Lecture 22 4/24/14

Question 1

Urinary System

Answer 1

part of the excretory system getting rid of the waste of the body, especially the nitrogenous waste, waste from protein breakdown. A lot of it will be excreted by the urinary tract.

Question 2

Function of Urinary System

Answer 2

maintain homeostasis by controlling the volume and composition of blood. Venus dilation. Increase in blood fluid volume, veins dilate to accommodate

Question 3

Major Components of Urinary System

Answer 3

2 Kidneys

2 Ureters

1 Bladder

1 Urethra

Question 4

Description of Kidneys

Answer 4

Left Kidney is a little bit higher than the right kidney. Because the liver is a solid organ pushing the right kidney down. About the size of your fist. Filter blood to produce urine. 50 gallons filtrate a day.

Excrete about 1500 ml. But depending on how hydrated you are.

Bean-shaped organs about 4 inches long and about 2-3 inches wide. They are located retroperitoneal along with
the adrenal glands and the ureters. Partially protected by the 11th and 12th ribs.

Shrink wrapped against the posterior abdominal wall

Question 5

Description of Ureters

Answer 5

Exhibit peristaltic waves.

Kidney stones; dump in the bladder, and has one tube that goes out of the body, the urethra.

Question 6

Kidney Physiology

Answer 6

Blood Vessels to the kidneys are fairly large in diameter, that means a lot of blood flow going to the kidneys every minute.

No increase in blood pressure because of Venus Dilation. But we got increase in blood flow in kidneys, so a little increase in pressure, but also increases filtration rate, the fluid movement in the kidneys. More fluid movement the less chance to reclaim or re-grab that stuff traveling through the kidneys, and more of it ends up as having to go to the bathroom.

Question 7

The 3 Layers Surrounding the Kidneys

Answer 7

Renal Fascia

Adipose Capsule

Renal Capsule

Question 8

Renal Fascia

Answer 8

outermost layer of thin fibrous connective tissue that anchors the kidneys to the surrounding
structures.

Question 9

Adipose Capsule

Answer 9

2nd layer, a mass of fatty tissue surrounding the capsule, which serves to protect the
kidney.

Question 10

Renal Capsule

Answer 10

the innermost layer, made of a transparent thick fibrous membrane.

Question 11

Microscopic Anatomy of the Kidney

Answer 11

Nephron

Question 12

Nephron

Answer 12

the functional unit of the kidney. Approx. 1 million per kidney. The nephron consists of a microscopic renal tubule and it’s vascular component .

Question 13

Two Types of Nephrons

Answer 13

Cortical Nephron

Juxtamedullary Nephron

Question 14

Cortical Nephron

Answer 14

it’s glomerulus is located in the cortical region of the kidney.

Peritubular Capillary bed is next the cortical nephron

Question 15

Juxtamedullary Nephron

Answer 15

located at the junction of the medulla and cortex of the kidney.

Vasarecta Capillary bed is a straight vessel.

Question 16

Filtration of the kidneys happen where?

Answer 16

In the papilla of pyramids

Question 17

Blood Supply to the Kidneys

Answer 17

Approx 1200 ml of blood pass through the kidneys each minute.

Question 18

Blood Supply through the kidneys

Answer 18

Vasa Recta

The Bowman’s Capsule

Question 19

Vasa Recta

Answer 19

Loops of thin walled vessels that dip along with the loop of henle into the deeper regions of the cortex and into the medulla. Found predominantly with the juxtamedullary nephrons.

Question 20

The Bowman’s Capsule

Answer 20

The initial portion of the nephron that surrounds the glomerulus. Functions to filter water and solutes in the blood

Question 21

Juxtaglomerular Apparatus

Answer 21

Region where the distal convoluted tubule contacts the afferent arteriole.

Sensitive to Blood Pressure changes

Endocrine tissue.

Question 22

The macula densa and the juxtaglomerular cells together account for what?

Answer 22

Secretion of renin and erythropoietin

Question 23

Blood Supply from larger to smaller to smaller describe the regions

Answer 23

Renal Artery -> Segmental Artery (3-4) -> Interlobar Veins -> Then will be in cortex; anastomosis -> Arcuate Veins or Artery -> Interlobular Veins or Artery -> off of the interlobular you have the afferent arterioles and globuli

Question 24

Steps in Urine Production

Answer 24

1. Glomerular Filtration

2. Tubular Reabsorption

Question 25

Glomerular Filtration

Answer 25

Forcing components of the plasma through the endothelial capsular membrane of the bowman’s capsule and into the proximal convoluted tubule.

Question 26

Factors involved in filtration

Answer 26

Blood Pressure

The Efferent Arteriole

Question 27

Blood Pressure Factor in Filtration

Answer 27

Forces water and other small solutes into the Bowman’s capsule. This fluid is now called filtrate

Question 28

The Efferent Arteriole Factor in Filtration

Answer 28

The efferent arteriole leaving the capsule is smaller than the afferent arteriole, so there is a resistance to outflow of blood from the capsule, thus forcing H2O, etc. to flow into the tubules.

Question 29

Factors opposing the production of filtrate

Answer 29

Capsular Hydrostatic Pressure

Blood Osmotic Pressure

Question 30

Capsular Hydrostatic Pressure Opposing the Production of Filtrate

Answer 30

filtrate that is already in the Bowman’s capsule and the proximal convoluted tubule push back against the components of the blood trying to enter the capsule.

Question 31

Blood Osmotic Pressure Opposing the Production of Filtrate

Answer 31

the increased number of solute molecules in the blood versus the smaller number of solute molecules in the filtrate pull water back toward the higher solute concentration in the plasma.

GFR (Glomerular Filtration Rate) – the amount of filtrate flowing into the capsule per unit time. This equals about 50 gallons per day and only about 1500ml leaves the body per day as urine.

Question 32

Tubular Reabsorption

Answer 32

The movement of filtrate from the tubules back into the blood of the vasa recta and peritubular capillaries

Question 33

Proximal Convoluted Tubule

Answer 33

60-70% of the volume of filtrate is reabsorbed here.

Almost 100% of the glucose and amino acids are reabsorbed back into the blood at this location. Sodium, potassium, magnesium, and bicarbonate ion are actively transported out of the filtrate here.

Osmotic pressure from the increase solute concentration outside the PCT draws H2O out of the PCT and into the Peritubular region

Highly Metabolic

Question 34

Descending Limb of the loop of Henle

Answer 34

The very thin descending limb of the loop of Henle is permeable to H2O but relatively impermeable to solutes. As the limb descends further into the medulla where the solute concentration is greater, more H2O is pulled out of the descending limb.

Question 35

Ascending Limb of the loop of Henle

Answer 35

The thick ascending limb of the loop of Henle is impermeable to H2O, but actively transports NaCl out of the tubule and into the peritubular space, so as the filtrate continues to rise toward the cortex of the kidney on its way to the DCT the mOsm/l concentration continues to decrease. However, because NaCl is actively transported out the ascending limb the mOsm/l concentration in this region (medulla) is very high (1200 mOsm/l)