Hormones and endocrine system Flashcards
how animals respond to changes in their internal environment
-changes in blood glucose level
-changes in osmotic pressure
how animals respond to changes in their external environment
-changes in temperature
-response to danger
what do communication system do
-detect changes
-generate appropriate responses
what nervous and endocrine system do
-work together in a coordinated and complimentary to achieve response
difference between Nervous and Hormonal system
hormonal system is:
-slow
-lasts longer
-it is widespread
Nervous system is:
-fast almost instantaneous
-short lived
-it is localised
name the major endocrine glands in human
-hypothalamus
-pineal gland
-pituitary gland
-thyroid gland
-parathyroid gland
-thymus
-adrenal glands (atop kidneys)
-pancreas
-Ovary (female)
-testes (Male)
what do hormones do?
- maintain homeostasis
- are secreted by endocrine (ductless) glands
directly into the bloodstream
-reach all parts of the body
react with specific receptor on target cells
-minute quantities produce significant effects
Different effects of Epinephrine hormone on the system?
- on alpha receptor , vessel constricts - effect intestinal blood vessel
-on Beta receptor, vessel dilates - effect on skeletal muscle blood vessel
another effect on Beta receptor - glycogen deposits , glycogen breaks down and glucose is released from cell
-effect on liver cell
what are 3 types of hormones?
proteins (water soluble)
-insulin, glucagon
amines (either water or lipid soluble)
-synthesised from amino acids usually tyrosine
-adrenaline
steroids (lipid soluble)
-cortisol, oestrogen and progesterone
describe lipid soluble hormones
- pass through the target cell membrane
-bind to an intracellular receptor
-Hormone receptor complex binds to DNA
*turns specific genes on or off
*new protein is synthesised
now describe water soluble hormones
-bind to receptors
* cell membrane target cell
-receptor protein
*activates a signal transduction pathway
-series of relay molecules
*transmits the signal
-cell response occurs
name 2 antagonistic
insulin and glucagon
describe the control of glucose with negative feedback
in the pancreas
alpha cells release glucagon
beta cells release insulin
when the blood glucose level rise, release of insulin triggers glucose uptake from blood
when the blood glucose level decrease, release of glucagon into blood
symptoms of hypothyroidism
weight gain
lethargy
cold
Intolerance
symptoms of Hyperthyroidism
weight loss
tremor
sweating
Hyperactivity
graves d
ophthalmology
