Urinary System Flashcards
removes them and filtering the blood as it passes through the kidneys
urinary system
Urinary system plays additional equally important functions, including the ff.
regulation of blood volume and chemical composition of blood,
lymph and other body fluids
regulate blood pH
blood pressure
concentration of red blood cells
production of vitamin D
It controlled by the nervous system, also stores urine until a convenient time for disposal and then provides the anatomical structures to transport this waste liquid to the outside of the body.
urinary system
The urinary system consists of ______ which filter blood to produce urine.
paired kidneys
Urine moves through the ureters to the _________ where it is stored until it is released.
urinary bladder
When released, urine travels through the _________ to the outside world.
urethra
urinary system’s functions
regulating the volume and composition of body fluids, removing waste products from the blood, and expelling the waste and excess water from the body in the form of urine.
- histologically apparent substructure of the renal cortex composed of glomeruli and proximal tubules.
Cortical labyrinth
- An anatomical unit of the kidney composed of the medullary pyramid and the overlying cortex.
Lobe (renal)
An anatomical subunit of a renal lobe that is centered on a single medullary ray.
Lobule (renal)
Collections of renal tubules coursing from the renal cortex to the medulla and centered around a collecting duct.
Medullary rays
The process by fluid and molecules selectively pass across the glomerular filtration barrier (plasma -> urine).
Ultrafiltration (renal)
cup-like structures receiving urine from the collecting ducts where it passes on to the renal pelvis and ureter
Calyces
arteriole carrying blood from the glomerulus to the capillary beds around the convoluted tubules and loop of Henle; portion of the portal system
Efferent arteriole
- tuft of capillaries surrounded by Bowman’s capsule; filters the blood based on size
Glomerulus
functional units of the kidney that carry out all filtration and modification to produce urine;
Nephrons
Nephrons are consist of the ff.
renal corpuscles, proximal and distal convoluted tubules, and descending and ascending loops of Henle; drain into collecting ducts
inner region of kidney containing the renal pyramids
Medulla
second capillary bed of the renal portal system; surround the proximal and distal convoluted tubules; associated with the vasa recta
Peritubular capillaries
extensions of the renal cortex into the renal medulla; separates the renal pyramids; contains blood vessels and connective tissues
Renal columns
outer part of kidney containing all of the nephrons; some nephrons have loops of Henle extending into the medulla
Renal cortex
- adipose tissue between the renal fascia and the renal capsule that provides protective cushioning to the kidney
Renal fat pad
- recessed medial area of the kidney through which the renal artery, renal vein, ureters, lymphatics, and nerves pass
Renal hilum
- medullary area of the renal pyramids where collecting ducts empty urine into the minor calyces
Renal papillae
- six to eight cone-shaped tissues in the medulla of the kidney containing collecting ducts and the loops of Henle of juxtamedullary nephrons.
Renal pyramids
The urinary system is composed of what?
pair of kidneys, ureters, bladder, and urethra
Kidneys are attached to the posterior abdominal wall and located behind the peritoneum, therefore they are called as ________.
retroperitoneal organs
The kidneys sit in the back of the abdomen between the levels of _________ vertebrae
T12 and L3 vertebrae
• The ______ kidney is slightly lower than the ______ kidney to accommodate the liver
right
left
• This capsule that covers the kidney is covered by shock-absorbing layer of adipose tissue called the ________, which is encompassed by a tough renal fascia.
renal fat pad
The ______ serve to firmly anchor the kidneys to the posterior abdominal wall in the retroperitoneal position.
fascia
It is the entry and exit site for structures servicing the kidneys: renal artery, renal vein, renal nerves, lymphatics, and the ureters.
renal helium
tiny structures in the renal pyramids, filter gallons of blood each day.
Nephrons
It reabsorb vital substances, remove unwanted ones, and return the filtered blood back to the body. It also create urine to remove all the waste.
kidneys
On frontal section the kidney reveals an outer region called the ________renal cortex and an inner region called the ________.
renal medulla
• On the longitudinal section, the kidney can be divided into the ff.
cortex, medulla, renal papilla and renal pelvis.
The concave border of the kidney is known as the ______, where the renal vessels (artery and vein) and nerves enter the kidney.
hilum (or hilus)
The renal artery and vein circulate huge amounts of blood – about _________ at rest, which is up to one-quarter of the heart’s total output
2 1/2 pints/min
It comprises approximately 2/3 of the renal parenchyma and contains most of the glomeruli and numerous cross-sections of tubules.
cortex
The ________ only has tubules and ducts and does not contain glomeruli.
medulla
Blood enters the kidneys through what?
renal arteries
These arteries branch into tiny capillaries that interact with urinary structures inside the kidneys (namely the nephrons).
Renal arteries
interlobar arteries, in turn, branch into the ff.
arcuate arteries, cortical radiate arteries, and then into afferent arterioles
afferent arterioles deliver blood into a modified capillary bed called the ________ which is a component of the “functional unit” of the kidney called the _________.
glomerulus
nephron
How many nephrons in each kidney
1.3 million nephrons
Each kidney contains over _______ tiny structures called nephrons.
1 million
It perform the primary function of the kidneys: regulating the concentration of water and other substances in the body.
Nephrons
• An ultrafiltrate of urine is formed in the _______ and is modified during its course through the medulla.
cortex
drive filtration .
glomeruli
responsible for reabsorbing, excreting and concentrating the urinary filtrate
tubules
What are the main components of the nephron include:
a. Glomerulus
b. Bowman’s space (surrounded by Bowman’s capsule
c. Proximal convoluted tubule
d. Proximal straight tubule
e. Loop of Henle (descending limb and ascending limb)
f. Distal convoluted tubule
g. Collecting duct (cortical and medullary)
h. Papillary duct
3 main steps of urine formation:
- Glomerular filtration
- Reabsorption
- Secretion.
they cleanse the blood of toxins and balance the constituents of the circulation to homeostatic set points through the processes of filtration, reabsorption, and secretion
Nephrons
It also function to control blood pressure (via production of renin), red blood cell production (via the hormone erythropoetin), and calcium absorption (via conversion of calcidiol into calcitriol, the active form of vitamin D).
nephrons
The nephrons also function to control blood pressure (via production of ______), red blood cell production (via the hormone ______), and calcium absorption (via conversion of calcidiol into _______, the active form of vitamin D).
renin
erythropoetin
calcitriol
• Each nephron consists of a blood supply and a specialized network of ducts called a ________.
tubule
• For each nephron, an afferent arteriole feeds a high-pressure capillary bed called the _______.
glomerulus
Blood is filtered by the glomerulus to produce a fluid that is caught by the nephron tubule, called the __________.
filtrate
What form the renal corpuscle?
glomerulus and glomerular capsule
• Blood exits the glomerulus into the ______.
efferent arteriole
The efferent arteriole then forms a second capillary network around the tubule, called the ________.
peritubular capillaries
It is a high pressured, fenestrated capillary with large holes (fenestrations) between the endothelial cells.
glomerulus
interdigitate with structures called pedicels and filter substances into the glomerular capsule. In (a), the large cell body can be seen at the top right corner, with branches extending from the cell body.
Podocytes
The smallest finger-like extensions are the ________.
pedicels
It transitions over the glomerulus as uniquely shaped cells
(podocytes)
Its major function is to reabsorb fluid, electrolytes and nutrients.
proximal tubules (PT)
It is responsible for roughly 98% of glucose and 65% of sodium reabsorption. It is located in the cortex and is composed of simple columnar epithelium joined together by tight junctions
Proximal tubules
It is highly permeable to water (which is easily transferred to the interstitium) and less permeable to solutes. On the other hand, the _______ is highly permeable to sodium but impermeable to water.
thin descending loop
thin ascending limb
The descending and ascending portions of the loop of Henle (sometimes referred to as the _______) are continuations of the same tubule.
nephron loop
hyperosmotic
salty
The distal convoluted tubule (DCT) is composed of what epithelium?
simple cuboidal epithelium
The functions of this segment include fine-tuning ion concentrations and acid-base balance to maintain homeostasis. The epithelium of this is also involved in reabsorption or excretion of bicarbonate and hydrogen ions to maintain blood pH.
DCT
• There are two distinct cell types present in the collecting tubules: what are these
intercalated cells and principal cells.
The __________ are the predominant cell type with short sparse microvilli and contain Na+/K+ ATPase pump and aquaporin, which is an anti-diuretic hormone [ADH]-regulated water channel.
principal cells
The __________ are fewer in number, but they are important for the regulation of blood pH. These cells will adjust bicarbonate or hydrogen ion reabsorption.
intercalated cells
interstitium is composed of _____ and ______
fibrocytes and occasional macrophages
It produce the extracellular matrix (collagen and glycosaminoglycans) , which surround the nephrons, duct, blood vessels, and lymphatics.
interstitial cells
The vessels that are responsible for reabsorbing all of the molecules that cross the tubular epithelial cells are called ________.
peritubular capillaries
Another aggregate of thin-walled vessels known as the __________.
vasa recta
It controls the rate of the glomerular blood flow depending on various factors such as hydration, blood volume and ion concentration.
juxtaglomerular apparatus (JGA)
JGA includes the _______ and _________
macula densa and juxtaglomerular cells
It is a short segment of the distal convoluted tubule that is located directly adjacent to the afferent and efferent arterioles at the vascular pole of the glomerulus.
macula densa
• The release of renin in the bloodstream causes hydrolysis of angiotensinogen to form ________.
angiotensin I
Angiotensin I is converted by _________ to angiotensin II. Angiotensin II triggers the adrenal glands to produce and release _________, which acts on tubules to upregulate sodium and water reabsorption back into the blood.
angiotensin-converting enzyme (ACE)
aldosterone
It is a protein that initiates the production of Angiotensin II, which acts as a powerful systemic vasoconstrictor and stimulates the release of the hormone aldosterone from the adrenal cortex.
Renin
It is a complex web of capillaries derived from the afferent arteriole.
glomerulus
The major players of the glomerular filtration barrier include:
endothelium, glomerular basement membrane, and podocytes.
These are characterized by numerous fenestrations.
glomerular endothelial cells
Another important component of the endothelial cell is the ________, which covers the luminal surface of the cell.
glycocalyx
It is composed of negatively charged glycoproteins and proteoglycans (sugar-protein molecules). filtering out negatively charged molecules, leukocytes, red blood cells, platelets and larger proteins.
glycocalyx
It is a product of the fusion of the basement membrane produced by endothelial cells and podocytes.
glomerular basement membrane (GBM)
They are epithelial cells. They provide structural and functional stability of the glomerulus.
Podocytes
It is a vital component of the glomerular filtration barrier. They are located on the “abluminal” (i.e., opposite of capillary lumen) surface of the capillary loop. Podocytes have numerous processes, similar to tentacles, that surround the capillaries.
podocyte
It provides structural integrity to the glomerular tuft and modulates glomerular perfusion through smooth muscle-like activity. These cells are also involved in the production and secretion of cytokines in response to glomerular injury.
mesangium
The blood enters the glomerular tuft via the _______ and exits via the ______.
afferent arteriole
efferent arteriole
• Secretion usually removes substances from the blood that are too large to be filtered (ex: _______) or those that are in excess in the blood (ex: __________).
antibiotics, toxins
H+, K+
Mechanisms of Recovery
by which substances move across membranes for reabsorption or secretion includes:
a. active transport
b. diffusion
c. facilitated diffusion
d. secondary active transport
e. osmosis.
It move two or more substances in the same direction at the same time
Symport mechanisms
It move two or more substances in opposite directions across the cell membrane.
antiport mechanisms
• Urine is about _____ water and ______ waste products.
95%
5%
It lines the ureters, bladder, and urethra. It is also referred to as transitional epithelium because it can transition from a plump rounded epithelium
Urothelium
