ENDOCRINE SYSTEM Flashcards
What are the 6 glands/organs of the endocrine system?
- Hypothalamus
- Pituitary gland
- Thyroid gland
- Adrenal gland
- Pancreas
- Parathyroid gland
What are the functions of the endocrine system?
- Regulates metabolism, water and electrolyte balance
- allows body to cope with stress, trauma and infection
- regulates growth
- controls reproduction
- regulates circulation and red blood cell production
- controls digestion and absorption of food
- regulates sleep
What do the endocrine and nervous system have in common?
- Target cell: needs specific receptor
- use chemical messengers (hormones and neurotransmitters)
- may have same chemical messengers - e.g., adrenaline/nonadrenaline
- usually negative feedback
- homeostasis
What is a hormone?
- Blood-borne chemical messenger: non-specific distribution
- Specific target: most hormones only affect a few types of cells, specific receptor
- Low concentration
Where is the pituitary gland located?
lies beneath hypothalamus with the optic chiasm (optic nerves crossing) between
What is the function of the posterior pituitary?
- Stores and releases hormones produced by the hypothalamus
- Connected by nerve fibres (hypothalamus to posterior)
What is the function of the posterior pituitary?
Releasing and inhibiting hormones from the hypothalamus, control release of anterior pituitary hormones
Where is the thyroid located and what hormones does it secrete?
- located in front of throat, between larynx and trachea
- secretes hormones
thyroxine, T4, T3 - Takes iodine and converts it into thyroid hormones
- also secretes calcitonin (decreases blood calcium)
What is the function of the thyroid hormones?
- Increase basal metabolic rate (increased heart function)
- stimulates protein synthesis and usage of fuels (to make ATP)
- enhanced sympathetic activity
What do the adrenal glands secrete?
- Adrenaline and noradrenaline
- releases glucose
CVS effects of adrenal glands
- Increases cardiac output (HR and SV)
- vasodilation of coronary and skeletal muscle blood vessels
- bronchodilation
- vasoconstriction
If BGL gets too high, how is homeostasis maintained?
Insulin is released (glycogenesis)
If BGL gets too low, how is homeostasis maintained?
glucagon is released (glycogenolysis, lipolysis, gluconeogenesis)
Define antagonistic and synergistic hormones
Antagonistic hormones - oppose each other’s actions
Synergistic hormones - their effects together are greater than the sum of their effects alone
