Nervous System - Chapter 13

Central nervous system

The part of the nervous system consisting of the brain and spinal cord.

Peripheral nervous system

The part of the nervous system that includes all the nerves outside the central nervous system, including cranial and spinal nerves.

Reflexes

Quick, automatic nerve responses triggered by specific stimuli.

Spinal reflexes

Reflexes that are controlled by the spinal cord alone without input from the brain.

Cervical enlargement

Region of the spinal cord that supplies nerves to the shoulders and upper limbs.

Lumbosacral enlargement

Region of the spinal cord that supplies nerves to the pelvis and lower limbs.

Spinal meninges

Three specialized membranes (dura mater, arachnoid mater, pia mater) that surround the spinal cord.

Monosynaptic reflex

A reflex that involves a single synapse between a sensory neuron and a motor neuron.

Polysynaptic reflex

A reflex that involves one or more interneurons between a sensory neuron and a motor neuron.

Dura mater

The outermost layer of the spinal meninges.

Arachnoid mater

The middle layer of the spinal meninges.

Pia mater

The innermost layer of the spinal meninges, which is firmly attached to the surface of the spinal cord.

Sensory neurons

Nerve cells that carry sensory information from the periphery to the central nervous system.

Motor neurons

Nerve cells that carry signals from the central nervous system to muscles and glands.

Neuronal pools

Functional groups of interneurons that process information and output signals within the CNS.

Dermatome

A specific bilateral region of skin supplied by a single pair of spinal nerves.

Reflex arc

The neural pathway that mediates a reflex action.

Reciprocal inhibition

The process by which the contraction of one muscle is accompanied by the relaxation of an antagonistic muscle.

Autonomic reflexes

Reflexes that control involuntary bodily functions, such as those involving smooth muscle, cardiac muscle, or glands.

Filum terminale

A thin thread of fibrous tissue that anchors the spinal cord to the coccygeal ligament.

Golgi tendon organs

Sensory receptors that sense tension in muscles and prevent excessive tension from damaging muscles or tendons.

Babinski reflex

A reflex that causes the toes to curl when the sole of the foot is stroked; normal in infants but may indicate CNS damage in adults.

Carpal tunnel syndrome

A condition caused by compression of the median nerve in the carpal tunnel, leading to pain and numbness in the hand.