Lecture 20: Urinary System Flashcards
What it the main function of the Urinary System?
Ensure optimal properties of the blood by removing metabolic wastes generated by body cells
How does the urinary system affect blood ionic composition?
It regulates blood ionic composition
What two systems regulate blood pH?
The urinary system and the respiratory system
How does the urinary system control the volume and blood pressure?
By controlling the amount of water that the body retains
What two hormones does the Urinary system produce?
Calcitriol and Erythropoietin
What does Calcitriol do?
Help balance out calcium and activate vitamin D
Why is the right kidney slightly lower?
Because the liver is in the way
What is the Hilum of the kidney?
The entrance and exit of vasculature, ureter and lymphatics
What is the Vasculature of the kidneys called?
The Renal Artery and Vein
What do the Ureters do?
Transports urine from the kidneys to the urinary bladder
What is the urinary bladder?
A muscular sac that stores urine
What protects the kidneys?
The skin, muscles, fat and floating ribs
Where are the kidneys found in relation to the peritoneum?
They are retroperitoneal (behind the peritoneum)
What is the Peritoneum?
The serous membrane lining the peritoneal (abdominal) body wall and organs
What is the Parietal Peritoneum?
The lining of the peritoneal cavity (body wall)
What is the Visceral Peritoneum?
The lining of the peritoneal organs (viscera)
Where is the Peritoneal cavity found?
Within the parietal peritoneum
What is the meaning of Retroperitoneal?
Behind or under or outside the peritoneal cavity
What is Perirenal fat?
The fat that surrounds the kidneys
What does the Renal Fascia do?
Surrounds the kidneys and anchors them to the abdominal wall
Where is the Peritoneal or Retroperitoneal fat found?
Behind the parietal peritoneum
What is the sequence from the Minor Calyces of the kidneys?
Minor Calyces > Major Calyx > Renal Pelvis > Ureters
What envelopes the kidneys?
The fibrous capsule
What is the Cortex of the kidney?
The outer part of the inside of the kidney
What does a Renal Pyramid have an entrance to?
A minor calyx via the renal papilla
What are the Calyx, Renal pelvis, and Ureter all made of?
Transitional epithelium
What is the order of Vasculature going into the kidneys?
Renal Artery > Segmental Artery > Interlobar Arteries > Arcuate Arteries > Interlobular Arteries
What is the order of Vasculature draining out of the kidneys?
Interlobular Veins > Arcuate veins > Interlobar veins > Renal Vein
What does each lobule connect to?
The functional unit of the kidney
What is the Renal Corpuscle?
The connection between the afferent arteriole and the nephron
Where does blood go once it comes out of the Nephron?
The Efferent arterioles
Where does the blood go from the Efferent arterioles?
Capillaries/Vasa recta
What is the functional unit of the kidney?
The Nephron
What makes up a nephron?
A corpuscle and a long tube
Where is blood filtered in the nephron?
The Corpuscle
What kind of tissue is the Nephron made of?
Simple epithelial tissue
What are the parts of the Nephron?
- Corpuscle
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting tubule
- Collecting ducts
Which part of the Nephron is in the Cortex of the kidney?
The corpuscle and the convoluted tubule
Which parts of the nephron is found in the Medulla?
The loop of henle and the collecting ducts
What does the distal convoluted tube have a close relationship with?
The Renal Corpuscle
What are the two types of nephrons?
- Cortical nephrons
* Juxtamedullary nephrons
What are the more common nephrons?
The Cortical nephrons
Physically describe the Cortical Nephron
- Mainly found in the cortex
* Small to nonexistent loop of henle
What is the function of the Cortical Nephron?
Reabsorption of the good stuff that got put in the tube that is supposed to be urine back into the vasculature
Physically describe the Juxtamedullary Nephron
Extremely large loop of Henle
What is the function of the Juxtamedullary Nephron?
To concentrate urine
What happens as the filtrate in the tubules goes through the medulla?
Because the medulla is super salty water leaves the filtrate and concentrates it
What causes everything from the blood to be pushed out into the Renal Corpuscle?
High blood pressure
Where is the Proximal Convoluted tube located?
Right next to the Renal Corpuscle
What does the proximal convoluted tube do?
Tries to reabsorb everything
What gets absorbed in the loop of Henle?
Water
Which part of the nephron has a hormonal effect?
The Distal Convoluted tube
How does the Distal Convoluted tube have a hormonal effect?
Depending on what is found in it is able to tell the body what needs to come back and what can be excreted
Where is the last chance to retain as much water as possible in the nephron?
The collecting tubule
Why are the Afferent and Efferent tubules different sizes?
To cause a difference in pressure to push out everything found in the capillaries
What are the two layers surrounding the corpuscle?
The Parietal and Visceral layers
What is the other name for the parietal layer inside the corpuscle and what is it made out of?
Bowman’s capsule and it is made of simple squamous epithelium
What is the other name for the visceral layer of the Renal Corpuscle?
Podocytes
What is Bowmans space?
The space between the parietal layer and the visceral layer of the renal corpuscle
Where does all the filtrate go from the glomerulus in the renal corpuscle?
It goes to Bowman’s space
What do Mesangial cells in the glomerulus do?
- Help or inhibit things from going into the Bowman’s space
- Act as macrophages and help with phagocytosis and put debris into the filtrate
- Helps with immune defense
What prevents large things from exiting the the glomerulus?
The basal membrane
What is unable to exit the Glomulerus?
- RBCs
- WBCs
- Large proteins
What is able to exit the Glomeruli and move into the Glomerular space?
- Small proteins
- Metabolites
- ions
- Water
- Vitamins
- Toxins
What happens in the kidneys if the blood pressure is too high?
A lot of the stuff will get pushed out of the blood and won’t be able to get reabsorbed
Which cells are the Macula densa associated with?
Juxtaglomerular cells
Which part of the nephron are the Macula Densa cells apart of?
The distal convoluted tubule
What do the Macula densa and the Juxtaglomerular cells say to each other?
The relay information about what needs to be kept in the filtrate and excreted and what needs to remain in the filtrate
What do the Juxtaglomerular cells secrete?
Renin
What does Renin secreted by the juxtaglomerular cells do?
Impacts the smooth muscle of arterioles, increasing the blood pressure through vasodilation
What part of the kidneys regulates blood pressure?
The macula densa of the DCT and the cells close to the corpuscle depending on what is found in the filtrate
What increases SA in the Proximal convoluted tubule?
Microvilli
What is the function of the Proximal convoluted tubule?
Reabsorption of organic nutrients, water and electrolytes and ions
What do the aquaporins in the loop of henle do?
Allow water go through the cells in order to be reabsorbed into the vasculature
How does the thicker part of the loop of henle work?
It is impermeable to water and allows sodium and chloride to enter back into the bloodstream
What is the Vasa Recta?
Capillary beds in the medulla that carry water away from the loop of henle to preserve the salt gradient
What occurs at the distal convoluted tubule of the kidneys?
Things that were unable to exit the blood in the glomerulus, like acids, toxins and drugs are secreted into the tubule to be excreted
What does Aldosterone help with in the distal convoluted tubule?
Reabsorption of sodium
What does the Collecting tubule of the nephron regulate?
The pH of blood and dehydration
What happens in the collecting tubule if a person is dehydrated?
ADH (antidiuretic hormone) will make the ducts more permeable to water
How does ADH affect the filtrate?
It concentrates it in the collecting tubules by allowing water to be reabsorbed into the blood
What is the ADH secreted by?
The pituitary gland
Where do the Ureters span?
From the renal pelvis to the urinary bladder
What are the muscular layers in the ureters?
Smooth and longitudinal layer
How does urine go done the ureters?
Via peristalsis
What kind of tissue is from the calyx onward?
Transitional (urinary) epithelium
Physically describe transitional epithelium?
Many layers that can go over top and stretch out
Which muscle does the ureter go overtop of?
The Psoas major
What artery does the Ureter have to go overtop of?
The common iliac artery
Where are the Ureteric openings and what do they do?
They are openings on the back of the bladder where ureters enter
Where are kidneys stones felt the most?
Sites of Ureteric constriction
What are the points of Ureteric constriction?
- Ureteropelvic junction - stone leaving the kidney (T10-L1)
- Stone crossing the common iliac vessels (T11-L2)
- Ureterovesical junction - Stone entering the urinary bladder (L1-L2)
What are the Rugae and where are they found?
Rugae are found in the urinary bladder caused by the muscles associated with it
What are the two Urethral sphincters?
- Internal
* External
What is the Detrusor muscle?
The three layers of smooth muscle of the bladder
Which parts of the bladder are controlled by the Autonomic nervous system?
- Detrusor muscle
* Internal urethral sphincter
Which of the Urethral sphincters are controlled by the somatic nervous system?
The external urethral sphincter
What is the Lamina Propria of the Urinary bladder filled with?
Immune cells
What does the Sympathetic innervation of the urinary system control?
- Contraction of the internal urethral sphincter
* Inhibits detrusor contraction
What does the Parasympathetic innervation of the urinary system control?
- Relaxation of the internal urethral sphincter
* Stimulation of detrusor contraction
What does Somatic innervation of the urinary system control?
The external urethral sphincter
What are the three parts of the Urethra in males?
Prostatic urethra, membranous urethra, penile urethra
