Urinalysis Lab Flashcards
What does the excretory system consist of?
kidneys, ureters, bladder, and urethra
What are the primary functions of the excretory system?
- excretion (eliminating metabolic waste products)
- regulates the amount of water in the body
- regulates concentrations of various electrolytes in the body fluids
- regulates the pH of blood.
what are the six roles kidneys play in the establishment of homeostasis?
- excretion of metabolic wastes products
- reabsorption of water and important nutrients
- regulation of plasma ion composition
- acid-base homeostasis
- blood pressure regulation
- hormone secretion
what are the three major regions of the kidney
- renal cortex
- renal medulla
- renal pelvis
Urine produced by the kidneys is sent for storage in the bladder by the ________, which are continuous with the renal pelvis. From the bladder, urine is drained by the ________.
ureters, urethra.
what is the functional unit of the kidney?
nephron
what is each nephron composed of?
- initial filtering component (the renal corpuscle)
- tubule specialized for reabsorption and secretion (the renal tubule)
renal corpuscle
initial filtering component
renal tubule
tubule specialized for reabsorption and secretion
where is the renal corpuscle located?
located within the renal cortex
what does the renal corpuscle consist of?
consists of the glomerulus and Bowman’s capsule.
Glomerulus
A capillary tuft that receives its unfiltered blood supply from an afferent arteriole of the renal circulation.
what does the glomerular blood pressure provide?
Provides the driving force for fluid and solutes to be filtered out of the blood and into the space made by Bowman’s capsule.
Non-filtered blood passes into the_______ ______ which then moves into the ______ _____ (collecting capillaries intertwined with the convoluted tubules) where substances may be secreted or reabsorbed or further down the nephron.
efferent arteriole, vasa recta
vasa recta
collecting capillaries intertwined with the convoluted tubules
Efferent venules from other nephrons combine to form the ____ _____?
renal vein
What is the Bowman’s capsule composed of?
Composed of an inner visceral (simple squamous epithelial cells) and outer parietal (simple squamous epithelial cells) layers.
What is the visceral layer of the Bowman’s capsule made of?
made of podocytes
what is the function of podocytes?
Send foot processes that interdigitate over the glomerulus forming filtration slits.
ultrafiltration (= glomerular filtration)
process of filtration of the blood
what is he normal rate of filtration?
125 ml/min
Small molecules (e.g., water, glucose, ions, amino acids, urea) pass freely through the slits. However, large molecules (e.g., proteins such as albumin) and cells (e.g., red blood cells and platelets) cannot pass. The filtrate enters the space
located between the visceral and parietal layers called the Bowman’s space.
Bowman’s space
The space located between the visceral and parietal layers of the Bowman’s capsule
what does the convoluted tubule consist of?
This tubule contains a single layer of cuboidal cells surrounding the lumen. These cells are covered with microvilli which increases the surface area for reabsorption
In addition to water, approximately ________ of the ions and almost all of the filtered organic solutes (e.g., glucose and amino acids) entering the proximal convoluted tubule are actively reabsorbed into surrounding the _______ ______.
two-thirds, peritubular capillaries.
From the proximal convoluted tubule, filtrate enters the _____ __ _____ which extends down into the renal medulla.
loop of Henle, renal medulla
What is the primary role of the Loop of Henle?
to concentrate the salt in the surrounding medullary space.
The descending limb of the loop of Henle is ________to water but ________ to solutes, thus water moves across the tubular wall into the medullary space and making the filtrate ________.
permeable, impermeable, hypertonic
The filtrate then enters the ascending limb which is ______ to water. In this region, Na+ , Cl− , and K+ are actively transported into the ________ ______, now making the filtrate hypotonic and the medullary space hypertonic (very salty).
impermeable, medullary space
Active transport of these ions from the ascending limb creates an osmotic pressure drawing water from the ________ ____ into the ________ _____.
descending limb, medullary space
where is the distal convoluted tubule located?
Located back in the renal cortex.
what does the distal tubule do?
excretes H+ and ammonium to regulate pH.
what is secreted into the distal tubule?
urea
what does the distal convoluted tubule do?
delivers filtrate to the collecting ducts that begin in the
renal cortex and extend deep into the medulla
The bladder is voided by the process of?
micturition via the urethra.
