KINE 2210- Weeks 1-4 Review

Neuroscience

Study of the nervous system and how it controls and coordinates functions such as movement, sensation, cognition, and behaviour.

Movement

The result of coordinated activity of the nervous, muscular, and skeletal systems.

Anatomical position

Standard reference position: standing upright, facing forward, arms at sides, palms facing forward, legs straight, feet together or slightly apart.

Sagittal plane

Plane dividing the body into left and right portions.

Midsagittal/median plane

Sagittal plane dividing the body into equal left and right halves.

Parasagittal plane

Sagittal plane dividing the body into unequal left and right portions.

Frontal/coronal plane

Plane dividing the body into anterior and posterior portions.

Transverse/horizontal plane

Plane dividing the body into superior and inferior portions.

Medial

Toward the body's midline.

Lateral

Away from the body's midline.

Anterior

Toward the front of the body.

Posterior

Toward the back of the body.

Superior

Toward the head or upper part of the body.

Inferior

Toward the feet or lower part of the body.

Rostral

Toward the front/nose of the brain; roughly equivalent to superior in the spinal cord.

Caudal

Toward the back of the brain; roughly equivalent to inferior in the spinal cord.

Flexion

Movement that decreases the angle between two body segments.

Extension

Movement that increases the angle between two body segments.

Abduction

Movement away from the body's midline.

Adduction

Movement toward the body's midline.

Medial rotation

Rotation of a body part toward the body's midline.

Lateral rotation

Rotation of a body part away from the body's midline.

Circumduction

Circular movement combining flexion, extension, abduction, and adduction.

Pronation

Rotation of the forearm so the palm faces posteriorly/downward.

Supination

Rotation of the forearm so the palm faces anteriorly/upward.

Dorsiflexion

Movement of the foot/toes toward the shin.

Plantarflexion

Movement of the foot/toes downward, away from the shin.

Inversion

Turning the sole of the foot medially.

Eversion

Turning the sole of the foot laterally.

Central nervous system (CNS)

Brain and spinal cord.

Peripheral nervous system (PNS)

All nervous tissue outside the brain and spinal cord, including peripheral nerves and ganglia.

Brain

Major component of the CNS responsible for processing information, planning, and controlling many functions.

Spinal cord

Part of the CNS that connects the brain with the peripheral nervous system and participates in reflexes.

Afferent signal

Sensory signal travelling toward the CNS.

Efferent signal

Motor signal travelling away from the CNS.

Decussation

Crossing of a neural pathway from one side of the nervous system to the other.

Sensory decussation

Crossing of a sensory neural pathway; location depends on the specific sensory pathway.

Motor decussation

Crossing of the corticospinal motor pathway at the pyramidal decussation in the caudal medulla.

Cerebral cortex

Outer layer of gray matter of the cerebrum containing many neuron cell bodies.

White matter

Brain or spinal cord tissue primarily composed of myelinated axons.

Basal nuclei

Deep gray-matter structures involved in movement control and other functions.

Frontal lobe

Anterior cerebral lobe involved in voluntary movement, planning, decision-making, and executive functions.

Parietal lobe

Cerebral lobe involved in processing somatosensory information and spatial awareness.

Temporal lobe

Cerebral lobe involved in hearing, memory, and aspects of language.

Occipital lobe

Posterior cerebral lobe primarily involved in visual processing.

Gray matter

Central region of the spinal cord containing neuron cell bodies, dendrites, and synapses.

White matter of spinal cord

Outer region containing ascending and descending myelinated axons.

Dorsal horn

Posterior gray-matter region of the spinal cord that processes primarily sensory information.

Ventral horn

Anterior gray-matter region containing cell bodies of somatic motor neurons.

Lateral horn

Region of spinal gray matter containing autonomic neurons, especially prominent in thoracic and upper lumbar regions.

Dorsal root

Root through which sensory information enters the spinal cord.

Dorsal root ganglion

Enlargement containing the cell bodies of sensory neurons.

Ventral root

Root through which motor information leaves the spinal cord.

Central canal

Small canal running through the spinal cord containing cerebrospinal fluid.

Cervical spinal cord

Upper section of the spinal cord associated with the neck and upper limbs.

Thoracic spinal cord

Section of the spinal cord associated primarily with the trunk.

Lumbar spinal cord

Section associated primarily with the lower trunk and lower limbs.

Sacral spinal cord

Lower section associated with the pelvis and lower limbs.

Coccygeal spinal cord

Smallest and most inferior spinal cord section.

Cervical enlargement

Enlarged region of the spinal cord containing additional neurons and connections needed to control the upper limbs.

Lumbar enlargement

Enlarged region containing additional neurons and connections needed to control the lower limbs.

Upper motor neuron (UMN)

Motor neuron located within the CNS that controls lower motor neurons.

Lower motor neuron (LMN)

Motor neuron whose axon exits the CNS and directly innervates skeletal muscle.

Neuron

Specialized cell that receives, processes, and transmits nervous-system information.

Dendrite

Neuron structure that primarily receives incoming signals.

Soma/cell body

Part of the neuron containing the nucleus and maintaining cellular functions.

Axon hillock/initial segment

Region where action potentials are typically initiated when threshold is reached.

Axon

Long neuronal process that conducts action potentials away from the cell body.

Myelin

Insulating material surrounding many axons that increases conduction speed.

Node of Ranvier

Gap between myelin segments where ion movement and regeneration of the action potential occur.

Axon terminal

End of an axon where neurotransmitters are released.

Concentration gradient

Difference in concentration of a substance between two regions that creates a tendency for particles to move from high to low concentration.

Electrochemical gradient

Combined influence of concentration and electrical gradients on ion movement.

Resting membrane potential

Electrical potential across a neuron's membrane when it is not producing an action potential; typically around -70 mV.

Na+/K+ pump

ATP-dependent pump that moves 3 Na+ out of a cell and 2 K+ into the cell.

Osmosis

Movement of water across a selectively permeable membrane in response to differences in solute concentration.

Depolarization

Membrane potential becomes less negative or more positive.

Repolarization

Return of membrane potential toward its resting negative value after depolarization.

Hyperpolarization

Membrane potential becomes more negative than the resting membrane potential.

Overshoot

Part of an action potential when membrane potential becomes positive.

Graded potential

Variable change in membrane potential whose size depends on stimulus strength.

Threshold

Membrane potential at which enough voltage-gated Na+ channels open to initiate an action potential.

Action potential

Rapid, all-or-none change in membrane potential that travels along an axon.

EPSP

Excitatory postsynaptic potential; graded depolarization that makes the postsynaptic neuron more likely to reach threshold.

IPSP

Inhibitory postsynaptic potential; graded change that makes the postsynaptic neuron less likely to reach threshold.

Spatial summation

Combination of postsynaptic potentials arriving from multiple synapses at approximately the same time.

Temporal summation

Combination of postsynaptic potentials from the same synapse arriving repeatedly in rapid succession.

All-or-none principle

Once threshold is reached, an action potential occurs at essentially full amplitude; stronger stimuli do not make individual action potentials larger.

Action potential depolarization

Phase caused primarily by rapid Na+ entry through voltage-gated Na+ channels.

Action potential repolarization

Phase caused primarily by K+ leaving the neuron through voltage-gated K+ channels.

Na+ channel inactivation

Closing/inactivation of voltage-gated Na+ channels that stops rapid Na+ influx during an action potential.

K+ channel opening

Opening of voltage-gated K+ channels that allows K+ to leave the neuron and contributes to repolarization.

Saltatory conduction

Rapid conduction of an action potential along a myelinated axon from node to node.

Continuous conduction

Propagation of an action potential along an unmyelinated axon through successive sections of membrane.

Refractory period

Period after an action potential when the neuron cannot or is less likely to generate another action potential.

Absolute refractory period

Period when another action potential cannot be generated regardless of stimulus strength.

Relative refractory period

Period when another action potential can occur but requires a stronger-than-normal stimulus.

Conduction velocity

Speed at which an action potential travels along an axon.

Factors increasing conduction speed

Larger axon diameter and greater myelination generally increase conduction velocity.

Stimulus intensity coding

Information about stimulus strength represented primarily by action potential frequency and recruitment of additional sensory neurons.