CHP 25 Control of body temp and water balance

Question 1

Kidneys/renal system

Answer 1

-filters blood-filters 1,100-2000 L fluid from the bloodstream daily
-regulate the volume and chemical makeup of the blood- removes toxins, metabolic wastes, excess ions
-returns substances to the blood such as glucose, amino acids, ions, and vitamins

-kidneys-critical function in elimination of metabolic wastes
Note-metabolism is defined as all the chemical reactions in the body
-examples of metabolic waste: CO2
nitrogenous wastes

Question 2

-nitrogenous wastes

Answer 2

byproduct of proteins and nucleic acids break down

-must be disposed of, i.e., excreted

Question 3

amino groups are converted into a substance called

Answer 3

urea

Question 4

urea is produced in the

Answer 4

liver

Question 5

urea is water soluble and therefore suitable for elimination from the body by being carried in the blood to the

Answer 5

kidneys

Question 6

Renal system-excretory system anatomy

Answer 6

-includes two kidneys, urinary bladder, to ureters, urethra

Question 7

Kidney

Answer 7

• bean shaped
• site of urine formation
• composed of hollow tubules called nephrons

Question 8

Ureters

Answer 8

-tubes that extends from each kidney to the urinary bladder
-carry urine-filtered blood that is ready for elimination
-urinary bladder-receives fluid from kidneys by a ureters and expels resulting fluid (urine) into outflow tube called the urethra

Question 9

Internal anatomy of the kidney

Answer 9

-two layers-outer layer-
-inner layer-renal medulla-
Note: renal cortex and renal medulla layers have an arrangement of tubules called nephrons
-nephrons-structural and functional unit of kidney
basic unit-essentially tubules with associated capillaries and arterioles

Question 10

Tubular elements of kidney and nephron

Answer 10

A-Bowman’s capsule-cup like and, completely surrounds grouping of capillaries called glomerulus
-note: together referred to as renal corpuscle
B-proximal tubule-
C-loop of Henle parts:
1-thin descending limb
2-thick and thin descending limb
D- distal tubule-
E-collecting ducts-

Microvasculature of nephrons
-nephron has 2 separate networks of capillaries:
1-blood flows from the renal artery into an afferent arteriole forming a Tuft of capillaries called the glomerulus
-site where filtrate is made
2-arteriole from the glomerulus branches and forms a second capillary network-called peritubular capillaries
-this surrounds the proximal and distal tubules
-involved with refining filtered blood that will eventually become urine
Note: filtrate-plasma derived fluid
-raw material that renal tubules process to form urine

Question 11

Kidney function

Answer 11

note: kidneys process 180 L of fluid per day but only 1% leaves the body and the rest is returned to circulation by the kidneys
mechanism-filtration, reabsorption, secretion, excretion

Question 12

Filtration-begins at the

Answer 12

Bowman’s capsule

Question 13

-fluid that filters through, from glomerulus capillaries, is captured by the Bowman’s capsule and enters its

Answer 13

lumen

Question 14

volume as filtrate that is filtered by glomerulus is referred to as

Answer 14

glomerular filtration rate

- important to maintain constant rate- 
- if too much filtrate forms, the flow  too fast for substances to be reabsorbed which would mean those substances get lost in the urine
- if too little filtrate is formed, the flow is too slow and even wastes get reabsorbed