STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE ENDOCRINE SYSTEM Flashcards
1
Q
These are all major glands of what system?
- Hypothalamus
- Pituitary
- Thyroid
- Parathyroid
- Pancreas
- Adrenals
- Ovaries and Testes
- Pineal gland
A
Endocrine system
2
Q
What glands secrete hormones to regulate many bodily functions, including growth and metabolism?
A
Major glands of the endocrine system
3
Q
True or False
Like the nervous system, the endocrine system is one of the body’s main communicators
A
True
4
Q
What is a specific cell with specific receptors that will respond to specific hormones?
A
Target Cell
5
Q
True or False
Only the target cells for a given hormone have receptors that bind and recognize that hormone
A
True
6
Q
All target cells will have how many receptors for a particular hormone?
A
2,000-100,000
7
Q
True or False
Hormones are either lipid-soluble or water-soluble
A
True
8
Q
Are these lipid or water soluble?
- steroid hormones
- thyroid hormones
- nitric oxide
A
Lipid soluble
9
Q
Are these lipid or water soluble?
- amino acids
a. short-chain; antidiuretic hormone
b. long-chain; insulin
A
Water soluble
10
Q
Hormones influence their target cells by chemically binding to what?
A
specific protein receptors
11
Q
True or False
only the target cells for a given hormone have receptors that bind and recognize that hormone
A
True
12
Q
What is known as the master switchboard because it’s the part of the brain that controls the endocrine system?
A
Hypothalamus
13
Q
What acts as the major link between the endocrine system and the nervous system?
A
Hypothalamus
14
Q
What hangs by a thin stalk from the hypothalamus and is called the master gland of the body because it regulates the activity of the endocrine glands?
A
Pituitary glands
15
Q
What is the total number of hormones that the hypothalamus secretes?
A
9
16
Q
What is the total number of hormones that the pituitary gland secretes?
A
7
17
Q
Together the hormones secreted by what play an important role in regulating virtually all aspects of growth, devlopment, metabolism, and homeostasis?
A
Hypothalamus and pituitary gland
18
Q
What attaches the pituitary gland to the hypothalamus?
A
a stalk like structure, the infundibulum
19
Q
Within the infundibulum, blood vessels termed what connect capillaries in the hypothalamus to capillaries in the anterior pituitary and carries hormones secreted by the hypothalamus to the anterior pituitary?
A
hypophyseal portal veins
20
Q
Gonadotropin-releasing hormone stimulates what?
A
FSH and LH
21
Q
Growth hormone-releasing hormone stimulates what?
A
HGH and IGF
22
Q
Growth hormone-inhibiting hormone inhibits what?
A
HGH and IGF
23
Q
Thyroid-releasing hormone stimulates what?
A
TSH
24
Q
Prolactin-releasing hormone stimulates what?
A
PR
25
Prolactin-inhibiting hormone inhibits what?
PR
26
Corticotropin-releasing hormone stimulates what?
ACTH
27
What is a gland about the size of a small grape that is divided into two lobes?
Pituitary gland (anterior and posterior)
28
Both lobes of the pituitary gland rest in the what?
Hypophyseal fossa
29
What is a cup shaped depression in the sphenoid bone?
hypophyseal fossa
30
What is a hormone that stimulates the endocrine gland to grow and secrete its hormones?
Tropic Hormones
31
What hormone promotes synthesis and secretion of Insulinlike Growth Factors(IGFs)
Human Growth Hormone (hGH)
32
What are proteins secreted mainly by cells in the liver, but is also secreted by cells in the skeletal muscles, cartilage, bones, and other tissues in response to stimulation of hGH ?
Insulinlike Growth Factors (IGFs)
33
What stimulates protein synthesis, help maintain muscle and bones mass, and promote healing of injury and tissue repair?
IGFs
34
What enhances the breakdown of triglycerides, which release fatty acid into the blood, and breakdown of liver glycogen, which releases glucose into the blood?
IGFs
35
What maintains blood concentration by means of a negative feedback loop?
hGH
36
What two hypothalamic hormones control secretion of hGH?
1. Growth Hormone-Releasing Hormone (GHRH)
a. low blood glucose levels
2. Growth Hormone-Inhibiting Hormone (GHIH)
a. above normal blood glucose levels
37
What stimulates the synthesis and secretion of thyroid hormones by the thyroid gland?
Thyroid-Stimulating Hormone (TSH)
38
What hormone from the hypothalamus controls TSH secretion?
Thyrotropin-Releasing Hormone (TRH)
39
What hormone initiates the development of ovarian follicles and stimulates follicular cells to excrete estrogen in females?
Follicle-Stimulation Hormone (FSH)
40
What hormone stimulates sperm production in the testes of men?
Follicle-Stimulation Hormone (FSH)
41
GnRH from the hypothalamus controls the secretion of what?
Follicle-Stimulation Hormone (FSH)
42
What hormone triggers ovulation, stimulates the formation of the corpus luteum in the ovary and the secretion of progesterone by the corpus luteum?
Luteinizing Hormone (LH)
43
What hormone along with FSH stimulates follicular cells to secrete estrogen?
LH
44
What hormones in males stimulates the testes to secrete testosterone?
LH
45
What hormone from the hypothalamus controls LH secretion?
GnRH
46
What initiates and maintains milk production by the mammary glands?
Prolactin (PRL)
47
What suppresses the release of prolactin (PRL) most of the time?
Prolactin-inhibiting Hormone (PIH)
48
During pregnancy, very high levels of estrogens promote secretion of what, which in turn stimulates the release of prolactin?
Prolactin-Releasing Hormone (PRH)
49
What controls the production and secretion of hormones called Glucocorticoids by the cortex (outer portion) of the adrenal gland?
Adrenocorticotropic Hormone (ACTH)
50
What hormone from the hypothalamus stimulates secretion of ACTH?
Corticotropin-Releasing Hormone
51
What hormone is found in small levels in humans and excessive amounts can cause darkening of the skin?
Melanocyte-Stimulating Hormone (MSH)
52
These are what kind of hormones?
1. HGH
2. TSH
3. FSH
4. LH
5. ACTH
Tropic Hormones
53
These are what kind of hormones?
1. Prolactin (PRL)
2. Melanocyte-stimulating hormone (MSH)
Direct acting hormones
54
These are hormones of what portion of the pituitary?
1. HGH
2. TSH
3. FSH
4. LH
5. PRL
6. ACTH
7. MSH
Anterior Pituitary
55
What contains axons and axon terminals of neurosecretory cells whose cell bodies are in the hypothalamus?
posterior pituitary
56
The posterior pituitary DOES NOT synthesize hormones, but it does store and release what two hormones?
1. oxytocin
| 2. antidiuretic hormone (ADH)
57
What is released in large quantities in the uterus just prior to childbirth to enhance contraction of smooth muscle cells in the wall of the uterus?
Oxytocin
58
What stimulates milk ejection from the mammary glands in response to the suckling infant?
oxytocin
59
What hormone has the following effects?
1. decreases urine output
2. causes kidneys to retain more water, thus decreasing urine volume
3. decreases water loss through sweating
4. causes constriction of arterioles, thus causing an increase in BP
ADH
60
If there was an absence of ADH, an individuals urine output would increase from 1-2 liters per day to what?
20 liters
61
These are hormones from what portion of the pituitary?
1. oxytocin
2. ADH
Posterior pituitary
62
The thyroid glands function is to run what?
the basal metabolic rate (BMR)
63
What is the rate at which the body uses energy while at rest to keep vital functions going, such as breathing, keeping the heart beating, and keeping the body warm?
Basal Metabolic Rate (BMR)
64
The butterfly shaped thyroid gland is located where?
just below the larynx
65
What is composed of right and left lobes on either side of the trachea and spherical sacs called thyroid follicles make up most of the gland?
Thyroid gland
66
The walls of each follicle consist of cells called follicular cells which produce what two thyroid hormones?
1. Thyroxine (T4)
| 2. Triiodothyronine (T3)
67
True or False
Most body cells have receptors for thyroid hormones
True
68
What increases the BMR, the rate of oxygen consumption under standard or basal conditions (awake, at rest, and fasting)?
Thyroid hormones
69
What hormones play an important roles in the maintenance of normal body temperature?
Thyroid hormones
70
What hormones also stimulate protein synthesis, increase the use of glucose and fatty acid for ATP production, increase the breakdown of triglycerides, and enhance cholesterol excretion, thus reducing blood cholesterol?
Thyroid hormones
71
Together with ____ and Insulin, thyroid hormones stimulate body growth, particularly the nervous and skeletal systems.
HGH
72
What is produced by the parafollicular cells of the thyroid gland?
Calcitonin(CT)
73
What decreases the level of calcium in the blood by inhibiting the actions of osteoclasts, the cells that breakdown bone?
Calcitonin (CT)
74
What are the small round masses of glandular tissue that are partially imbedded in the posterior surface of the thyroid gland?
Parathyroid Gland
75
Within the parathyroid glands are secretory cells called what, that release parathyroid hormone (PTH)?
Chief cells
76
What is the major regulator of the levels of calcium, magnesium, and phosphate ions in the blood?
PTH
77
What increases the number and activity of osteoclasts, which break down bone extracellular matrix and release calcium and phosphate into the blood ?
PTH
78
What hormone produces these changes in the kidney?
1. slows rate of calcium and magnesium lost from blood into urine
2. increases loss of phosphate from blood to urine
3. promotes formation of calcitrol
PTH
79
What substance acts in the gut to increase the rate of calcium, magnesium, and phosphate absorption from food into the blood?
Calcitrol
80
What can elevated levels of PTH cause?
1. bone pain
2. kidney stones
3. head aches
4. abdominal pain
81
What can low levels of PTH cause?
1. carpopedal spasms
2. abdominal cramps
3. muscle cramps
82
What is the flattened organ located in the curve of the duodenum, the first part of the small intestine?
Pancreas
83
Does the pancreas have both endocrine and exocrine functions?
Yes
84
The endocrine part of the pancreas consists of clusters of cells called the pancreatic islets or the what?
Islets of Langerhans
85
What cells secrete the hormone glucagon, the release is stimulated by the sympathetic division of the autonomic nervous system?
Alpha cells
86
What cells secrete the hormone insulin, release is stimulated by the parasympathetic division of the ANS?
Beta Cells
87
What is the main action of glucagon?
to increase blood glucose levels when it falls below normal
88
In contrast to glucagon, what hormone helps glucose move into cells, especially muscle fibers, which lower blood glucose levels when it is too high?
Insulin
89
The level of blood glucose controls secretion of both glucagon and insulin via what kind of feedback loop?
Negative feedback loop
90
What hormone promotes the uptake of amino acids into the body cells and increases the synthesis of protein and fatty acid within cells and is therefore an important hormone when tissues are developing, growing and being repaired?
Insulin
91
Where are the adrenal glands located?
one lying on top of each kidney
92
The adrenal cortex consists of how many zones, each of which synthesizes and secretes different steroid hormones?
three
93
What are the three zones of the adrenal cortex?
1. Outer zone (zona glomerulosa)
2. Middle zone (zona fasciculata)
3. Inner zone (zona reticularis)
94
What zone of the adrenal cortex releases hormones called mineral corticoids because of their effect on mineral homeostasis?
Outer zone (zona glomerulosa)
Aldosterone
95
What zone of the adrenal cortex releases hormones called glucocorticoids because they affect glucose homeostasis?
Middle zone (Zona fasciculata)
Cortisol
96
What zone of the adrenal cortex releases androgens (male/female sex hormones)?
Inner zone (zona reticularis)
97
What is the inner most region of the adrenal gland?
Adrenal medulla
98
What consists of sympathetic postganglionic cells of the ANS that are specialized to secrete hormones known as catecholamines?
Adrenal Medulla
1. epinephrine
2. norepinephrine
99
What is the major mineral corticoid of the Zona glomerulosa?
Aldosterone
100
What regulates homeostasis of the two mineral ions, sodium (Na+) and potassium ions (K+)?
Aldosterone
101
What increases reabsorption of Na+ from the urine into the blood and stimulates the excretion of K+ into the blood?
Aldosterone
102
What helps adjust blood pressure and blood volume and promotes the secretion of H+ in the urine?
Aldosterone
103
Secretion of aldosterone occurs as part of what pathway?
Renin-angiotensin-aldosterone pathway
104
Lowered blood pressures stimulates the kidneys to secrete what enzyme, which promotes a reaction in the blood that forms angiotensin I ?
Renin
105
As blood flows through the lungs, an enzyme known as Angiotensin converting enzyme (ACE) converts inactive angiotensin I into what?
The active hormone angiotensin II
106
What hormone stimulates the adrenal cortex to secrete aldosterone?
Angiotensin II
107
Aldosterone acts on the kidneys to promote the return of what to the blood, which in turns helps bring the blood pressure back to normal?
Na+ and water
108
What is the most abundant glucocorticoids from the Zona Fasciculata ?
Cortisol
109
What produced in the zona fasciculata increases the rate of protein breakdown, mainly in muscle fibers and thus increases the liberation of amino acids into the blood stream; amino acids may be used by the body cells for synthesis of new proteins or for ATP production?
Glucocorticoids
110
Glucocorticoids Actions
What happens upon stimulation of the glucocorticoids, liver cells may convert certain amino acids or lactic acid to glucose, which neurons and other cells can use for ATP production?
Glucose formation
111
Glucocorticoids stimulate the breakdown of what in adipose tissue?
Triglycerides
| Fatty acid is released into the blood to be used for ATP production by many blood cells
112
True or False
| Glucocorticoids have anti-inflammatory effects
True
| They inhibit WBC that participate in inflammatory response
113
True or False
| Glucocorticoids are involved in the immune response
True
| Depression of the immune response
114
A low blood level of cortisol stimulates neurosecretory cells in the _____ to secrete _____ to the anterior pituitary where it stimulates release of _____. ____ in turn stimulates cells of the adrenal cortex to secrete cortisol.
1. hypothalamus
2. Corticotropin-releasing hormone (CRH)
3. Adrenocorticotropic Hormone (ACTH)
4. ACTH
`
115
Zona Reticularis
| In both males and females, the adrenal cortex secretes small amounts of what?
androgens
116
True or False
| In males, the adrenal cortex secretes only small amounts of weak androgens
True
After puberty, androgens are also released in greater quantities by the testes. Thus the amount of androgens secreted the adrenal cortex in males is usually so low that their effects are insignificant
117
In females, adrenal androgens play an important role; they contribute to libido (sex drive) and are converted into what by other body tissues?
Estrogens (feminizing sex steroids)
118
After menopause, all female estrogens come from where?
conversions of adrenal androgens
119
Impulses from the hypothalamus stimulate the sympathetic preganglionic neurons, which in turn stimulate the cells of the ____ to secrete ____ and ____.
1. Adrenal medulla
2. epinephrine
3. norepinephrine
120
What two hormones greatly augment the fight-or-flight response?
1. Epinephrine
| 2. Norepinephrine
121
What are the organs that produces gametes? (sperm in males and oocytes in females)
Gonads
122
What are known as the female gonads?
Ovaries
123
Ovaries produce what female sex hormones?
1. estrogen
| 2. progesterone
124
Along with FSH and LH from the anterior pituitary, female sex hormones help regulate what cycles in the female body and help establish and maintain the feminine body shape?
1. menstrual cycle
2. maintain pregnancy
3. prepare mammary glands for lactation
125
What hormone inhibits the secretion of FSH?
Inhibin
126
During pregnancy, the ovaries and placenta produce a peptide hormone called what?
Relaxin
127
The testes of the male produce what?
testosterone, the primary androgen or male sex hormone
128
What is the small endocrine gland attached to the roof of the third ventricle of the brain at the midline?
Pineal Gland
129
What is the hormone secreted by the pineal gland that contributes to the setting of the body’s biological clock?
Melatonin
130
Aging
| As the levels of thyroid hormones (T3, T4, and calcitonin) decrease what happens?
Can cause:
1. decreased metabolic rate
2. increased body fat
3. hypothyroidism
131
Aging
| As parathyroid hormones rises what happens?
the rise in PTH and the fall in calcitonin decreases bone mass leading to osteoporosis
132
As we age, insulin is released more slowly causing what?
blood glucose levels to increase faster
133
As the ovaries decrease in size with age and estrogens decrease, they no longer respond to gonadtropins, this leads to conditions such as what?
1. osteoporosis
2. high blood cholesterol
3. atherosclerosis
134
What is any stimulus that produces a stress response?
Stressor
135
What is a sequence of bodily changes that can progress through stages?
Stress responses
136
What is the first stage of the stress response?
initial fight-or-flight response
137
Stress response: First stage
Initiated by nerves impulses from the ____ to the sympathetic division of the ____, including the adrenal medulla, quickly mobilizes the body’s resources for immediate physical activity.
1. hypothalamus
| 2. Autonomic nervous system (ANS)
138
Stress response: First stage
This stage brings in huge amounts of glucose and oxygen to the organs that are most active in warding off danger, what are they?
1. brain
2. skeletal muscles
3. heart
139
Stress response: First Stage
The reduction of blood flow to the kidneys, promotes the release of ____, which sets in motion the renin-angiotensin-aldosterone pathway. ____ causes the kidneys to retain Na+, which leads to water retention and elevated blood pressure. Water retention also helps to preserve body fluid volume in case of ________.
1. Renin
2. Aldosterone
3. Severe bleeding
140
What is the second stage of the stress response?
slower resistance reaction
141
What stage of the stress response is initiated in large part by the hypothalamus releasing hormones and is a longer lasting response?
Second stage
142
Is corticotropin-releasing hormone (CRH) involved in the second stage of the stress response?
yes
143
Stress response: Second stage
This stage stimulates the anterior pituitary to secrete what, which in turn stimulates the adrenal cortex to release more cortisol?
ACTH
144
Stress response: Second stage
True or False
Cortisol then stimulates the release of Angiotensin by the liver cells, breakdown of triglycerides into fatty acids, and catabolism of protein into nucleic acids. Tissues throughout the body can use the resulting glucose, fatty acids, and amino acids to produce ATP or to repair damaged cells.
False
Cortisol then stimulates release of GLUCOSE by liver cells, breakdown of triglycerides into fatty acids, and catabolism of protein into AMINO ACIDS. Tissues throughout the body can use the resulting glucose, fatty acids, and amino acids to produce ATP or to repair damaged cells.
145
In the stress response, does cortisol also help reduce inflammation?
Yes
146
Stress response: Second stage
Growth hormone-releasing hormone causes the anterior pituitary to secrete _____, acting via insulin like growth factor, ____ stimulates the breakdown of ____ and glycogen.
1. Human growth hormone (hGH)
2. hGH
3. Triglycerides
147
What stimulates the anterior pituitary to secrete thyroid stimulating hormone (TSH)?
Thyrotropin-Releasing Hormone
148
TSH promotes the secretion of what, which stimulates the increased use of glucose and for ATP production?
thyroid hormones
149
What stage of the stress response helps the body continue fighting a stressor long after the fight-or-flight response dissipates and is generally successful in seeing us through a stressful episode?
Resistance stage (second stage)
150
Occasionally the resistance stage fails to combat the stressor, the resources of the body may eventually become so depleted that they cannot sustain the resistance stage, this is known as what?
Stress response: Third stage: Exhaustion
151
Prolonged exposure to high levels of ___ and other hormones involved in the resistance reaction causes wasting of muscles, suppression of the immune system, ulceration of the GI tract, and failure of pancreatic ____.
1. Cortisol
| 2. pancreatic beta cells
152
True or False
| People under stress are at a greater risk for developing chronic disease or dying prematurely
True
