Endocrine & Autocrine Flashcards
What is the neurotransmitter used by the pre-ganglionic nerve axons of both the SNS & PSNS?
Acetylcholine
What kind of hormone uses a secondary messenger?
Water soluble hormones
Name 2 types of lipid-soluble hormones
Steroid hormones and thyroid hormones
What is the name of the receptor inside cells that responds to lipid-soluble hormones?
Nucleorecepter
What is the most common second messenger?
cAMP (cyclic AMP)
What do lipid-soluble hormones do inside cells?
Turn specific genes of the nuclear DNA on/off
What does the hypothalamus produce and where do they go?
Releasing and inhibiting hormones to the anterior pituatary
What produces releasing and inhibiting hormones?
The hypothalamus
Do water-soluble hormones use a transport protein?
No
What do paracrine hormones act on?
Nearby target cells
What do autocrine hormones act on?
The same cell
Describe the effect/process of water-soluble proteins on a cell
Bind with a surface receptor on cell (GPCR), activate adenyl cyclyse which converts ATP to cAMP, cAMP then activates protein kinases, activated protein kinases phosphorylate other protein kinases, causing a cascade and eventually producing a physiological response
What do endocrine hormones act on?
Distant target cells
What inactivates cAMP?
phosphodiesterase
What connects the pituitary with the hypothalamus?
The infundibulum and hypophyseal portal veins
How many hormones does the anterior pituitary gland produce?
At least 7
What is the first event to happen in the body due to danger?
Sympathetic nerve signals affecting various body functions
What is excessive stimulation of the sympathetic nervous system following emotional stress of exposure to cold known as?
Raynaud disease
What is a common symptom of Raynaud’s disease?
Chronic vasoconstriction leading to white appearance in fingers and toes
What neurotransmitter do post-ganglionic parasympathetic neurons release?
Acetylcholine
What neurotransmitter do post-ganglionic sympathetic neurons release?
Norepinephrine (or acetylcholine when acting on sweat glands)
Are post-ganglionic autonomic neurons myelinated?
No
Are pre-ganglionic autonomic neurons myelinated?
Yes
What is another name for neurons that release ACh?
Cholinergic
What is another name for neurons that release NE?
Adrenergic
What are the effectors of the autonomic nervous system?
Smooth muscle, cardiac muscle, glands
What is the effector of the somatic nervous system?
Skeletal muscle
What is the 2-neuron pathway also known as?
Autonomic
What is the 1-neuron pathway also known as?
Somatic
What is the sensory input of the autonomic nervous system?
Interoceptors
What is the sensory input of the somatic nervous system?
Special and somatic senses
What is the control of input for the autonomic nervous system?
Involuntary: limbic system, hypothalamus, brain stem & spinal cord
What is the control of input for the somatic nervous system?
Voluntary: cerebral cortex
What is meant by ‘inducible system’?
Up when we need it, down when we don’t
What branch of the autonomic nervous system is responsible for the alarm response?
Sympathetic
What branch of the autonomic nervous system is responsible for the relaxation response?
Parasympathetic
What are the effects of sympathetic control on the body? (12)
Increased heart rate
Dilated pupils
Dilation of bronchi in lungs and faster breathing
Decreased salivation
Constriction of peripheral blood vessels
Contraction of arrector pili muscles (goose flesh)
Increased sweat
Decreased digestion
Increased blood sugar
Increased blood pressure
Increased water retention
What are the effects of parasympathetic control on the body? (6)
Decreased heart rate
Contraction of pupils
Increased saliva
Constriction of bronchi - slower breathing
Dilation of peripheral blood vessels
Increased digestion
What does the hypothalamus regulate?
Behaviour patterns
Circadian rhythm
Eating & drinking
Homeostasis
What is the sympathetic nervous system associated with?
Exercise
Emotion
Excitement
What is the parasympathetic nervous system associated with?
Repletion
Rest
Relaxation
What is the ‘central trunk’ of the endocrine system?
HPA - hypothalamus, pituitary, adrenal glands
How many hormones does the hypothalamus produce to control the anterior pituitary?
9
How do hormones get from the hypothalamus to the anterior pituitary?
Hypophyseal portal veins
How many hormones does the pituitary produce to control endocrine organs?
7
What is the very outer layer of the adrenal gland called?
Capsule
What do the hypothalamus and pituitary gland control together?
Growth, development, metabolism, homeostasis
What is the inner layer of the adrenal gland called?
Medulla
What is the second-most outer layer of the adrenal gland called?
Cortex
Where are the adrenal glands found?
Just above the kidneys
What does the adrenal medulla produce?
Epinephrine & norepinephrine
What is the action of the adrenal medulla?
Enhance and sustain the immediate sympathetic alarm response
What stimulates the adrenal medulla?
Acetylcholine from preganglionic neurons
What is meant by ‘inducible system’
Up when we need it, down when we don’t
What does the adrenal cortex produce?
Mineralocorticoids (e.g. aldosterone) & Glucocorticoids (e.g. cortisol)
What stimulates the adrenal cortex to release glucocorticoids?
ACTH from the anterior pituitary
What stimulates the anterior pituitary to release ACTH?
CRH released from the hypothalamus
What stimulates the adrenal cortex to release mineralocorticoids?
Increased K+ and angiotensin 2 in blood
What is the principal action of mineralocorticoids released from the adrenal cortex?
Increase blood Na+ & water and decrease blood K+
(leading to increased blood volume and pressure)
What is the principal action of glucocorticoids released from the adrenal cortex?
Resistance reaction to stress, dampens inflammation and depresses immune system
What are the effects of the alarm response (5)?
Pounding heart
Cold sweat
Pale skin
Goose flesh
Rapid breathing
Why is it important for inflammation to be controlled?
So not too much tissue is broken down
What are the 6 actions of cortisol and their consequences?
Increase protein breakdown (AA available for protein synthesis)
Gluconeogenesis in the liver (Glucose available for ATP production)
Lipolysis in adipose tissue (Fatty acid availability)
Altered blood vessel sensitivity to vasoconstriction (BP increase)
Anti-inflammatory to limit tissue damage (Slower tissue repair and wound healing)
Alter immune responsiveness (increased susceptibility to some infections)
What inhibits the release of ACTH from the anterior pituitary?
Elevated cortisol levels
What inhibits the release of CRH from the hypothalamus?
Elevated cortisol
How fast does the alarm response occur?
Milliseconds-seconds
How fast does the extended alarm response occur?
seconds - minutes
What are the effects of the resistance reaction?
Increased glucose, fatty acids & amino acids
Elevated blood pressure
Reduced inflammation
Altered immunity
What are the 2 types of stress?
Eustress (acute)
Distress (chronic)
How fast does the resistance reaction response occur?
minutes - hours
What does the posterior pituitary gland release?
Oxytocin & ADH
