Homeostasis

Question 1

Detrusor muscle

Answer 1

a muscle that forms a layer of the wall of the bladder.

Question 2

Internal urethral sphincter

Answer 2

smooth muscle, contracted in normal state, involuntary control

Question 3

External urethral sphincter

Answer 3

skeletal muscle, voluntary control

Question 4

Micturition reflex

Answer 4

parasympathetic neurons firing causing detrusor muscle to contract, causing internal sphincter to relax

Question 5

Kidney function processes

Answer 5

1. Filtration
2. Secretion
3. Reabsorption

Question 6

Starling forces in filtration by kidney

Answer 6

1. Hydrostatic pressure in glomerulus&raquo_space; Bowman’s space
2. Osmolarity of blood > Bowman’s Space
3. Hydrostatic pressure&raquo_space; oncotic pressure - net flow from blood to Bowman’s capsule

Question 7

Nephron: what is absorbed and secreted in proximal convoluted tubule (PCT)

Answer 7

1. Reabsorption of: 70% of Na+, as well as Cl-, H2O, amino acids, glucose, water-soluble vitamins. Via vasa recta into interstitium.
2. Site of secretion of H+, K+, NH3, and urea

Question 8

Nephron: what is absorbed and secreted in loop of Henle

Answer 8

1. Descending limb: only permeable to water, with increasing osmolarity as go down.
2. Ascending limb: only permeable to salts, impermeable to water

Question 9

Countercurrent multiplier system

Answer 9

Flow of filtrate through the loop of Henle in opposite direction from the flow of blood through the vasa recta. Filtrate constantly being exposed to hypertonic blood in descending limb, ensuring max water reabsorption.

Question 10

Diluting segment: what type of cells lines it, how the filtrate becomes

Answer 10

Thickening of loop of Henle at transition from inner to outer medulla.

1. Cells lining the tube larger, larger amt of mitochondria, which enable active transport of ions.
2. Filtrate becomes hypotonic compared to interstitium - the only portion that urine is more dilute than blood. Important during overhydration.

Question 11

Distal convoluted tubule: what it responds to, what happens to urine

Answer 11

Responds to aldosterone (promotes Na reabsorption). Water follows the sodium, concentrating the urine

Question 12

Collecting duct: what it responds to

Answer 12

Responsive to both aldosterone & ADH

Question 13

What the filtrate mostly contains as it exits collecting duct

Answer 13

urea, uric acid, and excess ions

Question 14

Functions of Excretory System

Answer 14

1. Control BP
2. Control blood osmolarity
3. Control acid-base balance

Question 15

Skin/ Integument

Answer 15

1. Hypodermis
2. Dermis
3. Epidermis

Question 16

Hypodermis: what it is (layer of ___), what it has (what it’s composed of)

Answer 16

1. Layer of connective tissue

2. Has fat and fibrous tissue

Question 17

Layers of dermis (deepest to top, what it contains)

Answer 17

1. Reticular layer: sweat glands, blood vessels, hair follicle origins
2. Papillary layer: loose connective tissue

Question 18

Location of most sensory receptors (Meissner’s corpuscles, Merkel discs, Free nerve endings, etc.)

Answer 18

Dermis

Question 19

Layers of strata (deepest to top, what it contains)

Answer 19

Come, Let’s Get Sun Burnt

1. Stratum basale: contains stem cells & important for proliferation of keratinocytes (produce keratin)
2. Stratum spinosum: connected to each other, site of Langerhans cells
3. Stratum granulosum: keratinocytes die, lose nuclei
4. Stratum lucidum: only in hairless, thick skin - nearly transparent
5. Stratum corneum: has dozens of layers of flattened keratinocytes, forming barrier that prevents invasion by pathogens & helps to prevent loss of fluids & salt

Question 20

Calluses

Answer 20

excessive keratin

Question 21

Melanocytes: where it comes from, where it is, what it produces

Answer 21

From neural crest cells, in stratum basale. Produce melanin

Question 22

Langerhans cells

Answer 22

macrophages within stratum spinosum, presents antigens to T-cells

Question 23

Thermoregulation

Answer 23

1. Sweating

2. Arrector pili/piloerection

Question 24

Sweating: what it is controlled by, what it is promoted by, what happens to arterioles

Answer 24

1. Controlled by ANS
2. Promoted by postganglionic sympathetic neurons that utilize Ach
3. Arteriolar vasodilation also occurs

Question 25

Arrector pilli / piloerection

Answer 25

Trap layer of heated air near the skin.

Question 26

Shivering requires…

Answer 26

ATP

Question 27

Layers of fat

Answer 27

1. White fat = insulates body

2. Brown fat = less efficient in ETC, more heat energy released as fuel