Spinal Cord & Reflexes Flashcards
What is the cervical region of the vertebral column?
The first seven vertebrae in the neck (C1–C7).
What is the thoracic region of the vertebral column?
The twelve vertebrae in the upper and mid-back (T1–T12), each attached to a pair of ribs.
What is the lumbar region of the vertebral column?
The five vertebrae in the lower back (L1–L5).
What is the sacrum?
A triangular bone at the base of the spine, formed by five fused vertebrae (S1–S5).
What is the coccyx?
The small, triangular bone at the very end of the vertebral column (tailbone), made up of 3–5 fused vertebrae.
What is the vertebral foramen?
The opening in each vertebra through which the spinal cord passes.
What is the intervertebral foramen?
Small openings between adjacent vertebrae that allow spinal nerves to exit from the spinal cord.
What is the cervical region of the spinal cord responsible for?
Nerve signals to and from the upper limbs and neck.
What is the thoracic region of the spinal cord involved in?
Nerve signals for the torso and some parts of the abdomen.
What does the lumbar region of the spinal cord associate with?
The lower back and legs.
What is the sacral region of the spinal cord responsible for?
Nerves for the lower limbs and pelvic organs.
What is the cervical enlargement?
The thickened region of the spinal cord in the cervical area where nerves to the arms originate.
What is the lumbar enlargement?
The thickened region in the lumbar area where nerves to the legs originate.
What is the conus medullaris?
The tapered, cone-shaped end of the spinal cord, usually around the L1–L2 vertebrae.
What is the cauda equina?
A bundle of spinal nerves and nerve roots that extend from the conus medullaris, resembling a ‘horse’s tail.’
What is the filum terminale?
A delicate, fibrous strand that extends from the conus medullaris, anchoring the spinal cord to the coccyx.
What is the dorsal root ganglion?
A cluster of sensory neuron cell bodies located just outside the spinal cord, part of the sensory pathway.
What is the dorsal root?
The part of the spinal nerve that carries sensory (afferent) information from the body to the spinal cord.
What is the ventral root?
The part of the spinal nerve that carries motor (efferent) information from the spinal cord to muscles and glands.
What are spinal nerves?
Mixed nerves (both sensory and motor) formed by the fusion of dorsal and ventral roots that exit the spinal column.
What is the dorsal ramus?
The branch of a spinal nerve that supplies the muscles and skin of the back.
What is the ventral ramus?
The branch of a spinal nerve that supplies the muscles and skin of the front and sides of the body, including limbs.
What is white matter?
The part of the spinal cord that contains myelinated nerve fibers, forming the ascending and descending pathways.
What is the dorsal/posterior column?
A pathway in the white matter that carries sensory information such as touch and proprioception.
What is the ventral/anterior column?
A part of the white matter that carries both motor and sensory pathways.
What is the lateral column?
A portion of the white matter in the spinal cord, involved in motor control and sensory processing.
What is gray matter?
The central part of the spinal cord composed of neuron cell bodies, dendrites, and synapses.
What is the dorsal/posterior horn?
The region of gray matter in the spinal cord that processes sensory information.
What is the lateral horn?
Present in the thoracic and lumbar regions, this part of gray matter houses the cell bodies of autonomic motor neurons.
What is the anterior/ventral horn?
The region of gray matter that contains motor neurons responsible for voluntary muscle movements.
What is the gray commissure?
A bridge of gray matter that connects the two sides of the spinal cord.
What is the central canal?
A small, fluid-filled space in the center of the spinal cord that extends through its length, containing cerebrospinal fluid (CSF).
What is the anterior spinal artery?
The major artery that supplies blood to the front of the spinal cord.
What are the posterior spinal arteries?
Arteries that supply blood to the posterior (back) part of the spinal cord.
What are ascending pathways?
Nerve pathways that carry sensory information from the body to the brain.
What are descending pathways?
Nerve pathways that carry motor commands from the brain to muscles and glands.
What does decussate mean?
The crossing of nerve fibers from one side of the body to the other, as seen in many pathways like the corticospinal tract.
What is the dorsal column-medial lemniscus pathway?
An ascending pathway that transmits touch, vibration, and proprioception information from the body to the brain.
What is the anterolateral pathway?
An ascending pathway that carries pain and temperature sensations to the brain.
What is the spinocerebellar pathway?
An ascending pathway that carries information about muscle position and movement to the cerebellum.
What is an upper motor neuron?
A neuron that originates in the brain and carries motor commands to the spinal cord.
What is a lower motor neuron?
A neuron that directly innervates skeletal muscles and causes contraction.
What is the corticospinal tract?
A descending pathway that carries motor commands from the brain to spinal motor neurons, important for voluntary movement.
What is a reflex arc?
The neural pathway that controls a reflex, including the sensory neuron, interneuron (optional), and motor neuron.
What does ipsilateral refer to?
Referring to reflexes that occur on the same side of the body as the stimulus.
What does contralateral refer to?
Referring to reflexes that occur on the opposite side of the body as the stimulus.
What is a monosynaptic reflex?
A reflex that involves only one synapse between a sensory neuron and a motor neuron, such as the stretch reflex.
What is a stretch reflex?
A simple, monosynaptic reflex that causes a muscle to contract in response to its stretching.
What is a muscle spindle?
A sensory receptor in muscles that detects changes in muscle length and triggers the stretch reflex.
What is a polysynaptic reflex?
A reflex that involves multiple synapses and interneurons, such as the withdrawal reflex.
What is a withdrawal reflex?
A reflex that causes a body part to pull away from a painful stimulus, typically involving multiple synapses.
What is a Golgi tendon reflex?
A reflex that protects muscles from excessive force by inhibiting muscle contraction when tension is too high.
What is a Golgi tendon organ?
A sensory receptor located at the junction of muscles and tendons that monitors the tension or force exerted by the muscle.
