Spinal Cord - Lec. 17 Flashcards
Where does the spinal cord start and end
begins: medulla oblongata
ends: L1-2 vertebrae (ending part called conus medullaris)
Conus medullaris is anchored to the coccyx by a strand of fibrous tissue extending inferiorly from the conus medullaris that is called:
Filum terminale
What are the two regions of increased diameter regarding the spinal cord?
Cervical enlargement
- gives rise to the spinal nerves that innervate the upper limbs
Lumbar enlargement
- gives rise to the spinal nerves that innervate the lower limbs
What is A
Posterior median sulcus
What is B
Anterior median fissure
What is C
Central canal
What is D
White matter
What is E
Grey matter
What is white matter composed of
Myelinated axons
What is grey matter composed of
Un-myelinated axons and cell bodies
What is A
Posterior horn
What is B
Lateral horn
What is C
Anterior horn
What is A
Posterior columns
What is B
Lateral Columns
What is C
Anterior columns
Posterior, lateral and anterior columns of white matter contain:
Sensory and motor tracts
The posterior horn of the grey matter contains:
Cell bodies of interneurons that relay SENSORY signals up the spinal cord
The lateral horn of grey matter contains:
Cell bodies of AUTONOMIC motor neurons
Only present in T1-L2 and S2-S4 segments
The anterior horn of the grey matter contains:
Cell bodies of SOMATIC motor neurons
How many segments is the spinal cord divided into
31
How many pairs of cervical spinal nerves are there
8
How many pairs of thoracic spinal nerves are there
12
How many pairs of lumbar spinal nerves are there
5
How many pairs of sacral spinal nerves are there
5
How many pairs of coccygeal spinal nerves are there
1
What is A
Posterior root
What is B
Posterior root ganglion
What is C
Spinal nerve
What is D
Anterior root
What is the posterior root made up of
Axons of SENSORY neurons
What is a posterior root ganglion composed of
SENSORY Cell bodies
What is the spinal nerve made up of
Sensory and motor axons
What is the anterior root made up of
Axons of MOTOR neurons
True or false: signals entering the spinal cord never do so via the anterior root
True: anterior root is a one way street for motor axons
True or false: signals exiting the spinal cord never do so via the posterior root
True: posterior root is a one way street for sensory axons
Spinal nerves emerge from the vertebral column between adjacent vertebrae through _________.
The intervertebral foramina
C1 - C7 spinal nerves exit _________ to the their corresponding vertebrae
Superior
C8 spinal nerves exit ______ C7 & T1
Between
Thoracic/lumbar spinal nerves exit ________ to their corresponding vertebrae
Inferior
What is A
Intervertebral foramen
What is A
Cauda Equina (horses tail)
