AnP Chapter 13 (LO2) Flashcards
1
Q
Endocrine System
A
Consists of glands and clusters of hormone secreting cells in various organs including the brain, heart and small intestines
2
Q
Hormones
A
chemicals that influence almost every cell and organ in the body
3
Q
The endocrine system communicates through —– acting hormones placing it in charge of processes that happen more —– such as —-
A
The endocrine system communicates through slower acting hormones placing it in charge of processes that happen more slowly such as growth
4
Q
Endocrine glands
Exocrine glands
A
Endocrine glands: ductless and secrete hormones directly into the blood
Exocrine glands: secrete to surface
5
Q
Target cells
A
cells having receptors for that hormone
6
Q
Specificity
A
a hormone that acts only on cells with recpetors specific to that hormone
7
Q
Comparison of the endocrine and nervous systems
A
Endocrine system
Employs hormones to relay messages
Distributes hormones throughout the body via the bloodstream
Responds slowly to stimuli
Exerts long lasting effects
Adapts slowly to continual stimulation
Nervous system
Employs neurotransmitters to relay messages
Secretes neurotransmitters into tiny space of a synapse
Responds to stimuli quickly
Exerts short lived effects
Adapts quickly to continual stimulation
8
Q
Pituitary gland
A
exerts more influence on body processes than any other endocrine gland
pea sized and sits under hypothalamus cradled the sella turica
Pituitary gland is 2 distinct glands: anterior pituitary (adenohypophysis) and posterior pituitary (neurohypophysis)
9
Q
Anterior pituitary
A
larger, consists of glandular tissue
Synthesizes and secretes a number of very important hormones under the direction of the hypothalamus
10
Q
Releasing hormones
Inhibiting hormones
A
Releasing hormones: stimulate the anterior pituitary to secrete its hormones
Inhibiting hormones: suppress hormone secretion by the anterior pituitary
11
Q
Hypophyseal portal system
A
a system of blood vessels that the neurons of the hypothalamus release their hormones into
12
Q
Tropic (trophic):
A
hormones stimulate other endocrine cells to release their hormones
13
Q
Thyroid stimulating hormone (thyrotropin)
A
stimulates the thyroid gland to secrete thyroid hormone
14
Q
Growth hormone (somatotropin)
A
acts on the entire body to promote protein synthesis, lipid and carbohydrate metabolism and bone and skeletal muscle growth
15
Q
Prolactin
A
stimulates milk production in the mammary glands in females
In males it may make the testes more sensitive to LH
16
Q
Luteinizing hormone (LH)
A
a gonadotropin stimulates ovulation and estrogen and progesterone synthesis in females and the secretion of testosterone by the testes in males
17
Q
Adrenocorticotropic hormone (ACTH)
A
stimulates the adrenal cortex to secrete corticosteroids
18
Q
Follicle-stimulating hormone (FSH)
A
one of the gonadotropins-stimulate the production of eggs in the ovaries of females and sperm in the testes of males
19
Q
Acromegaly
A
when the epiphyseal plates have already fused when the hypersecretion occurs cartilage will form new bone causing hands, feet, face and jaw to enlarge
20
Q
Gonadotropin-releasing hormone
A
promotes secretion of FSH and LH
21
Q
Thyrotropin-releasing hormone
A
promotes secretion of TSH
22
Q
Corticotropin-releasing hormone
A
promotes secretion of ACTH
23
Q
Prolactin-releasing hormone
A
promotes secretion of prolactin
24
Q
Prolactin-inhibiting hormone
A
inhibits secretion of prolactin
25
Growth hormone- releasing hormone
promotes secretion of GH
26
Somatostatin
inhibits secretion of GH and TSH
27
Posterior pituitary
Made of neural tissue
Stores hormones synthesized by the hypothalamus
Hormones stored by the posterior pituitary are antidiuretic hormone (ADH) and oxytocin (OT)
28
Posterior pituitary How it works
The nerve fibers form the posterior pituitary originate in the hypothalamus
They hypothalamic neurons synthesize hormones which send down to the posterior pituitary to be stored
The posterior pituitary holds the hormones until stimulated by the nervous system to release them
29
Oxytocin
stimulates contraction of the uterus during childbirth
It also triggers the release of milk from the breasts during lactation
30
Antidiuretic hormone (ADH)
acts on the kidneys to reduce urine volume and prevent dehydration
Also called vasopressin
31
Hormone: GH: growth hormone (somatotropin)
- -target
- -principal effects
target
Throughout body including liver, bone, muscle and fat
principle effects
Growth and repair through the breakdown of proteins and fats
32
Hormone: PRL: Prolactin
- -target
- -principal effects
target
Mammary glands
effects
Milk secretion
33
Hormone: TSH: thyroid-stimulating hormone
- -target
- -principal effects
target
Thyroid gland
effects
Growth of the thyroid gland and secretion of thyroid hormone
34
Hormone: ACTH: adrenocorticotropic hormone
- -target
- -principal effects
target
Adrenal cortex
effects
Growth of and secretion of corticosteroids by the adrenal cortex
35
Hormone: FSH: follicle-stimulating hormone
- -target
- -principal effects
target
Ovaries; testes
effects
Female: growth of ovarian follicles and secretion of estrogen
Male: sperm production
36
Hormone: LH: luteinizing hormone
- -target
- -principal effects
target
Ovaries; testes
effects
Female: ovulation; maintenance of corpus luteum
Male: secretion of testosterone
37
Hormone:ADH: antidiuretic hormone
- -target
- -principal effects
target
Kidneys
effects
Water retention
38
Hormone:OT: oxytocin
- -target
- -principal effects
target
Uterus; mammary glands
effect
Stimulation of uterine contractions; stimulation of release of milk into ducts of mammary glands
39
anterior pituitary hormones include
GH: growth hormone (somatotropin)
PRL: Prolactin
TSH: thyroid-stimulating hormone
ACTH: adrenocorticotropic hormone
FSH: follicle-stimulating hormone
LH: luteinizing hormone
40
posterior pituitary hormones include
ADH: antidiuretic hormone
OT: oxytocin
41
Control of Pituitary Secretions
Releases hormones in phases or pulses
Central nervous system plays a role in controlling hormone secretion
42
Control of pituitary secretions by negative feedback
when the pituitary gland stimulates another endocrine gland ti secrete its hormone that hormone is then fed back to the pituitary telling it to stop further release of the tropic hormone
43
Pineal Gland
Produces melatonin
Tucked in the center of the brain on the roof of the brains third ventricle is the tiny, cone shaped pineal gland
44
Thymus
Secretes thymosin and thymopoietin which have roles in the immune system
Lies in the mediastinum just beneath the sternum
In children thymus gland Is large
45
Thyroid gland
Largest endocrine gland
Consists of two large lobes
Resides in the neck, just below the trachea where it is wrapped around the anterior and lateral portions of the trachea
can store hormones for later use
46
Isthmus
narrow band of tissue that connects the two lobes of thyroid gland
47
Thyroid follicles
tiny sacs that make up thyroid tissue
48
Thyroid colloid
thick fluid that fills each thyroid follicle
49
Sacs secrete 2 thyroid hormones
T3 (triiodothyronine) and T4 (Thyroxine)
50
Parafollicular cells
cells between the thyroid follicles that secrete the hormone calcitonin
51
Calcitonin
secreted when calcium levels rise, it triggers the deposition of calcium in bone thus promoting bone formation
52
Cretinism
condition characterized by retarded growth and sexual development, a low metabolic rate and mental retardation
53
Myxedema
swelling and firmness of the skin
54
Grave’s disease
results from a hypersecretion of TH that stimulates the bodys metabolism causing unexplained weight loss, increased heart rate, nervousness and exophthalmos
55
Exophthalmos
a protrusion of the eyeballs as a result of swelling of tissue behind the eye
56
Simple goiter
dietary deficiency of iodine
57
Parathyroid Glands
4 parathyroid glands located on the posterior surface of thyroid
58
Parathyroid hormone
secreted in response to low blood levels of calcium
Nerve and muscle function, blood clotting, cell membrane permeability, and the function of certain enzymes all depend on adequate calcium levels
59
PTH influence on bone
PTH inhibits new bone formation while stimulating the breakdown of old bone causing calcium to move out of bone and into the blood
60
PTH influence on kidney
PTH encourages the kidneys to reabsorb calcium while promoting the secretion of phosphate
Also prompts the kidneys to activate vitamin D necessary for intestinal absorption of calcium
61
PTH influence on intestines
after activation by the kidneys, vitamin D allows the intestines to absorb calcium from food; the calcium is transported through intestinal cells and into the blood
62
Regulation of Blood Calcium Levels
--Blood calcium excess
Blood calcium excess
Thyroid releases calcitonin
Calcium moves from blood to bone
Blood calcium levels decrease
Normal blood calcium levels
63
Regulation of Blood Calcium Levels
--Blood calcium deficiency
Blood calcium deficiency
Parathyroid releases PTH
Calcium moves from bones, kidneys, and intestines to blood
Blood calcium levels increase
Normal blood calcium levels
64
Triiodothyronine (T3) and Thyroxine (T4)
where its found
function
Most tissues
Increases rate of metabolism
65
Calcitonin
where its found
function
Bone
Increases deposition of calcium in bones lowering blood calcium levels
66
parathyroid hormone
where its found
function
Bone, kidneys
Increases blood calcium levels by increasing removal of calcium from bone reducing urinary excretion of calcium and increasing absorption of calcium by the intestines
67
Adrenal Glands
Perch on top of each kidney
Two distinct glands: adrenal medulla and adrenal cortex
68
Adrenal medulla
the inner portion, consists of modified neurons and functions as part of the sympathetic nervous system
69
Adrenal cortex
outer portion, 3 layers of glandular tissue and secretes corticosteroids
70
Corticosteroids
steroid hormones
71
Chromaffin cells
modified neurons that act as part of the sympathetic nervous system and secrete catecholamines
72
Catecholamines
prepare the body for physical activity by increasing heart rate and blood pressure
73
Adrenal medulla Boost glucose levels by:
Glycogenolysis: breaking down glycogen into glucose
Gluconeogenesis: converting fatty acids and amino acids into glucose
74
Zona glomerulosa
the outermost layer of the adrenal cortex
secretes glucocorticoids
75
Zona reticularis
the innermost layer of the adrenal cortex
secretes sex steroids
76
3 classes of hormones secreted by adrenal cortex
Mineralocorticoids:
Glucocorticoids:
Sex steroids
77
Mineralocorticoids:
aldosterone
78
aldosterone
the principal mineralocorticoids
Aldosterone acts on the kidneys to promote sodium retention and potassium excretion
In turn it also causes water retention
79
Glucocorticoids:
Cortisol:
80
Cortisol:
the principal glucocorticoids
Help the body adapt to stress and repair damaged tissue by stimulating the breakdown of fat and protein, converting fat and protein to glucose, and releasing fatty acids and glucose into blood
They have an anti inflammatory effect
They also suppress the immune system if secreted over a long term
Essential for maintaining a normal blood pressure
81
Sex steroids
Include a weak form of Androgen that is converted to the more potent androgen testosterone
Also includes small amounts of estrogen
82
Androgen
stimulate development of pubic and axillary hair and sustain sex drive in both sexes
83
hormone of adrenal medulla
Epinephrine
Norepinephrine
84
hormones of the adrenal cortex
Aldosterone
Cortisol
Adrenal androgens
Adrenal estrogens
85
hormone: epinephrine/norepinephrine
- -target
- -principal effect
Most tissues
Enhances the effects of the sympathetic nervous system
86
hormone: Aldosterone
- -target
- -principal effect
target
Kidney
effects
Promotes sodium retention and potassium excretion which leads to water retention
87
hormone: Cortisol
- -target
- -principal effect
target
Most tissues
effects
Stimulates the breakdown of fat and protein and the conversion of fat and protein to glucose; enhances tissue repair; anti inflammatory; in large amounts, inhibits the immune system
88
hormone: Adrenal androgens
- -target
- -principal effect
target
Sex organs
effects
Promotes growth of pubic and axillary hair; sex drive
89
hormone: Adrenal estrogens
- -target
- -principal effect
target
Sex organs
effects
Physiologically insignificant
90
Hypothalamic Pituitary Adrenal Axis
The amygdala signals the hypothalamus to activate the sympathetic nervous system and fight or flight response when a stressful event occurs
After 10 secs the initial surge of epinephrine begins to subside, the hypothalamic pituitary adrenal axis (HPA) axis is stimulated to help the body continue to cope
91
How it works Hypothalamic Pituitary Adrenal Axis
When stress continues the hypothalamus releases corticotropin releasing hormone (CRH)
CRH promotes the pituitary to release adrenocorticotropic hormone (ACTH)
ACTH travels to the adrenal cortex causing adrenal glands to secrete the glucocorticoid cortisol
Cortisol causing physiological changes design to give the body a burt of energy
92
Pancreas
Contains both endocrine and exocrine tissues
Majority acts like an exocrine gland
Lies just behind the stomach with its head tucked in the curve of the beginning of the small intestine and its tail reaching to the spleen
93
Acini
exocrine cells that secrete digestive enzymes into ducts that drain into the small intestine
94
Pancreatic islets (islets of Langerhans):
clusters of endocrine cells
Contain several different types of cells the main ones being alpha cells, beta cells, and delta cells
95
Alpha cells
Secrete glucagon
Gluconeogenesis between meals
96
Beta cells
Secrete the hormone insulin
After eating levels of glucose and amino acids in blood rise
97
Insulin
stimulates cells to absorb both of these nutrients from food causing blood glucose levels to fall
98
Delta cells
Secrete somatostatin
Inhibits release of glucagon, insulin and growth hormone
99
Somatostatin
A hormone that works within the pancreas to regulate the other endocrine cells
100
Regulation of Blood Glucose
Insulin and glucagon have opposite effects on levels of blood glucose which helps maintain blood glucose levels within normal range
101
how Regulation of Blood Glucose works
1. After eating blood glucose levels rise as glucose flows from the digestive tract into the bloodstream
2. High glucose levels stimulate beta cells of the pancreas to secrete insulin
3. Insulin triggers two reactions:
- --It stimulates the cells to take up more glucose
- --It cause the liver to take up glucose and store it as glycogen
- --The combined result is that glucose levels return to normal levels
4. When blood glucose levels drop below a certain point the alpha cells of the pancreas release glucagon into the blood
5. Glucagon stimulates the liver to break down stored glycogen into glucose which it then releases into the bloodstream
- --This causes the blood glucose level to rise
102
Diabetes
Results from an inadequate amount of insulin or from a diminished number of normal insulin receptors
103
Glycosuria
when excess glucose spills over into the urine
104
Polydipsia
kidneys produce more urine to flush out extra glucose
105
Polyphagia
people with untreated diabetes also experience continuous hunger
If left untreated the body begins to burn protein and fat for energy
106
Diabetic ketoacidosis
causing symptoms such as nausea, vomiting, fruity odor of the breath and possibly coma and death
107
Type 1 Diabetes
Average age at onset
Rate of onset
Percent of all diabetes
cause
Contributing factors
Treatment
Former name
Before age 30
Rapid
10%
Autoimmune condition in which the bodys antibodies attack the beta cells of thee pancreatic islets resulting in a deficiency of insulin
May be hereditary
Daily supplemental insulin, which may be administered by injection or via pump inserted under the skin in the abdomen
Juvenile-onset diabetes or insulin dependent diabetes mellitus
108
Type 2 Diabetes
Average age at onset
Rate of onset
Percent of all diabetes
cause
Contributing factors
Treatment
Former name
Usually after age 40
Gradual
90%
Cells become resistant to insulin in time the body stops producing enough insulin and the body can no longer use glucose effectively
Heredity combined with excess body weight. And sedentary lifestyle
Lifestyle change may control disease if not oral diabetic medications or insulin injections may be used
Maturity-onset diabetes or non-insulin dependent diabetes mellitus
109
hormone: glucagon
- target
- principal effects
target
-Primarily liver
effects
-Stimulates the break down of the stored form of glucose for release into the bloodstream
110
hormone: insulin
- target
- principal effects
target
-Most tissues
effects
-Stimulates the movement of glucose from the bloodstream into cells
111
hormone: Somatostatin
- target
- principal effects
target
-Pancreatic cells
effects
-Mainly helps regulate the secretion of other hormones of the pancreas
112
Gonads
Primary sex organs: Testes in males ovaries in females
Produce sex hormones
113
Estrogen
promotes the development of female characteristics and also contributes to the development of the reproductive system
114
Progesterone
helps maintain the uterine lining during pregnancy
secreted by the corpus luteum after ovulation
115
Certain cells in the body secrete other chemicals that help regulate function
Most significant is...
prostaglandins
116
prostaglandins
Made by cells throughout the body
Lipid molecules that integrate the activities of other cells
Released within the tissue where they are produced
Instead of influencing activities in distant organs prostaglandins influence activities of neighboring cells
Promote pain and fever, others act as vasodilators and vasoconstrictors
Involved in inflammation, blood clotting, uterine contraction, reproduction and digestion
