The endocrine system Flashcards
What is the endocrine system?
The endocrine system is a network of glands and hormones that is responsible for managing and maintaining bodily processes
What is the nickname for the pituitary gland?
The ‘master gland’
What is the function of the pituitary gland?
Some of the hormones released are important for regulating the endocrine system, hence the nickname ‘master gland’. Releases oxytocin, thought to be important for reproductive behaviour
What is the release of hormones by the pituitary gland controlled by?
The hypothalamus, the hypothalamus can therefore be seen to control and regulate the endocrine system in general
What do many of the hormones released by the pituitary gland do?
Control the secretions of other endocrine glands (rather than having a direct effect on cells and tissues in the body)
What is the function of the adrenal gland?
It is an important part of the fight or flight response as it facilitates the release of adrenaline
What is the function of the thyroid gland?
Produces thyroxine. This hormone affects cells in the heart (increases heart rate) and also affects metabolic rates which in turn affects growth rate
What is the function of the pineal gland?
Produces melatonin which affects regulation of arousal, biological rhythms and the sleep-wake cycle
What is the function of the testes?
They enable the release of testosterone (male hormone) responsible for development of male secondary sexual characteristic at puberty. Promotes muscle mass and muscle growth
What is the function of the ovaries?
They enable the release of oestrogen and progesterone (female hormone) regulates menstrual cycle and pregnancy
What is the role of adrenaline?
Adrenaline is released from the adrenal medulla in response to activation of the sympathomedullary pathway (sympathetic adrenomedullary pathway)
How does the sympathetic adrenomedullary pathway (SAM) work?
The hypothalamus recognises that there is a threat → It sends a message to the adrenal gland (specifically the adrenal medulla → this triggers the release of adrenaline to the endocrine system and noradrenaline in the brain → this prompts physiological changes
What are the effects of adrenaline in the fight or flight process?
→ Slows digestion to save energy for prioritised functions such as running
→ Inhibits salivary glands, causing a dry mouth
→ Heart rate increases to speed up the blood flow to vital organs and improve the spread of adrenaline around the body
→ Pupils dilate to improve vision
→ Increased production of sweat to facilitate temperature regulation
→ Muscles become tense to improve reaction time and speed
