Chapter 10 Course packet Flashcards
What is fluid within our cells called?
Intracellular fluid
What is the fluid that is within our bodies but outside of cells called?
Extracellular fluid or ECF
What is extracellular fluid (ECF) made up of?
Interstitial fluid and blood plasma
What does our proper function required?
A relatively stable internal environment
What is the urinary tract?
- Kidney (pair) » 2. Ureter (pair) » 3. Urinary bladder » 4. Uretha » 5. To the body surface
Kidney structure from the outside in
- Renal capsule <> 2. Cortex <> 3. Medulla <> 4. Renal pelvis <> 5. Ureter
The glomeruli are located in
The renal cortex
Where does the loop of henle with some of proximal and distal tubules run down?
They run down into the Renal medulla
Where can oxygen and solutes be reabsorbed?
The tubules and loop of henle
What is the blood flow
1.Afferent arteriole » 2.Glomerulus » 3.Efferent arteriole » 4.Peritubular capillaries along loop of Henle » 5.Venules » 6.Renal vein
As the collecting ducts run towards the center of the kidney, what do they tend to do?
Bunch together, giving the appearance of lobes (a.k.a. Renal pyramids)
Over the course of a day, the average adult human will gain and lose how much of water?
2.6L
How much water is ingested in solids?
850 milliliters
How much water is ingested in liquids?
1,400 milliliters
How much water is metabolically derived?
350 milliliters
How much total water gain in milliliters?
2,600 milliliters
How much water do we lose during urinary excretion?
1,500 milliliters
How much water is evaporated from lungs and sweat?
900 milliliters
How much water is eliminated in our feces?
200 milliliters
What is the total water loss
2,600 milliliters
What are the various ways to gain solute (anything not water)?
- Absorption from digested liquids and food
- Secretion from cells into ECF
- Respiration (O2)
- Metabolism
What are the various ways to loose solutes (mineral ions, metabolic wastes)?
- Urinary excretion (uric acid, urea)
- Respiration (CO2)
- Sweating
What is the location, driving mechanism, and what is moved for “filtration”
Location: Glomerulus
Driving mechanism: Blood pressure
What is moved: H2O, various small solutes
What is the location, driving mechanism, and what is moved for “Reabsorption”
Location: Proximal and distal (same as secretion but opposite directions)
Driving mechanism: Diffusion or active transport, osmosis for H2O
What is moved: H20, Na+, vitamins, amino acids, glucose
What is the location, driving mechanism, and what is moved for “Secretion”
Location: Distal and Proximal (same as reabsorption but opposite direction)
Driving mechanism: 1st secretion, then secretion
What is moved: H+, K+, uric acid, H2O-soluble foreign substances
What is the location, driving mechanism, and what is moved for “excretion”
Location: Lower collecting ducts and renal pelvis » ureter
Driving mechanism: Urination or Micturition
What is moved: Urine (1.5L of H2O a day plus solutes)
Quite a bit of fluid and solutes exit the circulatory system in the?
Glomerulus
There is higher blood pressure in what type of capillaries as opposed to other capillaries?
In glomerular capillaries
Glomerular capillaries are highly permeable to what?
H2O and small solutes
What fluid is called filtrate?
Glomerular capillaries are highly permeable to H2O and small solutes which is called filtrate
When does filtrate become urine?
Once it leaves the collecting duct
The proximal tubule is where there are many of what?
Protein “sodium pumps” that actively transport Na+ (sodium ions) out of the filtrate, negatively charged ions follow due to electrostatic attraction, H2O follows passively via osmosis
Most of the needed substances are reabsorbed, how many?
99% of H2O, 100% of glucose, 99.5% of sodium ions (Na+)
How many of the unneeded substances are reabsorbed?
Urea 44%
When substances move between the nephron tubules and the peritubular capillaries, it must enter the?
Interstitial fluid (inter fluid) of the kidney
Where does interstitial fluid increase?
Deeper into the medulla (closer to the kidney) and the solute concentration of the medullary CHECK THIS ONE IN THE BOOK
What causes kidney stones
High levels of uric acid and calcium salts can settle out of the urine
At the bladders opening to the uretha is what?
An involuntary smooth muscle internal urethral sphincter
What is further down the uretha?
There is a voluntary skeletal muscle external urethral sphincter
What are the parts of the Nephron?
- Glomerulus
- Proximal tubule
- Descending loop of Henle
- Ascending loop of Henle
- Distal tubule
- Collecting duct
What is the glomerulus permeability to H2O?
High
What is the glomerulus permeability to solutes?
High
What is the proximal tubule permeability to H2O?
High
What is the proximal tubule permeability to solutes?
High
What is the descending loop of Henle permeability to H2O
Yes, but not as high
What is the descending loop of Henle permeability to solutes
Low
What is the ascending loop of Henle permeability to H2O?
None
What is the ascending loop of Henle permeability to solutes
NaCI is actively pumped out
What is the permeability to H2O for the distal tubule
Yes, but influenced by ADH
What is the permeability to solutes for the distal tubule?
Limited, but influenced by Aldosterone
Is the collecting duct permeable to H2O?
Yes, but influenced by ADH
Is the collecting duct permeable to soltues?
Limited, but influenced by Aldosterone
What are the two hormones that help control the final water and sodium reabsorption?
ADH and Aldosterone
When does your solute concentration go up?
When you are dehydrated, or just ate a bag of salty pretzels
From posterior pituitary gland, secretion can be triggered if ECF solute concentration is too high or with dehydration/hemorrhage, it increases permeability to H2O in distal tubules and collecting ducts so that more H2O is reabsorbed from the filtrate back to the body. This results in less quantity but more HIGHLY concentrated urine.
ADH (Antidiuretic hormone)
From the adrenal cortex, secretion can be triggered by lower than normal levels of sodium ion (Na+) which increases active transport of Na+ by the distal tubule and collecting duct to reabsorb increased sodium ion (Na+) from the filtrate, the H2O passively follows. This results in less quantity, but NOT more concentrated urine.
Aldosterone
Your posterior pituitary gland starts to produce ADH, due to signals from?
The hypothalamus near the base of the brain (just slightly above the pituitary gland)
Your hypothalamus has what making you think you are thirsty?
A “thirst center” that will also inhibit saliva production, giving you “cotton-mouth”, and your brain interprets this as thirst
What is the formula for the respiratory system?
CO2 + H2O <> H2CO3 <> HCO3- + H+
Along with the respiratory system and the buffers in the blood what else plays a role in pH balance?
Kidneys
How does the nephron accomplish kidneys role in pH balance?
- The tubule cells can take CO2 from the capillaries, and through the respiratory formula, return bicarbonate (HCO3-) + Na+ to the capillary
- The secretion by the tubule cells of H+ into the lumen. In the filtrate, the H+ can combine with either bicarbonate (HCO3-), amino (NH3), or phosate
What are the 3 distinct areas of the kidney?
1) The renal cortex, which is the outer layer
2) The renal medulla, which is the middle layer
3) The renal pelvis, which becomes a ureter
What are nephrons?
Microscopic tubules that make urine
Urine is spurted from the ureter into the top of the bladder…
Continuously
A tube at the bottom of the bladder that opens to the outside of the body is called?
Urethra
What holds the urethra closed?
A sphincter muscle
The position of the kidneys in the abdominal cavity is maintained, in part, by the
overlying peritoneum
Each kidney is protected and stabilized in location by the
renal capsule, adipose capsule, and renal fascia
A glomerulus is?
is a capillary knot contained within the renal corpuscle
Components of the renal corpuscle include
the glomerulus and Bowman’s capsule
A nephron has two parts, and these are the CHECK
renal corpuscle and renal tubules
Each nephron empties into the
The collecting system
True or false…The distal convoluted tubule is responsible for active secretion of ions, acids, and other materials, selective reabsorption of sodium ions from the filtrate, and adjustment of the osmotic concentration and balance.
True
The main homeostatic function that occurs as a result of the work of the Loop of Henle is
water and salt conservation
In addition to the bladder, which other abdominopelvic cavity organ has an internal mucosa thrown into folds that disappear as the organ fills?
The stomach
Voluntary urination involves
relaxation of the external urethral sphincter and compression of the urinary bladder
Age-related changes in the urinary system include
reduced sensitivity to ADH