Nerves Revised Flashcards
Where do somatic nerves arise from?
Spinal cord
How do somatic nerves arise from the spinal cord?
Via sensory dorsal root and motor ventral root
Where would you find a mixed spinal nerve?
Intervertebral foramen
What are the two components of a mixed nerve?
Motor and sensory nerve fibres
What happens after the mixed spinal nerve leaves the intervertebral foramen?
It branches into dorsal and ventral rami
Where does the dorsal ramus supply?
Posterior trunk
Where does the ventral ramus supply?
Anterolateral trunk and the limbs
What does the dorsal root carry?
Sensory fibres
What does the motor root carry?
Motor fibres
What does the ventral rami carry?
Mixed motor and sensory fibres
What does the motor rami carry?
Mixed motor and sensory fibres
If the anterior horn of the spinal cord was damaged, which part of the body would be affected?
Anterolateral trunk
Limbs
If the posterior horn of the spinal cord was damaged, which part of the body would be affected?
Posterior trunk
If the dorsal root of the spinal cord was damaged, which part of the body would be affected?
Posterior trunk
If the ventral root of the spinal cord was damaged, which part of the body would be affected?
Anterolateral trunk
Limbs
If the anterior ramus of the spinal cord was damaged, which part of the body would be affected?
Anterolateral trunk
Posterior trunk
Limbs
If the posterior ramus of the spinal cord was damaged, which part of the body would be affected?
Anterolateral trunk
Posterior trunk
Limbs
Give an example of a muscle which the dorsal ramus can supply
Erector Spinae
Given an example of a muscle which the ventral ramus can supply
Intercostal muscles
Abdominal wall
What is cutaneous innervation?
An area of skin which is supplied by a specific cutaneous nerve
What does a cutaneous nerve contain?
Nerve fibres from several spinal nerves
How does a dermatome differ to a cutaneous nerve?
Dermatome is an area of skin supplied by one spinal nerve.
A cutaneous nerve can consist of fibres from many different spinal nerves.
Give an example of one area where the cutaneous nerves and dermatomes are the same.
Thorax
Abdomen
Where in the body do the cutaneous nerves and dermatomes differ?
Limbs
Which type of innervation is more specific-dermatome or cutaneous nerve
Dermatome
Where does the lateral antebrachial cutaneous nerve supply?
Lateral side of the forearm
Which level does the spinal nerves of the lateral antebrachial cutaneous nerve arise from?
C5-6
Where does the radial dorsal antebrachial cutaneous nerve supply?
Lateral side of the arm
Which level does the spinal nerves of the radial dorsal antebrachial cutaneous nerve arise from?
C5-6
Which joint occurs in the midline of the trunk at dermatome T2?
Sternomanubrial joint
What surface feature is present at dermatome T4?
Nipples
What surface feature is present at dermatome T10?
Umbilicus (belly button)
In which region is dermatome L1 found?
Inguinal region
What is the fatty white substance which surrounds the axon of some nerve cells?
Myelin
Which cells secrete myelin?
Schwann cells
What is the function of myelin?
Forms an electrically insulating layer
What forms a layer around a myelin sheath for each nerve fibre?
Endoneurium
What is the endoneurium composed of?
Thin layer of connective tissue
What surrounds each fascicle of nerve fibres?
Perineurium
In a nerve is big enough, what surrounds it?
Epineurium
Name the four components of a nerve
