Chapter 11 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are Hormones?

A

Chemical Messengers secreted by endocrine glands or tissues into the blood. Travel everywhere blood goes but they only affect “Target Cells” (Cells with receptors)

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

What is the Endocrine System?

A

Composed of the glands and cells that secrete hormones.

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

What does the Endocrine System help regulate?

A
  • Growth and Development
  • metabolism and H2O balance
  • Reproduction and stress responses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Endocrinology?

A

The study of the Endocrine System and the diagnosis and treatment of its disorders

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

What is the difference between Endocrine and Exocrine Glands?

A

Exocrine Glands –> Release their secretions to a tissue surface by way of ducts

Endocrine Glands –>Ductless and release their secretions into the blood

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

What are the differences between the Endocrine System and the Nervous System?

A

Endocrine System: Communicates by chemical signals only; Slower to respond and stop to a stimulus, Hormones go everywhere the blood goes, adapts relatively slowly, sometimes widespread affects

Nervous System: Communicates by chemical and electrical signals, responds and stops quickly to stimulus, Targets a specific organ, adapts quickly, and usually has local effects.

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

What do the Nervous System and Endocrine System have in common?

A
  • Some chemicals such as Norepinephrine and dopamine function as hormones and neurotransmitters
  • Some hormones are secreted by specialized neurons called neuroendocrine cells which functionally belong to both the endocrine and nervous system.
  • Hormones and neurotransmitters may have similar effects on the same target cells (e.g. norepinephrine and glucagon on liver)
  • Neurons sometimes trigger hormone secretion
  • Some hormones may stimulate or inhibit neurons
  • Regulate each other
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hormones are classified into 3 groups based on _______?

A

Structure

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

What are the 3 groups of Hormones

A

1) Steroid Hormones –> Lipids synthesized from cholesterol, and share its basic structure of 4 organic rings with varied side groups. (e.g. Testosterone and estradiol)
2) Monoamines –> Small molecules synthesized from the amino acids tyrosine and tryptophan. (e.g. Thyroxine and epinephrine)
3) Peptide Hormones –> Chains ranging from 3 to more than 200 amino acids long; ones with 50 or more amino acids or longer are considered proteins and some glycoproteins (proteins with a carbohydrate attached); Oxytocin is a small peptide hormone; insulin is a protein.

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

Peptide hormones and most monoamines are ________? (Hydrophobic or Hydrophilic?)

A

Hydrophilic, unable to pass into target cell

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

Steroid Hormones are _____? (Hydrophobic or Hydrophilic)

A

Hydrophobic, readily pass into cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What Hormone type Transcribes Genes?

A

Steroid Hormones

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

What kind of feedback control does hormonal control rely and what would be an example?

A

Negative Feedback - Blood Glucose regulation

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

What 2 organs usually take up Hormone Clearance via degradation or excretion?

A

Liver and Kidneys

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

What is an example of a hormone that is removed quickly?

A

Growth Hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an example of a hormone that stays in blood longer?

A

Thyroid Hormone

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

The Hypothalamus is attached to the posterior pituitary by the _________?

A

Infundibulum

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

What does the Hypothalamic Nuclei do?

A
  • Synthesizes Oxytocin and antidiuretic hormone

- Transport down fibers for storage in posterior pituitary (sends electrical signals to stimulate release)

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

What is the pituitary gland?

A
  • Important link in the neural and hormonal regulation of homeostasis
  • It is an endocrine gland controlling multiple body functions
  • Also known as the “Hypophysis”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The Pituitary gland is small but grows how much larger during pregnancy?

A

50%

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

How is the Pituitary Gland divided?

A

Anterior –> Develops from a pouch in the roof of the embryonic Pharynx (Throat).

Posterior –> Arises as a down-growth from the hypothalamus and retains its connection to the brain throughout life

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

What is the Hypophyseal Portal System?

A

Network of small blood vessels which connects the Hypothalamus to the Anterior Pituitary Gland. The Hypothalamus secretes chemical signals into the capillaries at its end of the portal system; these signals travel a short distance to the anterior pituitary. Here they leave the bloodstream through a 2nd capillary network and tell the anterior pituitary what to do.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The Hormones synthesized by the anterior pituitary gland are?

A

Peptide Hormones

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

What are the 6 Hormones Synthesized by anterior pituitary gland?

A

1) Follicle-Stimulating Hormone (FSH)
2) Luteinizing Hormone (LH)
3) Thyroid-Stimulating Hormone (TSH) - AKA Thyrotropin
4) Adrenocorticotropic Hormone (ACTH) - AKA Corticotropin
5) Prolactin (PRL)
6) Growth Hormone (GH) - AKA Somatotropin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is FSH?

A

Follicle-Stimulating Hormone

  • Stimulates maturation of follicles containing eggs
  • stimulates follicles to secrete estrogen
  • helps regulate ovarian and menstrual cycles
  • in males, stimulates production of sperm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is LH?

A

Luteinizing Hormone

  • Stimulates ovulation in females (The follicle left behind after ovulation develops into a yellowish structure called corpus luteum)
  • Stimulates corpus lutem to secrete progesterone (Maintains lining of uterus during pregnancy)
  • Stimulates testes to secrete testosterone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is TSH?

A

Thyroid-Stimulating Hormone

  • Stimulates Thyroid gland to secrete thyroid hormone (necessary for regulation of metabolism)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is ACTH?

A

Adrenocorticotropic Hormone

  • Stimulates adrenal cortex to secrete hormones called “Glucocorticoids” which are important in glucose, fat and protein metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is PRL?

A

Prolactin

  • Stimulates mammary glands to secrete milk
  • In males, it makes testes more sensitive to LH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is GH?

A

Growth Hormone

  • Promotes Tissue Growth by mobilizing energy from fat, raising levels of calcium and other electrolytes, and stimulating protein synthesis, mitosis, and cellular differentiation
  • Has widespread effects on the body and are most conspicuous during childhood and adolescence, but important for tissue maintenance and repair throughout life.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The posterior pituitary gland stores and releases 2 small hormones produced by the hypothalamic nuclei, what are they?

A

1) Oxytocin (OT)

2) Antidiuretic Hormone (ADH) - AKA Vasopressin

32
Q

What is OT?

A

Oxytocin

  • Stimulates Uterine smooth muscle (leads to contractions during labor and delivery; synthetic form sometimes given to induce labor)
  • Targets cells in Mammary glands (causes milk to flow to nipple)
  • Surges during sexual arousal and orgasm (may help transport sperm and play a role in emotional bonding)
33
Q

What is ADH?

A

Antidiuretic Hormone

  • Similar structure to Oxytocin
  • Regulates fluid balance by stimulating kidneys to retain H2O and stimulate kidneys to reduce urine output.
34
Q

What does Alcohol do to ADH release?

A

It inhibits it, which partially explains the increased urine production when one drinks alcohol.

35
Q

Where is the Pineal Gland located?

A

attaches to the roof of the 3rd ventricle

36
Q

What does the Pineal Gland secrete?

A

Melatonin (primarily during hours of darkness; plays a role in sleep and circadian rhythm; decreased levels may pose cancer risk)

37
Q

Where is the Thyroid gland located?

A

Adjacent to the trachea near thyroid cartilage. It is considered the largest Endocrine gland in adults.

38
Q

How much does the Thyroid gland weigh?

A

20-40 grams

39
Q

What are the 2 Thyroid Hormone forms?

A

1) Thyroxine (T4 or tetraiodothyronine) –> 90% of thyroid hormone and has 4 iodine atoms.
2) Triiodothyronine (T3) –> other 10%; only 3 iodine atoms.

40
Q

What happens when Thyroid Hormone reaches a target cell?

A
  • T4 is converted to T3.
  • T3 enters the nucleus and binds to receptors associated with the DNA
  • Stimulates increase in metabolic rate
  • Rise in ATP, Oxygen, fuel consumption, and heat production
  • Stimulates growth of bones, skin, and other tissue
  • Increases alertness
  • Crucial to development of fetal nervous system.
41
Q

What are C (Clear) Cells

A

Small clusters nestled between the follicles. They produce a peptide hormone called “Calcitonin” in response to elevated blood calcium levels.

42
Q

What is Calcitonin?

A

Peptide Hormone which inhibits the bone-resobing activity of osteoclasts and stimulates bone deposition by osteoblasts, thus promoting bone deposition. It is significant in children but has no significant effect in adults. No disease results from an excess or deficiency of this.

43
Q

How many Parathyroid Glands are there?

A

4 small ones usually located on the posterior surface of the thyroid although there location varies.

44
Q

What does the Parathyroid glands secrete?

A

Parathyroid hormone (PTH), the dominant calcium-regulating hormone in adults. In response to a blood calcium deficiency, it stimulates osteoclasts and inhibits osteoblasts, thereby dissolving bone and raising the blood calcium level.

45
Q

PTH stimulates the kidneys to produce ________?

A

Calcitriol –> promotes absorption of calcium in the digestive tract.

46
Q

What would happen if a person’s parathyroids were accidentally removed in the course of surgery?

A

Person would die within a few days of blood calcium deficiency

47
Q

What is the Thymus?

A

a Bilobed gland in the mediastinum superior to the heart. It is the site of maturation for certain white blood cells called “T- lymphocytes” which play a critical role in immunity.

48
Q

What does the Thymus secrete?

A

Thymosin and Thymopoietin which regulate the development and activity of T Lymphocytes and stimulate the development of other lymphatic organs.

49
Q

What are the endocrine cell clusters in the pancreas?

A

Pancreatic islets (islets of Langerhans)

50
Q

What are the 2 most important pancreatic hormones?

A

Insulin and Glucagon

51
Q

What is Insulin?

A

Produced by Beta Cells of Islets in response to a rise in blood glucose during and after a meal. It promotes the uptake of glucose by liver, muscle, and fat cells among others, and promotes glycogen synthesis and fat storage. These processes lower the blood glucose concentration

52
Q

What is Glucagon?

A

Produced by Alpha Cells of the islets in response to falling levels of blood glucose. It promotes the mobilization of fuels. Its primary action is on the liver, where it stimulates the breakdown of glycogen and the synthesis of glucose from proteins. These processes release glucose into the blood, raising its concentration and making it available to other tissues.

53
Q

What are the 2 distinct portions of the Adrenal Gland?

A

inner Adrenal Medulla and the outer Adrenal Cortex

54
Q

What does the adrenal medulla secrete?

A

Mainly Epinephrine and Norepinephrine –> 2 monoamines involved in stress response

55
Q

What is the Adrenal Cortex?

A

Produces steroid hormones (Corticosteroids) all of which are synthesized from cholesterol. It has 3 tissue layers that differ in their hormone output.

56
Q

What are the 3 tissue layers of the adrenal cortex?

A

1) Zona Glomerulosa
2) Zona Fasciculata
3) Zona Reticularis

57
Q

What is Aldosterone?

A

Produced only in the Zona Glomerulosa, nicknamed the “salt-retaining hormone.” It targets kidney cells and stimulates them to return Sodium ions to the blood instead of allowing them to be lost in the urine (Water follows the sodium by osmosis, so aldosterone also slows down the body’s rate of urinary water loss and helps to maintain blood volume and pressure)

58
Q

Aldosterone and some similar, minor hormones are collectively called _________?

A

Mineralocorticoids

59
Q

What is cortisol?

A

Another Corticosteroids produced only in the Zona Fasciculata and Zona reticularis.

  • Secreted in response to Adrenocorticotropic Hormone (ACTH) from the anterior pituitary gland
  • Raises the levels of blood glucose and other fuels, providing the body with the energy to respond to stress
  • Stimulates muscles to break down their own proteins and release the amino acids into circulation
  • Stimulates the liver to synthesize glucose from these free amino acids
  • Stimulates adipose tissue to break down fats, releasing fatty acids into circulation as a supplemental fuel.
60
Q

Cortisol and similar, lesser hormones are collectively called ___________?

A

Glucocorticoids

61
Q

What are the sex hormones?

A

Androgens and Estrogens –> Produced in both the zone fasciculata and zone reticularis.

62
Q

What do Androgens do?

A
  • Stimulate male development and reproduction
63
Q

In men, most male hormones are secreted from _______?

A

Testes; males adrenal androgens are of relatively minor importance

64
Q

What is the only source of Androgens for females?

A

Adrenal Cortex

65
Q

What is the principal adrenal androgen?

A

Dehydroepiandrosterone (DHEA) –> in the male fetus it plays an important role in development of the male reproductive tract. At sexual maturity, it acts in both sexes to stimulate development of pubic and axillary hair and apocrine sweat glands

66
Q

What are the Gonads?

A
  • Ovaries and Testes

- Function as both endocrine and exocrine glands.

67
Q

What are the Exocrine Products of the Gonads?

A

Egg and Sperm

68
Q

What are the Endocrine Products of the Gonads?

A

Gonadal Hormones, mostly steroids

69
Q

What do the Ovaries secrete?

A

Estrogen, Progesterone, and inhibin

70
Q

What does Estradiol and Progesterone do?

A
  • Regulates the ovarian and menstrual cycles
  • Prepare for and maintain pregnancy
  • Contribute to the development of the reproductive system.
71
Q

Inhibin is secreted by ________ and ________?

A

Follicle and Corpus Lutem

It is an inhibitory signal to the anterior pituitary gland that regulates the secretion of Follicle-Stimulating Hormone (FSH).

72
Q

What do the Testes secrete?

A

Testosterone and inhibin

73
Q

What is the source of Inhibin?

A

Sustentacular Cells

74
Q

What is the source of Testosterone?

A

Interstitial cells (Cells of Leydig)

75
Q

What does Testosterone do?

A
  • Sustains Sperm production and sex drive
  • Stimulates development of male reproductive system
  • stimulates development of masculine physique
76
Q

What is stress?

A

Any situation that upsets homeostasis and threatens one’s physical or emotional well being

77
Q

What are the 3 stages of Stress?

A

1) Alarm Reaction –> Mediated mainly by norepinephrine from sympathetic nerves and epinephrine from the adrenal medulla. These raise the heart rate, blood pressure, and blood glucose level; promote pulmonary ventilation; and prepare the body for actions such as fighting or escaping danger
2) Stage of Resistance –> Develops as stored glycogen is depleted but the demand for glucose still must be met. ACTH and cortisol are secreted to mobilize alternative fuels. Liver utilizes glycerol and amino acids to synthesize more glucose. Fatty acids and glucose are oxidized to make ATP.
3) Stage of Exhaustion –> Sets in as even one’s reserve alternative fuels are depleted. When fat stores are gone, the body begins breaking down more and more protein to meet its energy needs. Progressive wasting away of muscles and weakening of the body. Can result in death