4/26 Lecture E2 Flashcards
In what ways is the urinary system closely associated with the reproductive system?
1) shared embryonic development and adult anatomical relationship
2) collectively called the urogenital (UG) system
What are the functions of the kidneys? (8)
1) Filter blood and excrete toxic metabolic wastes
2) Regulate blood volume, pressure, and osmolarity
3) Regulate electrolytes and acid-base balance
4) secrete erythropoietin
5) help regulate calcium levels by participating in calcitriol synthesis
6) clear hormones from blood
7) detoxify free radicals
8) in starvation, synthesize glucose from amino acids
What is waste?
Any substance that is useless to the body or present in excess of the body’s needs
What is metabolic waste?
waste substance produced by the body
What are the steps in urea formation?
Proteins –> amino acids –> NH2 removed –> forms ammonia
What organ converts ammonia to urea?
the liver
What is uric acid a product of?
nucleic acid catabolism
What is creatinine a product of?
creatine phosphate catabolism
What is Blood Urea Nitrogen (BUN)?
The level of nitrogenous waste in the blood
What is the normal concentration of blood urea?
10-20 mg/dL
What does Azotemia mean?
elevated BUN
What does azotemia indicate?
renal insufficiency
What are the symptoms of uremia?
diarrhea, vomiting, dyspnea, weakness, and metabolic acidosis.
What does uremia stem from?
toxicity of nitrogenous waste
What is the treatment for uremia?
hemodialysis or organ transplant
What is excretion?
separating wastes from body fluids and eliminating them
What are the four body systems that carry out excretion?
1) respiratory system
2) integumentary system
3) digestive system
4) urinary system
What does the respiratory system excrete?
CO2, small amounts of other gases, water
What does the integumentary system excrete?
water, inorganic salts, lactic acid, and urea (in sweat)
What does the digestive system excrete?
water, salts, CO2, lipids, bile pigments, cholesterol, and other metabolic waste
What does the urinary system excrete?
many metabolic wastes, toxins, drugs, hormones, salts, H+, and water
Where is the kidney located?
posterior abdominal wall at level of T12 to L3
Why is the right kidney slightly lower?
Due to the large right lobe of liver
What rib crosses the middle of the left kidney?
Rib 12
T of F: the kidney, ureters, urinary bladder, renal artery and vein, and adrenal glands are all retroperitoneal
T
What is Murphy’s punch/sign
thoracic spine examination testing for kidney inflammation, infection and obstruction
What is the shape and size of a kidney comparable to?
the size of your fist, lateral convex surface and medial concave surface with a slit (hilum)
What does the hilum receive?
renal nerves, blood vessels, lymphatics, and ureter
What are the three protective tissue coverings around the kidney?
1) Renal fascia
2) Perirenal fat capsule
3) Fibrous capsule
What is the role of the renal fascia?
binds the kidney to the abdominal wall
What is the role of the perirenal fat capsule?
cushions the kidney and holds it into place
What is the role of the fibrous capsule?
encloses the kidney and holds it into place
How does the fibrous capsule connect to the renal fascia?
through collagen fibers
What is the renal parenchyma?
glandular tissue that forms urine
Shape and location of the renal parenchyma.
C-shaped in frontal section
What is the renal sinus?
cavity that contains blood and lymphatic vessels, nerves, and urine-collecting structures
What fills the gaps in the renal sinus and holds structures in place?
adipose tissue
What are the two zones of the renal parenchyma?
1) outer renal cortex
2) inner renal medulla
What are the two features of the renal medulla?
1) renal columns
2) renal pyramids
What are renal columns?
extensions of the cortex that project inward towards the sinus.
Within the kidney, what does the renal artery divide into?
segmental arteries
What are the segmental arteries of the kidney? (3)
interlobar, arcuate, and cortical radiate
Where are the interlobar arteries located?
through the renal columns, between pyramids
Where are the arcuate arteries located?
Arcing over the pyramids
Where are the cortical radiate arteries located?
in the cortex, above the arcuate arteries
How many nephrons does each afferent arteriole supply?
one
how does blood drain from the glomerulus?
by efferent arterioles
Where do most efferent arterioles lead to?
peritubular capillaries
What is the vasa recta?
a network of blood vessels within the renal medulla, supplying the nephron loop portion of the nephron
What is the renal blood pathway?
abdominal aorta –> Renal artery –> segmental arteries –> interlobar arteies –> arcuate artery –> cortical radiate arteries –> Afferent arteriole –> glomerulus –> efferent arteriole –> peritubular capillaries (or vasa recta!) –> cortical radiate veins –> arcuate veins –> interlobar veins –> renal veins –> inferior vena cava
Approximately how many nephrons does each kidney have?
about 1.2 million
What are the two principal parts that compose the nephron?
- renal corpuscle
2. renal tubule
What does the renal corpuscle do?
filters the blood plasma
what does the renal tubule do?
converts the filtrate into urine
What does the renal corpuscle consist of?
- glomerulus
2. A 2-layer glomerular capsule that encloses the glomerulus
What kind of tissue makes up the parietal outer layer of the glomerular capsule?
simple squamous epithelium
What kind of cells make up the visceral inner layer of the glomerular capsule?
podocytes
What separates the two layers of the glomerular capsule?
capsular space
What is the vascular pole?
the side of the corpuscle where the afferent arterial enters the corpuscle and the efferent arteriole leaves
What is the urinary pole?
opposite of the vascular pole, where the renal tubule begins.
What is another name for the renal tubule?
uriniferous tubule
what is a renal tubule?
duct leading from the glomerular capsule and ending at the tip (papillary end) of the medullary pyramid
What are the four regions of the renal tubule?
- proximal convoluted tubule
- nephron loop (loop of henle)
- distal convoluted tubule
- collecting duct (receives fluid from many nephrons)
true or false: the collecting ducts are shared by multiple nephrons
TRUE
From where does the proximal convoluted tubule arise from?
the glomerular capsule
What is the longest and most coiled region of the renal tubule
proximal convoluted tubule
What is the tissue type of the proximal convoluted tubule?
simple cuboidal epithelium
What type of tissues make up the thick segments of the loop of henle?
simple cuboidal epithelium
What type of tissues make up the thin segments of the loop of henle?
simple squamous epithelium
Where are the thick segments of the nephron loop located?
the initial part of the descending limb and part or all of the ascending limb
what are the thick segments mainly involved in?
active transport of salts and contain many mitochondria
What is a feature of the thin segments?
the cells are very permeable to water.
Where is the distal convoluted tubule located?
begins shortly after the ascending limb reenters the cortex (the end of the nephron)
which has microvilli: the Proximal Convoluted tubule, or the distal convoluted tubule?
the proximal convoluted tubule
what kind of tissue is the distal convoluted tubule made of?
simple cuboidal epithelium
How many papillary ducts end at the tip of each papilla?
30
what are collecting and papillary ducts lined with?
simple cuboidal epithelium
What is the flow of fluid from the point where the glomerular filtrate is formed to the point where urine leaves the body?
glomerular capsule –> proximal convoluted tubule –> nephron loop –> distal convoluted tubule –> collecting duct –> papillary duct –> minor calyx –> major calyx –> renal pelvis –> ureter –> urinary bladder –> urethra
What is the renal plexus?
nerves and ganglia wrapped around each renal artery
To which parts does the renal plexus provide nerve fibers to?
blood vessels and convoluted tubules of the nephron
what kind of innervation does the renal plexus provide to the abdominal aortic plexus?
sympathetic innervation
What does the sympathetic innervation to the abdominal aortic plexus do?
stimulation reduces glomerular blood flow and rate of urine production.
what does falling blood pressure stimulate the kidneys to do?
secrete renin
what is renin?
an enzyme that activates hormonal mechanisms to restore blood pressure
what is the function of the parasympathetic innervation of the kidneys?
that is unknown.
What are the four basic stages of urine formation?
1) glomerular filtration
2) tubular reabsorption
3) tubular secretion
4) water conservation
describe glomerular filtration
the creation of a plasma like filtrate of the blood
describe tubular reabsorption
the removal of useful solutes from the filtrate, returning them to the blood
describe tubular secretion
the removal of additional wastes from the blood, adding them to the filtrate
describe water conservation
the removal of water from the urine and its return to the blood. This concentrates wastes
