Intro to Nervous System Review (ANAT-1049)

Flashcards covering the anatomical and functional divisions of the nervous system, neuron structure, transmission mechanisms, and brain anatomy based on Week 5 ANAT-1049 notes.

Integration

The process by which the nervous system interprets and prioritizes inputs and "makes decisions".

Central Nervous System (CNS)

The anatomical division of the nervous system consisting of the Brain (cranium) and Spinal Cord (vertebral canal).

Peripheral Nervous System (PNS)

The anatomical division consisting of Cranial nerves (brain) and Spinal nerves (spinal cord) that relays information to and from the CNS.

Somatic Nervous System (SNS)

The functional division where the motor division innervates "voluntary" muscles and the sensory division transmits information from somatic effectors.

Autonomic Nervous System (ANS)

The functional division that innervates "involuntary" (visceral) effectors such as smooth muscle, cardiac muscle, and glandular tissue.

Neurons

The "excitable" cells responsible for the transmission of nerve impulses throughout the body.

Neuroglia

Supporting cells of the nervous tissue that retain the ability to reproduce and may number as many as 900 billion per nervous system.

Astrocytes

A type of neuroglia cell involved in supporting proper function of nervous tissue.

Dendrites

The receptive regions of a neuron that receive signals.

Axon

The impulse generating and conducting region of a neuron.

Node of Ranvier

Gaps in the myelin sheath along an axon.

Neurilemma

The sheath of Schwann cells surrounding an axon.

Axonal terminals

The secretory component of a neuron located at the end of the axon.

Sensory neurons (afferent)

Neurons that carry impulses from sensors or receptors to the CNS, with cell bodies located outside the CNS.

Motor neurons (efferent)

Neurons that carry impulses from the CNS to effectors (muscles/glands), with cell bodies located inside the CNS.

Interneurons

Also known as association neurons, these are found within the CNS and integrate sensory and motor function.

Depolarization

Occurs when a stimulus increases $Na^+$ permeability, causing the neuronal membrane to become less polarized ($Na^+$ influx).

Repolarization

The restoration of the membrane potential immediately following depolarization, caused by an increase in $K^+$ permeability and $K^+$ rushing out.

Synaptic cleft

The space between the axon of one neuron and the dendrite of another where no direct contact occurs.

Neurotransmitter

A chemical released from the presynaptic neuron into the synapse that binds to receptors on the postsynaptic membrane.

Acetylcholine

A neurotransmitter found at the neuromuscular junction.

Acetylcholinesterase

The specific chemical inactivator for the neurotransmitter acetylcholine.

White matter

Groups of myelinated axons that form nerve tracts in the CNS.

Gray matter

Regions containing nerve cell bodies, dendrites, and unmyelinated axon bundles; found on the surface of the brain as the cortex.

Nerve

A bundle of fibers located outside the CNS.

Ganglia

Clusters of nerve cell bodies located outside the CNS.

Tract

A bundle of fibers located inside the CNS.

Nucleus (Neural Tissue)

Nerve cell bodies and dendrites located inside the CNS.

Meninges

Three membranous inner layers covering the CNS: Dura Mater, Arachnoid Mater, and Pia Mater.

Dura Mater

The strong, white, fibrous 2-layered outer layer of the meninges that serves as the inner periosteum of the cranial bones.

Pia Mater

The thin, transparent membrane containing fine blood vessels that adheres to the surface of the brain and spinal cord.

Thalamus

Two lobes separated by the third ventricle that act as a relay for sensory impulses and are involved in cognition.

Hypothalamus

The floor of the diencephalon that regulates the ANS, body temperature, sleep-wake cycles, and the endocrine system.

Pons

The part of the brain stem that links the cerebellum with the brain stem, cerebrum, and spinal cord; it controls the rhythm of breathing.

Medulla Oblongata

The inferior part of the brain stem that provides autonomic control of visceral activities like heart rate and ventilation pace.

Cerebellum

Part of the brain responsible for precise timing of skeletal muscle activity, balance, and coordination of body movements.

Choroid Plexus

The structure within the brain ventricles where Cerebrospinal Fluid (CSF) is produced.

Cerebrum

The superior portion of the brain, making up over 80% of brain mass, dubbed the "seat of intelligence".

Corpus Callosum

The structure that connects the two cerebral hemispheres.

Wernicke's Area

An association area in the cerebral cortex responsible for language comprehension.

Broca’s Area

An association area in the cerebral cortex responsible for speech.

Foramen magnum

The opening in the occipital bone of the skull where the spinal cord exits.

Nerve Plexuses

Complex networks of nerves formed by the ventral rami of most spinal nerves (except T2 – T12).

Sympathetic Division

The "Fight or Flight" division of the ANS that mobilizes the body during stress by increasing heart rate and inhibiting digestion.

Parasympathetic Division

The "Rest and Digest" division of the ANS concerned with conserving energy and promoting normal digestion and waste elimination.