UR4 (pt. 1)

where on nephron is 60% + of Ca ions reabsorbed?

PCT

What does Parathyroid gland detect, and what’s result?

detects: low Ca2+ lvls

result: secretes parathyroid hormone (peptide hormone)

What detects low Ca lvls?

Parathyroid gland

What does Parathyroid hormone do?

• travels to kidneys to the DCT

• increases activity of

  • Ca channels

  • Na/Ca antiporter

to increase reabsorption of Ca!

What does parathyroid hormone promote?

Increased reabsorption of Ca!

Where on nephron does parathyroid hormone go?

DCT to increase activity of

• Ca channels

• Na/Ca antiporter

What type of hormone is Parathyroid Hormone?

Peptide hormone! (CANNOT enter cells)

T or F: Parathyroid hormone can enter the cell

FALSE! its a peptide hormone

Define diuretics

drugs that decreases plasma volume and increases urine volume

What does diuretics inhibit?

inhibits Na reabsorption, decreases H2O reabsorption

Exaples of diuretics:

• Furosemide

• K+-sparing diuretics

Furosemide - inhibits what, where on nephron?

inhibits reabsorption of Na @acsending LOH

• also messes w/ K+ symporter w Cl

What diuretic messes with K excretion?

FurosemideFurosemide - inhibits what, where on nephron?

K-sparing diuretics - inhibits what, where on nephron? AND HOW?

inhibits Na reabsorption @Cortical CD

• blocks aldosterone or Na channels

Diuretic flow chart

1. decreases Na reabsorption

2. increases Na and H2o excretion

3. decreases Blood volume.

4. decreases; venous return and stroke volume

5. decreases; cardiac output and BP

what is a byproduct of decreased CO?

decreased ECF

flow chart: urinary flow

calyx → renal pelvis → bladder

T or F: ureters have smooth muscle in them

TRUE!

define micturition

voiding/urinating

What are the 3 neural paths that the bladder is innervated by to control filling and peeing?

1. Parasympathetic

2. Sympathetic

3. Somatic motor (voluntary control)

this is the ONLY voluntary sphincter:

External urethral orifice (skeletal muscle)

What muscle surrounds bladder?

Detrusor (smooth muscle)

Smooth muscles vs. skeletal muscles of bladder:

smooth:

• detrusor

• interna; urethral sphincter

skeletal:

• external urethral sphincter

during filling of bladder, what is the innervation of detrusor, internal urethral sphincter, and external urethral sphincter?

1. Detrusor: SNS relax

2. Internal urethral sphincter: SNS contract

3. external Urethral sphincter: somatic motor contract via pudendal nerve

pudendal nerve innervated during filling or urinating?

filling: stims somatic motor to contract (by the external urethral sphincter)

Define flow chart of mechanoreceptors

1. bladder fills, signal sent to brain (degreee of fstretch)

2. sends at 200-400mL full

3. urgency depends on strength of signal

What receptors signal fullness of bladder to brain?

Mechanoreceptors

Bladder capacity:

800mL-1000mL (1L)

during urination of bladder, what is the innervation of detrusor, internal urethral sphincter, and external urethral sphincter?

1. Detrusor: PNS contract

2. Internal urethral sphincter: PNS relax

3. external Urethral sphincter: somatic motor relax