week 8 Flashcards
(20 cards)
what is the role of the endocrine system?
controls and monitors bodily functions using hormones
what’s the difference between endocrine and exocrine glands?
endocrine glands- secrete hormones directly into the bloodstream
exocrine glands- excrete externally (sweat, saliva)
what are the two classifications of hormones?
steroid hormones: lipid-based, from adrenal cortex and reproductive glands
amino acid hormones: protein-based, more common
what are the modes of action of hormone receptors?
- change cell permeability
- alter enzyme activity
- stimulate protein synthesis
- influence secretory activity
hormones affect only tissues/organs with their specific receptors
what is neural hormone secretion control?
- nerve fibres stimulate hormone release (e.g. adrenaline during fight or flight)
what is hormonal control?
- hypothalamus directs pituitary glands and guides other endocrine glands
- terminated by negative feedback loops
what is humoral control with an example?
- monitors and regulates substances in bodily fluids and takes action with imbalances
- high glucose in blood, insulin is released to help absorb it
what is the hypothalamus and its role?
integrates nervous+endocrine systems, produces hormones that control hypothalamus
what is the function of the pituitary gland?
secretes hormones, has anterior and posterior lobes
what are the hormones secreted by the anterior pituitary lobe and their functions?
- growth hormone (muscles, cartilage, bones)
- prolactin (milk production)
- adrenocorticotropin hormone (adrenal cortex release steroid hormones)
- thyroid stimulating hormone (release thyroxine, triiodothyronine)
- follicle-stimulating hormone (oestrogen, eggs, sperm)
- lutenizing hormone (ovaries: egg release, testes: testosterone)
what are the hormones secreted by the posterior pituitary lobe and their functions?
stores ADH and oxytocin
antidiuretic hormone
- body water levels
- lower urine, higher reabsorption
oxytocin
- labour, muscle contraction
what two hormones does the thyroid gland secrete?
thyroid hormone
- energy, metabolism, heat production
calcitonin
- calcium homeostasis
- lowers blood calcium (less absorption)
what does the parathyroid hormone release?
parathyroid hormone
- increases calcium levels
what hormone does the thymus gland secrete
thymosin
- t-lymphocyte development
- immune response
what are the hormones produced by adrenal glands and their functions?
adrenal medulla hormones
- adrenaline, noradrenaline
adrenal cortex hormones
- steroid hormones
- mineralocorticoids (main=aldosterone=sodium/water reabsorption in kidney, blood pressure)
- glucorticoids (main=cortisone, cortisol=glucose levels)
- sex hormones (estrogens, androgens:testosterone)
why is the pancreas both an endocrine and exocrine gland?
the pancreas releases hormones (endocrine) and digestive enzymes (exocrine)
what are Islets of Langerhans in the pancreas?
maintains blood glucose levels
alpha cells (secrete glucagon)
metal cells (secrete insulin)
what are the roles of insulin and glucagon?
insulin promotes glucose uptake and converts excess glucose into glycogen or fat, lowers glucose
glucagon converts glycogen into glucose and raises blood glucose levels
what are the functions of testes and ovaries ?
testes produce sperms and testosterone
ovaries produce eggs, oestrogen, progesterone, regulate menstrual cycle and breast development
what are the organs that produce these hormones and their function: erythropoietin, leptin, atrial natriuretic peptide, digestive hormones
erythropoietin- kidneys, stimulates red blood cell production
leptin- adipose tissue, suppresses appetite, increases energy
atrial natriuretic peptide- heart, stimulates sodium excretion
digestive hormones- stomach and intestines
