Endocrine System

Question 1

Be able to compare and contrast a simple neural reflex vs. neuroendocrine reflex.

Answer 1

Both-work through afferent neurons taking signals to the spinal cord then to target tissue:
-Simple-target tissue is directly innervated
-Neuroendocrine-release of neurohormone acts on distant cells

Question 2

Define “hormone” (classical understanding)

Answer 2

Chemical substances produced by ductless glands and secreted into the blood supply to affect a tissue distant from the gland.

Question 3

Define “hormone” (current understanding)

Answer 3

Hormones can be produced by single cells as well.
May not enter the bloodstream or target distant cells.

Question 4

Be able to list and describe the 5 types (6 given) of hormone modes of transmission.

Answer 4

-Epicrine
-Paracrine
-Endocrine
-Exocrine
-Neurocrine
-Autocrine

Question 5

Epicrine

Answer 5

Hormones pass through gap junctions of adjacent cells without entering extracellular fluid

Question 6

Paracrine

Answer 6

Hormones diffuse through interstitial fluid

Question 7

Endocrine

Answer 7

Hormones are delivered via the bloodstream

Question 8

Exocrine

Answer 8

Chemical substance is secreted to exterior of the body or into the digestive tract

Question 9

Neurocrine

Answer 9

-Hormones pass through synaptic clefts between neurons as do neurotransmitters
-Hormones can also be synthesized in a neuron and secreted directly into the blood from the axon

Question 10

Autocrine

Answer 10

Hormone is produced by a cell and acts on itself

Question 11

Be able to list the 4 biochemical categories of hormones.

Answer 11

-Amines
-Peptides
-Steroids
-Prostaglandins

Question 12

Amines

Answer 12

-Thyroid hormones
-Adrenal catecholamines

Question 13

Peptides

Answer 13

-Growth hormone (GH)
-Prolactin (PRL)
-Luteinizing hormone (LH)

Question 14

Steroids

Answer 14

-Estradiol (E2)
-Testosterone (T)
-Cortisol
-Progesterone

Question 15

Prostaglandins

Answer 15

PGF2

Question 16

Know some examples of pharmaceuticals that are administered to animals to control reproduction (names and what they mimic).

Answer 16

-Cystorelin & Factrel
-ECP
-Folltropin-V

Question 17

Cystorelin & Factrel

Answer 17

Affects Gonadotropin releasing hormone (GnRH)

Question 18

ECP

Answer 18

Affects estradiol

Question 19

Folltropin-V

Answer 19

Affects Follicle stimulating hormone (FSH)

Question 20

Know the “borders” of the hypothalamus in the brain.

Answer 20

-Anteriorly by the optic chiasma
-Posteriorly by the mammillary bodies
-Dorsally by the thalamus
-Ventrally by the sphenoid bone

Question 21

Know what the Sella Turcica is.

Answer 21

-The bony recess at the base of the brain
-Space created by the sphenoid bone

Question 22

Surge Center

Answer 22

-Releases Gonadotropin releasing hormone (GnRH)
-MALES DO NOT HAVE ONE

Question 23

Tonic Center

Answer 23

Releases Gonadotropin releasing hormone (GnRH)

Question 24

Be able to provide one example of a releasing hormone that comes from the hypothalamic neurons.

Answer 24

Gonadotropin releasing hormone (GnRH)

Question 25

Know the embryonic origin of the anterior vs. posterior pituitary gland.

Answer 25

-Posterior pituitary: Originates from the diencephalon (from the brain)
-Anterior pituitary: Originates from Rathke’s pouch (roof of the mouth)

Question 26

Hypothalamic regulation of the anterior pituitary.

Answer 26

-Hypothalamo-Hypophyseal Portal System
~Vein draining in the hypothalamus breaks up into a capillary bed within the anterior pituitary.
~Route by which releasing factors from the hypothalamus travel to cause release of hormones from the anterior pituitary

Question 27

Hypothalamic regulation of the posterior pituitary.

Answer 27

-Action potentials generated by the need for each of the stored hormones
-causes release of the substance into the blood supply.
-Neurons from specific nuclei extend into the posterior lobe where neurohormones are released into a simple arteriovenous capillary plexus.

Question 28

Be able to list the hormones synthesized/secreted by the posterior pituitary.

Answer 28

-ADH
-Oxytocin

Question 29

Know the embryonic origin of the anterior vs. posterior pituitary gland.

Answer 29

-Posterior pituitary: Originates from the diencephalon (from the brain)
-Anterior pituitary: Originates from Rathke’s pouch (roof of the mouth)

Question 30

Know what the Hypothalamo-Hypophyseal Portal System is and how it is involved in the release of hormones from the anterior pituitary

Answer 30

-The portal system is a complex of blood vessels within the stalk region
-The portal system carries hypothalamic hormones specifically to the anterior pituitary without dilution in the systemic blood: Allows rapid response and Little dilution of peptide hormones (peptide hormones have short half life)

Question 31

Know the 3 parts of the anterior pituitary gland.

Answer 31

-Pars distalis
-Pars intermedia: melanocyte stimulating hormone
-Pars tuberalis

Question 32

Know the 5 cell types of the principal part of the anterior pituitary and the hormone(s) synthesized/secreted by each.

Answer 32

-Somatotropes: Growth hormone (GH)
-Corticotropes: Corticotropin releasing hormone
-Mammotropes: Prolactin (PRL)
-Thyrotropes: Thyroid stimulating hormone (TSH)
-Gonadotropes: Follicle stimulating hormone (FSH)
and Luteinizing hormone (LH)