Lab study guide: spinal cord and nerves

Cervical enlargement

A region of the spinal cord that is enlarged to accommodate the nerves supplying the upper limbs

Lumbar enlargement

A region of the spinal cord that is enlarged to accommodate the nerves supplying the lower limbs

Cervical spinal nerves

Nerves that emerge from the cervical region of the spinal cord, specifically C1-C8

Thoracic spinal nerves

Nerves that emerge from the thoracic region of the spinal cord, specifically T1-T12

Lumbar spinal nerves

Nerves that emerge from the lumbar region of the spinal cord, specifically L1-L5

Conus medullaris

The tapered end of the spinal cord, typically located around the L1-L2 vertebrae

Cauda equina

A bundle of spinal nerves and spinal nerve rootlets that arise from the lower part of the spinal cord

Filum terminale

A fibrous extension of the pia mater that anchors the spinal cord to the coccyx

Spinal dura mater

The outermost layer of the meninges surrounding the spinal cord

Arachnoid mater

The middle layer of the meninges, located between the dura mater and pia mater

Pia mater

The innermost layer of the meninges that closely adheres to the surface of the spinal cord

Ventral/ anterior median fissure

A deep groove along the anterior midline of the spinal cord

Dorsal/ posterior median sulcus

A shallow groove along the posterior midline of the spinal cord

Central canal

A small channel in the center of the spinal cord that contains cerebrospinal fluid

Dorsal/ posterior horns

Regions of gray matter in the spinal cord that contain sensory neurons

Ventral/anterior horns

Regions of gray matter in the spinal cord that contain motor neurons

Lateral horns

Regions of gray matter in the spinal cord associated with the autonomic nervous system

Ventral root

The root of a spinal nerve that contains motor fibers

Dorsal root

The root of a spinal nerve that contains sensory fibers

Dorsal root ganglion

A cluster of sensory neuron cell bodies located in the dorsal root of a spinal nerve

Spinal nerve

A mixed nerve that carries both sensory and motor fibers

Dorsal/posterior white columns/funiculi

Regions of white matter in the spinal cord that carry sensory information to the brain

Ventral/anterior white columns/funiculi

Regions of white matter in the spinal cord that carry motor information from the brain

Epineurium

The outermost layer of connective tissue surrounding a nerve

Perineurium

The connective tissue that surrounds a fascicle of nerve fibers

Fascicle (nerve)

A bundle of nerve fibers within a nerve

Endoneurium

The innermost layer of connective tissue surrounding individual nerve fibers

Axon

A long, slender projection of a neuron that conducts electrical impulses away from the neurons cell body

Myelin sheath

A fatty layer that insulates axons and increases the speed of electrical impulses

Cervical plexus

A network of nerves formed by the anterior rami of C1-C5

Brachial plexus

A network of nerves formed by the anterior rami of C5-T1

Lumbar plexus

A network of nerves formed by the anterior rami of L1-L4

Sacral plexus

A network of nerves formed by the anterior rami of L4-S4

Phrenic nerve

innervates the diaphragm

Musculocutaneous nerve

Nerve that innervates the flexor muscles of brachium

Median nerve

Nerve that innervates the flexor muscles of antebrachium

Ulnar nerve

Nerve that innervates flexors of antebrachium and hand

Radial nerve

Nerve that innervates extensor of antebrachium and brachium

Axillary nerve

Nerve that innervates the deltoid and teres minor muscles

Femoral nerve

Innervates quadriceps,sartorius, pectineus, and iliacus

Obturator nerve

Innervate adductor muscles and gracilis

Tibial nerve

Innervates muscles in posterior thigh (except short head of biceps femoris), leg and foot

Common fibular nerve

Innervates short head of biceps femoris, tibialis anterior, fibularis, extensor of toes

Cerebral hemispheres

The right and left halves of the cerebrum

Diencephalon

Thalamus, hypothalamus, epithalamus

Cerebellum

the “little brain” at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

Brain stem

midbrain, pons, medulla oblongata

grey matter

neuron cell bodies and short, unmyelinated axons

White matter

Whitish nervous tissue of the CNS consisting of myelinated axons

Spinal cord white matter

Whitish nervous tissue of the CNS consisting of myelinated axons

spinal cord grey matter

neuron cell bodies and short, unmyelinated axons

Lateral ventricles

A set of paired ventricles lying within the cerebral hemispheres

Third ventricle

The midline ventricle that conducts cerebrospinal fluid from the lateral ventricles to the fourth ventricle

Cerebral aqueduct

connects the third and fourth ventricles

Fourth ventricle

Small triangular chamber between the pons and cerebellum

Gyri (gyrus)

Ridges of the brain

Sulci (sulcus)

Shallow grooves in the brains surface

Longitudinal fissure

Indentation that separates the cerebrum into right and left hemispheres

Frontal lobe

The lobe at the front of the brain associated with movement, speech, and impulse behavior

Central sulcus

separates frontal and parietal lobes

Precentral gyrus

anterior to the central sulcus

Parietal lobes

portion of the cerebral cortex lying at the top of the head and toward the rear

postcentral gyrus

posterior to the central sulcus

Occipital lobe

A region of the cerebral cortex that processes visual information

temporal lobes

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear

Lateral sulcus

separates temporal lobe from parietal and frontal lobes

Primary motor cortex (precentral gyrus)

the section of the frontal lobe responsible for voluntary movement

Primary somatosensory cortex (postcentral gyrus)

Site involved with processing of tactile and proprioceptive information

Visual/vision area (occipital lobe)

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

Thalamus

the brains sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in teh cortex and transmits replies to the cerebellum and medulla

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward

Pituitary gland

The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands

Pituitary gland

The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands

Epithalamus

Forms roof of 3rd ventricle has connections between limbic system and other parts of brain contains the pineal body (which secretes melatonin)

Pineal gland

Secretes melatonin

Midbrain

A small part of the brain above the pons that integrates sensory information and relays it upward

Pons

A brain structure that relays information from the cerebellum to the rest of the brain

Medulla oblongata

Part of the brainstem that controls vital life-sustaining unctions such as heartbeat, breathing, blood pressure, and digestion

Folia

Folds of the cerebellum