STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE URINARY SYSTEM Flashcards
What does the urinary system consist of?
wo kidneys,
two ureters,
one urinary bladder, and
one urethra
After the kidneys filter the blood, they return _______ to the bloodstream
most of the water and many solutes
What is the scientific study of the anatomy, physiology, and disorders of the kidneys
Nephrology
What is the branch of medicine that deals with the male and female urinary system, and the male reproductive system?
Urology
Functions of the Kidneys
Regulation of ion levels in the blood
Regulation of blood volume and blood pressure
Regulation of blood pH
Production of hormones
Excretion of wastes
Regulation of ion levels in the blood
The kidneys help regulate the blood levels of several ions, most importantly…..
sodium ions (Na+), potassium ions (K+), calcium ions (Ca2+), chloride ions (Cl-), phosphate ions (HPO4^2-)
Regulation of blood volume and blood pressure.
The kidneys adjust the volume of blood in the body by doing what?
returning water to the blood
eliminating it in the urine
Regulation of blood volume and blood pressure
the Kidneys regulate blood pressure by secreting the enzyme __________, which activates the renin–angiotensin–aldosterone pathway, by adjusting blood flow into and out of the kidneys, and by adjusting blood volume
renin
Regulation of blood pH
The kidneys regulate the concentration of H+ in the blood by a __________ variable amount of H+ in the urine.
excreting
Regulation of blood pH.
The kidneys conserve, _________ which is an important buffer of H+.
blood bicarbonate ions (HCO3)
Production of hormones
The kidneys produce what two hormones, what do they do?
1) Calcitriol, the active form of vitamin D, helps regulate calcium homeostasis
2) Erythropoietin, stimulates production of red blood cells.
Excretion of wastes.
By forming _____, the kidneys help excrete wastes
urine
Excretion of wastes.
What are parts of urine?
1) Ammonia and urea
2) Bilirubin
3) Creatinine
4) Uric acid
5) Other wastes excreted in urine are foreign substances from the diet, such as drugs and environmental toxins.
What part of the urine is from the breakdown of amino acids?
Ammonia and urea
What part of the urine is from the breakdown of hemoglobin
Bilirubin
What part of the urine is from the breakdown of creatine phosphate in muscle fibers?
Creatinine
What part of the urine is from the breakdown of nucleic acids
Uric acid
What are the pair of reddish organs shaped like kidney beans
kidneys……..
Where re the kidneys located?
abdominal cavity at the level of the 12th thoracic and first three lumbar vertebrae
True/false
The LEFT kidney is slightly lower than the RIGHT because the liver occupies a large area above the kidney on the right side.
FALSE
the right is lower
External Anatomy of the Kidneys
Near the center of the medial border is an indentation called the __________, through which the ureter leaves the kidney and blood vessels, lymphatic vessels, and nerves enter and exit.
renal hilum
External Anatomy of the Kidneys
Surrounding each kidney is the ___________, a connective tissue sheath that helps maintain the shape of the kidney and serves as a barrier against trauma
smooth transparent renal capsule
External Anatomy of the Kidneys
What surrounds the renal capsule and cushions the kidney. Along with a thin layer of dense irregular connective tissue, this also anchors the kidney to the posterior abdominal wall.
Adipose (fatty) tissue
Internal Anatomy of the Kidneys
Internally, the kidneys have two main regions. What are they?
Renal cortex
Renal medulla
Internal Anatomy of the Kidneys
What region of the kidney?
the outer light-red region
Renal cortex
Internal Anatomy of the Kidneys
What region of the kidney?
inner, darker red-brown region
Renal medulla
Internal Anatomy of the Kidneys
Within the _________ are several cone-shaped renal pyramids. Extensions of the ________, called renal columns, fill the spaces between renal pyramids.
- renal medulla
- renal cortex
Internal Anatomy of the Kidneys.
Urine formed in the kidney passes from thousands of papillary ducts within the renal pyramids into cuplike structures called what?
minor calyces
Internal Anatomy of the Kidneys
Each kidney has how many minor calyces?
8-12
From the Minor Calyces, urine next flows into 2-3 major calyces, and then into a single large cavity called the _______.
renal pelvis
Internal Anatomy of the Kidneys
The renal pelvis drains urine into a ______ which transports urine into the urinary bladder for storage and eventual elimination from the body.
ureter
Renal Blood Supply
About what percent of the resting cardiac output flows into the kidneys through the right and left renal arteries
20-25%
(1200 milliliters of blood per minute)
Renal Blood Supply.
Within each kidney, the renal artery divides into smaller and smaller vessels (segmental, interlobar, arcuate, interlobular arteries) that eventually deliver blood to the ________.
afferent arterioles
Renal Blood Supply
Each afferent arteriole divides into a tangled capillary network called a ________.
glomerulus
Renal Blood Supply
(a) Each afferent arteriole divides into a tangled capillary network called a _______.
(b) The capillaries of the glomerulus reunite to form an efferent arteriole.
(c) Upon leaving the glomerulus, each efferent arteriole divides to form a network of capillaries around the__________
(a) glomerulus
(c) kidney tubules
What are the blood vessels called in the kidney?
interlobular, arcuate, and interlobar veins and arteries
Renal Blood Supply
Ultimately, all interlobular, arcuate, and interlobar veins drain into what?
renal vein
The functional units of the kidney are the ______, numbering about a million in each kidney.
nephrons
A nephron consists of what two parts… what do they do?
(a) Renal corpuscle, where blood plasma is filtered.
(b) Renal tubule into which the filtered fluid, called glomerular filtrate, passes.
As the fluid moves through the renal tubules, wastes and excess substances are added, and useful materials are returned to the blood in the _________.
peritubular capillaries
The two parts that make up a renal corpuscle are the
glomerulus
glomerular (Bowman’s) capsule
what is a double-walled cup of epithelial cells that surrounds the glomerular capillaries
glomerular (Bowman’s) capsule,
Functions performed by the nephron
To produce urine, nephrons and collecting ducts perform three basic processes which include what???
glomerular filtration, tubular reabsorption, and tubular secretion
the basic functions performed by the nephron
_______ is the forcing of fluids and dissolved substances smaller than a certain size through a membrane by pressure
Filtration
________ is the first step of urine production. Blood pressure forces water and most solutes in blood plasma across the wall of glomerular capillaries, forming glomerular filtrate.
Glomerular filtration
the basic functions performed by the nephron
________ occurs as filtered fluid flows along the renal tubule and through the collecting duct:
Tubular reabsorption
Tubule and duct cells return about __% of the filtered water and many useful solutes to the blood flowing through peritubular capillaries.
99%
_________ also takes place as fluid flows along the tubule and through the collecting duct
Tubular secretion
The tubule and duct cells remove substances, such as ___________ from the blood peritubular capillaries and transport them into the fluid in the renal tubules.
wastes, drugs, and excess ions
The basic functions performed by the nephron.
By the time the filtered fluid has undergone tubular reabsorption and tublar secretion and enters the minor and major calyx it is called what?
Urine
As nephrons perform their functions, they help maintain homeostasis of the blood’s __________
volume and composition
True/False
Urine values vary considerably according to diet
True
Glomerular Filtration
The cells that make up the inner wall of the glomerular capsule, called _________, adhere closely to the endothelial cells of the glomerulus.
podocytes
Simple squamous epithelial cells form the _______ layer of the glomerular capsule.
outer
Together, the podocytes and glomerular endothelium form a __________ that permits the passage of water and solutes from the blood into the capsular space.
filtration membrane
Glomerular Filtration
Blood cells and most plasma proteins remain in the blood due to what?
they are too large to pass through the filtration membrane
Net Filtration Pressure
What is the pressure that causes filtration in the glomerular capillaries?
Blood Pressure?
Net Filtration Pressure
What two pressures OPPOSE glomerular filtration
Blood colloid osmotic pressure
Glomerular capsule pressure
When either of the OPOSING pressures increases what happens to glomerular filtration?
decreases
Normally blood pressure is greater than the two opposing pressures producing a net filteration pressure by about what?
10mmHg