Chapter 18

Question 1

What are the functions of the endocrine system?

Answer 1

Regulation of homeostasis
Specificity: growth and development, reproduction, regulation of cell metabolism and energy balance, regulation of body water content, regulation of electrolyte levels and mobilization of immune system

Question 2

What are the major organs of the endocrine system?

Answer 2

Hypothalamus, pituitary gland, thyroid gland, adrenal gland, pancreas, parathyroid glands, pineal gland

Question 3

Types of communication on cellular level

Answer 3

Direct= through gap junctions (example: cardiac)
Paracrine= through extracellular fluid (example: kidney and digestive track)
Endocrine= through blood stream (example: hormones)
Synaptic= across synaptic clefts (example: neurons)

Question 4

What are the 3 typical hormonal responses?

Answer 4

Change in gene expression
Change in cellular activities (move more and produce more)
Change in membrane permeability (especially in kidneys)

Question 5

What is alkaptonuria?

Answer 5

An autosomal recessive disorder
Mutation on homogentisate dioxygenase (protein found in kidney and liver)
body is not able to break down tyrosine and phenylalanine

Question 6

True or False
A single hormone will affect many but not all the organs

Answer 6

True because some cells do not have the same response as the same receptors

Question 7

How long are hormones active in the blood?

Answer 7

60 to 90 minutes

Question 8

What three things happen to hormones in the bloodstream?

Answer 8

Bind with receptors, breakdown in liver/ kidney and other enzymes break down the hormones

Question 9

What are the classification of hormones?

Answer 9

Amino Acids (tyrosine and tryptophan- thyroid hormone)
Peptide Hormones (glycoproteins and small proteins)
Lipid Derivatives (eicosanoids - signaling inflammation and pain, steroids)

Question 10

There are nearly _____ orphan GPCR receptors

Answer 10

240

Question 11

What are common secondary messengers of GPCRs

Answer 11

cAMP/cGMP
Calcium

Question 12

Intracellular gene expression

Answer 12

hydrophobic
change cell immediately
steroids (turn on transcription factors - turns on osteoblasts)
thyroid hormone (turn on gene expression and cellular metabolism)

Question 13

Direct Communication

Answer 13

happens between two cells of the same type and the cells must be in extensive physical contact

Question 14

Paracrine Communication

Answer 14

when two cells communicate within the same/single tissue

Question 15

autocrine communication

Answer 15

when messages affect the same cells that secrete them, and the chemicals involved are autocrines

Question 16

endocrine communication

Answer 16

when the endocrine system uses chemical messengers (hormones) to relay information and instructions between cells in distant portions of the body

Question 17

synaptic communication

Answer 17

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