as a barrier and prevents blood cells and protein molecules from entering the capsule?
- Glomerular Filtration
- Filtration membrane
Force that moves the fluid across the membrane
Filtration pressure
Fluid that enters the capsule
Filtrate
Blood lows through the kidneys at what rate per minute?
1200 mL per minute
How many liters of filtrate are formed in a 24-hour period and is reduced to 1-2 liters of urine?
180 liters (45 gallons)
What substances are useful to the body that are reabsorbed?
Wastes that remain in the filtrate are excreted in the urine.
glucose, water, and sodium
Percentage of reabsorption that takes place for each:
Proximal convoluted tubule?
Nephron loop (loop of Henle)?
Distal convoluted tubule?
What percentage of filtrate is excreted as urine?
- 65%
- 15%
- 19%
- 1%
Transport molecules and ions into the filtrate from the blood. Waste products of cellular metabolism (e.g. urea), some drugs, hydrogen ions, potassium ions, creatinine, histamine.
Tubular Secretion
What becomes toxic if allowed to accumulate in the body?
What helps regulate pH of the blood?
- Waste products (urea)
- Hydrogen ions
What consists of substances that are filtered minus the substances that are reabsorbed in the tubules. Plus the substances that are added by tubular secretion?
Urine
Secreted by adrenal gland. Acts on the kidney tubules, increases reabsorption of sodium. When sodium is reabsorbed: water follows by osmosis which reduces urine output
Aldosterone
What is released from pituitary gland?
Less water is lost from body. Makes distal convoluted tubule and collecting duct more permeable to water. What is this?
More water is lost from body. Makes tubules less permeable to water. What is this?
- Presence of ADH
- Absence of ADH
Produced by special cells in the heart. Promotes excretion of sodium and water. Acts directly on kidney tubules. Inhibits secretion of ADH, renin, and aldosterone: decreases blood volume and blood pressure.
Atrial natriuretic hormone (atriopeptin)
Enzyme produced by kidney. Secreted in response to low blood pressure and decreased blood sodium concentration. Promotes production of angiotensin II in the blood
Renin
Increases blood pressure from production of angiotensin II.
Powerful vasoconstrictor
Angiotensin II stimulates adrenal gland to secrete this. Acts of kidney tubules to conserve sodium and water. The angiotensin II increases blood volume and, consequently, increases bp.
Aldosterone
Act of expelling urine from the bladder (can hold up to 1 liter of urine)
Micturition
When bladder contains 200-400 ml of urine, stretch receptors in bladder wall trigger this. Automatic and involuntary response. Impulses are transmitted to detrusor muscle. Can be inhibited or stimulated by higher brain centers.
Micturition reflex
Most obvious changes in urinary system from aging occurs in what 2 parts?
Muscles weaken and become less elastic.
Bladder is unable to expand or contract as much as in younger people. Reduces capacity of bladder.
Awareness of need to urinate may be delayed in the elderly.
- urinary bladder and urethra
What organ has general atrophy of nephrons by age 80? This organ function is at 80%.
Tubules.
Walls thicken and are less able to reabsorb water o form concentrated urine. Collecting ducts are less responsive to ADH. May result in dehydration
- Diminish ability to reabsorb glucose and sodium
- Less efficient in secretion of ions and drugs
- Diminished ability to compensate for drastic changes in acid-base balance.
Kidney
