Chapter 26 The Urinary System Flashcards

1
Q

Functions of the Urinary System

A
  1. Excretes waste products
  2. Regulates composition of blood
  3. Produces Renin
  4. Produces Erythropoietin
  5. Activates Vitamin D
  6. Gluconeogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Functions of the Urinary System: Excretes waste products

A

like urea, uric acid, creatinine (nitrogenous wastes, made by our body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Functions of the Urinary System: Regulates composition of Blood

A

ions, pH, blood volume (how much water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Functions of the Urinary System: Produces Renin

A

(enzyme)
Angiotensinogen— Renin by kidneys—> Angiotensin 1 (inactive)—– ACE made by lungs–> Angiotensin II

  • occurs when blood pressure is to low
  • Angiotensin II causes vasoconstriction
  • ACE= angiotensin converting enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Functions of the Urinary System: Produces erythropoietin

A

in response to low oxygen levels

-erythropoietin stimulates erythropoiesis to make more RBCs made by the red bone marrow which will carry more oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Functions of the Urinary System: Activates Vitamin D

A

Skin makes (inactive) Vitamin D—> Liver Vitamin D–> active Vitamin D activated by the Kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Functions of the Urinary System: Gluconeogenesis

A

conversion of noncarbohydrates (fats) into glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the organs that perform the functions of the urinary system?

A

The Kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The other structures of the urinary system that store or carry urine out of the body are?

A
  • ureters
  • urinary bladder
  • urethra
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Anatomy of the Kidney

A
  • Retroperitoneal- located between dorsal body wall and parietal peritoneum
  • 3 layers of supportive tissue:
    1. Renal Fascia
    2. Adipose Capsule
    3. Renal Capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 Main Regions of the Kidney

A
  1. Renal Cortex
  2. Renal Medulla
  3. Renal Pelvis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the structural and functional units of the kidneys?

A

Nephrons

-there are over 1 million nephrons per kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Structure of a Nephron

A
  1. Renal Corpuscle

2. Renal Tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Structure of a Nephron: Renal Corpuscle

A
  • filtration of blood takes place here
  • consists of:
    a. Glomerulus
    b. Bowman’s Capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Structure of a Nephron: Renal Tubules

A
  • Filtrate is processed to form urine
  • consists of:
    a. Proximal Convoluted Tubule (PCT)
    b. Loop of Henle
    c. Distal Convoluted Tubule (DCT)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

2 kinds of Nephrons

A
  1. Cortical Nephrons

2. Juxtamedullary Nephrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

2 kinds of Nephrons: Cortical Nephrons

A
  • 85% of all nephrons
  • Most of the nephron located in cortex of kidney
  • Have short Loops of Henle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

2 kinds of Nephrons: Juxtamedullary Nephrons

A
  • 15% of all nephrons
  • Most of the nephron located near the border between the cortex and medulla of kidney
  • Have long Loops of Henle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Nephrons have 2 Capillary Beds

A
  1. Glomerulus- exchanges with Bowman’s capsule (filtration)

2. Peritubular Capillaries- exchange with the renal tubules (reabsorption and secretion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Nephrons have 2 Capillary Beds: Glomerulus

A

exchanges with the Bowman’s capsule (filtration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Nephrons have 2 Capillary Beds: Peritubular Capillaries

A

exchange with the renal tubules (reabsorption and secretion)

-Vasa Recta are peritubular capillaries that exchange with the long Loops of Henle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Flow of Blood Through the Kidneys

A

Renal Artery—-arteries—> afferent arterioles—->glomerulus (filtration)—->efferent arterioles—> peritubular capillaries or vasa recta (reabsorption and secretion)—>veins—>renal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Flow of Filtrate through the Kidneys

A

Filtrate forms in Bowman’s Capsule—-> PCT—> descending limb of loop of Henle—> ascending limb of loop of Henle—> DCT—> Collecting Ducts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Filtrate

A

fluid that enters the Bowman’s capsule and flows through the renal tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Urine
fluid leaving the collecting ducts
26
Kidney Physiology
- Blood flow through kidneys= 1200ml/min - GFR (rate of filtrate formation)= 120ml/min - Rate of urine formation= 1.2ml/min
27
Kidney Physiology: Blood flow through kidneys
1200ml/min
28
Kidney Physiology: GFR (rate filtrate formation)
120ml/min
29
Kidney Physiology: Rate of urine formation
1.2ml/min
30
3 Steps in Urine Formation
1. Glomerular Filtration- makes filtrate 2. Tubular Reabsorption- substance leave filtrate and enter the blood in peritubular capillaries 3. Tubular Secretion- substances leave the blood in peritubular capillaries and enter filtrate
31
Glomerular Filtration
- passive, nonselective process - Hydrostatic pressures force fluids across filtration membrane - Fluids move out of the glomerulus and into the Bowman's Capsule
32
The Filtration Membrane is
- Very Thin- 0.1 micrometers - Very Permeable- consists of: a. fenestrated capillaries (wall of glomerulus, has pores and clefts, very leaky) b. Podocytes (inner wall of the Bowman's capsule, has filtration slits) c. basal lamina
33
Glomerular Blood Hydrostatic Pressure (GBHP) is
55mmHg
34
``` NFP= HP(glomerulus) - (OP (glomerulus + HP (capsule)) NFP= +, then? NFP= -, then? ```
If NFP= +, then filtration occurs | if NFP= -, then reabsorption occurs
35
Regulation of Glomerular Filtration
- Myogenic Mechanism - Macula Densa Cells- chemoreceptors in ascending limb - Juxtaglomerular Cells- secrete Renin
36
What is secreted by Juxtaglomerular cells due to low blood pressure in glomerulus?
Renin | Angiotensinogen--renin--> angiotensin I---ACE--> angiotensin II
37
Tubular Reabsorption
- 99% of water and many solutes in the filtrate return to the blood - the chemical composition of the filtrate is adjusted
38
Tubular Secretion
- substances in the blood in the peritubular capillaries enter the filtrate in the renal tubules and collecting ducts - helps get rid of waste products - helps maintain blood pH
39
What happens in the first and second capillary beds?
1st- filtration | 2nd- tubular reabsorption + tubular secretion
40
Regulation of Glomerular Filtration: Myogenic Mechanism
-smooth muscle cells of afferent arteriole | able to dilate or constrict, automatically adjust diameter to make sure pressures are right
41
Regulation of Glomerular Filtration: Macula Densa Cells
chemoreceptors of the ascending limb (detect chemical composition of filtrate to adjust pressures going through glomerulus) -detect chemically adjustment of afferent arterioles
42
Regulation of Glomerular Filtration: Juxtaglomerular Cells
pressure sensors detect low pressures and will produce Renin (enzyme) Angiotensinogen---Renin--> Angiotensin I----> ACE---> angiotensin II -angiotensin II causes vasoconstriction; increase blood pressure throughout the body and kidneys
43
Filtrate Contains
- water - wastes (urea, uric acid, creatinine) - Ions (Na+, K+, Cl-, Ca+2, Mg+2) - Nutrients (glucose, amino acids, vitamins, lipids)
44
Tubular Reabsorption in different parts of the renal tubule
PCT Long Loops of Henle DCT + Collecting Ducts
45
Tubular Reabsorption in different parts of the renal tubule: PCT
most of selective reabsorption occurs here (select what gets back into the blood) -driven by the active transport of Na+
46
Tubular Reabsorption in different parts of the renal tubule: Long Loops of Henle
Reabsorption generates osmotic gradients in medulla
47
Tubular Reabsorption in different parts of the renal tubule: DCT + Collecting Ducts
reabsorption mainly regulated by hormones
48
PCT Tubular Reabsorption
Mechanism Na+ Primary active transport (Na+ K+ pump) Glucose, Secondary Active transport, use amino acids, specific carriers vitamins Water Osmosis by Obligatory water reabsorption Some ions Passive, Paracellular Urea, Uric Acid Lipids (lipid-soluble Passive, no specific carriers substances) Proteins Endocytosis & digested to amino acids Creatinine Not Reabsorbed
49
Long Loops of Henle Tubular Reabsorption
Descending Limb: water reabsorbed to blood (lose water, water comes out) Ascending Limb: solutes reabsorbed to blood (lose solutes, solutes leave) ``` Generates osmotic gradients in medulla (300- 1200 mOsmolar) Descending Limb is: -permeable to water -impermeable to solutes Ascending Limb is: -permeable to solutes -impermeable to water ```
50
DCT & Collecting Ducts Tubular Reabsorption
Regulated by Hormones Water Osmosis by facultative water reabsorption needs ADH Na+ Active transport of Na+ needs ALDOSTERONE Urea Passive, urea leaks out in deep parts of medulla
51
Tubular Secretion of Certain drugs, Urea & Uric Acid, H+ or bicarbonate ions, K+ ions
Secretion of: Located: Function: Certain Drugs PCT Rid body of drugs (Penicillin) Urea & Uric Acid PCT Rid body of waste products H+ or bicarbonate ions PCT Regulate blood pH K+ ions DCT & Collecting ducts Regulates blood K+
52
Osmolarity
of solute particles per 1 liter of water - a measure of a solution's ability to cause osmosis (water movements) - body fluids are maintained at 300 mOsm
53
Formation of Dilute Urine
- Stimulus is excess water in the body (low osmolarity <300 mOsm in plasma) - ADH release is inhibited; collecting ducts are impermeable to water - No facultative water reabsorption - Large volume of dilute urine excreted
54
Diuretic
substances that increase urine output
55
Formation of Concentrated Urine needs
- Medullary osmotic gradient (300- 1200 mOsm) | - Antidiuretic hormone (ADH) which causes collecting ducts to be permeable to water
56
Formation of Concentrated Urine
- Stimulus is dehydration (high osmolarity, >300mOsm in plasma) - ADH is released; collecting ducts permeable to water - Facultative water reabsorption occurs - Small volume of concentrated urine excreted
57
Countercurrent Mechanism
Osmotic gradients in the medulla are mainly due to the countercurrent mechanism It consists of: a. Countercurrent Multiplier- Long Loops of Henle which generate the gradient b. Countercurrent Exchanger- Vasa Recta which maintains the gradient
58
Countercurrent Mechanism: Countercurrent Multiplier
Long Loops of Henle which generate the gradient
59
Countercurrent Mechanism: Countercurrent Exchanger
Vasa Recta which maintains the gradient
60
Normal Urine Components
- 95% water - Urea - Uric Acid - Creatinine - Ions- Na+, K+, Phosphate, Sulfate, Ca++. Mg++, bicarbonate
61
Abnormal Urine Components
Possible causes -Glucose Diabetes Mellitus - Proteins Renal Disease, High BP - RBC Bleeding in urinary tract - WBC Infection - Bilirubin Liver Disease - Ketone Bodies Diabetes, extreme diets