Nervous System Review (Chapters 11-14)

Practice flashcards covering the anatomy and physiology of the nervous system, including cell types, membrane potentials, spinal cord structures, brain regions, and sensory mechanisms of memory and perception.

Central Nervous System (CNS)

Consists of the brain and the spinal cord.

Peripheral Nervous System (PMS)

Consists of sensory receptors and nerves, including 31 pairs of spinal nerves and 12 pairs of cranial nerves.

Afferent neurons

Sensory neurons that carry information such as touch, temperature, and pain to the brain.

Efferent neurons

Motor neurons that carry commands from the brain to move skeletal, smooth, or cardiac muscle.

Somatic Nervous System

The division of the nervous system that carries signals from the CNS to skeletal muscle, which is under conscious control.

Autonomic Nervous System (ANS)

The division of the nervous system that controls smooth and cardiac muscle, which is not under conscious control.

Sympathetic

A division of the ANS responsible for the "fight or flight" response.

Parasympathetic

A division of the ANS responsible for "rest and digest" functions.

Neuroglia

Helper cells in the nervous system that support neurons.

Cell body (soma)

The part of the neuron that contains the nucleus; functions as the communicator center.

Dendrites

Extensions of the neuron that receive signals and carry them to the cell body.

Axon

Extension of the neuron that carries signals from the cell body to the next cell.

Astrocyte

A type of neuroglia in the CNS responsible for overall neuron health, the blood brain barrier, and neurotransmitter production.

Microglia

A type of neuroglia in the CNS involved in cell cleanup and destroying foreign material.

Ependymal cell

A type of neuroglia in the CNS involved in cerebral spinal fluid (CSF) production.

Oligodendrocute

A type of neuroglia in the CNS responsible for myelin formation.

Schwann cell

A type of neuroglia in the PNS responsible for myelin formation.

Satellite cell

A type of neuroglia in the PNS responsible for the overall health of the neuron.

White matter

Myelinated nervous tissue.

Gray matter

Unmyelinated nervous tissue.

Saltatory conduction

The travel of an action potential along a myelinated axon where the signal jumps from one Node of Ranvier to the next.

Node of Ranvier

The space between myelin sections along an axon.

Continuous conduction

The travel of an action potential along an unmyelinated axon (gray matter).

Resting membrane potential

The negative state of a cell at rest, characterized by a high amount of $Na^+$ outside the cell and a high amount of $K^+$ inside the cell.

Sodium/potassium pump

A mechanism using $ATP$ energy to push sodium out and pull potassium back into the cell to reverse natural diffusion.

Depolarization

The process of taking away a cell's charge to make it less negative.

Hyperpolarization

Overcharging a cell to make it more negative than its usual resting state.

Threshold

The point a cell must hit when being depolarized; for a nerve cell, this is $-70\,mV$ at rest.

GratedPotential

Occurs when a cell receives multiple stimuli in the form of spatial or temporal summation.

Spatial summation

Stimuli coming in from multiple neurons simultaneously.

Temporal summation

Stimuli coming in from a singular neuron over time.

Absolute refraction

The period after a cell has crossed the threshold and is resetting, during which it cannot be stimulated.

Relative refraction

The period after the threshold where a cell has hyperpolarized; it can be stimulated, but it is harder to do than at rest.

Type A fibers

The fastest nerve fibers; large in size with lots of myelin, used for skeletal muscle control and sensory input.

Type B fibers

Small fibers with less myelin that are slower than Type A; used for smooth and cardiac muscle.

Type C fibers

The slowest nerve fibers; very small with no myelin.

Dorsal root

The path through which sensory information enters the spinal cord.

Ventral root

The path through which motor information (somatic and ANS) leaves the spinal cord.

Stretch reflex

A stereotyped response controlled by the muscle spindle that causes a muscle to contract to prevent tearing from being stretched.

Golgi Tendon reflex

A more intense version of the stretch reflex that causes the muscle to relax.

Phrenic nerve

The major nerve of the cervical plexus ($C1$-$C4$) important for the diaphragm and breathing.

Axillary nerve

A nerve of the brachial plexus ($C5$-$T1$) involving the shoulder for sensory and motor functions.

Median nerve

The "carpal tunnel nerve" involving the lateral and middle of the hand/wrist and muscles below the elbow.

Sciatic nerve

The nerve in the lumbosacral plexus ($L1$-$S4$) made up of the tibial and peroneal nerves.

Medulla

Brain region responsible for ANS activities like heart, lungs, vomiting, hiccuping, coughing, and sneezing.

Pons

Brain region containing the pontine sleep center for REM sleep and respiratory control.

Thalamus

The major relay for sensory information, sending it to the cerebrum.

Limbic System

The part of the brain that includes basic instincts such as reproduction, nutrition, memory, survival, and emotions.

Subarachnoid space

The space between the arachnoid and pia mater layers where CSF is located.

Mechanoceptors

Sensory receptors that detect touch, pressure, and vibrations.

Nocirecptors

Sensory receptors that detect pain, often activated when extreme hot or cold conditions damage tissue.

Wernicke

The brain area that interprets language that is heard or seen.

Brocca

The motor area of the brain used for speaking a language.

Alpha waves

Brain wave patterns observed at rest with eyes closed.

Beta waves

Brain wave patterns associated with mental concentration.

Theta waves

Brain wave patterns associated with frustration.

Delta waves

Brain wave patterns associated with deep sleep.

Consolidation

The process of converting short-term memory to long-term memory.

Declarative memory

Long-term memory of facts.

Procedural memory

Long-term muscle memory.