Endocrine System Pt.1

Question 1

What is direct communication?

Answer 1

Exchange of ions and molecules b/w adjacent cells through gap junctions
between cells of the same type

Question 2

What is paracrine communication?

Answer 2

When chemical signals transfer info from cell to cell w/n a single tissue
Transmission is through extracellular fluid to specific receptors on target cells

Question 3

What is autocrine communication?

Answer 3

Messages that affect the same cell that secrete them

Question 4

What is endocrine communication?

Answer 4

Communication by endocrine cells that release hormones that are transported in the bloodstream
Alters metabolic activity of many organs
Their target cells have receptors that read the hormonal messages

Question 5

What are exocrine glands?

Answer 5

Glands that release their contents through a duct that leads to epithelial surface

Question 6

What are merocrine glands?

Answer 6

Exocrine glands that release part of their contents by exocytosis (sweat and salivary glands)

Question 7

What are apocrine glands?

Answer 7

Exocrine glands where part of the cell is pinched off and becomes the secretion (mammary & odorous sweat glands)

Question 8

What are holocrine glands?

Answer 8

Exocrine gland where mature cell dies and becomes the secreted product (sebaceous glands)

Question 9

What are the three classes of hormones in the body?

Answer 9

Amino Acid Derivatives
Peptide Hormones
Lipid Derivatives

Question 10

What are Amino Acid Derivatives?

Answer 10

Small hormones related to amino acids.
Derivatives of tyrosine and tryptophan

Question 11

What are peptide hormones?

Answer 11

Chains of amino acids, Glycoproteins, and small proteins
and includes all hormones secreted by the hypothalamus, heart, thymus, GI, pancreas, posterior pituitary.

Question 12

What are glycoproteins?

Answer 12

Proteins that have more than 200 amino acids that have carbohydrate side chains (TSH,LH, FSH)

Question 13

What are examples of small proteins?

Answer 13

Insulin
GH
Prolactin

Question 14

What are lipid derivatives?

Answer 14

Hormones that coordinate cellular activity and affect enzymatic processes (blood clotting)

Question 15

What type of hormones are steroid hormones and what are some examples?

Answer 15

Lipid derivatives that come from cholesterol;
Androgens from testes in males
Estrogen and progesterone from ovaries in females
Corticosteroids from adrenal complex
Calcitriol from kidneys

Question 16

How do catecholamines and peptide hormones function in the body?

Answer 16

Not lipid soluble, unable to penetrate plasma membrane, and bind to receptor proteins on extracellular receptors

Question 17

How do Steroid and thyroid hormones function in the body?

Answer 17

They are lipid soluble and diffuse across plasma membrane and bind to receptors inside the cell.

Question 18

How long are free hormones functional in the body and why?

Answer 18

Less than an hour;
They diffuse out of bloodstream and bind to target receptors
are absorbed and broken down by liver and kidneys or
are broken down by enzymes in blood or interstitial fluids

Question 19

What are G protein coupled receptors and how do they work?

Answer 19

A hormone binds to an extracellular receptor and activates a G-Protein which when activated, increases cyclic AMP levels which acts as a second messenger within the cell

Question 20

What are the effects of secondary messengers such as cAMP?

Answer 20

Activation of enzymes or opening ion channels that may accelerate metabolic activity of the cell
(Epinephrine, norepinephrine, calcitonin, parathyroid hormone, ADH, ACTH, FSH, LH, TSH)

Question 21

How do steroid hormones affect DNA transcription?

Answer 21

Alters synthesis of enzymes or structural proteins because they directly affect activity and structure of target cell.

Question 22

What is down regulation of a hormone?

Answer 22

Presence of a hormone triggers a decrease in number of hormone receptors and when they’re too high, cells become insensitive to it.

Question 23

What is up regulation of hormones?

Answer 23

Absence of the hormone creates and increase in the receptors for it and become extra sensitive to the hormone

Question 24

What is humoral stimuli?

Answer 24

Change in extracellular fluid

Question 25

What is hormonal stimuli?

Answer 25

arrival or removal of a hormone

Question 26

What is neural stimuli?

Answer 26

neurotransmitters

Question 27

What does the pituitary gland do?

Answer 27

Releases nine important peptide hormones

Question 28

What is the pituitary gland and adrenal gland controlled by?

Answer 28

The hypothalamus

Question 29

What two hormones does the posterior pituitary gland release?

Answer 29

Antidiuretic Hormone / vasopressin (ADH) and oxytocin (OXT)

Question 30

What organ(s) does ADH (Vasopressin) directly affect?

Answer 30

Sent out when blood osmolarity increases (negative feedback);
Blood vessels contract and increase blood pressure
Kidneys (increased water reabsorption)

Question 31

What organ(s) does Oxytocin directly affect and how?

Answer 31

Mammary glands by allowing milk to be ejected.
Uterus (positive feedback) by contracting the uterus and dilating cervix (pushes baby out)