Renal system Flashcards
What does the renal system consist of?
Kidneys
Ureters
Bladder
Urethra
Draw and label the renal system
What is the external structure of the kidneys?
- Renal fascia - outer layer consiting of connective tissue that anchors kidney
- Adipose tissue - cushiosn from trauma
- Renal capsule - smooth connective tissue, protects kidneys from trauma and maintains shape
Draw and label the kidneys
What is the internal structure of the kidney?
- Renal corex - outer part, has projections that extend down
- Renal medulla - abundance of blood vessels and tubules of the nephrons
- Renal pelvis - upper portion of the ureter which is funnel shaped
What are nephrons?
Functional units of kidneys
What do nephrons consist of?
Glomerulus and renal tubulue
How many nephrons are in each kidney?
Approx. 1 million
What is the function of nephrons?
Filter blood
Perform selective reabsorption
Exrete unwanted watse products from the blood
What does the renal system help regulate?
The amount of water, salts, glucose, urea and other minerals in the body
What are the 5 sections of the nephron?
- Bowman’s capsule (Glomerulus)
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule.
- Collecting duct.
What happens in the nephron?
Filteration
Selective reabsorption
Secretion
What happens at the filteration stage?
This takes place in the glomerous
There is a leaky filteration membrane that permits the passage of water and solutes
As blood passes, water, chemicals and waste soak through the glomerous
This is called the filtrate
What does filterate consist of?
Water, waste products, salt, glucoe, electrolytes, potassium
What is glomerular filteration rate?
The amount of filterate that forms in both kidneys every minute
Approx. 100-120ml
What happens at selective reabsorption?
Substances essential for body function are reabsorbed
Only 1% of filtrate leaves the body
Glucose is entirely reabsorbed into the blood
What happens at the secretion stage?
Any substance not removed through filteration are secreted into the tubules from the capillaries
This ensure discharge of chemicals not needed by the body in urine
What 4 hormones are involves in reabsorption and secretion?
Antidieuretic
Angiotensin and aldosterone
Atrial natriuretic peptide
What does the antidiuretic hormone do?
Increasess permeability in tubules and more water is reabsorbed and less urine is passed
What do the hormones angiotensin and aldosterone do?
As blood volume and BP decrease, the kidneys secrete renin
Renin acts on angiotensiongen and converts it to angiotensin 1
This is transported to the lungs where there is angiotensin-converting enzymes.
It is converted into angiotensin 2
This is a short-acting vasoconstrictor and increased BP
What does the hormone atrial natriuretic peptide do?
Powerful vasodilator and is a produced by the atria in response to increase in BP
Stimulates the kidneys to excrete sodium and water, decreasing blood volume and BP
What are the normal characteristics of urine?
Colour - yellow-amber
Smell - mild smell
Volume - 1-2l in 24hrs
Turbidity - transparent when fresh but turns cloudy
pH - 4-6.8
What are ureters?
Tubular organs that transport urine through peristalisis
What is the bladder?
Hollow organ that stores urine
What are the 3 layers of the ureters?
Mucosa
Smooth layer
Fibrous connective tissue
Why does the bladder have rugae?
To allow the bladder to expand as it fills
What are the detrusor muscles?
Bladder muscles that contract to expel urine
Draw and label the bladder
What is the urethra?
Muscular tube that drains urine from the body
What are the urethra sphincer muscles?
Internal - involuntary
External - voluntary
Keep the urthera closed when urine is not being passed
What are the other functions of the kidney? (8)
- Maintain fluid and electrolyte balance
- Remove waste and excess fluid
- Synthesis hormones such as renin and angiotensin
- Produce erthropoitin which stimulates production of red blood cells
- Keeps bones strong by producing calcirtiol which maintains calcium levels
- Regulate pH by reabsorbing bicarbonate and extreting hydogen.
- When the body needs energy, fats and proteins are synthesised in the kidney to produce new glucose as energy
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