L5 BUT REALLY L7 -ANS Flashcards
What does the endocrine system do?
Collection of glands in an organism that release hormones directly into the circulatory system to be carried to distant target organs
ANS Features
signals are fast but do not last long
involuntary movements
neurotransmitters
transmit signals across a synapse like NMJ from a neuron to a muscle, cell, or gland.
Sympathetic Chain features
paravertebral chain as it runs parallel to the vertebrae
pre ganglionic fibres synapse here
allows fibres to ascend higher than T1 and descend lower than L2/3
A &; NA stand for
Adrenaline - Epinephrine
Noadrenaline -noepinephrine
ANS- Sympathetic - how does it affect the heart
Increases heart rate
ANS-Symp- affect trachea and bronchi
dilation
more space created- more air can be facilitated
ANS-Symp - affect arterioles
re-distribution of blood
constriction of organs to various degrees
strong constriction; skin,kidneys,addominal viscera & digestive tract
Weak constriction - heart,lungs,brain & skeletal muscles
ANS-SYMP-affect veins
constriction
cardiac output
amount of blood being pumped by heart per minute
ANS-Symp-affect on liver
blood glucose levels increase due to;
glycogenolysis- glucose is released from storage form
glyconeogenesis- new glucose is made
ANS-Symp- affect on skeletal muscle
more constriction - stronger contractions
glycogenolysis increases- new energy supply
ANS-Parasymp- affect on eye
constriction of pupil- circular muscle contracts (part of iris)
constriction of ciliary muscle for accomadation of near objects (zonular fibres slack)
NB; only when ciliary muscle contracts is there parasympathetic innervation
if its relaxed there is none
ANS-Parasymp- affect on all other organs is the opposite
heart; decreases heart rate
external sphincter muscle relaxes and urination occurs
liver; decreases blood glucose levels
skeletal muscle;relaxation
visceral/autonomic reflex
subconscious motor reflex relayed from organs and glands to the CNS through visceral afferent signalling
