ANS of Thorax

Question 1

features of sensory part of spinal nerves

Answer 1

Afferent
Enters posterior aspect of spinal cord
Cell body in spinal (dorsal root) ganglion
Ganglion=cluster of neural cell bodies outside the CNS

Question 2

features of motor part of spinal nerves

Answer 2

Efferent
Exits anterior aspect of spinal cord
Cell body in spinal cord (grey matter)

Question 3

function of dorsal rootlets

Answer 3

convey sensory information into spinal cord

Question 4

function of ventral rootlets

Answer 4

convey motor information away from spinal cord

Question 5

location of grey matter in spinal cord and function

Answer 5

ventral horn

contains cell bodies of lower motor neurons innervating voluntary muscles

Question 6

diseases of grey matter in spinal cord

Answer 6

poliomyelitis

Question 7

lateral horn

Answer 7

sympathetic system motor neurons cell bodies, present only in thoracic and lumbar areas

Question 8

dorsal horn sends what kind of impulses

Answer 8

sensory impulses

Question 9

white matter consists of

Answer 9

bundle of axons

Question 10

white matter tracts down from..

Answer 10

up to the brain from sensory tracts and down from brain to neurons in grey matter e.g. spinothalamic, corticospinal

Question 11

branches of spinal nerve

Answer 11

dorsal and ventral ramus

Question 12

what structure does the dorsal ramus supply

Answer 12

supplies dorsal 1/3rd of the body wall, no contribution to limbs

Question 13

what structures does the ventral ramus supply

Answer 13

supplies ventral 2/3rd of the body wall including the limbs

Question 14

direction of sensory (afferent) impulses

Answer 14

towards CNS

Question 15

Direction of motor (efferent) impulses

Answer 15

away from CNS

Question 16

Somatic sensation

Answer 16

we are acutely aware of these; well localized (e.g. sharp pain, touch) Generally originate in body wall structures rather than internal organs

Question 17

visceral sensation

Answer 17

: either imperceptible, only vaguely localizable, or only become perceptible in disease. From blood vessels and internal organs (viscera

Question 18

voluntary motor impulses function

Answer 18

control skeletal muscle over which we have voluntary control

Question 19

visceral motor impulses function

Answer 19

control muscle over which we do not normally have voluntary control

Question 20

sympathetic nervous system

Answer 20

Alert, wary, increases heart rate & contractility, blood pressure rises 
Blood vessels to muscles dilate 
-ready for running away 
Pupil dilation
•for good distant vision 
Bronchioles dilation
Close sphincters

Question 21

parasympathetic nervous system

Answer 21

Decreases heart rate and contractility 
Relaxes the gut tube muscle 
Pupil constriction
Bronchioles constriction
Open sphincters

Question 22

are preganglionic fibres myelinated or unmyelinated in sympathetic nervous system

Answer 22

myelinated

Question 23

are postganglionic fibres myelinated or unmyelinated in sympathetic nervous system

Answer 23

unmyelinated

Question 24

location of thoracic splanchnic nerves

Answer 24

Greater - T5 T9
Lesser - T10, T11
Least - T12

Question 25

3 types of splanchnic nerves

Answer 25

lumbar splanchnic sacral splanchnic thoracic

Question 26

where does the thoracic sympathetic trunk track down to

Answer 26

Continuation of cervical trunk Lies under the parietal pleura Crosses the diaphragm Continues as lumbar trunk

Question 27

where does T1 join

Answer 27

joins inferior cervical ganglion to form Stellate Ganglion

Question 28

preganglionic cell bodies of sympathetic cardiac plexus location

Answer 28

Preganglionic cell bodies | Lateral (grey) horn, upper thoracic cord

Question 29

postganglionic cell bodies of sympathetic cardiac plexus location

Answer 29

Cervical & upper thoracic ganglia in the sympathetic trunk. Post ganglionic fibres run to SA & AV nodes, coronary vessels & cardiac muscle

Question 30

preganglionic cell bodies of parasympathetic cardiac plexus location

Answer 30

Preganglionic fibres | vagus N. -relay in heart wall

Question 31

postganglionic cell bodies of parasympathetic cardiac plexus location

Answer 31

Postganglionic fibres | SA & AV nodes, coronary vessels

Question 32

main functions of cardiac plexus

Answer 32

Regulating heart rate Force of each contraction Cardiac output

Question 33

function of sympathetic cardiac plexus

Answer 33

Increase heart rate | Increase force of contraction Dilate coronary arteries

Question 34

function of parasympathetic cardiac plexus

Answer 34

Decreases heart rate Reduces force of contraction Constrict coronary arteries

Question 35

how is the myocardiocyte death signalled in to the body

Answer 35

Pain fibres (visceral afferents) are stimulated These run with sympathetic nerves Somatic senses also enter at this level The brain is unable to distinguish between visceral and somatic pain pain in somatic regions

Question 36

how is myocardiocyte referred to arm

Answer 36

Visceral afferents to lower cervical and upper thoracic segments of cord Referred to T1 – T4 dermatomes (arm)

Question 37

how is myocardiocyte referred to arm

Answer 37

Afferents from pericardium run along the phrenic nerve | C 3, 4, 5  pain in neck & jaw

Question 38

sympathetic function pulmonary plexus

Answer 38

Bronchodilation Vasoconstriction (NB – medications)

Question 39

parasympathetic function pulmonary plexus

Answer 39

Bronchoconstriction Mucus secretion Vasodilation Cough reflex (afferent)