Urinary System KuraCloud Q's Flashcards
Each kidney receives blood from the ________ artery.
renal
What is the name of the structure that is located superior of each kidney?
adrenal glands
Name and briefly describe the three main functions of the kidneys.
- excretion: removal of metabolic wastes from body fluids
- elimination: discharge of wastes from body
- homeostatic regulation of blood volume and solute concentration
Beyond filtration, what are the other homeostatic functions of the urinary system?
- regulation of blood volume
- regulation of blood pressure
- conserving valuable nutrients
- stabilisation of blood pH
- assisting liver in detoxification of poisons
- regulation of plasma ion concentrations
What internal structure of the kidney is the ‘functional unit’ of the kidney (i.e. the smallest structure that can carry out the functions of the urinary system)?
nephron
Nephrons consist of ________________________ .
renal corpuscle and renal tubule
Which of the above structures filters blood and what type of capillary allows this to occur?
glomerulus; fenestrated capillary
Which of the following structures returns filtered blood to the circulation?
efferent arteriole
What is the name of the fluid that enters the renal tubule?
filtrate
While travelling along the renal tubule, filtrate gradually changes in composition due to substances being _________ or _________ into or from capillaries that surround the nephron
reabsorbed; secreted
what are the functions of the renal corpuscle and renal tubule?
renal corpuscle
- filters blood
- filters glucose and small molecules from blood into filtrate
- retains proteins and large molecules (re too large to be filtered and return to blood)
renal tubule
- reabsorb 90% of water from filtrate
- reabsorbs useful organic nutrients that enter filtrate
- secrete waste products into filtrate
Filtrate passes from the distal convoluted tubule to the ______________ .
collecting duct
The three basic steps of urine formation are:
glomerular filtration
tubular reabsorption
tubular secretion
Is glomerular filtration a passive process or does it require energy?
Passive process - blood hydrostatic pressure forces fluids and solutes through the filtration membrane
What does the term glomerular filtration rate (GFR) mean?
amount of filtrate that the kidneys produce each minute
Extrinsic regulation of glomerular filtration rate (GFR) involves the nervous system and endocrine system. Which of the following are involved in the hormonal regulation of glomerular filtration rate if the homeostatic disturbance involves an abnormally low glomerular filtration rate?
- stimulates reabsorption of sodium ions and water
- stimulates secretion of aldosterone
- stimulates release of antiduiretic hormone (ADH)
illustrate how the Renin-Angiotensin-Aldosterone System (RAAS) corrects a decrease in glomerular filtration rate (GFR).
disturbed homeostasis (decreased GFR) –> stimulates release of renin –> activates angiotensin II –> which increases blood pressure and blood volume –> increase GFR –> homeostasis restored
Reabsorption is the process of recovering useful materials from the filtrate and returning them to the blood. The proximal convoluted tubule (PCT) is the first part of the renal tubule following the renal corpuscle. How much of the filtrate produced in the renal corpuscle is reabsorbed in the proximal convoluted tubule?
60-70%
What other substances are reabsorbed in the proximal convoluted tubule?
sodium ions
glucose
amino acids
Where does calcium ion (Ca2+) reabsorption occur and what hormone regulates this?
distal convoluted tubule; parathyroid hormone
Which hormone stimulates sodium ion (Na+) reabsorption from the distal convoluted tubule?
aldosterone
Which hormone stimulates cells of the collecting ducts to reabsorb water?
antidiuretic hormone (ADH)
Tubular secretion involves movement of substances from the blood into the filtrate. Almost all tubular secretion occurs in the ________________ .
distal convoluted tubule
what substances are secreted in the nephron?
- organic acids
- undesirable substances
- hydrogen ions
- bicarbonate
The hormone aldosterone also stimulates secretion of excess ____________ into the filtrate?
potassium ions
Urine formation occurs once the filtrate has undergone final modifications in the collecting ducts. Urine drains from the collecting ducts into the _____________ . Name the other structures that urine passes through, in the correct order, ending with the structure that excretes urine into the external environment
minor calyx
Urine then passes from the minor calyx into the major calyx which then drain into the renal pelvis. From the renal pelvis, urine drains into the ureters and then to the urinary bladder. Urine is excreted from the urinary bladder to the external environment via the urethra
what substances should be found in the urine of a normal healthy person?
- water
- urea
- sodium ions
- bicarbonate
- potassium ions
- calcium ions
What type of epithelial tissue permits stretch and recoil of the bladder?
transitional
What is the name of the structure near the glomerulus that is involved in both intrinsic (autoregulation) and extrinsic (nervous system and endocrine system) regulation of glomerular filtration rate (GFR)?
juxtaglomerular complex
The term erythropoiesis describes the _______________ .
production of red blood cells
the kidneys secrete erythropoietin in response to __________________ .
low oxygen levels in kidney tissues (or kidney hypoxia)
Why does the body produce more red blood cells in response to low tissue oxygen levels?
Red blood cells carry oxygen in the blood. Thus, increasing the number of red blood cells means that the blood can carry more oxygen to the tissues
