Gross Anatomy 1 - PNS Revision Flashcards
What is the name for a collection of nerve cell bodies in the CNS?
Nucleus
What is the name for a collection of nerve cell bodies in the PNS?
Ganglion
What cells produce myelin in the CNS?
Oligodendrocytes
What cells produce myelin in the PNS?
Schwann cells
What are the 2 main types of neurones?
Multipolar
Unipolar
What defines a neurone as multipolar?
If it has 2 or more dendrites
What type of neurones are all motor neurones of skeletal muscles and the autonomic nervous system?
Multipolar
Are cell bodies in the CNS unipolar or multipolar?
Multipolar
What is another name for unipolar neurones?
Pseudounipolar
How do unipolar neurones differ from multipolar neurones?
They have a double process
Are cell bodies in the PNS unipolar or multipolar?
Unipolar
Do sensory neurones tend to be unipolar or multipolar?
Unipolar
What is the name for a collection of axons surrounded by connective tissue and blood vessels in the CNS and the PNS?
CNS = tract PNS = nerve
Do tracts tend to be single or multi-modality?
Single
Which of the cranial nerves are only sensory?
Olfactory (CN I)
Optic (CN II)
Vestibulocochlear (CN VIII)
Which of the cranial nerves are only motor?
Oculomotor (CN III) Trochlear (CN IV) Abducent (CN VI) Spinal accessory nerve (CN XI) Hypoglossal nerve (CN XII)
Where does CN I attach to the brain?
Forebrain
Where does CN II attach to the brain?
Forebrain
Where does CN III attach to the brain?
Midbrain
Where does CN IV attach to the brain?
Midbrain
Where does CN V attach to the brain?
Pons
Where does CN VI attach to the brain?
Junction between the pons and medulla
Where does CN VII attach to the brain?
Junction between the pons and medulla
where does CN VIII attach to the brain?
Junction between the pons and medulla
Where does CN IX attach to the brain?
Medulla
Where does CN X attach to the brain?
Medulla
Where does CN XI attach to the brain?
Spinal cord
Where does CNXII attach to the brain?
Medulla
How many spinal nerves are there?
31
How many cervical spinal nerves are there?
8
Where are spinal nerves found?
In intervertebral foramina
How does the spinal nerves connect with the soma?
Via rami
How does the spinal nerves connect with the spinal cord?
Via roots and rootlets
Do sensory axons pass from the spinal nerve into the anterior or posterior root/ rootlets/ horn?
Posterior
Do motor axons pass from the spinal cord into anterior or posterior horns/ rootlets/ roots?
Anterior
Are spinal nerves sensory, motor or mixed?
Mixed
What type of nerve supply does each spinal nerve supply a body segment with? (3)
General sensory -> all structures
Somatic motor -> skeletal muscles
Sympathetic nerve -> skin and smooth muscle of arterioles
What is a dermatome?
An area of skin supplied with sensory innervation from a single spinal nerve
If an area of the body wall is numb, have you injured one or more than one nerve?
More than one (innervation of skin my adjacent spinal nerves shows overlap)
What is a myotome?
Skeletal muscles supplied with motor innervation from a single spinal nerve
Which dermatome covers the adam’s apple and back of the scalp?
C2
What dermatome covers the back of the neck and jugular notch?
C3
What dermatome covers the clavicle and shoulder tip?
C4
What dermatome covers the superior half of the arm when the arm is outstreched - AKA badge patch area?
C5
What dermatome covers the superior half of the forearm when the arm is outstretched down to the thumb and front of the index finger?
C6
what dermatome covers the middle finger and back of the index finger (+ corresponding area of the palm)?
C7
What finger covers the pinky and ring finger (+corresponding area of the palm)?
C8
What dermatome covers the medial forearm?
T1
What dermatome covers the medial arm and sternal angle?
T2
What dermatome falls over the male nipple?
T4
What dermatome falls over the umbilicus?
T10
What dermatome covers the groin?
L1
What dermatome covers the anterior thigh and middle area of the lower back?
L2
What dermatome covers the inner thigh, front of the knee and bottom area of the lower back?
L3
What dermatome covers the inner portion of the leg to the medial malleolus?
L4
What dermatome covers the outer portion of the leg and most of the inner foot?
L5
What dermatome covers the outer portion of the foot and heel (extending slightly up the leg)?
S1
What dermatome covers a back portion of the leg, back of the knee and back of the thigh?
S2
What dermatome covers the buttock?
S3
What dermatome covers the perineum?
S4
What dermatomes covers the perianal skin?
S5
What is the name for intermingled anterior rami from a number of adjacent spinal nerves?
Nerve plexuses
What spinal nerves contribute to the cervical plexus?
C1-C4
What structures does the cervical plexus supply?
Posterior scalp, neck and diaphragm
What spinal nerves contribute to the brachial plexus?
C5 - T1
What structure does the brachial plexus supply?
Upper limb
What spinal nerves contribute to the lumbar plexus?
L1-L4
What structure does the lumbar plexus supply?
Lower limb
What spinal nerves contribute to the sacral plexus?
L5-S4
What structures does the sacral plexus contribute to?
Lower limb, gluteal region and perineum
What is the other name given to sympathetic outflow?
Thoracolumbar outflow
Where do sympathetic fibres pass down in the spinal cord?
Lateral horns
Where do sympathetic fibres pass from the spinal nerves?
To the sympathetic chain
Where do sympathetic fibres pass from the sympathetic chain?
Into all anterior and posterior rami to supply the body wall
Into splanchnic nerves to supply organs
Do the sympathetic fibres travelling into splanchnic nerves synapse in the symapathetic chain?
Yes, unless they are supplying abdominopelvic viscera via abdominopelvic splanchnic nerves
Where do presynaptic sympathetic axons travelling to the heart synapse?
T1 or cervical paravertebral ganglia
What is the name of the splanchnic nerves which carry postsynaptic sympathetic axons to the heart and lungs?
Cardiopulmonary splanchnic nerves
Where do presynaptic sympathetic axons passing to the lungs synapse?
In upper thoracic paravertebral ganglions
Where are the prevertebral ganglia located?
Over the abdominal aorta
what is the name of the prevertebral ganglion for foregut nerves?
Celiac ganglion
What is the name of the prevertebral ganglion for kidney nerves?
Aorticorenal ganglion
What is the name of the prevertebral ganglion for midgut nerves?
Superior mesenteric ganglion
What is the name of the prevertebral ganglion for hindgut and pelvic/ perineal organ nerves?
Inferior mesenteric ganglion
Where do presynaptic sympathetic axons supplying the adrenal medulla synapse?
Directly onto the adrenaline/ noradrenaline secreting cells
How do presynaptic parasympathetic axons leave the CNS?
Via CNs III, VII, IX nad X
Via sacral spinal nerves
How do parasympathetic travel to the eye?
Via the ciliary ganglion
How do parasympathetic travel to the lacrimal gland and salivary glands?
Via the parasympathetic ganglia in the head
How do parasympathetic travel to the organs of the neck, chest and abdomen as far as the mid-gut?
Via the vagus nerve (synapses on the organ)
How do parasympathetic travel to the hindgut, pelvis and perineum?
Via the sacral spinal nerves (synapses on the organs)
What dermatome covers the xiphoid process?
T8
What dermatome covers the pubic symphysis?
T12