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Flashcards in Nervous system (A9) Deck (58):
1

'sick' patient

-will often be anxious and stressed
-a 'sick' patients body may be trying to look after itself in some way: self-preservation from danger of serious harm or death
-sick patient is a patient who is seriously unwell/dieing not just ill
-the dentist can see the effect of the sympathetic nervous system on arterioles (constricting to make skin look pale and feel cold), skin (hairs standing on end/goosebumps or sweat production) and pupils (dilating) which are warning signs that the patient is sick or frightened
-the sick patient will usually show the same signs of self preservation as the terrified jogger

2

dendrites

small short process of one call body that communicates with other cell bodies near it

3

composition of named nerve

-nerve cells/neurons are made up of nerve cell bodies with dendrites (small short processes that communicate with other nerve cell bodies) coming off of them
-an axon/nerve fibre (long process that can communicate with other cell bodies up to a metre away) contains a lot of neurons
-a named nerve contains a lot of nerve fibres/axons wrapped up in myelin sheath (chemical insulator)

4

myelin sheath

chemical insulator

5

axon

-nerve fibre/electrical cable
-long process that can communicate with other cell bodies up to a metre away
-a single nerve fibre can only conduct action potentials in relation to one function

6

6 functional types of nerve fibres

1-somatic sensory function
2-somatic motor function
3-special sensory function
4-visceral afferent function
5-sympathetic function
6-parasympathetic function

7

mixed nerve

-eg. intercostal nerve, phrenic nerve, vagus nerve
-can carry two or more functional types of nerve fibre to any given region of the body or structure

8

function of somatic sensory nerve fibres

tell the spinal cord/brain about a pain somewhere on the body wall (afferent)

9

function of somatic motor nerve fibres

tell a skeletal muscle to contract

10

function of special sensory nerve fibres

tell the brain about a 'special' sensation: sight, smell, taste, sound, balance

11

function of visceral afferent nerve fibres

tell the spinal cord/brain about a pain from an organ

12

function of sympathetic nerve fibres

tell cardiac or smooth muscle to contract or a gland to secrete

13

function of parasympathetic nerve fibres

tell cardiac or smooth muscle to contract or a gland to secrete

14

how do nerve cell bodies communicate with other nerve cell bodies

via dendrites and axons/nerve fibres:
-dendrites = small short process of one call body that communicates with other cell bodies near it
-axons/nerve fibre= long process that can communicate with other cell bodies up to a metre away

15

synapse

-near communication between 2 cells via neurotransmitter (?)
-chemicals drift across gap and join to receptors of next nerve cell

16

components of central nervous system

-brain
-spinal cord

17

components of peripheral nervous system

-peripheral = round the edge (of the brain and spinal cord/central nervous system)
-cranial nerves
-spinal nerves
-paravertebral sympathetic chains/trunks

18

cranial nerves

-12 pairs
-(mainly) connect with the brain
-eg. the vagus nerves

19

spinal nerves

-31 pairs
-connect with the spinal cord
-have named branches (mainly spinal nerves join to form named nerve) eg. phrenic nerve, long thoracic nerve, intercostal nerves
-spinal nerves supply the soma (body wall)
-spinal nerves have anterior ramus/branch and posterior ramus/branch

20

sympathetic chain/trunk

either of the pair (one on either side of spinal cord) of ganglionated longitudinal cords of the sympathetic nervous system of which one is situated on each side of the spinal column
-sympathetic trunks and branches = bilateral structures on the R.H.S and L.H.S of the vertebral column
-full length of vertebral column (not attached to the brain)

21

soma/body wall contents

-neck wall
-chest wall
-diaphragm
-abdominal wall
-pelvic wall
-all 4 limbs

22

axial section of spinal nerves

-segment of spinal cord
-anterior (motor) root of spinal nerve
-(large) anterior ramus of spinal nerves (contains axons of the neurons that supply the anterolateral part/front and side of the body wall)
-(small) posterior ramus of spinal nerve (contains axons of neurons that supply the most posterior part of the body)
-posterior root ganglion (aka dorsal root ganglion, where a lot of cell bodies gather together on posterior root/contains the cell bodies of the neurons, connects spinal nerve to posterior part of spinal cord)
-posterior (sensory) root of spinal nerve
-> all sensory axons go into posterior root to arrive at posterior part of spinal cord (for sensory function)
->spinal nerve = combination of anterior and posterior ramus
->sensory signals from anterior body wall travel in anterior ramus of spinal nerve and sensory signals from posterior body wall travel in the posterior ramus of the spinal nerve, they both synapse at the posterior root ganglion and enter the segment of spinal cord (central nerve system) via the posterior root of the spinal nerve, where they produce a response and motor signals leave the spinal cord via the anterior motor root of the spinal nerve and are then supplied to the posterior body wall via the posterior ramus of spinal nerve, and to the anterior body wall via the anterior ramus of spinal nerve
(anterior and posterior ramus join at on point, allowing this exchange of route)

23

ganglion

a structure containing a number of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber

24

dermatome map

-the 'segmental' (composed of separate parts or sections) arrangement of the spinal nerve supply to the body wall
-shows on surface of body which pair of spinal nerves supply each section/strip of the body wall

25

which spinal nerves supply nipple line on dermatome map

T4 spinal nerves

26

which spinal nerves supply umbilicus/belly button on dermatome map

T10 spinal nerves

27

functions of the nervous system

-allows us to sense our environment and effect an appropriate response
-composed of a sensory part, motor (responsive) part and central connections (in the brain or spinal cord) between the two parts
-protective function/helps to 'keep us safe' from:
->external environment (monsters etc)
->internal environment (heart, lungs, intestines etc)

28

divisions of the nervous system

-the nervous system is divided on the basis of physiological function into:
->the somatic nervous system (protects from external environment)
->the autonomic nervous system (senses and responds to our internal environment)

29

the somatic nervous system

-protects from/senses and responds to external environment
-somatic neurons supply the soma/body wall
-axons of sensory neurons are found in: spinal nerve branches (eg. intercostal nerves, phrenic nerves)
-axons containing somatic neurons can either be:
->somatic sensory nerve fibres/axons
->somatic motor nerves/axons
-voluntary (exception is reflexes)

30

the autonomic nervous system

-senses and responds to our internal environment changes (visceral afferents)
-autonomic neurons sense the internal environment
-involuntary/happens itself
-divided into sympathetic and parasympathetic
-parasympathetic is more dominating

31

axons/nerve fibres of sensory neurons/nerve cells can be found in which nerve branches

spinal nerve branches (eg. intercostal nerves, phrenic nerves)

32

somatic sensory nerve fibres/axons

carry sensory information from skin, parietal pleura, skeletal muscles, bones and joints

33

somatic motor nerve fibres/axons

-carry motor information to skeletal (striated) muscles (including the diaphragm)
-make skeletal muscle contract

34

components of somatic nervous system involved in a 'hand shake'

reaching out (skeletal muscles with feedback from joint receptors) -> taking hold (skeletal muscles with feedback from skin pressure receptors) -> hot? is this patient feverish? sweaty? (determined by temperature receptors) -> shaking (skeletal muscles with feedback from skin and joints) -> letting go (skeletal muscles with feedback from skin pain receptors)

35

factors sensed by the somatic sensory neurons

-touch
-pain
-temperature
-joint position

36

how do somatic motor neurons respond to the sensory information

skeletal/striated/voluntary muscle move the skeleton appropriately

37

how do somatic sensory and motor nerve fibres travel to and from the body wall

somatic sensory and somatic motor nerve fibres/axons travel in all spinal nerves and their branches/rami, to and from the body wall

38

sympathetic part of the autonomic nervous system

-activated when you have a fright
-'fight or flight' response
-action potentials are conducted along sympathetic axons

39

effect of sympathetic nervous system on internal environment

-heart (increases heart rate)
-arterioles (either dilate - skeletal muscle, or constrict - skin feels cold and looks pale)
-skin (makes hair stand on end aka goosebumps/ produces sweat)
-lungs (dilates bronchioles)
-gut/GI tract (reduces motility/closes sphincters)
-pupils (dilate, to be able to see safety in distance)
-liver (releases glucose)

40

parasympathetic part of the autonomic nervous system

-supplies motor axons to the same organs as the sympathetic nervous system (except the skin and arterioles)
-opposes/compliments the sympathetic system
-'rest and digest' response

41

homeostasis

=physiological steady state/ balance

42

homeostasis/balance between sympathetic and parasympathetic divisions of the autonomic nervous system

-parasympathetic (the well patient) dominates
-sympathetic (the sick or frightened patient) causes change in balance/homeostasis

43

type of nerve axons contained within intercostal nerves (branches of the spinal nerves)

-somatic motor and somatic sensory
-sympathetic (to skin and arterioles)
(^contained within all spinal nerves and branches)

44

type of nerve axons contained within the vagus nerve (cranial nerve X)

-somatic motor and somatic sensory
-parasympathetic (supplying organs within thoracic/abdominal cavity)

45

type of nerve axons contained within phrenic nerve (C3,C4,C5, branches from spinal nerve)

-somatic motor and somatic sensory
-sympathetic
(^contained within all spinal nerves and branches)

46

type of nerve axons contained within:
-the sympathetic trunk and branches
-abdominopelvic splanchic nerves

sympathetic

47

paravertebral ganglia of the sympathetic trunk

-ganglion at level of every single pair of spinal nerves

48

sympathetic supply to the soma (body wall)

-in fight or flight response, action potentials are generated in the autonomic centres in the brain, which are then conducted via the spinal cord into T1-L2 spinal ('thoracolumbar outflow')
-sympathetic axons then enter ALL spinal nerves and then ALL anterior and posterior rami to be carried in them to the whole body wall
->THORACOLUMBAR OUTFLOW

49

sympathetic supply to the organs (viscera)

-sympathetic nerve fibres/axons leave sympathetic trunk and go to organs via:
->CARDIOPULMONARY SPLANCHNIC NERVES (branches of the sympathetic chain, sympathetic axons travel through these to get to the heart and the lungs)
->ABDOMINOPELVIC SPLANCHNIC NERVES
-or on the surface of arteries (hitch a ride to the head and neck structures)

50

splanchnic

of or relating to the viscera or internal organs, especially those of the abdomen

51

sympathetic neurotransmitters

-acetylcholine in all paravertebral ganglia (between pre and post synaptic sympathetic neuron/ wherever there is a synapse on a ganglion)
-noradrenaline at all end organs eg. sinoatrial/SA node and arterioles (at synapse actually at the organ)

52

effect of drugs on sympathetic neurotransmitters

pharmacological agents (drugs) can target the sympathetic synapses to block the action of noradrenaline to eg. modifiy a patients blood pressure etc

53

parasympathetic craniosacral outflow

-craniosacral outflow = nerves containing parasympathetic axons travelling to only the organs, not the body wall (cranial + sacral spinal = craniosacral)
-the sacral spinal nerves contain parasympathetic nerve fibres
-cranial nerves that contain parasympathetic axons/nerve fibres
->CN III - occulomotor
->CN VII - facial
->CN IX - glossopharyngeal
->CN X - vagus (vagus nerve is especially involved in parasympathetic supply to the organs)

54

parasympathetic synapse

as there is no parasympathetic chain/trunk made up of ganglions like the sympathetic chain/trunk, the parasympathetic axons (from craniosacral outflow) synapse in the parasympathetic ganglia in the head and many in the walls of the organs

55

parasympathetic neurotransmitters

-acetylcholine at all parasympathetic ganglia and all end organs
-only 1 neurotransmitter involved in parasympathetic nervous system

56

effect of drugs on parasympathetic neurotransmitters

pharmacological agents (drugs) can target these synapses to block the action of acetylcholine and eg.dilate an asthmatic patients bronchioles etc.

57

summary of somatic nervous system

-branches of spinal nerves (eg. phrenic, long thoracic, intercostal) supply the body wall structures:
->skin
->fascia
->skeletal muscle
->bone
->joints
->parietal pleura
with somatic sensory and somatic motor axons

58

summary of autonomic nervous system

-sympathetic axons from the brain (via the spinal cord, spinal nerves and sympathetic trunks) to all organs, skin and arterioles (arterioles are important in BP control)
-plus: parasympathetic axons from the brain (via cranial nerves and also the spinal cord and sacral spinal nerves) to all organs
-plus: visceral afferents conduct pain signals from organs themselves