09 Nervous System 1 Flashcards
What does the central nervous system include?
The brain and the spinal cord
What is the central nervous system involved in?
Integration and control
What is the peripheral nervous system?
The peripheral nervous system (PNS) is the part of the nervous system that consists of the nerves and ganglia on the outside of the brain and spinal cord.
What is the function of the peripheral nervous system?
Communication between cns and the rest of the body
What is the sensory (afferent) division of the nervous system?
The afferent division consists of nerves that convey impulses to the central nervous system from the sensory receptors. Afferent means go towards
What is the motor (efferent) division?
The efferent division carries impulses from cns to effector organs
What is the autonomic (visceral) nervous system?
Involuntary: impulses from cns to cardiac muscle, smooth muscle, glands
What is the somatic nervous system?
Voluntary, impulses from cns to skeletal muscles, spinal nerves and cranial nerves
What can the autonomic nervous system be divided into?
The sympathetic and parasympathetic division
What is the sympathetic division?
Part of the autonomic nervous system involved in fight or flight and it is stimulatory
What is the parasympathetic division?
Part of the autonomic nervous system involved in digestion, inhibitory
Whats the difference between afferent and efferent?
Afferent is going towards and efferent is moving away to the muscles and glands/effectors overall
- If you were to give an overview diagram of the central nervous system, describe how you would draw it
Like this babes
- Label the following regions of the brain
There ya go
What is the role of the sulci in the brain?
In neuroanatomy, a sulcus (Latin: “furrow”, pl. sulci) is a depression or groove in the cerebral cortex. They divide each cerebral hemisphere into five lobes
What are the five anatomical areas of the cerebrum?
Frontal, parietal, temporal, occipital, insula (buried within the lateral sulcus)
All the anatomical areas of the cerebrum are named according to the bones they are beneath except the
Insula which is buried within the lateral sulcus
Each hemisphere of the brain has three basic regions, what are these?
The cerebral cortex, the white matter and the basal ganglia
What is the cerebral cortex?
The cerebral cortex is the cerebrum’s (brain) outer layer of neural tissue
How is the cerebral cortex described?
Grey matter; the executive suite; conscious mind
What is the function of the white matter?
Communication between cerebral areas
What is the basal ganglia?
Found deep in the brain, connecting cerebral cortex, thalamus and brainstem. The role is unclear.
*How would you draw a diagram showing grey matter and white matter in the brain?
Like this homie
The cerebral cortex contains what? Give three areas
Motor areas controlling voluntary movement. Sensory areas concerned with conscious sensation and association areas
The two hemispheres are symmetrical but they are not entirely equal in…
function
Each hemisphere is mainly concerned with the motor and sensory functions of the
opposite side of the body
What is hemianopsia?
Hemianopsia, or hemianopia, is a decreased vision or blindness (anopsia) in half the visual field, usually on one side of the vertical midline. The most common causes of this damage are stroke, brain tumor, and trauma.
There are three main functional areas of the cerebral cortex, what are these?
The primary motor area, the sensory area and the association area (higher order processing)
- Roughly point to where the primary motor area, the sensory area and the association areas are found
There ya go
*How is blood supplied to the brain? From which vessels?
From the aortic arch via the subclavian, carotid (common, internal, external) and vertebral arteries
What do the common carotid arteries divide to form?
The external carotid arteries and the internal carotid arteries
What do the external carotid arteries supply?
Supply the head external to the brain and the orbit including thyroid, larynx, face, scalp, tongue, teeth, muscles of mastication
What do the internal carotid arteries supply?
The orbits and most of cerebrum
How do the internal carotid arteries enter the skull?
Through carotid canal in temporal bone
What do the internal carotid arteries divide to form?
Anterior and middle cerebral arteries, which provide blood to 80% of cerebrum
- How would you show blood supply to the brain through a diagram
Like this
What supplies blood to the posterior of the brain?
The right and left vertebral arteries
What do the right and left vertebral arteries pair to form?
The basilar artery
What does the basilar artery divide to form?
The posterior cerebral arteries
If you have a middle cerebral artery stroke, how much of that hemisphere is affected?
About 40%
What is the cns protected by?
A series of protective membranes
From the brain to the skull, list the meninges and spaces present
Brain, pia mater, subarachnoid space, arachnoid, subdural space, dura mater, skull
What are the four functions of the meninges?
Cover and protect the cns. Protect blood vessels. Contain cerebrospinal fluid. Form partitions in the skull
*Label the following structures, the meninges
Done
What are the two parts of the dura mater?
The periosteal and the meningeal layer
What is the difference between the periosteal and the meningeal layer of the dura mater?
The periosteal layer is the superficial layer which serves as the skulls inner periosteum and the meningeal layer is a deep layer which is the actual dura mater
*Label the meninges on the spinal cord
There ya go
What is the strongest most durable layer out of the meninges
The dura mater
Where is the periosteal layer of the meninges found?
Found attached to the inner surface of the skull - this layer is absent in the spinal cord
What is the dural septa?
Where the two dural layers are fused they project to form partitions which limit the movement of the brain within the cranium
Give an example of a dural septa and where is it found in the brain?
The falx cerebri along the longitudinal fissure
Describe the composition of the arachnoid layer of the brain meninges
It is a loose covering, named for its web-like projections which secure it to the pia mater
What is a sulci?
In neuroanatomy, a sulcus (Latin: “furrow”, pl. sulci) is a depression or groove in the cerebral cortex.
What separates the arachnoid layer from the dura mater?
By a thin, fluid filled subdural space
Where in the brain is the arachnoid layer found?
Around the surface of the brain but not extending into the sulci
What separates the arachnoid layer from the pia mater?
The wider subarachnoid space
Describe the pia mater and where it is found in the brain
It is highly vascularised, clings tightly to the brain
Where is the spinal cord found?
enclosed in the vertebral column running from the foramen magnum of the skull to the level of l1 or l2
Function of the spinal cord is?
provides communication to and from the brain
What is the spinal cord protected by
like the brain, protected by bone, meninges and cerebrospinal fluid
How many pairs of spinal nerve roots issue from the spinal cord?
31 pairs
Where are the spinal nerves enlarged?
In the cervical and lumbosacral regions where the nerves serving the upper and lower limbs arise
What is cauda equina?
during development, the vertebral column grows faster than the spinal cord so lower spinal nerves chase their exit points inferiorly
What two parts make up the somatic nervous system
the spinal nerves and the cranial nerves - voluntary
How many spinal nerves are there
31 x 2
How many cranial nerves are there
12 x 2
The visceral nervous system/ autonomic nervous system can be divided into
the sympathetic and the parasympathetic
How can you remember the names of the 12 cranial nerve pairs?
Oh once one takes the anatomy final, apparently good vacations are heavenly
How can you remember whether the 12 cranial nerve pairs are sensory, motor or both?
Some say money matters but my brother says big brain matters most
Name the twelve cranial nerves
Olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, accoustic, glossopharyngeal, vagus, spinal accessory, hypoglossal
Is the following nerve sensory, motor or both? : olfactory
sensory
Is the following nerve sensory, motor or both? : optic
sensory
Is the following nerve sensory, motor or both? : oculomotor
motor
Is the following nerve sensory, motor or both? : trochlear
motor
Is the following nerve sensory, motor or both? : trigeminal
both
Is the following nerve sensory, motor or both? : abducens
motor
Is the following nerve sensory, motor or both? : facial
both
Is the following nerve sensory, motor or both? : auditory/
sensory
Is the following nerve sensory, motor or both? : glossopharyngeal
both
Is the following nerve sensory, motor or both? : vagus
both
Is the following nerve sensory, motor or both? : spinal accessory
motor
Is the following nerve sensory, motor or both? : hypoglossal
motor
What is the function of the olfactory nerve
smell
what is the function of the optic nerve
vision
what is the function of the oculomotor nerve
eye movement
what is the function of the trochlear nerve
eye movement
what is the function of the trigeminal nerve
facial sensation, mastication
what is the function of the abducens nerve
eye movement
what is the function of the facial nerve
facial expression, taste, salivation, tears
What is the function of the auditory nerve
balance, hearing
what is the function of the glossopharyngeal nerve
taste, salivation, innervation of pharynx
what is the function of the vagus
swallowing and talking, cardiac, gi tract, taste
what is the function of the accessory nerve
pharynx, larynx muscles, neck and shoulder movement
what is the function of the hypoglossal nerve
tongue movement
why is the auditory nerve sometimes described as both sensory and motor and not just sensory
because it has a small motor component that adjusts the sensitivity of the sense receptors
What does the vestibular branch of the auditory nerve transmit
afferent impulses related to equilibrium
what does the cochlear branch of the auditory nerve transmit
impulses related to hearing
where does the motor component of the auditory nerve come in?
adjusting the sensitivity of the sensory receptors
spinal nerves are named according to their
points of issue
*label the spinal nerves here
there ya go
why are there 8 cervical nerves but only 7 cervical vertebrae?
the first 7 spinal nerves arise superior to the vertebrae for which they are named , spinal nerve 8 arises inferior to the seventh cervical vertebrae
each spinal nerve attaches to the spinal cord via what structures?
the dorsal and ventral roots
what types of fibres do ventral roots contain
motor efferent fibres
what types of fibres do dorsal roots contain
sensory afferent fibres
what do the motor fibres coming from the ventral roots and the sensory fibres from the dorsal roots unite to form
the spinal nerve
*how would you draw a diagram of a somatic spinal nerve
there ya go
What is an area of skin innervated by a single spinal nerve called
a dermatome
What is hiltons law?
any nerve serving a muscle that produces a movement at a joint also innervates the joint and the skin over the joint
What is the brachial plexus?
it gives rise to virtually all the nerves that innervate the upper limb
what is the broad structure of the brachial plexus in five words
the roots, trunks, divisions, cords and major terminal branches
what is the root of the brachial plexus
the ventral rami of c5-t1
what are the major terminal branches of the brachial plexus nerve
the musculocutaneous, the median, ulnar, radial and axillary nerves
What does the radial nerve innervate?
the muscles on the back of the forearm which are the ones that extend the wrist and all fingers
what does the ulnar nerve innervate
muscles on the underside of the forearm, plus the flexors of digits 4 and 5
what does the median nerve innervate
muscles on the underside of the forearm including the wrist flexors and flexors of the thumb and first two fingers
*What does damaging the ulnar nerve result in
the digits 4 and 5 being hyperextended at the metacarpophalangeal joints but flexed at distal phalangeal joints
Why is damaging the ulnar nerve common?
the ulnar nerve is easily damaged - it is the funny bone at the elbow
What would damaging the median nerve result in?
digits 1-3 being hyperextended
why is damaging the median nerve not as common
because the median nerves runs deep and is well protected
what would damaging the brachial plexus nerve at the armpit cause
both the ulnar and median nerve being affected resulting in the brachial plexus claw
what does the autonomic visceral nervous system do
regulates glands, smooth muscle and cardia muscle
the autonomic visceral nervous system uses two neuron chain, what is this
the preganglionic neuron - from brain or spinal cord to autonomic ganglion outside cns. the postganglonic neuron, from ganglion to effector organ
What does the sympathetic nervous system do?
expends energy (catabolic) or stimulates
which nerves are involved in the sympathetic nervous system
spinal nerves t1 - l2
what does the parasympathetic nervous system do?
conserves energy (anabolic) or calms
Which nerves are involved in the parasympathetic section of the autonomic nervous system
cn 3 7 9 10 and s2-4
