CHAPTER 41 ~ Hormones

Question 1

endocrine cell

Answer 1

hormone secreting cell that releases these chemical signals to target cells that have receptors for those hormones

Question 2

exocrine cells

Answer 2

secrete signals into ducts that are connected to the “outside” (i.e. into GI tract, sweat or salivary glands)

Question 3

endocrine glands…

Answer 3

secrete hormones that circulate in blood

Question 4

paracrines

Answer 4

affect cells nearby, in immediate vicinity

Question 5

autocrine

Answer 5

affects the same cell that secreted it

Question 6

3 groups of hormones:

Answer 6

1. Peptides/proteins - water soluble, transported out of cell that made them through vesicles via exocytosis; their receptors must be on surface of target cells
2. Steroid hormones - lipid-soluble = they diffuse across membrane of cell that made them, but need carrier proteins to travel through blood; receptors MOSTLY intracellular, in cytoplasm or nucleus
3. Amine hormones - derived mostly from a.a. tyrosine, some water soluble, some lipid soluble.

Question 7

3 parts of surface receptors (for polar hormones) :

Answer 7

binding domain, transmembrane, and cytoplasmic domain

Question 8

binding domain:

of a surface hormone receptor

Answer 8

part that projects outside of plasma membrane for hormone molecule to bind to

Question 9

transmembrane domain:

of a surface hormone receptor

Answer 9

anchors receptor IN membrane

Question 10

cytoplasmic domain:

of a surface hormone receptor

Answer 10

part that juts out into cytoplasm, initiates target cell’s response-> activate enzymes: protein kinases or phosphatases through a secondary messenger activated cascade and activate or inactivated enzymes in cytoplasm, which are the cell’s response

Question 11

pituitary gland

Answer 11

link between nervous system and many endocrine glands

Question 12

posterior pituitary

Answer 12

releases 2 neurohormones: ADH (controls water retention in kidneys) and oxytocin (“cuddle hormone”)

Question 13

anterior pituitary

Answer 13

releases 4 tropic hormones: thyrotropin, adrenocorticotropin, luteinizing hormone, and follicle stimulating hormone; AND some NON-tropic hormones: growth hormone, and endorphines, etc.

Question 14

4 tropic hormones released by anterior pituitary:

Answer 14

thyropotin, adrenocorticotropin, luteinizing protein, and follicle-stimulating hormone
(all peptide and protein hormones)

Question 15

growth hormone:

Answer 15

stimulates cells to take up amino acids, stimulates liver to produce IGFs which stimulate bone and cartilage growth

Question 16

islets of Langerhans

Answer 16

endocrine portion of the pancreas (1-2%):

• produce insulin
• 3 types of cells produce hormones:
  
  • Beta cells = produce/secrete insulin
  • Alpha cells = produce/secrete glucagon
  • Delta cells = produce somatostatin

Question 17

Beta cells

Answer 17

produce/secrete insulin

Question 18

Alpha cells

Answer 18

produce/secrete glucagon

Question 19

Delta cells

Answer 19

produce somatostatin

Question 20

After a meal…

Answer 20

blood glucose levels rise as glucose is absorbed from food in gut; increased blood glucose stimulates Beta cells to produce insulin; insulin binds to cell receptor on membrane–>GLUT-4 move from cytoplasmic vesicles to the cell membrane = easier glucose uptake; if glucose concentration falls, beta cells of islets stop releasing insulin; cells shift to use glycogen and fat rather than glucose; if glucose falls way below normal, alpha cells release glucagon = stimulates liver to break down stored glycogen to release glucose into blood.

Question 21

cellular effects of insulin

Answer 21

binding of insulin to insulin receptors triggers response cascade resulting in exocytosis of intracellular vesicles containing GLUT-4 –>more GLUT-4 on plasma membrane = increased glucose uptake

Question 22

Diabetes Mellitus

Answer 22

affects 285 million worldwide, 5-10% in North America = type I, rest are type II

Question 23

TYPE I Diabetes

Answer 23

~10% of all cases, previously “juvenile diabetes”; due to auto-immune destruction of pancreatic Beta cells –>the insulin producing cells.

Question 24

TYPE II Diabetes

Answer 24

(adult-onset), ~90% of all cases, insulin resistance caused by lack sufficient functional insulin receptors in target cells; linked to obesity 90% of TYPE II are obese.

Question 25

symptoms of diabetes

Answer 25

weakness, lethargy, dramatic loss of body size/mass. with no insulin, glucose builds up in blood=water drawn out of cells through osmosis to counteract pH funkiness, = dehydration and more peeing.

Question 26

Acute complications of Diabetes

Answer 26

Ketoacidosis, and diabetic Hypoglycemia

Question 27

Ketoacidosis

Answer 27

an acute complication of diabetes, wherein liver switches to “starvation” mode and makes ketone bodies. Glucose and the ketone bodies cause raised blood osmolarity, water rushes into blood which leads to dehydration, and acidic ketone bodies lower blood pH, resulting in the diabetic Ketoacidosis

Question 28

Diabetic Hypoglycemia

Answer 28

occurs if insulin treatment is “overshot” –> lack of blood glucose results in coma and death

Question 29

Diabetic Retinopathy

Answer 29

severe vision loss/blindness resulting from diabetes

Question 30

Diabetic Neuropathy

Answer 30

kidney damage that can lead to chronic kidney failure, needing dialysis

Question 31

Diabetic Foot

Answer 31

combo of neuropathy and arterial damage cause skin ulcers, infection, necrosis, and gangrene, usually results in amputation

Question 32

heterotrophs

Answer 32

derive their nutrition from eating other organisms –> use food to obtain energy as well as building blocks for complex molecules

Question 33

calorie

Answer 33

amount of energy needed to raise the temp of one gram of water by 1ºC.

Question 34

metabolic rate

Answer 34

the measure of an animal’s overall energy needs that must be met by the animal’s food.

Question 35

basal metabolic rate

Answer 35

meabolic reate resulting from all of the essential physiological functions that take place in a resting state –> physical activity adds to basal energy requirement

Question 36

carbs stored in _____ and _____ as ______

Answer 36

carbs are stored in muscle cells and liver as glycogen

Question 37

_____ is the most important form of energy storage.

Answer 37

Fat is the most important form of energy storage; more energy/gram than glycogen and is stored more compactly

Question 38

when undernourished…

Answer 38

start “self-consumption” - metabolize glycogen (1 day) and fat stores (4-5 weeks); protein metabolization staved off for as long as possible

Question 39

Kwashiorkor

Answer 39

disease caused by chronic protein defficiency, when proteins start to be metabolized, blood plasma are first to be sacrificed = decrease in osmotic concentration of plasma, resulting in loss of fluid from blood to interstitial spaces = edema, or swelling occurs. accumulation of fluid in extremities and abdomen. Leads to organ damage and death

Question 40

when over-nourished…

Answer 40

glycogen reserves built up first, then excess carbs, fats, and proteins are converted to fat. = obesity = increased risk of high blood pressure, heart attack, and diabetes