Divisions of the Nervous System Flashcards
Anatomical axis
Cranial/Rostral - Caudial Superior - Inferior Lateral - Medial Distal - Proximal Dorsal - Ventral
What are the planes used in brain anatomy?
Coronal
Horizontal
Sagittal
What does ipsilateral mean?
Same side of the body
What does contralateral mean?
Opposite side of the body
What are the 3 main divisions of the nervous system?
- Central Nervous System
- Peripheral Nervous System
- Enteric Nervous System
What is the CNS?
Brain and spinal cord
What is the PNS?
Nerves and cell bodies to/from the brain and spinal cord
What is the enteric NS?
Neuronal cells of the GI tract
How many nerves are in the PNS?
43 pairs
Which nervous system has 43 pairs of nerves?
PNS
How are the nerves of the peripheral nervous system classed?
Cranial and spinal nerves
How many nerves of each subdivision are there in the PNS?
31 spinal pairs and 12 cranial pairs
Structure of peripheral nerves
- Contain axons, no dendrites
- No cell bodies
- Most are ‘mixed’
Do peripheral nerves contain dendrites?
No, only axons
Do peripheral nerves carry sensory input?
Yes but most are ‘mixed’ so carry motor outputs too
What is a fascicle?
A bundle of individually wrapped axons
Can fascicles be myelinated?
Yes
What is the endometrium?
Surrounds each individual axon for mechanical support
What is the perineurium?
What bundles each individual axon together into fascicles
What is the epineurium?
What encloses the fascicles with blood vessels?
_______ surrounds each individual axon. The axons are bundled by ________ into fascicles and closed with blood vessels by ______
Endoneurium, perineurium, epineurium
What are cranial nerves?
Peripheral nerves of the brain (12) pairs
Which cranial nerves are derived from the forebrain?
Cranial nerves I and II
Cranial nerve I and II are derived from the _______
Forebrain
Which cranial nerves are from the brainstem?
Cranial nerves III to XII
Which cranial nerve is derived from the brainstem but also has a spinal cord connection?
Cranial nerve XI
Accessory nerve
What is cranial nerve X?
The Vagus nerve
Are all cranial nerves mixed?
No
Are all spinal nerves mixed?
Yes
What are the 5 sets of spinal nerves called?
- Cervical
- Thoracic
- Lumbar
- Sacral
- Coccygeal
Define rami
Spinal nerve branch. Important for pattern of innervation
Define dermatome
Areas of the body innervated by specific spinal nerves.
How can dermatomes be used in clinical medicine?
Help neurologists identify sites of damage
How can the PNS be divided based on function?
Somatic(voluntary)/Visceral(involuntary)
Afferent(sensory)/Efferent(motor)
Difference between motor axons in somatic and autonomic nervous systems
Somatic - Motor axons go straight to muscle
Autonomic - Motor axons connect with another cell in a ganglion, this cell innervates the muscle
Are pre-ganglionic axons myelinated?
Yes
Are post-ganglionic axons myelinated?
No
Do sympathetic or parasympathetic ganglia lie close to the spinal cord?
Sympathetic
Parasympathetic ganglia like close to ___ _____
The target
What does does the location of ganglia mean about the length of fibres?
Sympathetic ganglia are mostly close to the spinal cord, therefore, the pre-ganglionic fibres would be short
Parasympathetic pre-ganglionic fibres are long as the ganglia lie close to target
Are sympathetic post-ganglion adrenergic or cholinergic?
Adrenergic
Are parasympathetic post-ganglion adrenergic or cholinergic?
Cholinergic
