Introduction to the Nervous System Flashcards
Notable anatomy of a neuron
axon, body, dendrites, myelin sheath
Ganglion
collection of nerve cell bodies in the PNS
Tract
bundles of axons around CNS
Nerve
Bundle of axons in the PNS
Modalities of axons
Somatic sensory
somatic motor
special sensory
visceral afferent
sympathetic
parasympathetic
Modalities of the spinal nerve and branches
somatic motor, somatic sensory and sympathetic
Cranial nerves
mixed
motor (efferent)
action potential goes towards the body wall, cavity or organ
Sensory (afferent)
action potential towards the brain
Features of the spinal cord
Connects with the brain
passes through the foramen magnum
protected by the vertebral column
The four segments of the spinal cord
cervical (C1-C7)
thoracic (T1-T12)
Lumber (L1xL5)
Sacral (S1-S5) and coccygeal (Co)
Where are the two enlargements on the spinal cord?
Cervical and Lumbosacral
Why are there enlargements?
Innervation and control of limbs
The _____ and _____ nerve roots descend and form the _____ _____
Lumbar, Sacral, Cauda equina
Feature near L1&2
Conud Medullaris
PNS
Peripheral nervous system
peripheral nervous system
nerve tissue outwith the CNS
Peripheral nerves
Bundles of axons wrapped by connective tissue, travelling to/from same structure
Spinal nerves
connects with spinal cord
Cranial nerve
connect with brain
Autonomic nerves
innervate organs, smooth muscle and glands
Autonomic nerve examples
Visceral afferents, sympathetic nerves, parasympathetic nerves
where do spinal nerves connect?
spinal cord, bilaterally, 31 pairs
how are spinal nerves named?
after the vertebrate above it, except when they’e in the cervical region, where theyre named after the vertebrate below
where do spinal nerves supply?
the soma (body wall)
where are the spinal nerves located?
in the intervertebral foramen
where do the nerves connect after the IV foramen
the structures of the soma via the rami
the spinal cord via roots and rootlets
posterior rami
supply small posterior strip of the soma
Anterior
supply the remainder of the posterior part, the lateral and anterior parts of the strips of soma
where else does the anterior rami supply (via the plexus)
all limbs via the plexus (networks of intertwined anterior rami
cervical plexus
C1-C4 anterior rami
supplies the posterior scalp, neck and diaphragm
Brachial plexus
C5-T1 anterior rami
supplies the upper limb
Lumbar plexus
L1-L4 anterior rami
supplies thr lower lim
Sacral plexus
L5-S4 anterior
supplies the lower limb, gluteal region and perineum
Dermatome
area of skin supplied by both the anterior and posterior rami of a spinal nerve (with exceptions to thr limbs)
T4 dermatome
nipple
T10 dermatome
umbilicus
Cranial Nerves
CN I-XII
Sensory Motor or Both
C I
Olfactory Nerve
Sensory (Special)
CN II
Optic Nerve
Sensory (Special)
CN III
Oculomotor Nerve
Motor
CN IV
Trochlear Nerve
Motor
CN V
Trigeminal Nerve
Both
CN VI
Abducent Nerve
Motor
CN VII
Facial Nerve
Both
CN IX
Glossopharyngeal Nerve
Both
CN X
Vagus Nerve
Both
CN XI
Spinal accessory nerve
Motor
CN XII
Hypoglossal Nerve
Motor
Soma
the body wall including the head, neck, chest and back wall, diaphragm, abdominal and pelvis wall and the limbs
three sensory receptors
mechanoreceptors
thermoreceptors
nociceptors
mechanoreceptors
coarse and fine touch, vibration, proprioception
thermoreceptors
temperatures
Nociceptors
pain (sharp, stabbing, well localised)
Somatic sensation pathway to the brain
sensory receptor stimulated
anterior ramus
plexus
dorsal root ganglion
dorsal root
dorsal rootlet
posteriot horn
cross over midline and action potential ascends towards brain
Motor innervation pathway to skeletal muscle
