GU A&P (Male) Flashcards
The urinary system consists of what
2 kidneys, 2 ureters, one urinary bladder, and one urethra
What is nephrology
The scientific study of the anatomy, physiology, and disorders of the kidneys
What is urology
The branch of medicine that deals with the male and female urinary system, and the male reproductive system
What are the five functions of the kidneys
Regulation of ion levels in the blood
Regulation of blood volume and blood pressure
Regulation of blood pH
Production of hormones
Excretion of waste
What do the kidneys regulate
Regulate the concentration of hydrogen in the blood by excreting a variable amount of hydrogen in the urine
What hormones do the kidneys produce
Calcitriol - the active form of vitamin D helps regulate calcium homeostasis
Erythropoietin - stimulates production of red blood cells (think EPO = doping)
What waste is being excreted from the Kidneys
Ammonia and urea, bilirubin, creatinine, urine acid
Where are the kidneys located
On either side of the vertebral column, at T-12 to L-3 retroperitoneal
Near the center of the medial border is what
An invention called the renal hilum
What surrounds the renal capsule and cushions the kidney
Adipose (fatty) tissue
Along with a thin layer of dense irregular connective tissue, the adipose tissue anchors the kidney to the posterior abdominal wall
What are the main regions of the kidneys (internally)
Renal cortex - an outer light red region
Renal medulla - an inner, darker red-brown region
What is located within the renal medulla
Several cone-shaped renal pyramids
Extensions of the renal cortex called renal columns
What are minor calyces
Urine formed in the kidney passes from thousands of papillary ducts within the renal pyramids into cuplike structures
Each kidney has how many minor calyces
8-12
From the minor calyces, urine next flows into 2-3 MAJOR calyces, and then into a single large cavity called what
The renal pelvis
How much of the resting cardiac output flows into the kidneys through the right and left renal arteries
About 20-25% (1200 milliliters of blood per minute)
How does the renal blood supply flow *****
Afferent arterioles -> glomerulus -> efferent arterioles -> peritubular capillaries -> peritubular veins -> ultimately, veins drain into the renal vein
What are the nephrons
The functional units of the kidney (about a million in each kidney)
A nephron consists of what parts
Renal corpuscle - where blood plasma is filtered
Renal tubule - filtered fluid, called glomerular filtrate, passes
What are the parts that make up a renal corpuscle
The glomerulus and the glomerular (Bowman’s) capsule, a double-walled cup of epithelial cells that surrounds the glomerular capillaries
What are the main sections of the renal tubule
Proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule
The loop of Henle extends downward into the renal medulla, where it is called _________
And returns to the renal cortex as the __________
The descending limb
Ascending limb
To produce urine, nephrons and collecting ducts perform what functions
Glomerular filtration, tubular reabsorption, and tubular secretion
The nephron performs what basic processes to produce urine, nephrons, and collecting ducts
Glomerular filtration, tubular reabsorption, and tubular secretion
What is the first step of urine production
Glomerular filtration
Blood pressure forces water and most solutes in blood plasma across the wall of glomerular capillaries
Glomerular filtrate
Tubular reabsorption occurs as
Filtered fluid flows along the renal tubule and through the collecting duct: tubule and duct cells return about 99% of the filtered water and many useful solutes t the blood flowing through peritubular capillaries
What is tubular secretion
The tubule and duct cells remove substances, such as wastes, drugs, and excess ions from blood in the peritubular capillaries and transport them into the fluid in the renal tubules
By the time the filtered fluid has undergone tubular reabsorption and tubular secretion and enters the minor and major calyx is called what
Urine
The cells that make up the inner wall of the glomerular capsule, called podocytes, adhere closely to what
The endothelial cells of the glomerulus
The podocytes and glomerular endothelium form a filtration membrane that permits the passage of what
Water and solutes from the blood into the capsular space
The pressure that causes filtration is the blood pressure from where
The glomerular capillaries
What other pressures oppose glomerular filtration
Blood colloid osmotic pressure and glomerular capsule pressure
Normally blood pressure is greater than the two opposing pressures producing a net filtration pressure of what
10 mmHg
Net filtration pressure forces a large volume of fluid into the capsular space about how much for males and females
Males - 180 liters daily
Females - 150 liters daily
What is the calculation for net filtration pressure
Net filtration pressure = glomerular capillary blood pressure - (blood colloidal osmotic pressure + glomerular capsule pressure)
Decreased blood flow into the glomerulus, which decreases net filtration pressure is what
Constriction of the afferent arteriole
What slows outflow of blood and increases net filtration pressure
Constriction of the efferent arteriole
The amount of filtrate that forms in both kidneys every minute is called what
Glomerular filtration rate (GFR)
What is the GFR in adult males and adult females
Males - 125 mL/min
Females - 105 mL/min
What happens if the GFR is too high
Needed substances pass so quickly through the renal tubules that they are unable to be reabsorbed and pass out of the body as part of urine
What happens if the GFR is too low
Nearly all the filtrate is reabsorbed and waste products are not adequately excreted
Hat is ANP and what does it promote
Atrial Natiuretic peptide which is a hormone
Promotes loss of sodium ions and water in the urine in part because it increases glomerular filtration rate
Cells in the atria of the heart secrete more ANP if the heart is stretched more and occurs when
Blood volume increases
ANP acts on the kidneys to increase loss of sodium ions and water in urine, which does what
Reduces the blood volume back to normal
The blood vessels of the kidneys act by sympathetic neurons of the autonomic nervous system and when active cause what
Vasoconstrictions
With greater sympathetic stimulation, as occurs with exercise or hemorrhage, the afferent arterioles are constricted more than what
Efferent arterioles
Typically what amount of water is reabsorbed
99%
Only 1% of the water in glomerular filtrate actually leaves the body in urine
What reabsorbs 65% of the filtered water, 100% of the filtered glucose and amino acids, and large quantities of various ions such as sodium, potassium, chloride, bicarbonate, calcium and magnesium
Proximal convoluted tubule cells
Water moves by what into peritubular capillaries
Osmosis
The most important hormonal regulators of ion reabsorption and secretion are what
Angiotensin II and aldosterone
In the proximal convoluted tubules, what enhances reabsorption of Na+ and Cl-
Angiotensin II
What stimulates the adrenal cortex to release aldosterone
Angiotensin II
What is the major regulator of blood K+ level
Aldosterone-stimulated secretion of K+
What is the major hormone that regulates water reabsorption
Antidiuretic hormone (ADH)
Which operates via negative feedback
The kidneys can produce as little as how much of very concentrated urine each day when ADH concentration is maximal (severe dehydration)
400-500 mL
Lower-than-normal level of calcium in the blood stimulates the parathyroid glands to release what
Parathyroid hormone
The volume of urine eliminated per day in a normal adult is how much
1 to 2 liters (about 1 to 2 quarts)
Water accounts for about how much of the total urine volume of urine
About 95%
Each of the two ureters transports urine from the renal pelvis of one of the kidneys to what
The urinary bladder
The ureter consists of what layers
The inner layer (mucosa) - containing transitional epithelium with an underlying layer of areolar connective tissue
The middle layer (smooth muscle) - this is where the peristaltic contractions occur
The outer layer (consists of areolar connective tissue) - contains the blood vessels, lymphatic vessels, and nerves
What is transitional epithelium able to do
Stretch - a marked advantage for any organ that must accommodate a variable volume of fluid
Urinary bladder capacity averages how much
700-800 mL
Like the ureters, the mucosa of the urinary bladder contains what
Transitional epithelium, which allows for stretching
The muscle layer of the urinary bladder wall consists of three layers of smooth muscle called what
The destructor muscle
