16 Endocrine Flashcards
(183 cards)
1
Q
What are the 6 main endocrine glands
A
Pituitary Thyroid Parathyroid Adrenal Pineal Thymus
2
Q
What organs have both endocrine and exocrine functiona
A
Pancreas
Gonads
3
Q
What other tissues and organs produce hormones
A
Adipose Pockets of Cells in : small intestine Stomach Kidney Heart
4
Q
What are hormones
A
Chemical substances secreted by cells into extra cellular fluid
- end up in blood
5
Q
What is the main function of hormones
A
To regulate the metabolic function of other cells
6
Q
What are the two classifications of hormones
A
Amino acid based
Steroids
7
Q
List some amino acid hormones
A
Amines Thyroxine Peptide Protein hormones Insulin
8
Q
List some steroid hormones
A
Gonadal
Adrenocortical
9
Q
What are steroid hormones synthesized from
A
Cholesterol
10
Q
What cells respond to hormones
A
Target cells
11
Q
What are 5 responses to hormones
A
Alter plasma membrane permeability Stimulate protein synthesis Activate or deactivate enzyme systems Induce secretory activity Stimulate mitosis
12
Q
What are the 2 ways that hormones alter cell activity
A
Bind to receptor on membrane
Directly activate gene
13
Q
What hormone type can directly activate a gene
A
Only steroid hormones
Lipid soluble
14
Q
How do amino acid hormones initiate cell response
A
Bind to receptor
Intracellular response via second messengers
cAMP
15
Q
What 3 factors does target cell activation depend on
A
Blood levels of hormone
Relative number of receptors on target cell
Affinity of those receptors for the hormone
16
Q
Describe up regulation
A
Target cells form more receptors in response to hormone
17
Q
Describe down regulation
A
Target cells lose receptors in response to hormone
Desensitize
18
Q
What are the forms that hormones circulate in blood
A
Free
Bound
19
Q
What hormone type is must be bound to plasma protein
A
Steroids and thyroid
20
Q
What do the concentrations of circulating hormones reflect
A
Rate of release
Speed of Inactivation and removal from body
21
Q
How are hormones removed from the blood
A
Degrading enzymes
Kidneys
Liver enzyme systems
22
Q
What type of control system controls blood levels of hormones
A
Negative feedback systems
23
Q
What are the 3 stimuli types
A
Humoral
Neural
Hormonal
24
Q
Describe humoral stimuli
A
Secretion or hormones in direct response to changing blood levels of ion and nutrients
25
Describe neural stimuli
Nerve fibers stimulate hormone release
26
Describe hormonal stimuli
Release of hormones in response to hormones produced by other endocrine organs
27
Example of humoral stimuli
Concentration of calcium in blood
Decline in Ca stimulates parathyroid gland to secrete PTH
PTH causes Ca concentration to increase
Stimulus is now removed
28
Example of neural stimuli
Preganglionic sympathetic fibers stimulate adrenal medulla to secrete catacholamines
29
What are catacholamines
Epinephrine
| Norepinephrine
30
Example of hormonal stimuli
Hypothalamic hormones stimulate the anterior pituitary
| Pituitary hormones then stimulate targets to secrete more hormones
31
What is nervous system modulation
The nervous system can override normal endocrine controls
32
Example of nervous system modulation
Control of blood glucose levels
Under stress need more glucose
Hypothalamus and SNS are activated to supply more glucose
33
Another name for the pituitary
Hypophysis
34
Another name for anterior pituitary
Adenohypophysis
35
Another name for posterior pituitary
Neurohypophysis
36
What is posterior pituitary made of
| What is it's function
Neural tissue
| Receives, stores, and releases hormones from hypothalamus
37
What is anterior pituitary made of
| What is its function
Glandular tissue
| Synthesize and secretes a number of hormones
38
Which pituitary lobe is a downgrowth of hypothalamic tissue
Posterior
39
Describe the hypothalamic hypophyseal tract
Neural connection between hypothalamus and posterior pituitary
40
What hormones do nuclei of hypothalamus synthesize
Oxytocin
| Antidiuretic hormone
41
What is stored in posterior pituitary
Oxytocin
| Antidiuretic hormone
42
What portion of pituitary is epithelial tissue
Anterior lobe
43
How is anterior pituitary connected to the hypothalamus
Vascular connection
| Hypophyseal portal system
44
Describe hypophyseal portal system
Primary capillary plexus
Hypophyseal portal veins
Secondary capillary plexus
45
What type of hormones in hypothalamus send stimuli to anterior pituitary
Releasing hormones
| Inhibiting hormones
46
Name the hormones of the adenohypophysis
```
Growth hormone GH
Prolactin PRL
Thyroid stimulating TSH
Adrenocorticotropic ACTH
Follicle stimulating FSH
Luteinizing LH
```
47
Name the tropic hormones
TSH
ACTH
FSH
LH
48
Name the gonadotropins
FSH
| LH
49
Describe function of growth hormone
Stimulate most cells
Target bones and skeletal muscle
Promote protein synth
Encourage use of fat as fuel
50
What is stimulated by GH to produce insulin like growth factors
Liver
Skeletal muscle
Bone
Cartilage
51
What are somatomedins
Insulin like growth factors
52
What do insulin like growth factors do
Indirectly mediate the effects of GH
Promote protein synth
skeletal muscle and bone growth
53
What are the direct effects of GH
Use fats for fuel - lipolysis
Inhibit glucose uptake by tissue cells
Release glucose from liver - elevate blood glucose
54
What does lipolysis do
Elevate blood fatty acid levels
55
What are glycogenolysis and gluconeogenesis
Break down glycogen to glucose
Synth glucose from lactic acid and noncarb
Both elevate blood glucose levels
56
What hormones regulate secretion of GH
| Where do they come from
Growth hormone releasing hormone GHRH
Growth hormone inhibiting hormone
GHIH
Hypothalamus
57
Hyper secretion of GH in children
Gigantism
58
Hypersecretion of GH in adults
Acromegaly
| Overgrowth of areas still responsive to GH
59
Hyposecretion of GH in adults
No problem
60
Hyposecretion of GH in children
Pituitary dwarfism
| Small kid
61
What is thyrotropin
Thyroid stimulating hormone
62
What does thyroid gland control
Metabolism
63
What is function of Thyrotropin
Stimulate normal development and secretory activity of thyroid
64
What triggers thyrotropin TSH
Hypothalamic peptide
| Thyrotropin releasing hormone TRH
65
What blocks the release of TRH and TSH
Rising blood levels of thyroid hormone
GHIH inhibits TSH
Not growing turn down metabolism
66
What is another name for corticotropin
Adrenocorticotropic hormone ACTH
67
What is function of ACTH
Stimulate adrenal cortex to release corticosteroids
68
What triggers the release of ACTH
Hypothalamic corticotropin releasing hormone CRH
69
What blocks release of CRH and ACTH
Rising blood levels of cortisol
70
When is CRH released
In daily rhythm- high morning, dropping
| Stress: blood loss, low blood glucose, happiness, anxiety
71
Basic Function of gonadotropins
Regulate function of ovaries and testes
| FSH stimulates gamete production
72
When are gonadotropins absent
Prepubertal
73
What triggers gonadotropins
Hypothalamic gonadotropin releasing hormone GnRH
74
Function of gonadotropins in females
LH/ FSH maturation of ovarian follicle
LH trigger ovulation
LH promote synth/ release of estrogen/ progesterone
75
Function of gonadotropins in males
LH stimulate interstitial cells of testes to produce testosterone
76
What is another name for LH in males
Interstitial cell stimulating hormone ICSH
77
Function of prolactin PRL
Stimulates mammary gland development
Milk production
Unknown in males
78
What 3 hormones control prolactin release
Prolactin inhibiting hormone PIH
Prolactin releasing factors PRF
Estrogen
79
Describe what occurs to prolactin release before menstruation
Estrogen stimulates PRF, PRL
| Inhibits PIH
80
What occurs to prolactin when placental estrogen, progesterone, and lactogen are present
Stimulate PRF, PRL
| Inhibits PIH
81
How are mechanoreceptors involved in PRL release
Mechanoreceptors send afferent impulses to hypothalamus
Stimulate PRF
Inhibit PIH
82
What is prolactin inhibiting hormone
Dopamine
| From hypothalamus
83
What is function of ADH
Influence water balance
84
What is function of oxytocin
Stimulate smooth muscle contractions of uterus and breasts
| Triggers milk ejection reflex
85
What monitors the solute concentration of the blood
Osmoreceptors in hypothalamus
86
If solute levels are high ADH...
ADH preserves water
87
If solute levels are low ADH...
ADH is not released
| Water loss
88
What inhibits ADH release
Alcohol
| Copious urine
89
What occurs with inadequate ADH how is it caused
Diabetes insipidus
| From head injury damaging hypothalamus of posterior pituitary
90
What is the largest endocrine gland
Thyroid
| Connected by isthmus
91
What do thyroid follicles produce
Glycoprotein thyroglobulin
92
Describe colloid
Thyroglobulin + iodine
| Precursor of thyroid hormone
93
What do para follicular cells secrete
Calcitonin
94
What does thyroid hormone consist of
2 iodine containing thyroglobulin compounds
T4- thyroxine
T3- triiodothyronine
95
What occurs when iodine attaches to thyroglobulin
Forms T1 and T2
96
What forms T3 and T4
T1 and T2 linked together
97
When are T3 and T4 release into the bloodstream
When colloid is endocytosed and combined a lysosome, where T3 and T4 are cleaved and diffuse into blood
98
What does TSH bind to
Follicle cells of thyroid gland
99
Which is released more from follicle T3 or T4
T4
100
Is T3 or T4 primarily responsible for effects of TH
T3
| Enzymes in liver and other tissues can convert T4 to T3
101
What cells respond to thyroid hormone
Virtually all cells in body increase metabolic rate
102
How is TH release stopped
Negative feedback
High TH, shut off TSH
TRH can override this is necessary- during pregnancy
103
What is target of TRH
Anterior pituitary
104
What are the effects of TH
Elevate rates of oxygen and energy consumption
Heat production
Increase HR and force of contraction- increase BP
Regulate tissue growth
Develop skeletal/ nervous systems
Maturation
Reproduction
105
What causes hypothyroid
Too little TSH or TRH
Iodine deficiency- lack of TH
Thyroid gland removed
106
Describe hypothyroid in adults
```
Myxedema
Low metabolic rate
Chilled
Thick dry skin
Lethargy
Mental sluggishness
Puffy eyes
```
107
Hypothyroid in children
Cretinism
Mental retardation
Disproportionate body
Thick neck and tongue
108
What causes goiter
Enlarged thyroid
| From lack of iodine
109
Symptoms of Hyperthyroid
```
Graves disease
Elevated metabolic rate
Nervousness
Sweating
Weight loss
Exophthalmos from tissue getting edematous/ fibrous
```
110
Describe graves disease
```
Hyperthyroid
Autoimmune disease
Serum has abnormal antibodies against follicle cellar
Antibodies mimic TSH
Continuous TH release
```
111
Why are plasma Ca levels closely regulated
To prevent changes in neuromuscular excitability
112
Why is intracellular Ca important
For excitation contraction coupling
113
Why is extra cellular Ca important
Neuromuscular excitability
114
What happens with low extracellular Ca
Na influx is higher
Cell closer to threshold
Muscle may spasm randomly
In diaphragm causes asphyxiation
115
What happens with high extra cellular Ca
Decrease Na influx
Hyper polarize- depress excitability
Cause increased cardiac contractions
116
What is the function of calcitonin
Lowers blood Ca levels in children
117
What is the antagonist to parathyroid hormone
Calcitonin
118
What is calcitonin target
| What action occurs
Targets skeleton
Inhibits osteoclasts- ca not released from bone
Stimulates Ca uptake/ incorporation into bony matrix
119
What regulates calcitonin levels
Negative feedback
Humoral
Ca ion concentration in blood
120
What is another name for PTH
Parathormone
121
What is function of parathyroid hormone
```
Increase Ca levels
Stimulate osteoclasts
Enhance reabsorption of Ca by kidneys
Secretion of phosphate by kidneys
Increase absorption of Ca by intestinal mucosa by activating Vit D
```
122
What hormone is most important for controlling calcium levels
Parathyroid hormone
123
What inhibits release of PTH
High blood Ca levels
124
What are symptoms of hyperparathyroid
Bones soft and deformed- Ca leached out
Elevated blood Ca- hypercalcemia
Depression of nervous system
Formation of kidney stones from Ca in kidneys
125
What causes hyperparathyroid
Tumor
126
What are symptoms of hypoparathyroid
Increased excitability of neurons
| Respiratory paralysis
127
What causes hypoparathyroid
Gland trauma
Removal
Mg deficiency- needed for PTH
128
What is inner adrenal medulla made of
Neural tissue
| Part of SNS
129
What is outer adrenal cortex made of
Glandular tissue
130
How rapidly can catecholamines be released
Peak at 30 seconds
131
Roles of epinephrine
Dilate bronchioles
Dilate coronary and skeletal muscle vessels
Increase HR and force
Spare glucose
Inhibit insulin release, promote glucagon
Promote lipolysis, glycogenolysis, and gluconeogenesis
132
Roles of norepinephrine
Peripheral vasoconstriction
| Raise BP
133
What area of the adrenal gland secretes catecholamines
| What triggers secretions
Adrenal medulla
| SNS responds to short term stress
134
Describe Hyposecretion of catecholamines from adrenal medulla
None
| Not problem because of SNS
135
Describe hyper secretion of adrenal medulla
Tumor called pheichromacytoma
| Symptoms: hypertension, hyperglycemia, excessive sweating
136
What does the adrenal cortex secrete
Corticosteroids
137
What are the three layers of the adrenal cortex
Zona glomerulosa
Zona fasciculata
Zona reticularis
138
What does zona glomerulosa produce
Mineralcorticoids
| Mainly aldosterone
139
What does zona fasciculata produce
Glucocorticoids
| Mainly cortisol
140
What does zona reticularis produce
Gonadocorticoids
| Mainly androgens
141
What is role of mineralcorticoids
Regulate electrolytes in extra cellular fluids
142
What does aldosterone do
Maintain Na balance by reducing excretion
Stimulates reabsorption of Na by kidneys
Secretion of K
143
What stimulates aldosterone secretion
Rising K levels
Low Na levels
Decrease BP/ volume
144
What are the major mechanisms for aldosterone secretion
Renin-angiotensin mechanism
Plasma concentration of Na/ K
ACTH
Atrial natriuretic peptide ANP
145
Describe how renin angiotensin mechanism works
Kidneys release renin when blood volume drops
Leads to angiotensin 2
Stimulates aldosterone release
146
How do plasma concentrations influence secretion of aldosterone
By directly influencing the zona glomerulosa
147
How does the ACTH aldosterone secretion mechanism work
By causing small increases of aldosterone during stress
148
What does ANP do for aldosterone secretion
Inhibits activity of zona glomerulosa
149
What is the roll of cortisol
Help body resist stress
150
How does cortisol reduce stress
```
Sparing glucose for brain
Promote gluconeogenesis
Promote fatty acid release from adipose
Amino acid release from cells
Suppress the immune system
```
151
Important details about gonadocorticoids
Small amount of androgens and estrogen secreted
| Contribute to onset of puberty and female sex drive
152
What are the 3 disorders of the adrenal cortex
Adrenogenital syndrome
Cushings disease/syndrome
Addison's disease
153
Important details about androgenital syndrome
Tumor of zona reticularis
Masculation of females
Femalization of dudes
154
What causes cushings disease
Excess levels of glucocorticoid
155
Difference between cushings disease/ syndrome
Disease- ACTH releasing tumor
| Syndrome- glucocorticoid drugs, like cortisol
156
Symptoms of cushings disease
```
Immune system depressed
Protracted/ exaggerated stress response
Lipid reserves mobilized
Peripheral proteins broken down
Adipose redistribution- moon face
```
157
What causes Addison's disease
Too little mineralcorticoids/ glucocorticoid
| - ACTH deficiency
158
Symptoms of Addison's
Weak
Loose weight
Low BP/ volume
Can't tolerate stress
159
What do alpha cells produce
Glucagon
160
What do beta cells produce
Insulin
161
What is glycogenolysis
Glycogen to glucose
162
What is gluconeogenesis
Synth of glucose from lactic acid and noncarbohydrates
163
What is glucagon
28 amino acid polypeptide hormone
| Potent hyperglycemia agent
164
What does glucagon target and promote
Liver
Release of glucose to blood
Glycogenolysis
Glyconeogenesis
165
What is insulin
51 amino acid protein
| With 2 amino acid chains linked by disulfide bonds
166
How is insulin made
Synth as part of proinsulin then excised by enzyme
| Released as insulin
167
What are functions of insulin
```
Lower blood glucose levels
Enhance transport of glucose into cells
Catalyzes oxidation of glucose for ATP
Polymerizes glucose into glycogen
Converts glucose to fat
```
168
Hyperglycemic effects...
Glucagon
169
Hypoglycemic effects of...
Insulin
170
What causes diabetes mellitus
Hyposecretion
Hypo activity
Of insulin
171
What are 3 signs of DM
Polyuria
Polydipsia
Polyphagia
172
Describe polyuria
Huge urine output
173
Describe polydipsia
Excessive thirst
174
Describe polyphagia
Excessive hunger and food consumption
175
Describe hyperinsulinism
Excessive insulin secretion
| Results in hypoglycemia
176
What causes type 1 DM
Autoimmune disease
177
What causes type 2 DM
Down regulation of insulin receptors
178
What is the function of metatonin
Day/ night cycles
| Physiological processes that show rhythmic variations
179
What hormone does heart produce what does it do
Atrial natriuretic peptide ANP
Reduce BP/ volume
Reduce blood Na concentration
180
What hormone is produce by gastrointestinal tracts
Enteroendocrine cells release local acting digestive hormones
181
What hormones are produced by kidneys
| What do they do
Renin and EPO
Regulate aldosterone- blood volume
Production of red blood cells
182
What hormone does skin produce
| What is its function
Cholecalciferol
| The precursor of Vit D
183
What hormone does adipose issue release
| Function
Leptin
Satiety
Increased energy expenditure
