Anatomy 1 Flashcards
What two types of cells for myelin sheath and where are they located?
Oligodendrocytes in CNS
Schwann Cells in PNS
What is are the most common types of neurones and where are they found?
- Multipolar (Skeletal muscle and ANS) and cell body in CNS (First/presynaptic neurone for ANS)
- Unipolar (Cell body in PNS)
Describe the path of a motor impulse from the brain to the effector?
- Action potential towards body wall, body cavity or or organ
- Upper motor neuron within a motor tract
- To lower motor neuron withing cranial or spinal nerve
Describe the path of a sensory impulse from sensory receptors to brain
- From primary afferent neurone or visceral afferent within cranial or spinal nerve
- To second order neurone within a sensory tract
What are the terms used for nerve cell bodies in the CNS and PNS?
CNS- Nucleus
PNS- Ganglion
What are the terms used for bundles of axons in the CNS and PNS
CNS- Tract
PNS- Nerve
Define the term nerve
A bundle of axons travelling to/from the same region or structure
Nerves can carry signals from the same modality or mixed modalities, what does this mean?
- Same modality (all somatic motor, all somatic sensory, special sensory, sympathetic, parasympathetic or visceral afferent
How many pairs of spinal nerves are there?
31
- 8 cervical pairs
- 12 thoracic pairs
- 5 lumbar pairs
- 5 sacral pairs
- 1 coccygeal pair
Describe how a spinal nerve divides as it leaves the spinal cord
- Rootlets
- Roots
- Where it becomes spinal nerve
- Anterior and posterior rami
How do the anterior and posterior rami differ?
Anterior
- Larger
- Supplies anterolateral body wall
Posterior
- Smaller
- Supplies posterior body wall
Describe the path of sensory axons to the spinal cord
- Spinal nerve
- Posterior roots
- Posterior rootlets
- Posterior horn of spinal cord
Describe the path of motor axons from the spinal cord (Starting at spinal cord)
- Anterior horn of spinal cord
- Anterior roots
- Anterior rootlets
- Spinal nerve
What does each dermatome receive in terms of innervation?
- Own general sensory supply
- Own motor supply to skeletal muscles
- Own sympathetic nerve supply to the skin (Controls skin arterioles, arrector muscles and sweat glands)
What is a dermatome?
A single segment of the body skin that is supplied by a single pair of spinal nerves
Which dermatome is the male nipple in
T4
Which dermatome is the umbilicus in
T10
Which dermatome group covers the posterior scalp, neck and shoulder
C2-4
Which dermatome group covers the upper limb
C5-T2
Which dermatome group covers the lower limb, gluteal region and perineum
L2-Co1
What is a nerve plexus
A mixing of anterior rami forming a network
Which spinal nerves contribute to the cervical plexus and where does it innervate
C1-4
Posterior scalp, Neck wall and diaphragm
Which spinal nerves contribute to the brachial plexus and where does it innervaet
C5-T1
Upper limb
Which spinal nerves contribute to the lumbar plexus and where does it innervate
L1-4
Lower limb
Which spinal nerves contribute to the sacral plexus and where does it innervate
L5-S4
Lower limb, gluteal region and perineum
What is a myotome
The skeletal muscles supplied by both the anterior and posterior ramus of a single spinal nerve.
Which spinal nerves are accompanied by a sympathetic outflow
T1-L2
How does the sympathetic outflow reach the head, neck organs and skin
They hitch a ride with arteries
What are the facial signs of Horner’s syndrome?
Ipilateral ptosis due to lack of sympathetic innervation of levator palpebrae superioris
Ipsilateral miosis due to lack of sympathetic innervation of dilator pupillae
Reduced sweatingof ipsilateral side due to lack of innervation of skin sweat glands.
Which nerves have parasympathetic outflow?
CN III, VII, IX and X
Sacral nerves
