Chapter 26 & 27 - The Urinary System Flashcards
What are the 4 components of the urinary system?
Kidneys (2), Ureters (2), Urinary bladder (1), Urethra (1)
Name the 8 functions of the kidneys
Regulation of the BLOOD IONIC COMPOSITION, Regulation of the PH of blood, regulation of the BLOOD VOLUME, regulation of BLOOD PRESSURE, maintenance of BLOOD OSMOLARITY, production of HORMONES, regulation of blood GLUCOSE LEVEL, EXCRETION of wastes and foreign substances.
For the kidneys to regulate the pH in blood, what happens?
The kidneys excrete H+ into urine and conserve bicarbonate ions and HCO3
To regulation the blood volume, what do the kidneys do?
They conserve or eliminate blood in the urine
How do the kidneys help to regulate blood pressure?
They secrete the enzyme renin which raises blood pressure
How do the kidneys help to maintain the blood’s osmolarity?
The separately regulate the the loss of water and solutes in urine.
The kidneys produce what 2 hormones?
Calcitriol & erythropoietin
This hormone is an active form of vitamin D which helps in the absorption of calcium from food in the GI tract into the blood.
Calcitriol
This hormone stimulates the production of blood cells.
Erythropoietin
How do the kidneys help to regulate the blood glucose level?
They can synthesize glucose from certain amino acids during gluconeogenesis
This is the process by which non-carbohydrate sources are used to make glucose; this glucose can be released into the blood as needed.
Gluconeogenesis
Ammonia and urea are wastes from the breakdown of?
Amino acids
Bilirubin results from the breakdown of?
Hemoglobin
Creatinine results from the breakdown of?
Creatine phosphate in muscle
Uric acid results from the breakdown of?
Nucleic acids
Kidneys excrete wastes by forming?
Urine
Paired reddish kidney-bean shaped organ
Kidney
What is the position of the kidneys?
Retroperitoneal (posterior) to the peritoneum of the abdominal cavity and at the level of the lumbar vertebrae
Which kidney is slightly lower than the other? Because?
The right / the space occupied by the liver
The kidneys regulate what 3 things within blood? They produce?
The composition, volume, pressure / urine
A typical adult kidney is how long? Wide? Thick?
4-5 inches / 2-3 inches wide / 1 inch thick
The fissure at the concave medial part of the kidney from which the ureter, blood vessels (renal artery & renal vein), lymphatic vessels, and nerves exit?
The renal hilum
What are the 3 layers of tissue that surround each kidney?
renal fascia, adipose capsule, renal capsule
This tissue layer surrounding the kidneys is a superficial layer, a thin layer of connective
Renal fascia
This is the middle layer of tissue surrounding each kidney that is composed of fatty tissue and protects the kidneys.
Adipose tissue
This is the deep layer of tissue surrounding the kidneys. It is composed of connective tissue and is continuous with the outer coat of the ureter. It protects the kidney and maintains its shape.
Renal capsule
Internally, the kidneys have superficial outer layer that is called? A deeper inner layer called? Which one is usually darker colored than the other?
Renal cortex / renal medulla / the medulla is generally darker
These are cone-shaped and are found in the renal medulla
Renal pyramids
The pointed end of each renal pyramid is called?
Renal papillae
These are the portions of the renal cortex that extends between the renal pyramids?
Renal columns
This is the functional unit of the kidneys and produces urine.
Nephron
Each has about how many nephrons?
About 1 million
These nephrons are found primarily in the cortex and make up what percentage of nephrons?
80-85%
These nephrons extend from the cortex into the medulla and make up 15-20% of nephrons.
Juxtamedullary nephrons
Urine drains from a nephron through ducts that lead to cuplike structures called?
Calyces
This calyx is small and more numerous (8-18 per kidney)? This calyx is larger and less numerous (2-3 per kidney)
Minor calyx / major calyx
Name the order in which urine flows.
Renal papillae ➡ minor calyx ➡ major calyx ➡ becomes urine ➡ renal pelvis ➡ ureter ➡ urinary bladder.
Where does urine flow first?
Minor calyx
After passing through the minor calyx, urine flows into?
The major calyx
From the major calyx, urine drains into a single large cavity called?
The renal pelvis
This is a cavity within the kidney that contains part of the renal pelvis, the clayces, and branches of the renal blood vessels and nerves.
Renal sinus
2 parts of a nephron
Renal corpuscle & renal tubule
The part of a nephron where blood plasma is filtered.
Renal corpuscle
The renal corpuscle consists of what 2 parts?
Glomerulus and glomerular (bowman’s) capsule
This is the capillary network of the renal corpuscle (a cluster of capillaries around the end of a kidney tubule where waste products are filtered from the blood).
Glomerulus
This part of the renal corpuscle that surrounds the capillaries?
Glomerular (bowman’s) capsule
Part of the nephron where the filtered fluid passes.
Renal tubule
The renal tubule of a nephron consists of what 3 parts?
Proximal convoluted tubule, loop of henle, distal convoluted tubule.
The renal corpuscle and both convoluted tubules lie within what part of the kidney?
The renal cortex
The loop of henle lies within which part of the kidney? It returns to?
Extends into the medulla and returns to the renal cortex
Cortical nephrons have what size loops of henle?
Short
Juxtamedullary nephrons have what size loops of henle?
Long
The distal convoluted tubules of several nephrons empty into?
A collecting duct
Collecting ducts unite to form? This drain into?
Papillary ducts / minor clyces
These form the entire wall of the Bowman’s capsule, renal tubule, and wall ducts
a single layer of epithelial cells
The number of nephron cells is?
constant from birth
Will new nephrons form is they are injured or diseased?
no
If one kidney is surgically removed, what happens?
The remaining kidney enlarges and eventually is able to filter blood at about 80% of the rate of two normal kidneys
From the renal pelvis, the urine passes out of the kidneys through?
the ureters
A ureter is a tube that carries urine from each kidney to?
the urinary bladder
how long is a ureter?
10-12 inches
This type of contraction of the walls of the ureters push urine towards the bladder. What also contributes?
Peristaltic contractions / pressure and gravity
The 3 layers of the ureters
mucosa, muscularis, adventitia
This layer of the ureter is the deepest layer. It is a mucous membrane with transitional epithelium (stretches) and an underlying lamina propria of connective tissue mucus that protects the cells in the walls from acidic pH of urine.
mucosa
This middle layer of the ureter wall is composed of an inner layer of longitudinal muscles and an outer layer of circular muscles (opposite that of the GI tract which has inner circular and outer longitudinal). The distal end of the ureters have an additional longitudinal muscle layer outside of the circular muscles.
muscularis
This is the superficial layer of the wall of the ureters. It is made of connective tissue and contains blood vessels, lymphatic vessels, and nerves.
adventitia
This is a hollow muscular organ that temporarily stores urine.
urinary bladder
The bladder does this as it fills with urine. What happens once the bladder is full?
stretches / empties
From the urinary bladder, urine passes through this before it heads out of the body through?
urethra / external urethral orifice
In the floor of the urinary bladder is a small triangular area called?
trigone
The trigone contains the openings from? (2)
ureters & internal urethral orifice
this is the opening into the urethra
internal urethral orifice
The trigone is smooth in appearance but the rest of the urinary bladder has folds in the mucosa called?
rugae
The wall of the urinary bladder has the same 3 layers as?
the ureters
What allows the urinary bladder to stretch?
transitional epithelium
The muscularis of the urinary bladder has the three layers of muscle arranged like that of?
the distal ureters
involuntary circular, smooth muscle forms this which surrounds the internal urethral orifice
involuntary circular smooth muscle
This is composed of skeletal muscle and is located inferior to the internal urethral sphincter
external urethral sphincter
What is the outermost layer of the urinary bladder?
The adventitia of connective tissue
Pressure builds up within the bladder as it?
fills with urine
The pressure from urine within the bladder compresses the ureters to prevent?
the urine from flowing back up towards the kidneys
Despite the pressure that compresses the openings of the ureters, this can still happen?
microorganisms can still spread to the kidneys and cause infection
This is a small tube leading from the internal urethral orifice in the floor of the urinary bladder to the exterior of the body.
Urethra
This is the passageway for discharging urine from the body. It also discharges semen in males.
The urethra
The opening of the urethra to the exterior of the body is?
external urethral orifice
How long is the female urethra?
1.5 inches
The male urethra is how long?
8 inches
The 3 main regions of the male urethra
Prostatic, membranous, spongy
This part of the urethra passes through the prostate.
prostatic
The part of the urethra passess through the deep muscles of the perineum.
membranous
This part of the urethra passes through the penis
spongy urethra
The discharge of urine from the urinary bladder is called?
micturition (urination)
When the volume of urine within the bladder reaches about this much, the pressure stimulates stretch receptors in the wall.
200-400 mL
The stretch receptors send nerve impulses to?
the micturition center.
Where is micturition center located?
in the sacral region of the spinal cord
Parasympathetic impulses travel from the micturition center to the wall of the bladder which causes it to contract and cause?
The urethral sphincter to relax.
The maturation center also inhibits somatic motor neurons that innervate the skeletal muscle in the external urethral sphincter causing?
it to relax
What occurs as the external urethral sphincter relaxes?
urination
The cerebral cortex allows us to do what to our urine for a limited period of time. How does this work?
hold it / by exerting voluntary control over the external urethral sphincter and pelvic floor muscles.
oxygenated blood is carried to the kidneys by?
the right and left renal arteries
the right and left renal arteries branch from?
the abdominal aorta
within each kidney, the renal arter divides into?
several levels of smaller arteries (segmental, interlobar, arcuate, interlobular)
interlobular arteries enter the renal cortex and branch into?
afferent arterioles
Each nephron receives one afferent arteriole which divides into a tangled, ball-shaped capillary network called?
glomerulus
From the glomerulus, the capillaries reunite to form?
an efferent arteriole
efferent arterioles divide to form these which surround the renal tubule part of the nephron
peritubular capillaries
this consists of long capillaries that loop into the medulla of some nephrons
vasa recta
the peritubular capillaries reunite to form several levels of these? (2)
venules (peritubular) and small veins (interlobular, arcuate, interlobar)
Deoxygenated blood exits the kidneys through?
right and left renal veins
The right and left renal veins lead to?
the inferior vena cava
to produce urine, nephrons and collecting ducts perform these 3 basic processes
glomerular filtration, tubular reabsorption, tubular secretion