C14 - Hormonal Communication Flashcards
What is the role of an endocrine gland?
Secrete hormones into blood stream
Describe the role of the pituitary gland
Secrete
- growth hormone for bones and muscles
- ADH - increases reabsorption of water in kidney
- Gonadotrophins - development of ovaries and testes
Describe the role of the pineal gland
secrete
- melatonin - reproductive development and daily cycles
Describe the role of the thyroid gland
secrete:
- thyroxine - controls rate of metabolism, rate at which glucose is used in respiration, promotes growth
Describe the role of the thymus
secretes:
-thymosin - promotes production and maturation of WBCs
Describe the role of the adrenal gland
secretes:
- adrenalin - increases heart rate, breathing and blood glucose levels
Describe the role of the glands in the pancreas
secrete:
- insulin - converts glucose to glycogen
- glucagon - converts glycogen to gluose
Describe the role of the glands in the testis
secrete:
-testosterone - sperm production and secondary sexual characteristics
Describe the role of the glands in the ovary
Secrete:
- oestrogen - ovulation and secondary sexual characteristics
- progesterone - prepares uterus lining for receiving an embryo
Compare Nervous and hormonal communication
(DS SPITS) Duration ---N (short) H (slow and long) Speed ----N (fast) H (slow) Structures ----N (neurones) H (glands/secretory cells) Pathway ----N (neurones) H (bloodstream) Information ----N(electrical impulses) h (hormones/chemicals) Target ----N(localised) H(whole organ/tissue) Similarities ----cell signalling
How do steroid hormones work
hormones that can work their way through the phospholipid bilayer, binding to proteins, act as TRANSCRIPTION factor to effect change
What are the chemical properties of steriod hormones
Derived from cholestrol
hydrophobic
insoluble in water
How do non-steroid hormones work
bind to receptor on plasma membrane
affect cellular processed through second messengers
Give an example of a second messenger
CAMP
What are the chemical properties of non-steriod hormones
proteins
water soluble
What hormones are produced in the adrenal medulla?
Adrenelin
What hormones are produced in the adrenal cortex?
- cortisol
- aldosterone
- androgen
What is cortisol?
Steroid hormone produced in adrenal cortex
increases blood sugar levels
acts on GLUCOCORTICOID receptor in nulceus
What is aldosterone?
Steriod hormone produced in adrenal cortex
controls blood pressure and sodium conversion in kidney
MINERALCORTICOID receptor in nucleus
What is androgen?
Steriod hormone produced in adrenal cortex
precursor to testosterone and oestrogen
What is adrenaline?
non-steriod hormone produced in adrenal medulla
controls fight/flight response and glycogenolysis (which will increase blood sugar levels)
What part of the nervous system controls the production of noradrenaline?
Autonomic sympathetic
What part of the nervous system controls the production of acetylchloine?
Autonomic parasympathetic
Describe how adrenaline acts on a cell to increase the availability of glucose
Adrenalin binds to receptor site on cell surface membrane
Enzyme (adenylyl cyclase) inside membrane is activated
ATP converted to CAMP (second messenger)
CAMP activates a cascade of enzymes that eventually convert glycogen to glucose
Describe the process in the body (starting at the amygdala) that result in the release in adrenalin in bloodstream
amygdala sends signal to hypothalamus
Sympathetic NS activated
noradrenaline released
causes adrenal medulla to release adrenaline
Describe the process in the body (starting at the amygdala) that result in the release in cortisol etc. in bloodstream
amygdala sends signal to hypothalamus
pituatory gland releases ACTH (precursor to cortisol)
Arrive at adrenal cortex
Converted and released
In the pancreas, what is resposible for digestive enzymes?
Acini cells
In the pancreas, what is resposible for blood sugar hormones?
Islets of langerhans
alpha - glucagon
beta - insulin
What. is the name of the process converting glycogen to glucose
glycogenolysis
What. is the name of the process converting glucose to glycogen
Glycogenesis
What. is the name of the process producing glucose from non-carbohydrate sources
Gluconeogenesis
Describe how an increase in glucose leads to insulin being released
Resting potential in cell (-70mV)
BS levels rise - Glucose enters cell via facilitated diffusion
Glucose is matabolised and ATP is produced
ATP binds to K channels, causing them to close
K+ can not diffuse out, pd rises (-30mV)
Voltage gated Ca2+ channels rise
Ca2+ enter cell, causing excretory vesicles to release insulin via. exocytosis
What is type 1 diabetes?
loss of beta cells
failure to produce enough insulin
genetic predispoition/autoimmune
What is type 2 diabetes?
- failure to respond to insulin
- caused - excessive body weight/ insufficient excercise
What are the symptoms of diabetes?
Weight loss
Hunger
Tiredness
Glucose in urine
What are the treatments for diabetes?
Type 1 - regular BS monitoring insulin injection Type 2 - drugs - exercise -regulation of food
Pancreatic transplants
What controls our heart rate
Autonomic NS
Medulla oblongata
What do the 2 centres in the Medulla oblongata that control our heart rate do?
1- increase bpm sympathetic ns accelerator nerve 2- decrease bpm - parasymapthtic ns vagus nerve
What are 2 receptors that help control our bpm and where are they found
Barorecetors blood pressure aorta, vena cava, carotid arteries Chemoreceptors - conc of chemicals eg. CO2 aorta, cartoid artery, medulla
How do receptors change our bpm
Impulses sent to SAN, thus changing bpm
How do Adrenaline and noradrenaline change our heart rate
Change frequency of SAN impulses directly
