Autonomic and endocrine systems Flashcards
Describe the sympathetic nervous system?
Fight or flight response: exercise, emotion, excitement
Describe the parasympathetic nervous system?
Relaxation response: repletion, rest, relaxation
Describe the actions of the sympathetic response?
Increased rate and force of heart contraction, contraction of erector pili muscles in skin and sweating, pupil dilation, decreased salivation, constriction of blood vessels (especially in extremities), dilation of bronchi, increased blood sugar levels, increased blood pressure, increased water retention, decreased digestion
Describe sympathetic nerves?
Spine > pre ganglionic neuron > ganglion (cell bodies) > post ganglionic neuron > effector cell
What neurotransmitter is used on the pre and post ganglionic neurons in sympathetic nerves?
Pre ganglionic neurons - acetylcholine
Post ganglionic neurons - norepinephrine
What neurotransmitter is used on the pre and post ganglionic neurons in sympathetic SWEAT GLAND nerves?
Pre ganglionic neurons - acetylcholine
Post ganglionic neurons - acetylcholine
Describe the actions of the parasympathetic response?
Decreased rate and force of heart contraction, contraction of pupils, increased salivation, dilation of blood vessels, constriction of bronchi, increased digestion
Describe parasympathetic nerves?
Spine > pre ganglionic neuron > ganglion > post ganglionic neuron > effector cell
What neurotransmitters are used in parasympathetic nerves?
Pre ganglionic neuron - acetylcholine
Post ganglionic neuron - acetylcholine
Name the endocrine organs?
Hypothalamus, pineal gland, pituitary gland, thyroid, parathyroid, thymus, kidneys, pancreas, stomach, liver, skin, ovaries, testes, adrenal glands
Describe the pathway of circulating hormones?
Endocrine cell > secretes hormone > bloodstream > faraway target cells
Describe the pathway of paracrine hormones?
Endocrine cell > secretes hormone > paracrine receptors > nearby target cells
Describe the pathway of autocrine hormones?
Endocrine cell > secrets hormone > autocrine receptors > same cell target cell
Describe how lipid soluble hormones function?
Hormone diffuses into cell, activated receptor-hormone complex alters gene expression, new mRNA directs synthesis of specific proteins in ribosomes, new protein alters cell activity
Describe how water soluble hormones function?
Hormone binds to surface receptor to activate G protein releasing adenyl cyclase, adenyl cyclase converts ATP to cAMP, cAMP acts as 2nd messenger and activates protein kinases, activated protein kinases phosphorylate other enzymes, phosphorylated enzymes catalyse reactions that produce physiological responses
Describe the pathway of the hypothalamus-pituitary axis?
Hypothalamus releases corticotropin releasing hormone (CRH), travels along hypophyseal portal veins to pituitary, stimulates anterior pituitary gland to release corticotropin, travels through capillaries to the adrenal cortex which releases cortisol to endocrine organs. Cortisol acts in a negative feedback loop to inhibit CRH secretion.
What are the functions of cortisol?
Protein breakdown, gluconeogenesis, lipolysis, resistance to stress, vasoconstriction, anti-inflammatory, immune depression
What does CRH do?
CRH stands for corticotropin releasing hormone and it is a hormone which is released from the hypothalamus to stimulate the pituitary gland to release corticotropin
What does corticotropin do?
It is released from the pituitary gland and travels through the capillaries to stimulate the adrenal cortex
Describe the endocrine stress response?
Sympathetic autonomic nervous system activation, mobilise resources for immediate physical activity, glucose and oxygen consumption, alertness and activity, reduce tissue damage, ward off danger or flee
Describe the endocrine resistance reaction?
Slower and longer lasting, associated with the hypothalamus-pituitary axis and cortisol production
Describe how the endocrine and autonomic systems function together to respond to sudden stress/alarm?
Sympathetic autonomic nervous system activation and endocrine stress response
