hormones and skin Flashcards
what are hormones
chemical substances produced by a gland and carried by the blood, which alter activity of one or more specific target organs
some role of hormones are:
homeostasis
growth
reproduction
what are endocrine glands
ductless glands that secrete hormones directly into the blood
what secrete substances - not hormones- through a duct eg. salivary glands
exocrine glands
what gland is the pancreas
both endocrine and exocrine (secrete insulin + glucagon and digestive enzymes)
what are the major endocrine glands
Male:
pituitary gland
thyroid gland
adrenal gland
pancreas
testis
Female:
pineal gland
thyroid gland
adrenal gland
pancreas
ovary
what is homeostasis
the maintenance of a constant internal environment
what is secreted from the adrenal gland
adrenaline= in fight or flight situations
what is secreted from the pancreas
insulin & glucagon= regulation of blood glucose levels
what is secreted from the ovaries
oestrogen= development of female secondary sexual characteristics, control of menstrual cycle and pregnancy
what is secreted from the testes
testosterone= development of male secondary sexual characteristics
what is secreted from the pituitary gland
FSH,LH= control of menstrual cycle and pregnancy
what are the effects of adrenalin
- pupil dilation
- faster and deeper breathing (more O2 supply + more CO2 removal)
- increased pulse rate (more O2 and glucose supply + more CO2 removal)
- increased blood glucose concentration (target: live, which converts stored glycogen to glucose and releases it into the blood)
what is negative feedback
the system of control in which a change triggers responses that counteract the charge ie. is the level of something rises, the control systems reduce it again
what happens if blood glucose increases
pancreas secretes insulin
liver takes up excess glucose and converts it to glycogen for storage
blood glucose decreases
what happens if blood glucose decreases
pancreas secretes glucagon
liver converts glycogen to glucose and releases it into the blood
blood glucose increases
what are the symptoms of diabetes
- high blood glucose levels
- glucose detected in urine
- thirst, frequents urination, weight loss
what is the cause of diabetes type 1
results from failure to produce insulin, autoimmune disease
what is an autoimmune disease
when the immune system can’t tell the difference between your own cells and foreign cells, causing the body to mistakenly attack normal cells
what is the treatment for diabetes
insulin injections, regulated diet, exercise
how does the body lose heat
through the skin by conduction, convection, radiation, evaporation
how does the body gain heat
internally from respiration and externally from surroundings
why is temperature control important
enzymatic reactions, diffusion, etc
what do hair erector cells do
contracts to raise hairs
what does the epidermis of the skin do
protect from UV light
what are the three layers of skin
epidermis
dermis
fatty tissue
what does your body do if you are overheating
vasodilation
sweating
hairs lie flat so heat can escape
what does the body do if you are overcooling
vasoconstriction
shivering
hairs erect and trap air
sweating stops
