A&P II Unit 4
Stretch receptors
Distension of the bladder while filling stimulates _________ in the bladder wall which sends impulses to the spinal cord resulting in a reflex action which keeps the sphincter muscles closed
Large proteins
During glomerular filtration all solutes except _______ leave the blood and enter the Bowman's capsule
Tubular secretion
Elimination of material not filtered out
Excretion
Elimination of metabolic wastes (urea)
Egestion
Elimination of undigested food
Active transport
Energy is required to reabsorb materials that are more concentrated in the blood than in the filtrate
Carbonic acid
Excess carbon dioxide in the blood may enter the kidney tubular cells where it combines with water to for __________ which dissociates into bicarbonates and HYDROGEN ions which then are released into the urine where they are "buffered" by phosphates
Effective filtration pressure
Sum of pressure favoring filtration in capillaries
Peritubular capillaries
Surround the tubules of CORTICAL nephrons
Boman's capsule
Surrounds the glomerulus in the nephron unit
Tubular reabsorption
Selective reuptake of nutrients, electrolytes, etc
Ascending
Sodium is reabsorbed in the _____ branch of the loop of Henle
Glomerulus
Special capillary bed between two ARTERIOLES; it is a high-pressure system because of the SHORT afferent arteriole leading into it; serves as the major site of filtration of the blood in the kidney
Medulla
The ______ of the kidney is composed mostly of collecting ducts and some loop of Henle; triangular-shaped RENAL PYRAMIDS make up the bulk
Glomerular filtration rate
The amount of filtrate produced per minute
Glycogenolysis
The breakdown of glycogen to glucose
Hydonephrosis
The buildup of water or urine in the kidney; kidney stones may block the passage of urine and cause backup of urine into the kidney
Detrusor
Muscle that forms most of the upper wall of the body of the URINARY BLADDER
Peristaltic waves
Movement of urine down the ureter occurs due to gravity and _______
External urethral sphincter
Muscle composed of skeletal muscle and is under voluntary control (D); found between the urethra and the body wall
Internal urethral sphincter
Muscle composed of smooth muscle and is under involuntary/autonomic control (C)
Urochrome
A bile pigment found in urine which is a waste product formed during the destruction of HEMOGLOBIN; yellow color of urine is due to
Respiratory acidosis and metabolic acidosis
Adjustments to the acid-base balance made by the kidney help to "compensate" for
Gluconeogenesis
Among the functions of the kidney is ___________ which is the production of CARBOHYDRATES (glucose) from non-carbohydrate courses such as amino acids and fatty acids
Osmotic diuresis
An increase in urine output due to excess glucose in the urine
Diuresis
An increase in urine output; may be due to a DECREASE in the antidiuretic hormone released by the POSTERIOR pituitary
Increase
An increased blood volume will result in a __________ in blood pressure
Cystitis
An infection of the urinary bladder
20
Approximately ____ percent of cardiac output enters the renal circulation
More
As the filtrate moves down the loop of Henle it becomes ______ concentrated
Less
As the filtrate moves up the loop of Henle it becomes _____ concentrated
The blood pressure is higher in the glomerulus than in other capillary beds
Because the relative short arteriole (afferent) entering the glomerulus; the constriction of the efferent arteriole, and constriction of afferent arteriole
Shorter
Bladder infections are more common in females than in males because the urethra is
Renal fascia
Covers the kidneys along with renal fat capsule which holds them in position and attached the kidney to surrounding structures
Creatine
Muscle deterioration is noted by increased amounts of ______ in the urine
Urination
Formation of urine
Juxtaglomerular apparatus
Formed by the AFFERENT arteriole and the NEPHRON TUBULE; formed where the afferent arteriole comes into contact with a convoluted tubule (proximal or distal); produces and secretes RENIN
Male urethra
Functions in both micturition and reproduction and is longer than the female urethra; consist of three regions: prostatic, membranous, and spongiosum
Sodium
Glucose, other nutrients, and most solutes are reabsorbed via co-transport with _____ in the proximal convoluted tubule
Proximal convoluted tubule
Has a "brush-border" epithelium--microvilli that increase the surface area for reabsorption; the MAJOR site of tubular reabsorption (reabsorption of solutes)
Kidney
Highly metabolic organ which requires rich blood supply; approximately 1/4 of the cardiac output passes through the kidney per minute
Renin, erythropoietin
Hormones produced and secreted by the kidneys
Aldosterone
INCREASES the reabsorption of sodium in the ascending loop of Henle AND distal convoluted tubule and thus INCREASES water reabsorption thereby INCREASING blood volume--produced and secreted by the ADRENAL CORTEX
Ascending loop of Henle
Impermeable to water but permeable to solutes; primarily involved in the reabsorption of sodium
Uric acid
In humans, comes from the metabolism of nucleic acid such as DNA and RNA
Antidiuretic hormone
Increases the reabsorption of water in the collecting duct; secreted by the hypothalamus/posterior pituitary
Aldosterone
Increases the sodium channels, increases the production of sodium/potassium pumps, and increases energy production
Pyelitis
Infection of kidney/ureter
Urethritis
Infection of the urethra
Facilitated diffusion
Initially most solute molecules are reabsorbed as they move from an area of high concentration to an area of lower concentration using carrier molecules
myogenic, tubuloglomerular, renin-angiotensin mechanisms
It is very important to maintain the proper pressures in the glomerulus, thus there are several mechanisms for maintaining glomerular filtration
Proximal convoluted tubule
Link the Bowman's capsule to the loop of Henle; primarily involved the reabsorption of nutrients
Distal convoluted tubule
Link the loop of Henle to the collecting ducts; primarily involved in tubular secretion
Myogenic mechanism
Low blood pressure results in a decreased stretching of vessel walls causing a reflex of vasoconstriction which will then increase blood pressure
Tubuloglomerular mechanism
Low blood pressure will result in decreased filtrate flow and results in the MACULA DENSA releasing ATP which causes vasoconstriction and thus raise the blood pressure
Water
Main component of urine
Specific gravity
Measurement that is used to determine the CONCENTRATION OF SOLUTES in the urine
Diuretics
Medications that are taken to increase urine output
Cortical
Most nephron units are ______ nephrons which means that the loop of Henle is SHORT and REMAINS in the cortex
Ureter
Muscular duct connecting the kidney to the urinary bladder; enters the kidney at the HILUM and expands into the funnel-shaped RENAL PELVIS; inner lining consists of transitional epithelium which allows for expansion
Urethra
Muscular duct connecting the urinary bladder to the outside
Hydrogen ions, urea, drugs
Normally secreted into the urine
Spongy urethra
Passes through the penis of a male
Descending loop of Henle
Permeable to water but impermeable to solutes
Angiotensin
Powerful VASOCONSTRICTOR and also INCREASES the production and secretion of ALDOSTERONE by the adrenal cortex
Pyuria
Presence of WBC's (pus) in the urine--would indicate a bacterial infection
Collecting duct
Primarily involved in completing the reabsorption of water
Carrier-mediated transport
Reabsorption of MOST solutes occurs through
Vasa recti
The capillaries surrounding the loop of Henle of juxtamedullary nephrons (descending and ascending ducts) are termed; Reabsorption is facilitated here because the blood and filtrate flow in OPPOSITE directions (counter-current mechanism)
Podocytes
The endothelium of the Bowman's capsule is composed of ______ --special cells of the Bowman's capsule, which wrap around the glomerular capillaries
Renal pelvis
The expanded end of the ureter inside the kidney; the ureter enters the kidney and expands into a funnel shaped pelvis which collects urine from the collecting ducts
Prostate gland
The first portion of the male urethra is surrounded by the; the first region of the male urethra attached to the urinary bladder is known as the prostatic urethra because it passes through the
Increase
The kidney helps regulate the acid/base balance. An increase in blood CO2 results in carbon dioxide moving into the tubular cells, combining with water forming carbonic acid which dissociates into bicarbonates and hydrogen ions, The bicarbonates move back into the blood and buffer hydrogen ions in the blood, while the hydrogen ions move into the urine and combine with phosphates. Thus the pH of the blood will ________--become less acidic
Vitamin D
The kidney metabolizes _______ to its active form calcifeol which is needed for the absorption of CALCIUM
Retroperitoneal
The kidneys are said to be _________ since they lie against the dorsal abdominal wall behind the PARIETAL peritoneum
Renin-angiotensin mechanism
The major mechanism of control; low blood pressure causes the juxtaglomerular apparatus to release RENIN which converts a plasma protein to ANGIOTENSIN, Angiotensin II stimulates the adrenal CORTISOL to produce ALDOSTERONE which increases in reabsorption of SODIUM in the ascending loop of Henle resulting in an increase in blood pressure
Urea
The major nitrogenous waste product in urine in humans; most common solute in urine
Filtration
The movement of molecules through a porous membrane due to a difference in PRESSURE
Cortex
The nephron units are primarily located in the ______ of the kidney; outer portion of the kidney
Glycosuria
The presence of glucose in the urine
Ketonuria
The presence of ketone bodies in the urine which suggested the breakdown of FAT to produce fuel molecules
Creatinine
The result of breakdown of proteins
Trigone
The triangular area at the base of the urinary bladder where the ureter and urethra are connected
Renal fat capsule
Tough, fibrous connective tissue that surrounds the kidney, protection of the kidney from blows to the back is furnished by the
Ureter and urinary bladder
Transitional epithelium lines the
Acidic
Urine is normally more _____ than blood
Micturition
Voiding of urine
Parasympathetic reflex
When convenient, ________ beginning in the pons causes contraction of the DETRUSOR muscle of the bladder and the relaxation of EXTERNAL urethral sphincter muscles
Reabsorbed
When determining the GFR, a substance that is not normally _______ is injected into the blood and following a period of time its concentration in the blood when injected is divided by its concentration in the URINE
Ptosis
When the attachments (renal fascia and renal fat capsule) become weak so the kidney descends in the abdominal cavity causing a "kink" in the ureter; "fallen kidney"