The Endocrine System: Flashcards
Adrenaline:
hormone released from the adrenal medulla, acts on heart and circulatory system to increase heart rate and blood pressure; important part of fight or flight response
Hormone:
chemical released from endocrine glands into the bloodstream that acts on target structures to alter their functions or to release other hormones
Gland:
body organ that releases hormones into the bloodstream
The endocrine system:
network of glands throughout the body releasing hormones to affect and organise the body’s physiological systems; the pirtuitary gland is the ‘master’ gland in the endocrine system
The function of the endocrine system:
-hormones are chemical message or substances, usually released from glands, which can control or regulate the activity of particular cells or organs in the body
-the network of glands is called the endocrine system
-glands making up the endocrine system secrete hormones directly into the bloodstream or circulatory system
-the arousal produced by adrenaline is one of the most obvious normal effects, but in fact the range of hormones and their effects is enormous, and they plan an important part in many areas of behaviour
Thyroxine: endocrine gland + effects
-endocrine gland: thyroid
-effects: regulates the body’s metabolic rate and protein synthesis
Adrenaline and nonadrenaline: endocrine gland + effects
-endocrine gland: adrenal medulla
-effects: fight or flight response, increased heart rate and blood flow to brain and muscles, release of stored glucose and fats for use in fight or flight response
Glucocorticoids: examples, endocrine gland + effects
-examples: cortisone, cortisol, and corticotesterone
-endocrine gland: adrenal cortex
-effects: further release of stored glucose and fats for energy expenditure, suppression of the immune system and the inflammatory response
Mineralocorticoids: endocrine gland + effects
-endocrine gland: adrenal cortex
-effects: these regulate the water balance of the body through water and sodium reabsorption in the kidneys
Androgens: example, endocrine gland + effects
-main example: testosterone
-endocrine gland: testes
-effects: development of male secondary sexual characteristics at puberty + promotes muscle mass and muscle growth
Oestrogens: main example, endocrine gland + effects
-main example: oestradiol
-endocrine gland: ovaries
-effects: regulation of female reproductive system, menstrual cycle and pregnancy
Melatonin: endocrine gland + effects
-endocrine gland: pineal
-effects: regulation of arousal, biological rhythms and the sleep-wake cycle
Pituitary:
-the ‘master gland’ is the pituitary, it is known as this because many of the hormones released by the pituitary gland control the secretions of other endocrine glands, rather than having direct effects on cells and tissues in the body
-the pirtuitary is located in the cranial cavity, just below the hypothalamus, to which it is directly connected
-the pirtuitary releases oxytocin and vasopressin, release of pirtuitary hormones into the bloodstream is directly controlled by the hypothalamus
-note that the hypothalamus controls the release of hormones from the pirtuitary gland, and can therefore be seen to control and regulate the endocrine system in general
Hormones released by the pirtuitary gland and their effects:
-the endocrine system therefore has a vital role in the internal physiological regulation of the body
-it works closed with the ANS in this regard
-although the contribution of the endocrine system is essentially to regulate the internal physiological processes of the body, some aspects do become important to psychologists when we look at situations such as stress and threats
(Anterior pirtuitary) ACTH: target organs and/or effects
adrenocortical trophic hormone
-adrenal cortex, stimulating release of glucocorticoids such as cortisone and corticotesterone + key component in the stress response
(Anterior pirtuitary) TSH: target organs and/or effects
thyroid stimulating hormone
-thyroid gland, stimulating release of thyroxine
(Anterior pirtuitary) Prolactin: target organs and/or effects
-mammary glands, stimulating milk production and release
(Anterior pituitary) FSH: target organs and/or effects
follicle stimulating hormone
-ovaries and testes, stimulating release of ovarian follicles and promoting spermatogenesis
(Posterior pirtuitary) ADH: target organs and/or effects
vasopressin or antiduretic hormone
-involved in regulating the water balance of the body, stimulates water reabsorption by kidney and increases blood volume
(Posterior pirtuitary) Oxytocin: target organs and/or effects
-important in promoting uterine contractions in childbirth and lactation after birth
