Lecture 28: Gross Structure of the Kidney Flashcards
What % of male bodies are water?
60%
What % of female bodies are water?
55%
Why do males have higher % of water in their body?
Males tend to have more muscle which holds more water
Why do females have lower % of water in their body?
Women tend to have more adipose which doesn’t hold water as well
What proportion of total body water is extracellular?
1/3
What proportion of total body water is intracellular?
2/3
Balance of what’s crucial?
Water
How does the urinary system maintain balance?
By filtering our blood
What does the urinary system expel?
4
- Excess water
- Excess salts
- Wastes of metabolism
- Many toxins and drugs
How much blood flows through the kidneys per minute?
1.2 Litres
How much urine does a typical person produce in a day?
800-2000 mL
What is urine?
Waste products, excreted to maintain balance within the body
What is excreted in normal urine?
4
- Water
- Salts
- Urea
- Metabolites (Hormones, Small proteins)
pH is not tightly what?
Regulated
Urea is influenced by?
What is excreted
What does urine pH fluctuate between?
Approximately 4.6 - 8
What is Urine useful for?
Diagnostic tool for disease states
What is contained in abnormal urine?
3
- Large proteins
- RBC
- Glucose
What is selective filtration largely dependant on?
The size of the molecules being filtered
To be effective the urinary system needs a what?
Delivery system for blood
To be effective the urinary system needs a selective what?
Filtration system
To be effective the urinary system needs a filtrate what?
Recovery system (Reabsorption)
To be effective the urinary system needs a system to return what?
Recovered/filtered fluid to body
To be effective the urinary system needs a system to remove filtrate from where?
The body
To be effective the urinary system needs the ability to communicate with what?
Relevant parts of the body
To be effective the urinary system needs to be adaptable to what?
Meet the body’s changing needs
What are the main component of the Urinary system?
4
- 2 kidneys
- 2 Ureters
- Urinary bladder
- Urethra
What does each kidney have?
Its own ureter
What do ureters extend down and empty into?
The urinary bladder
What extends down from the urinary bladder?
A single urethra
The structure of the kidneys allows blood to be bought into close proximity with what and for what?
Close proximity with nephrons for filtering
The structure of the kidneys allows blood that has been filtered to do what?
Leave the kidneys
The structure of the kidneys allows a pathway for urine to be removed from the kidney and then for what to happen?
It to be stored and then excreted
What level of vertebrae are the kidneys between?
T12 - L3
What ribs provide protection to the kidney?
11th/12th
The convex sides of the kidneys do what?
Face laterally
The medial surface of the kidneys have a concave notch called the what?
Hilum
What moves through the hilum?
4
- renal blood vessels
- Lymphatics
- Nerves
- Ureter
What does the liver do to the right kidney?
Pushes it down slightly
What sits on top of the kidneys?
Adrenal glands
The kidneys are where?
Retroperitoneal
What is meant by the kidneys being retroperitoneal?
They are located on the posterior abdominal wall, covered on the anterior side by the peritoneum
What surrounds and protects the kidneys?
Fat
What are the 3 regions of the kidney?
- Renal cortex
- Renal medulla
- Renal pelvis
What is the fibrous capsule?
A fibrous capsule that surrounds the kidney providing protection
What does the inner medulla divide into?
Renal pyramids
What does each renal pyramid end in?
A papilla
The renal cortex is a continuous layer that contains what?
Renal columns which extend between the renal pyramids
What do the cortex and medulla contain?
Multiple functional lobes
How many lobes are there per kidney?
5-11
What is contained in a lobe?
- One medullary pyramid
- All the cortex that surrounds it
What are kidney lobes made of?
Nephrons, typically thousands per lobe
Where do nephron endings finish?
In the minor calyx
Where does urine drain from?
Each papilla
What does urine drained from a papilla collect in?
In a calyx
What do calyces join to form?
Renal pelvis
What happens to the renal pelvis as it exits the hilum to become the ureter?
It narrows
What is the flow of urine in the kidney?
5
- Papilla
- Minor calyx
- Major calyx
- Renal pelvis
- Ureter
How is urine produced?
By filtering waste products from the blood into the nephron
Where does filtration occur?
In the cortex of the kidney
Where does the renal artery arise from?
The abdominal aorta
Branching arteries get smaller until what?
They reach the cortex
Veins return filtered blood from the cortex to where?
The renal vein, then to the IVC
The afferent arteriole does what?
Delivers blood from the arteries to the glomerulus
What is the glomerulus is made of?
Glomerular capillaries
What occurs at the glomerular capillaries?
Filtration
The efferent arteriole does what?
Carries blood from the glomerulus to the peritubular capillaries
What do the peritubular capillaries do?
Carry blood to veins
Nerve supply to the kidney is from a network of autonomic nerves and ganglia called the what?
Renal plexus
What do sympathetic nerves act to adjust in the kidneys?
The diameter of renal arterioles and this regulates blood flow
What are nephrons?
Microscopic functionl units of the kidney
The bulk of the kidney is made from what?
Nephrons
What do nephrons do?
3
- Filter blood
- Selectively reabsorb or secrete
- Produce urine
What is a renal corpuscle?
Where blood from the glomerulus and the nephron meet
What is the renal corpuscle made from?
2
- Glomerulus
- Glomerular capsule
What makes up the nephron?
5
- Renal corpuscle
- Proximal convoluted tubule
- Nephron loop
- Distal convoluted tubule
- Collecting duct
A single collecting duct is shared by what?
Multiple nephrons
