Endocrine System

Question 1

What are the four homeoestatic parameters?

Answer 1

1. Blood pressure
2. Water levels
3. Temperature
4. pH

Question 2

What are the three basic classes of hormones?

Answer 2

1. Amino acid hormones: some are water soluble
2. Peptide hormones: all are water soluble
3. Lipid hormones: none are water soluble

Question 3

How is the effect lipid soluble hormones different than water soluble hormones

Answer 3

Lipid soluble hormones last longer and have a more perminant effect because they affect gene transcription

Question 4

Phosphate chemical forumla

Answer 4

PO₄^3-

Question 5

Which hormones are secreted directly from the posterior pituitary?

Answer 5

1. ADH (Antidiuretic hormone)
2. Oxytocin

Question 6

ADH (Antidiuretic hormone)

Answer 6

Trigger: Rise in electrolyte concentration or a fall in blood pressure

Released by: Neurosecretory neurons in the posterior pituitary

Effects:

1. Stimulates kidneys to reabsorb water
2. Peripheral vasoconstriction
3. Increased thirst

* suppressed by alcohol

Question 7

Oxytocin

Answer 7

Trigger: Childbirth, sex, breastfeeding

Released by: Neurosecretory neurons in the posterior pituitary

Effects: Smooth muscle contraction, increased bonding, letdown reflex

Question 8

Hypophyseal portal system

Answer 8

Blood enters the hypothalamus at the median eminence.

Question 9

Which hormone is secreted by the Pars Intermedia of the Pituitary gland?

Answer 9

MSH (Melanocyte stimulating hormone)

Question 10

Answer 10

Question 11

Adrenocorticotropic hormone

ACTH

Answer 11

Trigger: Corticotropin releasing hormone (CRH)

Released by: Anterior pituitary

Target: Adrenal Cortex

Effects: Secretion of glucocorticoids

Question 12

Thyroid releasing hormone

(TRH)

Answer 12

Trigger: Thyroid stimulating hormone (TSH)

Released by: Anterior pituitary

Target: Thyroid gland

Effects: Secretion of Thyroid hormones T3 and T4

Question 13

Growth Hormone

(GH)

Answer 13

Trigger: Growth hormone releasing hormone

Released by: Anterior pituitary

Target: Skeletal muscle, cartilage, bone, etc

Effects: Stimulation of growth

Question 14

Follicle Stimulating Hormone

(FSH)

Answer 14

Trigger: Gonadotropin releasing hormone (GnRH)

Released by: Anterior pituitary

Target: Gonads

Effects: Stimulation of follicle production (F) or spermatogenesis (M)

Question 15

Lutenizing Hormone

(LH)

Answer 15

Trigger: Gonadotropin releasing hormone (GnRH)

Released by: Anterior pituitary

Target: Gonads

Effects: Stimulation of corpus luteum production (F) or testosterone production (M)

Question 16

Prolactin

Answer 16

Trigger: Prolactin releasing hormone (PRH)

Released by: Anterior pituitary

Target: Mamary glands

Effects: Milk production

Question 17

Melanocyte stimulating hormone

(MSH)

Answer 17

Trigger: Unknown

Released by: Anterior pituitary (pars intermedia)

Target: Melanocytes

Effects: Production of melanin

Question 18

Colloid

Answer 18

proteins suspended in liquid

Question 19

What substance is found in the middle of thyroid follicles?

Answer 19

Colloid containing thyroglobulin

Where thyroid hormone is created and stored

Question 20

Thyroid Hormone

Answer 20

Trigger: TRH (Thyroid Releasing Hormone)

Released by: Thyroid Follicular cells

Target: Many

Effects:

• Increases ATP production by binding to mitochondrial receptors
• Activate synthesys of enzymes involved in energy utlilzation

Question 21

Calcitonin

Answer 21

Trigger: High blood Ca2+ levels

Released by: Thyroid C-cells

Target: Bones and kidneys

Effects: Lower blood Ca²⁺ by inhibiting osteoclasts and stimulating Ca²⁺ excretion by the kidneys

Question 22

Parathyroid hormone

Answer 22

Trigger: Low blood Ca²⁺ levels

Released by: Parathyroid glands

Target: Bones and kidneys

Effects: Increases blood Ca²⁺ levels by stimulating osteoclasts, inhibiting osteoblasts, increases reabsorption of Ca²⁺ in the kidneys

Question 23

Which hormones affect blood calcium levels?

Answer 23

1. Calcitriol absorb Ca²⁺ along digestive tract
2. Growth Hormone Stimulate osteoblasts
3. Thyroxine Stimulate osteoblasts (with GH)
4. Sex Hormones Stimulate osteoblasts
5. Parathyroid Hormones Stimulate osteoclasts, inhibit osteoblasts, kidneys
6. Calcitonin Stimulates osteoblasts, inhibit osteoclasts, kidneys

Question 24

Which enzyme oxadizes Iodine ions for the creation of thyroid hormone?

Answer 24

Thyroid Peroxidase

Question 25

Which enzyme catalyzes iodine to attach to the tyrosine on the thyroglobulin molecules?

Answer 25

Thyroid Perioxidase

Question 26

Which molecule binds T3 and T4 upon entry to the bloodstream?

Answer 26

Thyroid binding gobulins

Question 27

Thyroid binding globulins | (TBGs)

Answer 27

Made in the liver Bind T3 and T4 thyroid hormone to make it more water soluble for transport through the blood stream.

Question 28

What is the functional difference between T3 and T4 thyroid hormones?

Answer 28

More T4 is secreted. T3 is more active. Many tissues will convert T4 to T3 by removing an Iodine atom.

Question 29

Where are thyroid hormone receptors located in the cell?

Answer 29

In the nucleus. (Thyroid hormone crosses the cell membrane with the help of transport proteins.)

Question 30

Which category of hormone does thyroid hormone fall into?

Answer 30

amine hormones

Question 31

Which molicule stores thyroid hormone, and where is it stored?

Answer 31

Thyroglobulin stores thyroid hormone in the colloid-filled lumins of thyroid follicles

Question 32

Thyroid hormone structure

Answer 32

Question 33

What are the five layers of the adrenal gland?

Answer 33

1. Capsule - connective tissue outer layer 2. Zona glomerulosa (mineralocorticoids) 3. Zona fasciculata (glucocorticoids) 4. Zona reticularis (gonadocorticoids) 5. Adrenal medula (epinephrine / norepinephrine)

Question 34

Zona glomerulosa

Answer 34

Layer of the adrenal cortex that releases mineralocorticoids

Question 35

Zona fasciculata

Answer 35

Layer of the adrenal cortex that releases glucocorticoids

Question 36

Zona reticularis

Answer 36

Layer of the adrenal cortex that releases gonadocorticoids

Question 37

Adrenal medula

Answer 37

Most interior part of the adrenal gland Releases epinephrine and norepinephrine when stimulated by the sympathetic nervous system

Question 38

Mineralocorticoids

Answer 38

**Trigger:** Drop in blood Na⁺ or drop in blood pressure **Released by:** The Zona Glomerulosa in the adrenal cortex **Target:** Kidneys, sweat glands, salivary glands, pancreas **Effects:** Stimulates conservation of Na⁺ and elimenation of K⁺ **\*** Also increases sensitivity of salt receptors in the tongue

Question 39

Glucocorticoids

Answer 39

**Trigger:** Corticotropin releasing hormone (CRH) **Released by:** The Zona Fasciculata in the adrenal cortex **Target:** Many cells **Effects:** Increased glucose synthesis and glycogen formation, release fatty acid into blood, antiinflamitory

Question 40

Which hormones are glucocorticoids?

Answer 40

Cortisol and Corticosterone

Question 41

Gonadocorticoids

Answer 41

**Trigger:** Adrenocorticotropic Hormone (ACTH) **Released by:** The Zona Reticularis of the adrenal cortex **Target:** Many cells **Effects:** Secondary sex characteristic development, sex drive **\*** Mostly weak androgens, which are converted at their target cells, some estrogen

Question 42

Epinephrine / Norepinephrine

Answer 42

**Trigger:** Sympathetic nervous sytem activation **Released by:** The Adrenal Medula **Target:** Many cells **Effects:** Raise blood pressure & heartrate, peripheral vasoconstriction, dialate airways, limit digestion, etc

Question 43

Melatonin

Answer 43

**Trigger:** Light through optic nerve **Released by:** Pineal gland **Target:** The brain **Effects:** Sleepiness

Question 44

Which parts of the pancreas produce hormones?

Answer 44

The pancreatic islets

Question 45

Pancreatic α cells

Answer 45

Produce Glucagon

Question 46

Pancreatic β cells

Answer 46

Produce Insulin

Question 47

Glucagon

Answer 47

**Trigger:** Low blood sugar **Released by:** α cells in pancreas **Target:** The liver **Effects:** Break down glycogen to glucose, glucose synthesis, release of glucose by the liver

Question 48

Insulin

Answer 48

**Trigger:** High blood sugar **Released by:** β cells in pancreas **Target:** Skeletal muscle cells (among others) **Effects:** Enhances membrane transport of glucose, inhibits the breakdown of glycogen to glucose, inhibits glucose synthesis

Question 49

Which hormone do the kidneys secrete?

Answer 49

Erythropoietin

Question 50

Erythropoitein

Answer 50

**Trigger:** Low oxygen levels in the kidney **Released by:** Kidneys **Target:** Bone marrow **Effects:** Creation of more red blood cells

Question 51

Leptin

Answer 51

**Released by:** Adipose cells **Target:** Central Nervious System **Effects:** Stimulate increased energy expenderature, saity, permissive effect on puberty, mensturation?