Intro To Endocrines

Question 1

Endocrine gland

Answer 1

Ductless gland

Pours secretions directly into the circulation to affect the target cells

Question 2

Glands with ducts

Answer 2

Exocrine glands

Question 3

Pancreas exocrine and endocrine part

Answer 3

Exocrine- digestive enzymes (acinar cells)
Endocrine- insulin and glucagon (islets of langerhans)

Question 4

Primary function of endocrine system

Answer 4

Produce hormones

Question 5

Other functions of endocrine system

Answer 5

Preserve homeostasis of minerals, enzymes (enzyme reactions), vitamins, hormones (active status)

Reproduction, growth development
Regulate internal environment- water balance, ions, temp
Stimulates growth
Initiation of stress response
Metabolism
Gene expression
Protein synthesis

Question 6

Neuroendocrine theory of aging

Answer 6

Altered biologic activity of hormones
Altered circulation levels of hormones
Altered secretory responses of endocrine glands
Altered metabolism of hormones
Loss of circadian control of hormone release

Question 7

Aging and endocrine disorders

Answer 7

Diabetes mellitus
Hypothyroidism

Atypical endocrine cell damage
Genetically programmed cell change
Chronic wear and tear
Alterations in responsiveness of target organs
Loss of self regulation leading to disorders

Question 8

Three types of hormones

Answer 8

Peptide/ protein hormones
Steroid hormones
Amino acid derived and amine hormones

Question 9

Peptide/ protein hormones

Answer 9

Hydrophilic or lipophobic

Water soluble to allow easy transport into bloodstream

Synthesized in ER

Need surface receptor to pass across lipid based cell membrane

May need a second messenger system to modify protein

Examples- insulin parathyroid hormone

Question 10

Steroid hormone

Answer 10

Derived from cholesterol (estradiol, androgens, cortisol, aldosterone)

Lipid soluble and can diffuse across the membrane

Move by diffusion, needs a protein carrier as not hydrophilic

Synthesized in adrenal cortex, and smooth ER

Examples- estrogen, androgen, cortisol

Question 11

Amino acid derived and amine hormones

Answer 11

Some act like peptide hormones, and some like a steroid hormones

Peptide hormones
-Catecholamines (Neurotransmitters)

Steroid hormones
- Thyroid hormones (tyrosine)

Question 12

Autocrine

Answer 12

Cells have receptors for their own secreted factors (itself)
liver regeneration

Question 13

Paracrine

Answer 13

Cells respond to secretion of nearby cells (neighbor)
Healing wounds

Question 14

Endocrine

Answer 14

Cells respond to factors (hormones) produced by distant cells
(Distant)

Question 15

Hypothalamus

Answer 15

Highest level of endocrine control

Neural and hormonal pathways
Integrates the nervous and endocrine systems

Question 16

How does the hypothalamus exert hormonal control?

Answer 16

Via hypothalamus pituitary axis

Releasing hormone stimulates synthesis, and secretion disorders
Inhibiting hormone’s prevent synthesis and secretion

Question 17

How is the anterior lobe connected to the hypothalamus?

Answer 17

Through hypophyseal portal venous blood

Question 18

How is the posterior lobe connected to the hypothalamus?

Answer 18

Axons descend from hypothalamus to the posterior lobe

Question 19

Parathyroid and medullar adrenal

Answer 19

Not influenced by pituitary hormones

Not part of the hypothalamus pituitary axis

Question 20

Anterior lobe/ adenohypophysis/ glandular tissue

Answer 20

Growth hormone/ somatotropin (peptide)
Thyroid stimulating hormone TSH (peptide)
Adrenocorticotropic hormone ACTH (peptide)
Prolactin PRL (peptide)
Gonadotropin FSH or LH (peptide)
Melanocyte stimulating hormone MSH (peptide)

Question 21

Posterior lobe/ neurohypophysis nervous tissue

Answer 21

Supraoptic nucleus
Paraventricular nucleus

ADH (antidiuretic hormone/ vasopressin)

Oxytocin
- Uterine contractions and milk ejection from the breast

Question 22

Positive and negative feedback regulation

Answer 22

Normal or increased activity of target glands (circulating hormones) have a negative feedback to the hypothalamus pituitary axis
- no releasing of factors, no hormone production

Diminished circulating hormones have a positive stimuli to hypothalamus to pituitary
- release factors for hormone production

Question 23

Synergism

Answer 23

Combined effect is greater than the sum of individual effects

Question 24

Permissiveness

Answer 24

Need a second hormone to get full effect

Question 25

Antagonism

Answer 25

Functional antagonism ( one substance opposes the action of another)

Competitive inhibitors (compete for the same receptor)

Glucagon opposes insulin

Question 26

Primary pathology due to what?

Answer 26

Issues with the last endocrine gland in pathway

Question 27

Secondary pathology due to what?

Answer 27

Pituitary gland

Question 28

Tertiary pathology due to what?

Answer 28

Hypothalamus

Question 29

Metabolic clearance rate

Answer 29

Rate of disappearance of the hormone (concentration of the hormone)

Metabolic destruction by tissues are degradation by the target cells
- Degradation is mainly by enzymes found in the liver or kidney

1. Binding with tissues
2. Excretion by liver into bile
3. Excretion by kidneys into the urine

Depends on half-life

Question 30

Primary hypersecretion

Answer 30

Due to problem with adrenal cortex

CRH- low
ACTH- low
cortisol- high

Question 31

Secondary hypersecretion

Answer 31

Due to pituitary problem

CRH- low
ACTH- high
Cortisol- high

Question 32

Tertiary hypersecretion problem

Answer 32

Due to hypothalamic problem

CRH- high
ACTH- high
Cortisol- high