Lab Quiz 7 (Spinal cord and reflexes)

Spinal cord

Column of nerve fibers that extend down through the vertebral canal and is one of two parts of the central nervous system

Meninges of the CNS

• dura mater

• Arachnoid matter

• Pia matter

Dura mater

• outer layer of meninges

• Tough dense connective tissue

• Dural sinuses

• Epidural space

Arachnoid Mater

• middle meninge layer

• Web-like

• Subarachnoid space contains CSF

Pia Mater

• inner meninge layer

• Attached to surface of the brain and spinal cord

• Contains blood vessels and nerves

• Nourishes CNS

Posterior median sulcus

• shallow groove in the spinal cords midline that separates the two posterior funiculi

Anterior median fissure

• a deep groove in the midline of the spinal cords anterior surface

Central Canal

• aka ependymal canal or spinal foramen

• CSF filled space that runs longitudinal through the spinal cord

Gray Matter

• gray tissue in the brain and spinal cord

• Getting its color from unmyelinated axons

Gray commissure

• thin strip of gray matter that connects the spinal cords two halves and surrounds its central canal

Gray Commissure parts

• anterior horn

• Lateral horn

• Posterior horn

White matter

• tissue found in the brain and spinal cord

• Gets its color from myelinated axons

Posterior funiculus

• region of sensory white matter in the spinal cords midline that is crucial for transmitting specific types of sensory information to the brain

• Connect both halves by the posterior median sulcus

Lateral funiculus

• White matter tract in the spinal cord that contains ascending and descending nerve fibers tracts running on the lateral aspects

Anterior funiculus

• white matter region of the spinal cord that contains nerve fibers running along the anterior aspect with both ascending and descending nerve fibers

Roots of the spinal nerve

• posterior roots

• Posterior root ganglia

• Anterior roots

Posterior roots of the spinal nerve

• bundle of of sensory nerves that emerges from the dorsal side of the spinal cord

Posterior root ganglia

• clusters of nerve cells that transmit sensory messages of touch and pain

• Located at the base of each spinal nerve

Anterior roots of the spinal nerve

• motor pathways that carry nerve impulses away from the spinal cord to the skeletal muscles and other parts of the body

• emerge from the ventral side of the spinal cord

Subarachnoid space

• space between the arachnoid mater and the pia maater

• Contains CSF

Corticospinal tract

• descending tract whose fibers conduct motor impulses to skeletal muscles

Fasciculus gracilis

• ascending tract to the brain to interpret touch, pressure and body movements

Lateral Spinothalmic

• ascending tract to the brain to give rise to sensations of temperature and pain

Posterior Spinocerebellar

• ascending tract to the cerebellum necessary for coordination of skeletal muscles

Reticulospinal

• descending tract whose fibers conduct motor impulses to sweat glands and muscles to control tone

Denticulate ligament

• band of pia mater that anchors the dura mater to the spinal cord

Dural Sinus

• channel through which venous blood flows

Epidural space

• separates the dura mater from the bone of the vertebrae

Stretch reflex

• a reflex only involving a single synapse between a sensory and motor neuron within the gray matter of the spinal cord

Examples of stretch reflexes

• patellar

• Calcaneal

• Biceps

• Triceps

• Plantar

Withdrawal reflexes

• reflexes that are polysynaptic requiring the involvement of interneurons along with sensory and motor neurons

Patellar reflex

Calcaneal reflex

Biceps reflex

Triceps reflex

Plantar reflex