Urinary System Flashcards
Overview of the urinary system
The main components of the urinary system
• 2 kidneys – secret urine
• 2 ureters – transport urine to the bladder
• Urinary bladder – collects and holds urine
• Urethra – transports urine externally
• Adrenal glands – produces hormones The main components of the urinary system
• 2 kidneys – secret urine
• 2 ureters – transport urine to the bladder
• Urinary bladder – collects and holds urine
• Urethra – transports urine externally
• Adrenal glands – produces hormones
Functions of the urinary system and the kidneys
- Bodys main excretory system- for urine.
- Kidneys are the main functional component- specifically the nephrons. Other structures are primarily for transport and storage.
what are the functions of the kidneys?
*excretion
*regulation of blood composition and concentration e.g calcium, potassium.
*regulation of blood volume and interstitial fluid - e.g excrete/ preserve water.
*regulation of bp (production of enzyme renin, increases bp) , and blood pH (acid base balance).
*regulation of calcium homeostasis (hormone calcitriol) , blood glucose (production of glutamine- gluconeogeneiss to produce glucose) .
*red blood cell production
*excretion of metabolic waste products and toxins.
features of the structure of the kidneys
- Paired structures on posterior abdominal wall, lateral to transverse process of spine.
- ovoid in shape- 10-12cm long, 5-7cm wide and 2.5cm thick.
- Retroperitoneal structures- fixed in place.
- anatomical location- T12-L3
- partially protected by the ribs (11th and 12th)
- Level of the kidneys changes with respiration- as you breathe In they move down.
- They lie obliquely with the upper pole being more medial and posterior than the lower pole which is more anterior and lateral.
how do the right and left kidney sit in the body, which one is higher than the other and why?
-Right kidney- situated in the right hypochondrium and right lumbar regions.
-Left kidney- Approx 2.5cm higher than the right kidney- liver pushes the right kidney down. Situated in the left hypochondrium and left lumbar regions.
what is the regional anatomy of the right kidney?
Superior- Right adrenal gland
Anterior- Right lobe of liver, Duodenum, Hepatic flexure
Posterior- Right hemidiaphragm, Posterior abdominal wall
what is the regional anatomy of the left kidney?
Superior- Left adrenal gland
Anterior-Spleen,Stomach,Pancreas, Jejunum, Splenic flexure
Posterior - Left hemidiaphragm, Posterior abdominal wall
why are the supporting tissues of the kidneys important?
Attachment and protection from trauma and infection- acts as a shock absorber.
what are the different supporting tissues around the kidneys?
Outer renal fascia –
- Fibrous connective tissue surrounding kidneys and adrenal glands
- Anterior – Gerota fascia- posterior abdominal wall
- Posterior – Zuckerkandl fascia, fuses with posterior abdominal wall- keeps the kidneys in place.
- Middle Perirenal / perinephric fat- Approximately 2.5cm thick (shock absorber)
Deep peripheral fibrous capsule of kidney
- Smooth transparent membrane; collagen and elastin
- Maintains shape
what is the perirenal space, and what does it contain?
- deep to renal fascia, continues across both sides passes anterior to the spine.
contains both:
- kidneys
- adrenal glands
- renal vessels and hila
- perirenal fat
describe the gross anatomy of the kidney
Bean-shaped, Convex laterally, Concave medially
- 10-12cm long, 5-7cm wide, 3cm thick
- Left normally slightly longer and thinner
- 150 grams
- Hilum medially (small depression on the concave, medial aspect)
- where blood vessels converge, point where everything goes into a structure.
what main components make up the internal structure of the kidneys?
-cortex, medulla, calyces, renal pelvis, renal hilum, renal sinus.
internal structure of kidney- what is the cortex
Reddish-brown granular tissue
* Surrounds and extends into medulla
* Extend internally between pyramids- renal columns
internal structure of kidney- what is the medulla?
Darker in colour
* Contains cone-shaped renal pyramids – approximately 8-18
* Striped appearance – tubules and capillaries
* Central apex – renal papilla
* The tips of the pelvis drain into the minor calyces then the major calyces and then the single renal pelvis to the ureter.
internal structure of kidney- what is the calyces
- Collect urine from papillae
- (8-18) minor to major (2/3) calyces
- Transitional epithelium lined – impermeable
- Smooth muscle walls – peristalsis of urine- collects urine from pyramids. mass transit and movement of urine.
internal structure of kidney- what is the renal pelvis
- Direct continuation from calyces
(similar structure)
- Funnel-shaped
- Continuous with ureter- takes urine out of calyces into there ureter
internal structure of kidney- what is the renal hilum
- Renal artery enters, renal vein exits
- Lymphatic vessels and nerves
- Ureter exits
internal structure of kidney- what is the renal sinus
- Cavity inside medulla
- Contains calyces, renal pelvis, and
blood vessels
what is the microscopic anatomy of the kidneys made up of?
- nephrons
- collecting ducts
collecting ducts are lined with
-principal cells
intercalated cells
what are the nephrons
the functional unit of the kidney; 1-2million per kidney.
Each nephron includes a filter, called the glomerulus, and a tubule.
The nephrons work through a two-step process: the glomerulus filters your blood, and the tubule returns needed substances to your blood and removes wastes.
what are collecting ducts?
- Fewer in number (1000s); drain several nephrons
- Drain urine from nephron through renal pyramids to calyces
- Give striated appearance to pyramids
- Supported by connective tissue and neurovascular structures to supply tissues
- Lined with:
- Principal cells – receptors for antidiuretic and aldosterone hormones; maintain water and Na+
- Intercalated cells – role in homeostasis of blood pH. Microvilli on surface.
what are there functions of the nephron, and what 3 processes does it consist of?
- Homeostasis of blood composition
- Urine production
- Three processes:
1.Glomerular filtration (takes it all out to a separate vessel)
2.Tubular reabsorption (takes what it needs back; most of it)
3.Tubular secretion (gets rid of what’s left
what are the 2 types of nephrons? why do we get 2 different types?
Two types of nephrons dependent on location and minor differences in structure and blood supply:
Cortical 85%
* Located in renal cortex except small part extending into medulla
* Surrounded by peritubular capillaries
Juxtamedullary
* Located closer to cortex/medulla junction
* Loop extends deep into medulla
* Role in producing concentrated urine
* Surrounded by Vasa recta capillary network
what is the renal corpuscule- golmerulus
- Literally means ball of wool
- Very convoluted bunch of tiny arterial capillaries
- From afferent arteriole, leaves via efferent arteriole
- Fenestrated – lots of pores to allow free passage of fluid and solutes
- High pressure throughout- helps filtration process.