Introduction to Endocrinology

Question 1

The multiple activities of the cells, tissues, and organs of
the body are coordinated by the interplay of several types
of chemical messenger systems:

Answer 1

1. neurotransmitter
2. endocrine hormones
3. neuroendocrine hormones
4. paracrine
5. autocrine
6. cytokines

Question 2

neurotransmitter

Answer 2

released by axon terminal into the synaptic junction and act on nerve cell function

Question 3

endocrine hormone

Answer 3

released by gland or specialized cell into the circulatory system act on target cells locally at a different location

Question 4

neuroendocrine hormone

Answer 4

released by neurons into the circulatory system act on target cellls locally at a different location in the body

Question 5

paracrine

Answer 5

released by cells into the ecf that act on neigbouting target cells of the same type

Question 6

autocrine

Answer 6

secreted by cells into the extracellular fluid and affect the function of the same cells
that produced them.

Question 7

cytokines

Answer 7

are peptides secreted by cells into the
extracellular fluid and can function as autocrines,
paracrines, or endocrine hormones. Examples of
cytokines include the interleukins and other lymphokines that are secreted by helper cells and act on
other cells of the immune system (see Chapter 35).
Cytokine hormones (e.g., leptin) produced by adipocytes are sometimes called adipokines

Question 8

adrenal medulla and pituatry gland secrete hormone cause?

Answer 8

they are stimulated by a nerve impulse

Question 9

neuroendocrine glands location and what do they release and etc?

Answer 9

present in hypothalamus have axons that terminate with posterior pituitary and median eminence and release hormones like antidiuretics hormone and oxytocin and hypophysiotropic hormones that control the secretions of anterior pituitary

Question 10

endocrine hormone funcions

Answer 10

released into circulatory system act on receptors on the target cells to initiate many chemical reactions

Question 11

examples of endocrine hormones

Answer 11

growth hormone (anterior pituitary) 
thyroxine (thyroid )

Question 12

adrenocorticotropic hormone

Answer 12

from the anterior pituitary gland specifically stimulates
the adrenal cortex, causing it to secrete adrenocortical
hormones and ovarian hormones

Question 13

a person would become sluggish in the absence of what hormone

Answer 13

thyroxine and triiodothyronine

Question 14

Proteins and polypeptides hormones

Answer 14

including hormones
secreted by the anterior and posterior pituitary
gland, the pancreas (insulin and glucagon), the
parathyroid gland (parathyroid hormone), and
many others

Question 15

steroids hormones

Answer 15

secreted by the adrenal cortex (cortisol and
aldosterone), the ovaries (estrogen and progesterone), the testes (testosterone), and the placenta
(estrogen and progesterone)

Question 16

Derivatives of the amino acid tyrosine,

Answer 16

secreted by
the thyroid (thyroxine and triiodothyronine) and
the adrenal medullae (epinephrine and norepinephrine). There are no known polysaccharides or
nucleic acid hormones.

Question 17

3 amino acid hormone example

Answer 17

thyrotropin releasing hormone

Question 18

200 amino acid hormone example

Answer 18

growth hormone and prolactin

Question 19

how protein and peptide hormones are synthesized

Answer 19

Protein and peptide hormones are synthesized on the rough end of the endoplasmic reticulum of the different endocrine cells, in the same fashion as most other proteins. They are usually synthesized first as larger proteins that are not biologically active (preprohormones) and are cleaved to form smaller prohormones in the endoplasmic reticulum. These prohormones are then transferred to the Golgi apparatus for packaging
into secretory vesicles. In this process, enzymes in the vesicles cleave the prohormones to produce smaller, biologically active hormones and inactive fragments. The vesicles are stored within the cytoplasm, and many are bound to the cell membrane until their secretion is
needed. Secretion of the hormones (as well as the inactive fragments) occurs when the secretory vesicles fuse with the cell membrane and the granular contents are extruded into the interstitial fluid or directly into the blood stream by exocytosis.

Question 20

stimulus for exocytosis for hormones

Answer 20

increased ca concentration and depolarization of plasma membrane
or increase cAMP and protein kinase concentration

Question 21

steriod hormone storage and production

Answer 21

made by cholesterol

3 cyclohexyl ring and 1 cyclopentyl ring combined into one structure

Question 22

Amine Hormones Are Derived From Tyrosine

Answer 22

The
two groups of hormones derived from tyrosine, the
thyroid and the adrenal medullary hormones, are formed
by the actions of enzymes in the cytoplasmic compartments of the glandular cells

Question 23

production and release of thyroid gland

Answer 23

The thyroid hormones are
synthesized and stored in the thyroid gland and incorporated into macromolecules of the protein thyroglobulin, which is stored in large follicles within the thyroid gland. Hormone secretion occurs when the amines are split from thyroglobulin, and the free hormones are then released into the blood stream. After entering the blood,
most of the thyroid hormones combine with plasma proteins, especially thyroxine binding globulin, which slowly
releases the hormones to the target tissues.

Question 24

epinephrine and norepinephrine

Answer 24

Catecholamines are taken up into preformed vesicles and stored until secreted. Similar to the protein hormones stored in secretory granules, catecholamines are also released from adrenal medullary cells by exocytosis. Once the catecholamines enter the circulation, they can exist as free form or conjugated

Question 25

Negative Feedback Prevents Overactivity of Hormone | Systems.

Answer 25

once the hormone is released the negative feedback control makes sure the hormone is not oversecreted it occurs in all levels like gene transcription, translation steps in synthesizing hormones steps involved in processing or storing hormones or could be the activity of the target tissues

Question 26

positive feedback occurs in what hormones

Answer 26

lutenizing hormone that acts on the ovaries to release estrogen which causes more secretion of LH

Question 27

water soluble hormones transportation

Answer 27

like peptides and catecholamines are dissolved the the plasma transported from the site of sythynsis and released from the capillaries into the interstitial fluid at the target site

Question 28

steroid hormone thyroid transportation

Answer 28

circulate in the blood while being mainly bound to plasma proteins. Usually less than 10 percent of steroid or thyroid hormones in the plasma exist free in solution. For example, more than 99 percent of the thyroxine in the blood is bound to plasma proteins. However, protein-bound hormones cannot easily diffuse across the capillaries and gain access to their target cells and are therefore biologically inactive until they dissociate from plasma proteins.

Question 29

Two factors can increase or decrease the concentration of a hormone in the blood

Answer 29

rate of hormone released and rate of hormone cleared from the plasma (METABOLIC CLEARANCE RATE)

Question 30

METABOLIC CLEARANCE RATE is measured by

Answer 30

the rate of disappearance of hormone | over the concentration of hormone

Question 31

hormones are cleared from the plasma in several ways

Answer 31

metabolic destruction by tissues binding with the tissues excretion by liver into bile excretion by kidneys into urine

Question 32

excessive steroid hormones are when

Answer 32

liver is diseases because sterioid hormes are conjugated in the liver and secreted in bile

Question 33

Hormones are sometimes degraded at their target cells

Answer 33

by enzymatic processes that cause endocytosis of the cell membrane hormone-receptor complex; the hormone is then metabolized in the cell, and the receptors are usually recycled back to the cell membrane.

Question 34

Most of the peptide hormones and catecholamines are water soluble and circulate freely in the blood. They are usually degraded

Answer 34

by enzymes in the blood and tissues and rapidly excreted by the kidneys and liver, thus remaining in the blood for only a short time. For example, the halflife of angiotensin II circulating in the blood is less than a minute.

Question 35

Hormones that are bound to plasma proteins are | cleared from the blood

Answer 35

at much slower rates and may remain in the circulation for several hours or even days. The half-life of adrenal steroids in the circulation, for example, ranges between 20 and 100 minutes, whereas the half-life of the protein-bound thyroid hormones may be as long as 1 to 6 days.

Question 36

In or on the surface of the cell membrane receptor hormones

Answer 36

e. The membrane receptors are specific mostly for the protein, peptide, and catecholamine hormones

Question 37

. In the cell cytoplasm receptor hormones

Answer 37

sterioids

Question 38

In the cell nucleus receptor hormones

Answer 38

The receptors for the thyroid hormones are found in the nucleus and are believed to be located in direct association with one or more of the chromosomes

Question 39

hormones effects its target tissue by

Answer 39

forming a hormone target complex

Question 40

hormones that use receptor tyrosine kinase signaling

Answer 40

``` fibroblast growth factor insulin insulin like growth factor 1 lectin prolactin growth hormone vascular endothelial growth factor ```

Question 41

Intracellular Hormone Receptors and Activation of | Genes.

Answer 41

hormones are steroid hormones, thyroid hormones, adrenal and cortical hormones vitamin d attaches to the receptors that are inside the cell and then combine with hormone response element and eother activates or represses the transcription of genes or making of mrna

Question 42

hormoes exert intercellular actions by

Answer 42

activating cAMP which is the second messenger and it does the rest of the work

Question 43

examples of other second messenger

Answer 43

caclium- calmodulin | and products of membrane phopholipid breakdown

Question 44

sterioid hormones increase

Answer 44

protein production

Question 45

steps takes by steroid hormone in protein production

Answer 45

1. The steroid hormone diffuses across the cell membrane and enters the cytoplasm of the cell, where it binds with a specific receptor protein. 2. The combined receptor protein–hormone then diffuses into or is transported into the nucleus. 3. The combination binds at specific points on the DNA strands in the chromosomes, which activates the transcription process of specific genes to form mRNA. 4. The mRNA diffuses into the cytoplasm, where it promotes the translation process at the ribosomes to form new proteins.

Question 46

thyroid hormone increase

Answer 46

gene transcription