Study guide for spine quiz 1 SE

Sagittal Plane

Divides body into left and right halves.

Flexion

Decreasing the angle between bones.

Extension

Increasing the angle between bones.

Dorsiflexion

Bending the foot upward at the ankle.

Plantarflexion

Bending the foot downward at the ankle.

Frontal (Coronal) Plane

Divides body into front and back halves.

Abduction

Moving a limb away from the midline of the body.

Adduction

Moving a limb toward the midline of the body.

Lateral Flexion/Bending

Bending the trunk or neck to the side.

Inversion

Turning the sole of the foot inward.

Eversion

Turning the sole of the foot outward.

Transverse (Horizontal) Plane

Divides body into upper and lower halves.

Rotation

Turning a body part around its long axis.

Medial/Internal Rotation

Turning toward the midline.

Lateral/External Rotation

Turning away from the midline.

Pronation

Rotating the forearm so the palm faces posteriorly.

Supination

Rotating the forearm so the palm faces anteriorly.

Horizontal Abduction

Moving a limb horizontally away from midline.

Horizontal Adduction

Moving a limb horizontally toward the midline.

Circumduction

A circular movement combining flexion, abduction, extension, and adduction.

Pre-synaptic Sympathetic Fibers

Fibers that originate from the IML of the spinal cord from T1 to L2/L3.

Intermediolateral Cell Column (IML)

Location of pre-synaptic sympathetic neurons in the spinal cord.

White Rami Communicantes

Nerve fibers that connect spinal nerves to the sympathetic trunk.

Sympathetic Trunk

A chain of sympathetic ganglia that runs alongside the vertebral column.

Post-synaptic Sympathetic Fibers

Fibers originating from sympathetic ganglia that innervate target organs.

Gray Rami Communicantes

Unmyelinated fibers that exit the sympathetic trunk.

Dermatomes

Areas of skin supplied by a single spinal nerve that provide sensory information.

C_2 Dermatome

Posterior half of the skull cap, extending from the occiput to just below the external occipital protuberance.

C_3 Dermatome

The supraclavicular fossa, covering the lower posterior and lateral neck region, up to the clavicle.

C_4 Dermatome

The top of the acromioclavicular joint, specifically the superior aspect of the shoulder and clavicular region.

C_5 Dermatome

The lateral side of the antecubital fossa, encompassing the lateral deltoid, lateral arm, and radial aspect of the forearm.

C_6 Dermatome

The dorsal surface of the proximal phalanx of the thumb, extending along the radial forearm and thumb region.

C_7 Dermatome

The dorsal surface of the proximal phalanx of the middle finger, covering the central posterior forearm and the middle three fingers.

C_8 Dermatome

The dorsal surface of the proximal phalanx of the little finger, including the ulnar forearm and the little finger.

T_1 Dermatome

The medial side of the antecubital fossa, covering the medial arm and forearm down to the wrist.

S_1 Dermatome

The lateral heel, extending to the lateral aspect of the foot and sometimes the plantar surface.

Myotomes

Groups of muscles innervated by a single spinal nerve, responsible for specific motor functions.

C_5 Myotome

Elbow flexion (primarily biceps and brachialis muscles) and shoulder abduction (deltoid).

C_6 Myotome

Wrist extension (primarily extensor carpi radialis longus and brevis) and also contributes to elbow flexion (biceps).

C_7 Myotome

Elbow extension (primarily triceps brachii), wrist flexion, and finger extension.

C_8 Myotome

Finger flexion (primarily flexor digitorum profundus and superficialis) and thumb extension.

T_1 Myotome

Finger abduction (primarily abductor digiti minimi and other intrinsic hand muscles) and adduction.

Sensory Neuron Cell Bodies

Located in dorsal root ganglia (DRG).

Motor Neuron Cell Bodies

Located in the ventral horn of the spinal cord.

Somatic Motor Neurons

Lower motor neurons that innervate skeletal muscle.

Pseudounipolar Neurons

Neurons located in dorsal root ganglia, transmitting sensory information.

Cauda Equina

A bundle of spinal nerves extending from the conus medullaris.

Conus Medullaris

The tapered end of the spinal cord, terminating around L1/L2.

Filum Terminale

Fibrous extension anchoring the spinal cord to the coccyx.

Visceral Sensory Information

Sensory information from internal organs.

Somatic Sensory Information

Sensory information from body wall, limbs, and head.

Three-neuron pathway

Pathway typically followed by somatic sensory information to the cerebral cortex.