Chapter 18

Question 1

describe direct intercellular communication

Answer 1

adjacent cells coordinate cellular activities by exhanging ions and molecules across gap junctions

Question 2

describe paracrine intercellular communication

Answer 2

cells within a single tissue communicate with each other through the rleease and receipt of chemical messages

Question 3

describe autocrine intercellular communication

Answer 3

chemical messeges affect the same cell that secretes them

Question 4

describe endocrine intercellular communication

Answer 4

chemical messengers relay information and instructions between cells in distant portions of the body

Question 5

describe synaptic intercellular communication

Answer 5

when neurons release a neurotransmitter at a synapse very close to cells that have appropriate receptors

Question 6

what are the three classes of hormones?

Answer 6

amino acid derivatives, peptide homrones, lipid derivatives

Question 7

what are catecholamines?

Answer 7

amino acid derivatives derived from tyrosine (epinephrine, norepinephrine, and dopamine)

Question 8

what are the two groups of peptide hormones?

Answer 8

• glycoproteins
• short polypeptide

Question 9

what are the two groups of lipid derivative hormones?

Answer 9

• eicosanoids (arachidonic acid)
• steroid hormones (cholesterol)

Question 10

what if a cell does not have a receptor for a specific hormone?

Answer 10

the hormone will have no effect on the cell

Question 11

what is down regulation?

Answer 11

a decrease in number of receptors, cell becomes less sensitive to high levels of hormone

Question 12

what is up regulation?

Answer 12

an increase in number of receptors, cell becomes more sensitive to high levels of hormone

Question 13

what is a secondary messenger?

Answer 13

intermediary molecule that appears in response to initial hormone-receptor interaction

Question 14

what are the three secondary messengers?

Answer 14

cAMP, cGMP, and calcium

Question 15

when a hormone binds to an intracellular receptor, what occurs?

Answer 15

• genes activated
• rate of transcription altered
• metabolic activities of cell altered
• rate of ATP production increased

Question 16

what type of homeostatic feedback controls hormone secretion?

Answer 16

negative feedback

Question 17

what are the three ways hormone secretion can be triggered?

Answer 17

• humoral stimuli: change in composition of extracellular fluid
• hormonal stimuli: arrival or removal of a specific hormone
• neural stimuli: arrival of neurotransmitters at neuroglandular junctions

Question 18

what part of the brain is attached to the pituitary gland and has both endocrine and nervous system function?

Answer 18

the hypothalamus

Question 19

in what structure of the sphenoid bone is the pituitary gland?

Answer 19

within the sella turcica, a depression in the sphenoid bone

Question 20

which hormones does the hypothalamus produce?

Answer 20

ADH, CRH, GHRH, GnRH, OXT, somatostatin, TRH

Question 21

what is TRH produced by?

Answer 21

the hypothalamus

Question 22

what does TRH do?

Answer 22

stimulates the release of TSH from anterior pituitary

Question 23

what is CRH produced by?

Answer 23

the hypothalamus

Question 24

what does CRH do?

Answer 24

stimulates the release of ACTH from the anterior pituitary

Question 25

what is GnRH produced by?

Answer 25

the hypothalamus

Question 26

what does GnRH do?

Answer 26

stimulates the release of FSH and LH from anterior pituitary

Question 27

what does TSH do?

Answer 27

stimulates release of T3 and T4 from thyroid gland

Question 28

what does ACTH do?

Answer 28

stimulates the adrenal cortex to produce cortisole and aldosterone

Question 29

what does FSH do?

Answer 29

ovaries: secretes estrogen, follicle development testes: stimulation of sperm maturation

Question 30

what does LH do?

Answer 30

stimulates gonads to produce androgens, estrogen, and progesterone

Question 31

what does PRL do?

Answer 31

stimulates milk production in mammary glands

Question 32

what does GH do?

Answer 32

stimulates growth by protein synthesis, lipid mobilization and catabolism

Question 33

what does MSH do?

Answer 33

increases melanin synthesis in epidermis

Question 34

what does ADH do?

Answer 34

stored in posterior pituitary to then target kidneys: reabsorbs water & elevates blood volume and pressure

Question 35

what does OXT do?

Answer 35

secreted by hypothalamus, stored in posterior pituitary for later use mammary glands: labor contractions and milk ejection prostate gland: contractions

Question 36

what pituitary hormone is associated with diabetes insipidus? what is it?

Answer 36

ADH; occurs when posterior lobe of pituitary glands no longer release adequate amounts of the hormone

Question 37

what amino acid is the building block for thyroid hormones?

Answer 37

tyrosine

Question 38

the production of which hormones would be adversely affected if our diets were low in iodine?

Answer 38

T3 & T4; iodide ions are needed to form them

Question 39

Which anterior pituitary hormone affects the synthesis and release of thyroid hormones?

Answer 39

TSH, thyroid stimulating hormone

Question 40

Which two hormones are produced by thyroid gland follicular epithelium?

Answer 40

T3 & T4

Question 41

What is the function of T3?

Answer 41

responsible for metabolism, mood, and body temperature

Question 42

What is the function of T4?

Answer 42

transport T3 where needed to increase energy utilization, oxygen consumption, growth, development; precursor to T3

Question 43

What hormone is produced by thyroid gland C cells? What is its function?

Answer 43

calcitonin; decreases blood calcium concentrations by stimulating bone formation

Question 44

where are the parathyroid glands located in the body?

Answer 44

embedded in the posterior surfaces of the thyroid gland

Question 45

what hormone is produced by the parathyroid gland principal cells?

Answer 45

PTH, parathyroid hormone

Question 46

what is the function of PTH?

Answer 46

increases Ca2+ concentration; stimulates osteoclast consumption of bone

Question 47

where are the adrenal glands located in the body?

Answer 47

superior to each kidney

Question 48

where are the renal medulla and renal cortex located?

Answer 48

renal medulla: inner region of kidney renal cortex: outer region surrounding medulla

Question 49

what is the collective name for the adrenal cortex-produced hormones?

Answer 49

corticosteroids

Question 50

which zone of the adrenal cortex produced mineralocorticoids?

Answer 50

zona glomerulosa

Question 51

which zone of the adrenal cortex produces glucocorticoids?

Answer 51

zona fasciculata

Question 52

what are the three glucocorticoid hormones?

Answer 52

cortisol, corticosterone, cortisone

Question 53

which zone of the adrenal cortex produces androgens?

Answer 53

zona reticularis

Question 54

which two catecholamine hormones are produced by the adrenal medulla?

Answer 54

epinephrine and norepinephrine

Question 55

where is the pineal gland located in the body?

Answer 55

posterior portion of the roof of the third ventricle

Question 56

what are hormone-secreting cells in the pineal gland called?

Answer 56

pinealocytes

Question 57

what hormone is produced by the pineal gland?

Answer 57

melatonin

Question 58

which organ has both endocrine and exocrine functions?

Answer 58

the pancreas

Question 59

what are the endocrine and exocrine functions of the pancreas?

Answer 59

endocrine: secretes insulin and glucagon exocrine: secretes digestive enzymes into duodenum

Question 60

what is another name for pancreatic islets?

Answer 60

islets of Langerhans

Question 61

what are the four hormones in the pancretic islets? what hormone does each secrete?

Answer 61

alpha: glucagon beta: insulin delta: GH-IH (growth inhibiting) pancreatic polypeptide cells: PP

Question 62

what is the function of insulin?

Answer 62

- lowers blood sugar - facilitates uptake of glucose - forms and stores lipids and glycogen for energy

Question 63

what is the function of glucagon?

Answer 63

- raises blood sugar - promotes glucose synthesis and glycogen breakdown in liver - raises glucose concentration

Question 64

what are three indicators of diabetes mellitus?

Answer 64

polyuria (frequent urination), polydipsia (increased thirst), polyphagia (excessive hunger)

Question 65

what is the cause of type 1 diabetes mellitus?

Answer 65

inadequate insulin production

Question 66

what is the cause of type 2 diabetes mellitus?

Answer 66

abnormal response to normal amounts of insulin

Question 67

what two hormones are produced by the kidneys and what are their functions?

Answer 67

- erythropoietin (EPO): stimulates red blood cell production in red bone marrow - calcitriol: stimulates calcium and phosphate absorption, stimulates Ca2+ release, inhibits PTH secretion

Question 68

what two hormones are produced by the heart and what are their functions?

Answer 68

natriuretic peptides (ANP & BNP): increase water and salt loss at kidneys, decrease thirst, suppress secretion of ADH and aldosterone

Question 69

what hormone is produced by the thymus and briefly state its function?

Answer 69

thymosins: coordinate and regulate immune response

Question 70

what hormone is produced by adipose tissue and briefly state its function

Answer 70

leptin: suppression of appetite, permissive effects on GnRH and gonadotropin synthesis

Question 71

what hormones are produced by intersitial endocrine cells of the testes?

Answer 71

androgens: support maturation of sperm, protein synthesis in skeletal muscles, male secondary sex characteristics

Question 72

what hormone is produced by both the nurse cells of the testes and the follicular cells of the ovaries?

Answer 72

inhibin, which inhibits the secretion of FSH

Question 73

what other hormone is secreted by the follicular cells of the ovaries? what is its function?

Answer 73

estrogens: support follicle maturation, female secondary sex characteristics and associated behaviors

Question 74

what hormone is produced by the corpus luteum in the ovaries? what is its function?

Answer 74

progesterone: prepares uterus for implantation and mammary glands for secretory activity

Question 75

what are antagonistic and synergistic hormone effects?

Answer 75

antagonistic: opposing actions, net result depends on balance between hormones synergistic: hormones that have additive effects, net result being greater than sum of individual effects