Lecture 14 content Flashcards
Neural tube
- forms?
- what becomes what?
- filled?
- Nerves?
- Ectoderm folds inward to for holow tube
- anterior end swells - becomes hollow - hollow brain
- posterior portion - Hollow - spine and central canal
- filled with CSF
- segmented from brain (12) and spinal cord (31)
What is the typical cross section of the spinal cord?
Cortex: white matter = myelinated axons (more superficial)
Medulla: Grey matter = cell bodies , unmyelinated axons
central canal filled with CSF
Name the 3 meningeal layers superficial to deep
Dura mater - sub dural space Arachnoid - sub arachnoid space Pia mater
Describe the Dura mater?
thick, fibrous, outermost
- target for epidural block
- endosteum of the brain case
- epidural space btw dura mater and vertebral canal
- subdural space between dura and arachnoid
Describe the arachnoid Layer
thin intermediate layer (spider web like)
- subarachnoid space between arachnoid and Pia mater
- blood vessels supported by arachnoid trabeculae
- sub arachnoid space filled with CSF
- target for spinal tap
Describe the Pia mater layer
vascular, innermost layer, adheres to gyri
- Pia mater is firmly attached to the spinal cord
- blood vessels from network on surface of cord
What is meningitis?
inflammation of meninges: bacteria, virus, inury
- any meningeal layer
what is the general structure of the spinal cord?
18 inches long
- conus medullaris
- filum terminale
- posterior median sulcus
- anterior fissure
conus medullaris
tapered conical termination of cord
filum terminale
- fibers extending from conus > coccyx
Posterior median sulcus
shallow longitudinal groove
anterior median fissure
deep longitudinal groove
where do spinal nerves leave/enter spinal column?
intervertebral foramen
What does the dorsal root contain?
sensory nerves and their bodies
What does the ventral root contain?
motor neurons
What does the dorsal Ramus innervate?
skin/muscles of back
What does the ventral ramus innervate?
- skin/muscles of thorax, abdomen, limbs
rami communicantes is part of what system?
ANS
- Rami: contain sensory and motor
What nerve is superior to C7, T1, T2
- named on what is above it! C7 = Nerve C7 -------------------------This is where it switches T1 = C8 T2 = T1
How many spinal nerves are their? what are the segments?
31 pairs of spinal nerve 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
What is referred pain? (convergent - projecton)
convergent - projecton) = perception does not equal source of pain
when the pain that you are feeling are not in the place where the problem is (heart attack = left arm)
What is Dermatomes?
segmented innervation of skin
What are the 3 nerve plexus?
what do they provide?
- cervical plexus (C1 - C5)
- Brachial plexus (C5 - T 1)
- Lumbosacral plexus (T12 - S4)
Nereves that provide motor input to a muscle
provide sensory feed - back from m.s. and skin
Name the branch of the Cervical plexus and what they innervate?
(C1 - C5)
- phrenic nerve (C3) - controls contraction of the diaphragm
Neck muscles , levator scapulae, part of trapezius and SCM
Name the branch of the Brachial Plexus and what they innervate? (ARMUM)
(C5 - T1)
axillary n. - deltoid and teres minor
radial n. - all extensors (arm, forearm, wrist, fingers)
Median n. - flexors of wrist and fingers
ulnar n. - flexor carpi ulnaris
Musculocutaneus n. - flexors of the arm and forearm
What is a upper plexus injury?
Erbs palsy
What is a lower plexus injury?
Klumpk’es palsy
Name the branches of the lumbosacral plexus? and what do they innervate?
- (T12-S4)
gluteal n - gluteal muscles
obturator n. adductors of thigh
femoral n. - extensrs of the knee (vastus m. rectus femoris m.)
tibial n - semi’s, biceps femoris (long head) flexors of ankle
Fibular n. - biceps femoris (short head) fibularis muscles
Fibular n. - dorsi-flexors of ankle/toes
Pudendal n. Gi/Ug sphinters, external genitalia (S2-S4)
what are reflexes characterized by?
Development history: innate or acquired
processing site: brain or spinal cord
circuit complexity: monosynaptic or polysynaptic
motor response: somatic or viceral (ANS)
What is the 5 step process?
- stimulis of the receptors pain or stretch
- sensory neuron (dorsal root) sends info to the CNS
- Relays info
- sensation relayed to brain
- sensation replayed to pool of motor neurons - Motor neuron (ventral root) is activated
- Peripheral effectors respond muscles and glands
What is a cerebrovascular accident?
(CVA stroke)
What is paralysis?
loss of motor control
What is parapelegia?
Paralysis of the lower limbs (L1)
What is Hemalegia?
paralysis of one side of the body
What is quariplegia?
paralysis of all 4 limbs C6 C4
What is Spina Bifida?
malformation of spine and spinal cord
