Flashcards in Endocrine System Deck (30)
What does the sympathetic system do?
Fight or flight
Dilate pupils, inhibit salvation, increase heart beat, relax airway, inhibit stomach, stimulate glucose release, inhibit activity of intestines, secrete epinephrine and norepinephrine, relax bladder and promote ejactulation and vaginal contraction
What does the parasympathetic system do?
Rest and Digest
Constrict pupils, stimulate saliva, slow heartbeat, constrict airways, slow heart beat, stimulate stomach, inhibit release of glucose, stimulate intestines, contract bladder, promote erection of genitals
Where do sympathetic divisions priorities?
Brain, heart, skeletal muscles
When does vasoconstriction of blood vessels to skin occur?
During stress or exercise to minimise blood loss if injury occurred
What does your nervous system use to send messages?
What does your endocrine system use to send messages?
Where does neurocrine communication occur?
Anterior and posterior pituitary, adrenal medulla
Where is the thymus?
What happens to the thymus over time?
Fully formed at birth, involutes after puberty and in late teens is mostly fat
What is the role of the thymus?
Maturation of bone marrow derived stem cells into immunocompetent T cells (thymic cell education)
Produced thymosin which is a hormone to promote T cell maturation
Where do hormones control and regulate?
Reproduction, metabolism and energy balance, growth and development, body defenses, general homeostasis and water, nutrient, and electrolyte balance of the blood
What are the different types of hormones?
Peptide, steroid, thyroid, catecholamines
What does the hypothalamus do as a whole?
Keeps tabs on whats going on all over the body
What does the hypothalamus do individually?
osmolality of plasma
Feeding, satiety and GIT regulation
Autonomic input via connections to the sympathetic and parasympathetic systems
What does the hypothalamus produce?
6 hormones- 4 stimulatory and 2 inhibitory to anterior pituitary
What are the two lobes of the pituitary?
Anterior and posterior
What is the portal system called involving the anterior pituitary?
Hypothalamo- hypophyseal portal system
What is stress?
A state of real or perceived threat to homeostasis
What are the behavioural effects of stress?
increased awareness, improved cognition, euphoria and enhanced analgesia
What are the physiological adaptations of stress?
increased cardiovascular tone, repression rate and intermediate metabolism, inhibition of feeding, digesting, growth, reproduction and immunity
Where are the effectors of stress located?
Hypothalamus, anterior lobe of the pituitary and the adrenal gland
What are the adrenal cortical hormones?
Glucocotricoids and mineralocorticoids
What occurs in a fight or flight response?
Increased blood pressure
Glucose enters blood stream
Shut down non emergency services
What is included in the HPA axis?
Hypothalamus, anterior Pituitary, Adrenal cortex
What neurones are present in the ANS?
Presynaptic neurone whose cell body is in CNS and postsynaptic neurone whose cell body is in peripheral ganglion
What is the adrenal gland split into?
Medulla-middle (chromaffin cells which release adrenaline and noradrenaline when signalled- equivalent to postsynaptic neurones so neurocrine)
What does adrenaline and neuroadrenaline do?
Breaks down glycogen into glucose increasing blood glucose, blood pressure, breathing rate, metabolic rate and causes increased alertness and decreased digestion
What hormones do the posterior pituitary secrete?
Oxytocin and ADH
Both made in hypothalamus and travel down neuronal axons
What does the pineal gland do?
produces melatonin which controls circadian rhythms
Inhibits release of LH and FSH
Calcifies in early adult hood so is visible in X-rays