Endocrine System 1

Question 1

What are the differences between endocrine & nervous system?

Answer 1

The NS uses electrical impulses which provides much faster and briefer responses while the ES uses hormones which provide slower & more sustained responses

Question 2

What are the functions of the ES?

Answer 2

Affect reproduction, growth, development, conception, metabolism, stress responses & aging

Question 3

What is the function of endocrine glands?

Answer 3

Release their products directly into the bloodstream without ducts to target cells & thus are highly vascularized

Question 4

What two components make up the ES?

Answer 4

Endocrine glands & endocrine tissue

Question 5

What are endocrine glands?

Answer 5

Primary function to produce hormones such as the pituitary, thyroid, PT, adrenal & pineal glands

Question 6

What are endocrine tissue?

Answer 6

Located in organs that perform other functions such as the pancreas, hypothalamus, gonads

Question 7

What are hormones?

Answer 7

Chemical messengers released by endocrine glands into the bloodstream to stimulate or regulate specific body cells or functions

Question 8

How do hormones only affect certain cell despite their wide reach?

Answer 8

Hormones only act on cells that have specific receptors - target cells

Question 9

How many receptors does each target cell have?

Answer 9

2000-10,000

Question 10

What is down-regulation?

Answer 10

An excess of hormones can decrease the receptors in target cells and decrease the effect of hormones

Question 11

What is up-regulation?

Answer 11

A deficiency of hormones can increase the receptors in target, and increase the effects of hormones

Question 12

What hormone has receptors across the body?

Answer 12

Thyroid hormone

Question 13

What are the two types of hormones?

Answer 13

Local & circulating (common) hormones

Question 14

What are circulatory hormones?

Answer 14

Circulating hormones pass from secretory cells to the bloodstream.

Question 15

What are local hormones?

Answer 15

Affect the secretory cells that released them or neighboring cells without entering the bloodstream.

Question 16

What are the two types of LH hormones?

Answer 16

Paracrines & autocrines

Question 17

What is the function of paracrines?

Answer 17

LH that stimulate neighboring cells

Question 18

What are the two chemical classes of hormones?

Answer 18

Lipid & water soluble hormones

Question 19

What are lipid soluble hormones?

Answer 19

Steroid (Aldosterone & testosterone) & Thyroid hormones (T3, T4)

Question 20

What are water-soluble hormones?

Answer 20

Amine, peptide & protein hormones

Question 21

What are the mechanism of lipid-soluble hormones?

Answer 21

Bound to transport-proteins, diffuse through the plasma membrane & have intracellular receptors

Question 22

What is the function of lipid-soluble hormones?

Answer 22

Activate intracellular receptors which generate the formation & activation of genes to synthesize new proteins that alter the cell’s activity.

Question 23

What are the mechanism of water-soluble hormones?

Answer 23

Unbounded, cannot enter plasma membrane & have extracellular receptors

Question 24

What is the function of water-soluble hormones?

Answer 24

Binding to their receptors cause the activation of the G protein (first messenger) which leads to a cascading series of events activating adenylate cyclase which converts ATP into cAMP which acts as the second messenger to activate protein kinases which phosphorylate cellular proteins that cause physiological responses.

Question 25

What 3 factors control hormones?

Answer 25

Humoral, neural & hormonal stimuli

Question 26

What are humoral stimuli & example?

Answer 26

Hormones released due to chemical changes in blood. For example PTH due to low blood Ca+2

Question 27

What are neural stimuli & example?

Answer 27

Hormones released by nervous impulses, such as the hypothalamus which stimulates the release of ADH & Oxytocin from posterior pitutary

Question 28

What is the hypothalamus-posterior pituitary axis?

Answer 28

Forms a nervous connection where the neurosecretory cells bodies of the hypothalamus produce hormones that are stored in their secretory axon vesicles in the posterior pituitary

Question 29

How are hormones released from the posterior pituitary gland?

Answer 29

When hypothalamus is stimulated, it causes the release of the hormones from the posterior pituitary gland to their surrounding capillaries.

Question 30

What are the two posterior pituitary hormones?

Answer 30

ADH - increases water absorption and oxytocin - causes contracting of birth canal walls

Question 31

What are hormonal stimuli & example?

Answer 31

Hormones which stimulate the release of hormones from endocrine glands. For example, the hypothalamus-anterior pituitary connection causes release of hormones from the hypothalamus which stimulate hormones in the AP to release hormones that cause other endocrine organs to secrete hormones

Question 32

What is the hypothalamus-anterior pituitary connection?

Answer 32

The hypothalamus & anterior pituitary are connected by the hypophyseal portal vein system allows which enables hypothalamic hormones to be transported to the anterior pituitary to target the tropic AP hormones

Question 33

What are the seven hormones of the AP

Answer 33

(FSH), (LH), (ACTH) (GH) (TSH) (MSH) & Prolactin

Question 34

What is the function of FSH?

Answer 34

Sperm production & oocytes development & estrogen production

Question 35

What is the function of LH?

Answer 35

Testosterone production & ovulation & oestrogen progesterone production

Question 36

What is the function of (ACTH)?

Answer 36

Causes secretions of glucocorticoids (cortisol) from adrenal cortex

Question 37

What is the function of GH?

Answer 37

Promotes growth of body tissues

Question 38

What is the function of TSH?

Answer 38

Release of thyroid hormones

Question 39

What are the adrenal gland hormones?

Answer 39

Cortex = Mineralocorticoids (Aldosterone), Glucocorticoids (Cortisol) Medulla = Epinephrine & norepinephrine stress responses