Unit Four Exam Flashcards
Nervous tissue consists of
Cell body, dendrites and axons
Function of nervous system
Senses stimuli and transmits signals called nerve impulses from one part to another
What signals are transmitted in nervous tissue
Nerve impulses
The fundamental functional unit of the nervous system is the
Neuron
Another name for cell body
Soma, perikarion
Majority of the axons are enveloped in coverings called
Myelin or neurilemma
Myelin is
A single layer of phospholipids
Neurilemma is
Multilayered myelin sheaths for larger axons
What is a synapse
One nerve axons comes together with the dendrite of another nerve
What is monosynapses
Only two nerves involved
What are polysynapses
More than two nerves are involved
What are afferent nerves
Conduct nerve impulses from periphery to the CNS
What are efferent nerves
Conducts nerve impulses from the CNS to the periphery
Interneurons AKA
Association neurons
What are interneurons
Nerves that form a network of interconnecting neurons that connect the afferent nerves to the efferent nerves
Where are interneurons
Inside the spinal cord
What are the two types of nervous systems
CNS and PNS
What part of the CNS is a direct continuation of the brain
Encephalon
The spinal cord is called
Medulla spinalis
Spinal cord begins at
Foramen magnum
Spinal cord ends at
Conus medularis
Where in the adults spine does the conus medullaris occur
L1/L2
Where in Childrens spine does the conus medullaris occur
L3/L4
What are the two major enlargements of the spinal cord
Cervical and lumbar
Where is the cervical enlargement
C4-T1
What gives rise to the brachial plexus
Cervical enlargement
Where is the largest circumference of the cervical enlargement
C5/C6
Where is the lumbar enlargement
T9/L2
What gives rise to the sacral plexus and cauda equina
Lumbar enlargement
Where is the largest circumference of the lumbar enlargement
T12
What is larger lumbar or cervical
Cervical
What are ganglion
Nerve cells bodies located outside the CNS
What are dorsal root ganglion
Located inside the IVF
Where does the Nerve C1 arise from
Between occiput and atlas
C8 nerve arises from
Between C7 and T1
Where do the nerves arise from
Below the respective vertebrae
Function of meninges
Protect and stabilize the CNS
What are the three layers of the meninges
Duramater, arachnoid, piamater
Inner most meninges
Pita mater
Aka of Pia
Tender mother
Describe pia mater
Thin and delicate
What is the inner part of pia mater
Pia-glia or pia intima
Describe pia glia
Avascular and adherens to the spinal cord
What is the outer part of pia mater
Epi pia
What layers surround the spinal cord and spinal nerves to IVF
Inner and outer part of pia mater
Epi pia description
Contains blood vessels
When Epi Pia attaches to dura matter as
Dentiuclate (dentate) ligaments
What is the space between pia and arachnoid mater
Subarachnoid space
What is in subarachnoid space
CSF
Describe arachnoid
Totally avascular
Arachnoid continues to
S2
What is leptomeninges
Both pia and arachnoid mater together
Subdural space contains
Interstitial fluid
Aka of dura mater
Theca or pachymenix
Dura mater continues to
S2
Dura mater attaches to the
Foramen magnum, posterior aspect of vertebral body of C2 and C3
Dura mater attaches to PLL by means of
Hofmanns ligaments
Epidural space contains
Fat, loose CT, extensive epidural venous plexus (batsons plexus)
Where does the epidural anesthesia get placed
Epidural space
Function of dentiuclate ligament
Stabilizes meninges so they do not fold upon one another
What is the film terminale
Helps anchor the spinal cord in place
AKA of filum terminale
Central ligament of spinal cord, coccygeal ligament
Where is the filum terminale
Extends from conus medullaris to 1st coccygeal segment
Filum terminale is made up of
All meninges layers until S2 then only pia mater to coccyx
Where do cell bodies and synapses occur
Gray matter
Cell bodies of interneurons and motor neurons are found in the
Gray matter
The synapses between sensory and motor and interneurons occurs in the
Gray matter
Upper motor neuron lesions involves the
CNS
Hyper reflexia is
Spastic paralysis- inability to move an extremity due to spastic muscles and increased deep tendon reflexes
Lower motor neuron lesions involve the
PNS
Hypo reflexia or a reflexia is
Flaccid paralysis- loss of muscle tone and absences of tendon reflexes
How many pairs of PNS spinal nerves
31
PNS pairs contain both
Sensory and motor nerves
How many pairs of PNS exit through bony foramen
29
Each spinal nerve is formed by the convergence of
Dorsal root and ventral root within the IVF
Out of IVF, spinal nerve divides into
Dorsal ramus and ventral ramus
What is the posterior primary division
Dorsal ramus
What is the anterior primary division
Ventral ramus
Spinal nerves are named based on
Cord level of their origin
How many pairs of cervical nerves
8
How many pairs of thoracic nerves
12
How many pairs of lumbar nerves
5
How many pairs of sacral nerves
5
How many pairs of coccygeal nerves
1
Dorsal ramus innervates
Skin and deep muscles of the back and neck
Ventral ramus innervates
Ventrolateral aspect of the trunk and the extremities
Dorsal roots are what type of fibers
Afferent fibers (sensory)
Ventral roots are what type of fibers
Efferent (motor)
Cervical spinal nerves exit above or below their vertebrae
Above
Do the thoracic, lumbar, sacral and coccygeal spinal nerves exit above or below their vertebrae
Below
What is a plexus
A group of nerves that come together as one
What are the three major plexus in the spine
Cervical, brachial and lumbosacral
What forms the cervical plexus
Ventral rami of C1 through C4
The cervical plexus supplies
Cutaneous innervation to the dorsolateral part of head, neck, shoulders, deep cervical muscles, SCM, trapezius via ANSA cervicalis
Brachial plexus is formed by
Ventral rami of C5 to T1
Brachial plexus supplies
Upper extremities
Roots are off of
Spinal nerves
Trunks divided into
Upper, middle and lower
Divisions divide into
Anterior and posterior
brachial plexus Cords are named for their
Position in relation to the axillary artery, lateral posterior and medial
What is the name of a sympathetic trunk
Ascending sympathetic trunk
Ascending sympathetic trunk supplied by nerves from
Cervical nerve roots all the way to T6
Ascending sympathetic trunk has how many cervical ganglions
3
What are the three cervical ganglion of ascending sympathetic trunk
Inferior cervical ganglion, middle cervical ganglion, and superior cervical ganglion
Aka of inferior cervical ganglion
Stellate ganglion
Inferior cervical ganglion located where
C7/T1
Middle cervical ganglion located at
C5/C6
Superior cervical ganglion located where
C2/C3
Where is ganglion of impar
Anterior to the sacro-coccygeal region
What is the most caudal ganglion of the sympathetic trunk
Ganglion impar
Brachial plexus contains
R, T, D, C, B
Lumbar plexus formed by
Ventral rami of L1 to L4
Lumbar plexus contains
Roots, Divisions and branches
Lumbar plexus supplies the
Lower extremities
Lateral femoral cutaneous nerve located
L2/L3
Sacral plexus located where
L4-S5
Sciatic nerve located where
L4, L5, S1, S2
Sciatic nerve made up of
Common peroneal nerve and tibial nerve
What of lumbar plexus form the femoral nerve
Posterior (dorsal) branches, L2-L4
What of the lumbar plexus forms the obturator nerve
Anterior (ventral) branches, L2-L4
Sacral plexus arises from
Anterior branches of L4, L5 and S1-S3
What of sacral plexus forms the tibial nerve
Anterior (ventral) branches of L4-S3
What of sacral plexus form common peroneal nerve
Posterior (dorsal) branch of L4-S2
Meralgia paresthetica involves what nerves
L2-L3 nerves
What is meralgia paresthetica
Sensory disturbances in the anterolateral thigh
The sacral plexus lies just anterior to what muscle
Piriformis muscle
Celiac plexus AKA
Solar plexus
Celiac plexus located where
L1 vertebrae
Pelvic plexus lies where
Anterior to ventral surface of sacrum
Pelvic plexus associated with what ganglions
4-5
Facet degeneration is cause of
Disc degeneration
Disc degeneration is the cause of
Facet degeneration
