Endocrine Function I Flashcards Preview

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Flashcards in Endocrine Function I Deck (39):
1

5 basic functions of hormones

1. Maintenance of consistency of chemical composition of extra and intracellular fluids
2. Regulation of growth and development of the body, plus development of male and female sex characteristics
3. Promotion of sexual maturation, maintenance of sexual rhythms and facilitation of the reproductive process
4. Regulation of energy production; stabilization of the metabolic rate; tight regulation of salt, water, CHO, fat, and protein metabolism
5. Helping the body adjust to stress

2

3 major classes of hormones

Protein
Steroid
Amino Acid Derivatives

3

Protein:
- its specific chemical composition

amino acid chains (water soluble, travel through bloodstream without carrier)

4

Protein:
- examples

All "P" organs: Pituitary, hyPothalamus, Parathyroid, Portions of the GI tract, and Pancreas

5

Protein:
Mechanism of action

These (along with catecholamines or protein-bound hormones), effect their cellular action by binding to cellular receptors. They need a "second messenger" to pass their cellular message to interior of cell.

6

Why is a second messenger necessary?

The first messenger is the protein polypeptide, or catecholamine hormone itself, because it is not lipid-soluble, it cannot pass through the membrane.

7

The second messenger is _____ ______, formed by adenyl cyclase catalysis

cyclic AMP (cAMP)

8

Steroid Hormone:
- derivation

derived from cholesterol

9

Steroid Hormone:
- What is the nucleus for all steroid hormones

Perhydrocyclopentanophenanthrene

10

Steroid Hormone:
- They are hydrophobic and require ____ _____ to be transported in blood. Must dissociate from carrier to be biologically active; the ______ hormone is biologically active

Carrier Proteins
FREE

11

Steroid Hormone:
- Metabolism

They must be catabolized by liver to water-soluble, inactive forms. Hydroxylation, Oxidation, or reaction with glucuronic acid or sulfate forms conjugates, which are excreted in urine

12

Steroid Hormone
- mechanism of action

Lipid-soluble so pass through cell membrane, then they associate with a specific cytoplasmic receptor protein. This is transported to cell nucleus, inducing messenger RNA synthesis

13

Aromatic Amine Hormones are small molecules derived from the amino acid ________

tyrosine

14

Aromatic Amine Hormones:
- examples

Includes both thyroid hormones and catecholamines hormones from the adrenal medulla

15

Aromatic Amine Hormone:
- Are ______-_______ and require carrier proteins, principally albumin, for transport in bloodstream

water-insoluble

16

Aromatic Amine Hormone:
- Catabolism and excretion

Catabolized in liver by deiodination or oxidation to inactive forms to be excreted

17

Aromatic Amine Action:
- Thyroid Hormones use what pathway to enter the cell?

mRNA pathway

18

Aromatic Amine Action:
- Catecholamines use what pathway to enter the cell?

use the second messenger (cAMP) pathway

19

ESSAY: What is the importance of feedback mechanisms?

without feedback, homeostasis is not maintained and person gets "sick"

20

ESSAY: Explain negative feedback

When you have too much final product, you send signals to the first and second steps to tell them not to produce any more stimuli.

21

ESSAY: Explain positive feedback

Usually in pregnancy, keep producing estrogen: increase estrogen -> increase in FSH/LH -> increase in feedback -> increase in estrogen

22

What does the hypothalamus synthesize from specialized neurosecretory cells?

neurocrine polypeptide releasing factors

23

What is the interaction of hypothalamic releasing factors and anterior pituitary hormones

The hypothalamus can produce releasing AND inhibiting factors that will work on the anterior pituitary to produce more hormones.

24

Antierior pituitary produces either trophic or direct-acting hormones. How do they elicit their effects on the target organ?

Trophic: stimulate another endocrine gland to manufacture a second hormone that affects metabolism
Direct acting: elicit effects directly one the target organ

25

What does the posterior pituitary do?

stores and releases (does NOT manufacture) hypothalamic hormones

26

What are the two hormones that posterior pituitary stores?

ADH (vasopressin) and Oxytocin

27

General causes of primary hormonal dysfunctional states

involves the target organ producing hormone

28

General causes of secondary hormonal dysfunctional states

generally involves the trophic hormone produced at the pituitary level

29

General causes of tertiary hormonal dysfunctional states

generally involves the releasing factors produced at the hypothalamic level

30

What is the clinical usefulness of baseline level tests?

Randomly drawn specimen that reveals hyper- or hypo function, but does not reveal the mechanism or level of dysfunction

31

What is the clinical usefulness of stimulation tests?

Used to assess a HYPOFUNCTIONING endocrine organ; useful in determining the reserve capacity of an endocrine organ to produce hormone

32

What is the clinical usefulness of suppression tests?

used to assess a HYPERFUNCTIONING endocrine organ; useful in pinpointing the level of dysfunction

33

Primary Hyperpituitarism:
- hormone involved in the most common dysfunction

Prolactin-secreting adenoma is the most common

34

Primary Hyperpituitarism:
- time frame in which growth hormone dysfunction causes acromegaly and gigantism

Giganism: too much growth before growth plate or long bones seal (childhood)
Acromegaly: after closure so growth of cartilage areas (later on in life)

35

Most common cause of secondary hyperpituitarism `

neurogenic tumors of the hypothalamus

36

Two common causes associated with panhypopituitarism

Hemorrhages and tumors are most common causes

37

Typical hormone levels associated with panhypopituitarism

Onset is gradual with initial loss of GH, LH, and FSH, followed by TSH, ACTH, and finally PRL

38

Disease state associated with a deficiency of antidiuretic hormone

diabetes insipidus

39

Disease state associated with a excess of antidiuretic hormone

SIADH