The Nervous System Part 1 Flashcards
What does the CNS and PNS consist of?
- CNS: brain and spinal cord
- PNS: nerves which pass to and from the CNS (Cranial and spinal nerves)
- Is motor information transmitted to voluntary or involuntary areas and what part of the nervous system transmits it?
- What muscles/organs is motor information carried to?
- To voluntary skeletal muscle via somatic nervous system
- To carciac muscle, glands and involuntary smooth muscle of organs and blood vessels via
What is the neuron structure and what are the 2 types?
- Nucleated cell body with dendrites (cytoplasmic processes) and the axon
1. afferent neurons: carry sensory info to the cns
2. efferent neurons: carry motor info away from cns
Where does the spinal cord end?
Between the 1st and 2nd lumbar vertebrae forming the conus medullaris
What is the grey matter in the spinal cord composed of?
- Cell bodies of neurons (and their glial cells)
Arranged as a - Dorsal (posterior) horn
- Ventral (anterior) horn
What is the white matter in the spinal cord composed of?
- Nerve fibres
- The white colour results from the myelinated axons
Label the transverse section of the spinal cord
What is the bundle of spinal nerves at the end of the spinal cord called?
Cauda equina (from L2-S5)
What is the purpose of the cervical and lumbar enlargements on the spinal cord?
The limbs have a lot of muscles. The more motor neurons, the more cell bodies needed to feed the muscles in the limbs
Where are the brachial plexus and lumbar and sacral plexi found in the spinal cord?
- Brachial plexus: Cervical enlargement between C5-T1
- Lumbar and sacral plexi: Lumbar enlargement between T11 and L1
What does the subarachnoid space contain and what is it located between?
- Cerebrospinal fluid (CSF)
- Between pia and arachnoid mater
What is the lumbar cistern? What’s its clinical significance?
- An area of subarachnoid space which extends from the conus medullaris
- Where a lumbar puncture and spinal anasthesia are administered
What are spinal nerves structure?
Each nerve begins as an anterior (motor) and posterior (sensory) nerve root. These unite at the intervertebral foramina forming a single single spinal nerve
The spinal nerve leaves the vertebral canal via intervertebral foramina and divides into 2.
What are the 2 ramis?
- Posterior rami: supplies nerve fibres to synovial joints of the vertebral column, deep back muscles and overlying skin
- Anterior rami: supplies nerve fibres to much of the remaining area of the body, motor and sensory
What is a nerve plexus?
A network of nerve fibres
What is a ganglion?
A collection of neuronal cell bodies situated outside the CNS.
What is the spinal cord continuous with?
The medulla oblongata
What is the space between the bones of the vertebral canal and the dura mater?
- Epidural space
How many cranial nerves are there and what info do they carry?
Which nerve is the exception?
- 12 pairs of cranial nerves
- Sensory info from and motor info to the head and neck
- Vagus nerve innervates the structures in the thorax and abdomen