Chapter 18 Flashcards

1
Q

Exocrine glands

A

Secrete their products into ducts that carry the secretions into body cavities, the lumen of an organ, or the outer surface of the body

include sweat glands, oil glands, mucus, and digestive glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Endocrine glands

A

Secrete their products into the interstitial fluid surrounding the secretory cells rather than into ducts who then diffuse into blood capillaries then blood carries them to target cells throughout the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the endocrine glands include?

A

Pituitary, thyroid, parathyroid, adrenal and pineal glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Down-regulation

A

If a hormone is present in excess the number of target cell receptors decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Up regulation

A

When a hormone is deficient the number of receptors may increase

making the target cell more sensitive to a hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What other organs can secrete hormones?

A

Hypothalamus
thymus
pancreas
ovaries
testes
kidneys
stomach
liver
small intestine
skin
heart
adipose tissue
placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Circulating hormones

A

Pass from the secretory cells that make them into interstitial fluid and then into the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Local hormones

A

Act locally on neighbouring cells or on the same cell that secreted them without entering the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Paracrines

A

Local hormones that act on neighbouring cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Autocrines

A

Hormones that act on the same cell that secreted them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three lipid soluble hormones?

A
  1. Steroid hormones
  2. Thyroid hormones
  3. Nitric oxide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Steroid hormones are derived from what?

A

Cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is synthesized by attaching iodine to the amino acid tyrosine?

A

Thyroid hormones T3 and T4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What lipid soluble hormone is both a hormone and a neurotransmitter?

A

Nitric oxide (NO)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the three water soluble hormones?

A
  1. Amine hormones
  2. Peptide and protein hormones
  3. Eicosanoid hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are Amine hormone synthesized?

A

By decarboxylating and otherwise modifying certain amino acids they are called amines because they retain an amino group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some examples of peptide hormones and protein hormones?

A

Peptide: antidiuretic and oxytocin
Protein: Growth hormone and insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What’s an example of Glycoprotein hormones?

A

Thyroid stimulating hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two major types of Eicosanoids?

A

Prostaglandins and leukotrienes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do water soluble hormone molecules circulate in the blood plasma?

A

In a “free” form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do you lipid soluble hormone molecules move through the blood?

A

Via transport proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the three functions of the transport protein?

A
  1. They make lipid soluble hormones temporarily water soluble thus increasing their solubility in blood
  2. They retard passage of small hormone molecules through the filtering mechanism in the kidneys thus slowing the rate of hormone loss in the urine
  3. They provide a ready reserve of hormone already present in the bloodstream
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Free fraction

A

The .1 to 10% of the molecules of lipid soluble hormones that are not bound to a transport protein that diffuse out of capillaries, bind to receptors and trigger responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

First messenger

A

When a water soluble hormone binds to its receptor at the outer surface of the plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Second messenger
The first messenger causes production of the second messengers inside the cell where specific hormone stimulated responses take place
26
What is a common second messenger?
Cyclic adenosine monophosphate
27
Permissive affect
When a hormone will only work if there was Recent exposure from a second hormone
28
Synergistic effect
When the effect of two hormones acting together is greater than the sum of their individual effects
29
Antagonistic effects
When one hormone opposes the actions of another hormone the two hormones have an antagonistic effect
30
Control of hormone secretion
The release of most hormones occurs in short bursts with little or no secretion between bursts when stimulated an endocrine gland will release its hormone in more frequent bursts increasing concentration of the hormone in the blood
31
What are the three things hormone secretion is regulated by?
1. Signals from the nervous system 2. Chemical changes in the blood 3. Other hormones
32
What are the other words and terms for pituitary gland?
Hypophysis and “master” endocrine gland
33
What gland controls the “master” gland?
Hypothalamus
34
Infundibulum
Stalk connecting the hypothalamus and pituitary
35
Anterior pituitary
Also called adenohypophysis 75% of glands weight Made of epithelial tissue Two parts: pars distalis and pars tuberalis
36
Posterior pituitary
Also called neurohypophysis Made of neural tissue Two parts: pars nervosa and pars intermedia
37
What are the five anterior pituitary cells?
1. Somatrophs 2. Thyrotrophs 3. Gonadotrophs 4. Corticotrophs 5. Lactotrophs
38
Somatrophs secrete what hormones?
Growth hormone and somatropin
39
Thyrotrophs secret what hormone?
Thyroid-stimulating hormone
40
Gonadotrophs secret what hormone?
Follicle stimulating hormone and lutenizing hormone
41
Lactotrophs secrete what hormone?
Prolactin
42
Corticotrophs secret what hormone?
Adrenocorticotropic hormone (ACTH)/ corticotropin and melanocyte stimulating hormone (MSH)
43
What is prolactin inhibiting hormone?
Dopamine
44
What is growth hormone inhibiting hormone?
Somatostatin
45
Hypophyseal portal system
Blood flows from capillaries in the hypothalamus into portal veins that carry blood to capillaries of the anterior pituitary Allows communication between hypothalamus and anterior pituitary Link between nervous system and endocrine system
46
Superior hypophyseal arteries
Branches of the internal carotid arteries bring blood into the hypothalamus at the junction of the median eminence of the hypothalamus and the infundibulum and divide into a Capillery network called the primary plexus of the hypophyseal portal system
47
Neurosecretory cells
Clusters of neurons above the optic Chiasm
48
Tropic hormones
Anterior pituitary hormones that act on other endocrine glands
49
How does GH exert its growth promoting affects indirectly through small protein hormones?
With insulin-like growth factors (IGFs) / somatomedins
50
What are the specific functions of insulin like growth factors(IGFs)?
1. Increase growth of bones and soft tissues 2. Enhance lipolysis 3. Decrease glucose uptake
51
How is growth hormone regulated by GHRH and GHIH?
1. GHRH is secreted by the hypothalamus. Due to Hypoglycemia, decrease blood levels of fatty acids, increase blood levels of amino acids, deep sleep, increased activity of the sympathetic nervous system, and other hormones including testosterone, estrogen, thyroid, hormones and ghrelin 2. Once secreted, GHRH enters the hypophyseal portal system and flows to the anterior pituitary where it stimulates somatotrophs to secrete GH 3. GH Acts directly on various cells to promote certain metabolic reactions in liver, bone, skeletal muscle, and cartilage GH is converted to IGF’s which intern promote growth of bone, skeletal muscle, and other tissues 4. Elevated levels of GH and IGFs inhibit release of GHRH and GH 5. GHIH is secreted by the hypothalamus 6. GHIH enters the hypophyseal portal system and flows to the anterior pituitary where it prevents the somatotrophs from secreting GH by interfering with the signaling pathway used by GHRH
52
Adrenocorticotropic hormones
Secreted by Corticotrophs Controls the production and secretion of cortisol and other glucocorticoids by the cortex of the adrenal glands
53
Stored hormones In posterior pituitary?
Oxytocin and anti diuretic
54
Thyroid gland
Composed of right and left lobes connected by the Isthmus, anterior to the trachea Made of thyroid follicles, follicular cells, and a basement membrane Produces thyroxine and triiodothyronine Paraflicular cells produce calcitonin
55
Steps for synthesis and secretion of t3 and t4?
1. Iodide trapping 2. Synthesis of thyroglobulin 3. Oxidation of iodide 4. Iodination of tyrosine 5. Coupling of t1 and t2 6. Pinocytosis and digestion of colloid 7. Secretion of thyroid hormones 8. Transport in the blood
56
Functions of thyroid hormones?
1. Increase basal metabolic rate 2. Enhance actions of catecholamines 3. Regulate development and growth of nervous tissue and bones
57
Calcitonin
Produced by parafollicular cells of the thyroid gland Decrease the level of calcium in the blood by inhibiting the action of osteoclast
58
Parathyroid gland
One superior and one inferior the parathyroid glands are attached to each lateral thyroid lobe =4 Chief cells produce parathyroid hormone Oxyphil cells don’t produce anything normally
59
Parathyroid hormone
Major regulator of calcium, magnesium and phosphate levels Elevate bone resorption Slows the rate at which calcium and magnesium are lost from the blood into the urine increases loss of HPO 42- Promote formation of calcitriol
60
Adrenal glands
Superior to each kidney Consists of adrenal cortex and adrenal medulla Produces steroid hormones: Norepinephrine, epinephrine, dopamine
61
Adrenal cortex
Zona glomerulosa: mineralcorticoids Zona fasciculata: glucocorticoids Zona reticularis: androgens
62
Mineralcorticoids
Aldosterone Regulates homeostasis of sodium ions and potassium ions and also promote excretion of hydrogen ions in the urine
63
The renin angiotensin-aldosterone (RAA) pathway That controls secretion of aldosterone
1. Stimuli that initiate the renin angiotensin aldosterone pathway include dehydration, sodium deficiency, or haemorrhage 2. These conditions cause a decrease in blood volume 3. Decrease blood volume leads to decrease blood pressure 4. Lower blood pressure stimulate certain cells of the kidneys call juxtaglomerular cells to secret the enzyme renin 5. Renin in blood increases 6. Renin converts angiotension a plasma protein produced by the liver into angiotension 1 7. Blood containing increase levels of angiotension one circulates in the body 8. As blood flows through capillaries particularly those of the lungs the enzyme angiotensin-converting enzyme converts angiotension one into the hormone angiotension two 9. Blood level of angiotension 2 increases 10. Angiotension two stimulates the adrenal cortex to secrete aldosterone 11. Blood containing increase levels of aldosterone circulates to the kidneys 12. In the kidneys aldosterone increases reabsorption of sodium which in turn causes reabsorption of water by osmosis as a result less water is lost in the urine aldosterone also stimulates the kidneys to increase the secretion of potassium and hydrogen into the urine 13. Increased water reabsorption by the kidneys, blood volume increases 14. As blood volume increases blood pressure increases to normal 15. Angiotension 2 also stimulates contraction of smooth muscle in the walls of arterrials the resulting vaso construction of the materials increases blood pressure and thus helps raise blood pressure to normal
64
Effects of glucocorticoids?
1. Protein breakdown 2. Glucose formation 3. Lipolysis 4. Resistance to stress 5. Anti-inflammatory 6. Depression of immune responses
65
Androgens
Testosterone and estrogen
66
Adrenal medulla
Hormone producing cell called chromaffin cells synthesize epinephrine and norepinephrine
67
Pancreas
Cells called acini that produce digestive enzymes With clusters of pancreatic islets
68
Cells types of the pancreatic islets
1. Alpha/ A cells produce glucagon 2. Beta/ B cells produce insulin 3. Delta/ D cells somatostatin 4. F cells secret pancreatic polypeptide
69
Insulin secretion is also stimulated by
1. Acetylcholine the neurotransmitter liberated from axon terminals 2. Amino acids arginine and Lusine which would be present in the blood at higher levels after a protein containing meal 3. Glucose dependent insulinotropic peptide
70
Glucagon is stimulated by
Increase activity of a sympathetic division of the ANS A rise in blood amino acid if blood glucose level is low