Homeostasis

Question 1

excretory system

Answer 1

serves many function, including the regulation of blood pressure, blood osmolarity, acid-base balance, and removal of nitrogenous wastes

Question 2

Kidney

Answer 2

Filters blood and produces urine.

Question 3

nephron

Answer 3

Question 4

detrusor muscle

Answer 4

Muscle in bladder that contracts under parasympathetic tone.

Question 5

internal urethral sphincter

Answer 5

Made of smooth muscle and contracted in its normal state.

Question 6

external urethral sphincter

Answer 6

Consists of skeletal muscle and is under voluntary control.

Question 7

Micturation reflex

Answer 7

Stretch receptors in bladder ⇒ CNS ⇒ Parasympathetic neurons ⇒ detrusor muscle contraction/internal sphincter relaxation

• voluntary contraction of external sphincter causes urination

Question 8

Secretion

Answer 8

Movement of salts, acids, bases, and urea directly into tubule by active or passive transport.

Question 9

Reabsorption

Answer 9

Compounds that are filtered or secreted are taken back up for use. Glucose, amino acids, and vitamins are always reabsorbed. ADH inserts AQP to increase amount of water reabsorbed.

Question 10

Proximal Convoluted Tubule

Answer 10

reabsorbed: amino acids, glucose, water-soluble vitamins, salts, water

Secreted: hydrogen ions, potassium ions, ammonia and urea.

Found in renal cortex

Question 11

Loop of Henle

Answer 11

Descending limb: permeable to only water

Ascending limb: permeable to only salts (creates gradient for water to move out of descending limb

Question 12

Distal convoluted tubule

Answer 12

Reabsorbed: sodium (aldosterone) and water

Secreted: wastes

Question 13

Collecting Duct

Answer 13

Water reabsorption due to ADH and aldosterone. “point of no return.”

Question 14

Aldosterone

Answer 14

Release by adrenal cortex in response to decreased blood pressure.

Question 15

ADH

Answer 15

Peptide hormone synthesized by the hypothalamus and released by the posterior pituitary in response to high blood osmolarity.

Question 16

Bicarbonate buffer system

Answer 16

If blood pH is low, increased respiratory rate and excretion of hydrogen ions/absorption of bicarbonate

If blood pH is high, decreased respiratory rate and excretion of bicarbonate/absorption of hydrogen ions.

Question 17

Skin

Answer 17

Protects from exposure to the elements and invasion by pathogens.

Layers: Epidermis, Dermis, Hypodermis

Question 18

Epidermis

Answer 18

Stratified Squamous epithelium (keratinocytes)

Melanocytes: produce melanin and pass it on to keratinocytes

Come Let’s Get Sun Burned

Question 19

Dermis

Answer 19

Sweat glands, blood vessels, and hair follicles originate in the dermis. Most sensory receptors are also located in the dermis i.e. meissner’s corpuscles, ruffini endings, and pacinian corpuscles

Question 20

Hypodermis

Answer 20

Connects skin to the rest of the body. Contains fat, fibrous tissues, and large vessels.

Question 21

Thermoregulation

Answer 21

Hot conditions: sweating and arteriolar vasodilation

Cold conditions: adipose insulation, piloerection, superficial arteriole constriction, and shivering