chp 16. Flashcards
1
Q
Endocrine system
A
acts with nervous system to coordinate and integrate activity of body cells
2
Q
Endocrine system responses are _____ than nervous system responses
A
slower but longer lasting than nervous system responses
3
Q
Endocrinology
A
study of hormones and endocrine organs
4
Q
Endocrine system controls and integrates:
A
- Reproduction
- Growth and development
- Maintenance of electrolyte, water, and nutrient balance of blood
- Regulation of cellular metabolism and energy balance
- Mobilization of body defenses
5
Q
Exocrine glands
A
- Produce nonhormonal substances (examples: sweat, saliva)
- Have ducts to carry secretion to membrane surface
6
Q
Endocrine glands
A
- Produce hormones
- Lack ducts
7
Q
List the Endocrine glands
A
pituitary, thyroid, parathyroid, adrenal, and pineal glands
8
Q
Hypothalamus is a
A
neuroendocrine organ
9
Q
Some have exocrine and endocrine functions
A
Pancreas, gonads, placenta
10
Q
Hormones
A
long-distance chemical signals; travel in blood or lymph
11
Q
Autocrines:
A
chemicals that exert effects on same cells that secrete them
NOT hormones
12
Q
Paracrines
A
ocally acting chemicals that affect cells other than those that secrete them
NOT hormones
13
Q
Amino acid–based hormones
A
Amino acid derivatives, peptides, and proteins
-water-soluble
14
Q
Steroids
A
Synthesized from cholesterol
Gonadal and adrenocortical hormones
-lipid-soluble
15
Q
Target cells
A
tissues with receptors for a specific hormone
16
Q
Hormone act on target cells any of the following:
A
- Alter plasma membrane permeability and/or membrane potential by opening or closing ion channels
- Stimulate synthesis of enzymes or other proteins
- Activate or deactivate enzymes
- Induce secretory activity
- Stimulate mitosis
17
Q
Which hormone act on G protien?
A
Water-soluble hormones
18
Q
Amino acid–based hormones, except thyroid hormone, exert effects through
A
second-messenger systems
19
Q
Cyclic AMP (cAMP) signaling mechanism
A
- Hormone (first messenger) binds to receptor
- Receptor activates a G protein
- G protein activates or inhibits effector enzyme adenylate cyclase
- Adenylate cyclase then converts ATP to cAMP (second messenger)
- cAMP activates protein kinases that phosphorylate (add a phosphate) other proteins
20
Q
PIP2-calcium signaling mechanism
A
Hormone-activated G protein activates a different effector enzyme: phospholipase C
-splits into two second messengers
- Diacygylcerol
- Inositol Trisphosphate
21
Q
Lipid soluble hormone mechanism
A
- hormone diffuses through plasma membrane and binds to intracellular receptor
- Receptor-hormone complex enters the nuclues
- receptor-hormone complex binds to specific DNA region
- transcription of gene to mRNA
- mRNA directs protein synthesis
22
Q
Blood levels of hormones controlled by
A
Controlled by negative feedback systems
Increased hormone effects on target organs can inhibit further hormone release
23
Q
Hormone release is triggered by:
A
Endocrine gland stimuli
Nervous system modulation
24
Q
Endocrine glands are stimulated to synthesize and release hormones in response to one of three stimuli:
A
Humoral stimuli-Changing blood levels of ions and nutrients directly stimulate secretion of hormones
Neural stimuli-Nerve fibers stimulate hormone release
Hormonal stimuli-Hormones stimulate other endocrine organs to release their hormones
25
Nervous System Modulation
Nervous system can override normal endocrine controls
26
Target cell activation depends on three factors:
1.Blood levels of hormone
2.Relative number of receptors on/in target cell
3.Affinity (strength) of binding between receptor
and hormone
27
Up-regulation
target cells form more receptors in response to low hormone levels
Down-regulation: target cells los
28
Down-regulation:
target cells lose receptors in response to high hormone levels
Desensitizes the target cells to prevent them from overreacting to persistently high levels of hormone
29
steriods and thyroid hormone attached to
plasma protien
30
Hormones can be removed from blood by:
Degrading enzymes or
Kidneys or
Liver
31
lipid soluble hormones come from where?
Adrenal cortex, gonads, and thyroid gland*
32
Water-soluble hormones come from where
all other hormones
33
half-life of lipid soluble hormones
long
34
half-life of water soluble hormones
short
35
location of receptors for lipid soluble hormones
inside cell
36
Location of receptors for water-soluble hormones
on plasma membrane
37
Permissiveness
one hormone cannot exert its effects without another hormone being present
38
Synergism
more than one hormone produces same effects on target cell, causing amplification
39
Antagonism
one or more hormones oppose(s) action of another hormone
40
Hypothalamus is connected to pituitary gland (hypophysis) via stalk called
infundibulum
41
Posterior pituitary: composed of ____ that secretes ___
Neural issue, neurohormones
42
Posterior lobe, along with infundibulum make up the
neurohypophysis
43
Anterior pituitary: consits of
consists of glandular tissue
44
Posterior lobe Maintains neural connection to hypothalamus via
hypothalamic-hypophyseal tract
45
posterior lobe secretes
oxytocin-birth contractions, breast milk-> positive feedback
| ADH-antideretic, absorbs water from kidneys, causes vasoconstriction
46
anterior lobe consists of
Hyposphyseal portal system
Primary capillary plexus
Hypophyseal portal veins
Secondary capillary plexus
47
Hypothalamus secretes releasing and inhibiting hormones to
anterior pituitary to regulate hormone secretion
48
Diabetes insipidus
ADH deficiency,
| loose fluids, vasodilation
49
Syndrome of inappropriate ADH secretion (SIADH
ADH hyper secretion, retention of fluids
50
Anterior pituitary hormones, which ones are tropic and which ones are not
- Growth hormone (GH)
- Prolactin (PRL)
tropic:
Thyroid-stimulating hormone (TSH) (tropic)
Adrenocorticotropic hormone (ACTH) (tropic)
Follicle-stimulating hormone (FSH) (tropic)
Luteinizing hormone (LH) (tropic)
51
Growth hormone
Produced by
Direct actions on
Dont take in
- produced by somatotropin cells
- direct actions of metabolism
- don't take in glucose, use fatty acids
52
hyper secretion of GH
gigantism in children- 8ft tall
| acromegaly-overgrowth of hands, feet, and face
53
hyposecrection of GH
| Adults vs. Children
children-pituitary dwarfism-4ft
| in adults no problem
54
thyroid-stimulating hormone
stimulates normal development and secretory activity of thyroid
55
hypothalamus, anterior pituitary gland, target cells
releasing, stimulation, hormone
56
Adrenocorticotropic hormone
stimulates adrenal cortex to release corticosteroids
57
Gonadotropins (FSH and LH)
FSH stimulates production of gametes (egg or sperm)
LH promotes production of gonadal hormones
testosterone, estrogen, progesterone
58
Prolactin (PRL)
-stimulates milk production
59
thyroid gland shape
butterfly shaped gland
60
Isthmus
median mass connecting two lateral lobes of thyroid
61
Follicles:
hollow sphere of epithelial follicular cells that produce glycoprotein thyroglobulin
62
Colloid
fluid of follicle lumen (middle portion_ contains thyoglobulime
63
Thyroid produces hormones called:
t4 (thyroxine)-two tyrosine, 4 iodine
t3-(triiodothyronine)-two tyrosine's, 3 iodine
64
thyroid hormone effects
basal metabolic rate and heat production, tissue and growth development, maintains blood pressure
65
thyroid hormone synthesis 7 steps
1. thyroglobulin is made
2. iodine goes into cell and put into lumen (colloid)
3. iodine becomes oxidized
4. iodine attaches to tyrosine to form DIT and MIT
5. DIT and MIT join to make T3 and T4
6. thyroglobulin endocytose and joined with lysosome
7. lysosome cleave t3 and t4 and form the thryogobuline and hormones diffuse into blood stream
66
myxedema
hypo secretion of TH, low metabolic rate, puffy eyes, constipation, lethargy
67
goiter
lack of iodine, decreases TH levels
68
cretinism
hyposecretion of TH in infants, intellectual disabilities and short body size
69
Graves disease
hyper secretion of TH, elevated metabolic rate, eyes protrude
70
calcitonin
antagonist to parathyroid hormone, inhibits osteoclast activity
71
parathyroid hormone
4-8 yellow-brown glands embedded in posterior aspect of thyroid
72
parathyroid hormone function
stimulate osteoclasts to digest bone matrix and release Calcium into blood.
- enhances reabsorption of calcium and secretion of phosphate by kidneys
- increase activation of vitamin D in kidney
73
Hyperparathyroidism
due to parathyroid gland tumor
| Calcium leaches from bones, causing them to soften and deform
74
Osteitis fibrosa cystica
severe form resulting in easily fractured bones,
| to much parathyroid hormone
75
Hypoparathyroidism
following gland trauma or removal can cause hypocalcemia
| Results in tetany (muscles contract and can't reverse, respiratory paralysis, and death
76
adrenal gland
-pyramid shaped on top kidneys
-adrenal cortex- three layers
adrenal medulla-nervous
77
adrenal cortex produces
corticosteroids
Zona glomerulosa
Zona fasciculata
Zona reticularis
78
Zona glomerulosa
Mineralocorticoids-aldosterone-stimulates Na+ reabsorption and K+ elimination in kidneys
79
Zona fasciculata
Glucocorticoids-cortisol
80
Zona reticularis
Gonadocorticoids-androgens
81
adrenal medula releases
epinephrine and norepinephrine
82
aldosteron regulators
Renin-angiotensin-aldosterone mechanism- kindey-relases renin, produces, angiotensin II stimulates aldosterone release
Plasma concentration of K+- K+ in blood increases stimulates release of aldosterone
ACTH (adrenocorticotropic hormone)-stress, anterior pituitary releases ACTH, stimulates release of aldosterone
Atrial Natriuretic peptide-increase blood pressure and/or blood volume, releases ANP, releases aldosterone
83
Aldosteronism
hypersecretion usually due to adrenal tumors, hypertension
84
Glucocorticoids function
Increase blood glucose during lonterrm stress
Influence metabolism of most cells and help us resist stressors
Keep blood glucose levels relatively constant
-cortisonl causes increase in blood levels of glucose
85
Cushing's syndrome/disease
hyper secretion of glucocorticoids, cortisol
depresses cartilage/bone formation, immune system
moon face, buffalo hump
86
Addison's disease
hypo secretion of mineralocorticoids
| decrease in glucose, weight loos, sever dehydration
87
Gonadocorticoids
weak androgens
88
Adrenogenital syndrome
masculinization
- Not noticeable in adult males
- females and prepubertal males
- boys- reproductive organs mature
females: beard clitoris resembles small penis
89
Catecholamines: epinephrine, norepinephrine effects
-vasoconstriction
| increase heart rate and blood glucose levels
90
Hyposecretion and Hypersecretion
| of catecholamines
Hyposecretion
-no problems
Hypersecretion
hyperglycemia, increased metabolic rate, rapid heart beats
91
Pineal gland
melatonin,
- Timing of sexual maturation and puberty
- Day/night cycles
- Physiological processes that show rhythmic variations (body temperature, sleep, appetite)
- Production of antioxidant and detoxification molecules in cells
92
Pancreas has both
```
exocrine and endocrine cells
Acinar cells(exocrine)
Pancreatic islets (edoncrine0
-alpha
-beta
```
93
Acinar cells
produce enzyme-rich juice for digestion
94
Pancreatic islets
| alpa and beta
- Alpha (α) cells produce glucagon (hyperglycemic hormone)
| - Beta (β) cells produce insulin (hypoglycemic hormone)
95
Glucagon
Glycogenolysis
Glucogenesis
Extremely potent hyperglycemic agent
Glycogenolysis-break down gylogen to glucose
Glucogenesis -sythesize glucose
96
Insulin
Secreted when blood glucose levels increase
| -lowers blood glucose
97
Diabetes mellitus (DM) can be due to:
Hyposecretion of insulin: Type 1
| Hypoactivity of insulin: Type 2
98
Glycosuria
excess glucose is spilled into urine
99
polyuria
polydispia
polyphagia
ketonuria
Polyuria: huge urine output
Glucose acts as osmotic diuretic
Polydipsia: excessive thirst
From water loss due to polyuria
Polyphagia: excessive hunger and food consumption
Cells cannot take up glucose and are “starving”
ketonuria: ketone bodies in urine
100
Hyperinsulinism
Excessive insulin secretion
Causes hypoglycemia: low blood glucose levels
Symptoms: anxiety, nervousness, disorientation, unconsciousness, even death
Treatment: sugar ingestion
101
Gonads produce same steroid sex hormones as those of adrenal cortex, just
more amounts than adrenal cortex
102
Ovaries produce
estrogens and progesterone
103
Estrogen
Maturation of reproductive organs
Appearance of secondary sexual characteristics
With progesterone, causes breast development and cyclic changes in uterine mucosa
104
Testes produce
testosterone
- Initiates maturation of male reproductive organs
- Causes appearance of male secondary sexual characteristics and sex drive
- Necessary for normal sperm production
- Maintains reproductive organs in functional state
105
Placenta
secretes estrogens, progesterone, and human chorionic gonadotropin (hCG)
