PNS and ANS Flashcards
what is the function of the central nervous system
centre for all mental activity and regulates and maintains homeostatsis
what are the structures of the PNS
nerves and ganglia
how many spinal nerves are there
31
what cranial nerves attach to the forebrain
1 and 2
describe the afferent (sensory) division of the PNS
transmits impulses from receptors to the CNS
somatic afferent fibres - carry impulses from skin, skeletal muscle and joints
visceral afferent fibres - carry impulses from viscerl organs
what are the two subdivisions of the efferent (motor) divsion of the PNS
somatic and autonomis nervous system
what is the role of the somatic nervous system
provides conscious control of skeletal muscles
what is the role of the autonomic nervous system
parasympathetic and sympathetic
- cardiac and smooth muscle and secretory glands
what is the craniosacral system
the preganglionic neuronal cell bodies in the brain stem or sacral levels of spinal cord
-part of parasympathetic nervous system
what cranial nerevs are part of the parasympathetic nervous system
III - oculomotor
VII - facial
IX - glossopharyngeal
X - vagus
where is the parasympathetic nervous system
in the lateral horn of gray matter from S2 - S4
what does the Parasypathetic nervous system supply
head, visceral cavities of trunk and external genitalia
_______ is a neurtransmitter secreted by the preganlionic and postganglionic fibres of the Parasympathetic nervous system
Acetylcholine
describe the cranial outflow for the oculomotor nerve in the Parasympathetic nervous system
constricts pupils
describe the cranial outflow for the facial nerve in the Parasympathetic nervous system
tears, nasal mucus and saliva
describe the cranial outflow for the glossopharyngeal nerve in the Parasympathetic nervous system
parotid salivary gland
describe the cranial outflow for the vagus nerve in the Parasympathetic nervous system
- stimulates digestive glands
- Increases motility of smooth muscle in digestive tract
- decreases heart rate
- causes bronchial constriction
describe the sacral outflow of the parasympathetic nervous system
S2-S4
- pelvic splanchnic nerves
- 2nd half of large intestine
- all pelvic organs
what is the thoracolumbar system
the sympathetic nervous system where preganglionic neuronal cell bodies are located in the lateral horn of grey matter from T1 - L2
where is noradrenalne released from
by most postganlopnic fibres in the sympathetic nervous system
what does T1-3 control in the sympathetic nervous system
dilates pupils, inhibits salivation
what does T4-6 control in the sympathetic nervous system
accelerates heartbeat, relaxes bronchi
what does T7-11 control in the sympathetic nervous system
inhibits peristalsis and secretion in stomach
stimulates glucose production and realease
secretion of adrenaline and noradrenaline
what does T12-L2 control in the sympathetic nervous system
inhibits bladder contraction
stimulates genital organs
what are the two types of ganglia
sensory and autonomic ganglia
where are sensory ganglia found
in the dorsal root ganglia of spinal nerves and on the ganglia of some cranial nerves
what is the role of the sensory ganglia in the dorsal root ganglia of spinal nerves
transmits messages relating to pain, touch, temperate from the PNS to the CNS
what is the role of sensory ganglia in cranial nerves
have special sensory function
e,g. trigeminal ganglion, contains the sensory nerve fibres from the head
the cell bodies of preganglionic neurons are located in the _______
grey matter of the CNS
the cell bodies of the postganglionic neurons are located in the _______
autonomic ganglia
the axons of the postganglionic neurons terminate in the ________
effector organs (smooth muscle, cardiac muscle or glands)
what are the three groups of autonomic ganglia
- sympathetic chain ganglia
- prevertebral ganlia
- parasympathetic ganglia
describe sympathetic chain ganglia
recieve input from lateral horn of thoracic and lumbar spinal cord
relay information relating to stress and danger
describe prevertebral ganglia
innervate all abdominal and pelvic organs (not adrenal)
