4.5 Endocrine System Part B Flashcards
What are steroids?
Hormones or chemical substances
What are hormones derived from?
The lipid molecule cholesterol
What elements are steroids composed of?
They are composed of carbon, hydrogen, and oxygen rings
What is a characteristic of steroids in terms of solubility?
Steroids are soluble in water
Where in the body are steroids made?
Made in the adrenal glands and gonads
Where the adrenal gland located?
Above the kidney (on top of the kidney)
How many adrenal glands are there?
Two
What is the outer adrenal cortex regulated by?
Hormones Cortisol and aldosterone
What is the inner adrenal medulla regulated by?
Nerves epinephrine and norepinephrine
What is estrogen?
Secondary sexual characteristic in females
What is estrogen used for? EPM
Egg production
Pregnancy preparation
Regulation of menstrual cycle
What is progesterone used for in the body? BPR
Regulation of female menstrual cycle
Pregnancy preparation
Birth preparation
What is testosterone?
Secondary sexual characteristics in males
What is testosterone use for?
The production of sperm
What some gonoic steroids?
Estrogen, progesterone, testosterone
what is secreted during a stress reaction? what affect does this reaction have?
An enhance secretion of a number of hormones such as glucocorticoids catecholemine, growth hormone and prolactin. This effect increases the movement of energy sources and adapt an individual to new circumstances
What does glucocorticoids or cortisol promote the conversion of? how does it increase blood sugar?
The hormone promotes the conversion to amino acids to glucose by increasing fat breakdown to fatty acids. It also decreased glucose uptake by the muscle cells and brings about an increase in blood sugar in response to stress
Where are catecholamines released from? what does this reaction cause? (8)
Pituitary releases catecholamines. This leads to increased cardiac output (the quantity of blood pumped by the heart in a given period of time), skeletal muscle blood flow, sodium retention, reduces intestinal movement, cutaneous (skin) vasoconstriction (thermoregulatory response to cold exposure), increased glucose, bronchiolar dilatation and behavioral activation.
when is vasopressin released? Where is it released from? what does it stimulate the release of? During chronic stress, what is there a preferentiable expression of?
Acute stress leads to the rapid release of vasopressin from the hypothalamus along with the corticotropin-releasing hormone or CRH. Vasopressin can also stimulate the secretion of the Adrenocorticotropic hormone ACTH from the pituitary thereby enhancing the effect of CRH. During chronic stress, there is a preferential expression of hypothalamic vasopressin over CRH. This has the effect of decreasing hypothalamic response by negative feedback – thereby keeping stress hormones consistently high.
what happens to gonadotropins during stress? what does this cause? what can prolong exposure to stress cause? what happens to the gonadotropin releasing hormone?
In stress, there is suppression of circulating gonadotropins and gonadal steroid hormones leading to disruption of the normal menstrual cycle. Prolonged exposure to stress can lead to complete impairment of reproductive function. Gonadotropin-releasing hormone (which stimulates sex hormone release) to the pituitary is decreased, due to increased endogenous (internal) CRH secretion.
what happens to thyroid during stressful conditions? T3 and T4 levels? what happens to the thyroid stimulating hormone?
Thyroid function is usually down-regulated during stressful conditions. T3 and T4 levels (a measure of thyroid hormones) decrease with stress. Stress inhibits the thyroid-stimulating hormone (TSH) secretion through the action of glucocorticoids (ACTH, cortisol) on the central nervous system.
What type of stress releases the growth hormone? what happens to growth hormone levels during stress? what are the effects of growth hormones during psychological stress?
The growth hormone (GH) level is increased during acute physical stress. The level can increase up to two- to tenfold. Because of its insulin-antagonistic effect (does not like insulin), growth hormone may enhance metabolic activity. In psychological stress, however, growth hormone responses are rarely seen. Rather there is a growth hormone secretory defect with prolonged psychosocial stress.
what can happen to prolactin levels during stress
Depending on the local regulatory environment at the time of stress, prolactin levels can either increase or decrease. However, the significance of the change in the prolactin level is uncertain. It may affect the immune system or some aspect of homeostasis.
what happens to insulin during stress?
Insulin may decrease during stress. This along with an increase in its antagonistic hormones can contribute to stress-induced hyperglycemia.
what is the function of white adipose tissue? het
control hunger
energy expenditure
body temperature
