BIO110 Neuroscience Master Flashcards

Vocabulary flashcards based on BIO110 Neuroscience lecture notes, covering neuron anatomy, glial cell types, action potentials, muscle physiology, and spinal cord structures.

Neuron

The functional unit of the nervous system, composed of a cell body (soma), dendrites, and an axon.

Dendrites

The basic parts of a neuron that receive incoming signals.

Soma (Cell body)

The part of the neuron that contains the nucleus and integrates information.

Axon

The part of the neuron that conducts action potentials away from the cell body.

Axon hillock

The specific region of a neuron where action potentials begin.

Myelin

Fatty insulation surrounding axons that serves to speed nerve impulse conduction.

Nodes of Ranvier

Gaps in the myelin sheath where saltatory conduction occurs.

Sensory (afferent) neurons

Neurons that detect environmental changes and carry information to the CNS.

Motor (efferent) neurons

Neurons that carry commands from the CNS to muscles or glands.

Interneurons

The most abundant type of neuron; these connect neurons within the CNS.

Glial cells

Support cells of the nervous system, including oligodendrocytes, Schwann cells, astrocytes, and microglia.

Oligodendrocytes

Glial cells in the CNS that form the myelin sheath.

Schwann cells

Glial cells in the PNS that form the myelin sheath.

Astrocytes

Glial cells responsible for maintaining the blood-brain barrier.

Microglia

Glial cells that remove pathogens and debris from the nervous system.

Ependymal cells

Glial cells that circulate cerebrospinal fluid (CSF).

Cerebrospinal fluid (CSF)

Protective fluid surrounding the CNS, also found in the central canal.

Synapse

The junction between two neurons consisting of a synaptic cleft (gap) and chemical messengers.

Neurotransmitters

Chemical messengers stored in synaptic vesicles and released into the synaptic cleft.

Calcium ($Ca^{2+}$)

The ion that triggers the release of neurotransmitters when it enters the axon terminal.

Resting membrane potential

The electrical state of a neuron at rest, which is about $-70\,mV$.

Sodium ($Na^+$)

The ion most concentrated outside the cell; its entry into the neuron causes depolarization.

Potassium ($K^+$)

The ion most concentrated inside the cell; its exit from the neuron causes repolarization.

Sodium-potassium pump

A pump that maintains ion gradients by moving $3\,Na^+$ out and $2\,K^+$ in.

Hyperpolarization

A state where the membrane potential becomes more negative than its resting value.

Threshold

The membrane potential, about $-55\,mV$, required to trigger an action potential.

Action potential

A rapid electrical impulse that follows the all-or-none principle.

Absolute refractory period

The period during which no second action potential can be generated.

Relative refractory period

The period during which a second action potential is possible but requires a stronger stimulus.

Saltatory conduction

The process where a nerve impulse jumps between the Nodes of Ranvier.

Sarcomere

The functional unit of skeletal muscle.

Actin

The thin filament in muscle fibers.

Myosin

The thick filament in muscle fibers.

Tropomyosin

A protein that blocks binding sites on actin.

Troponin

The protein to which calcium binds to initiate muscle contraction.

Neuromuscular junction (NMJ)

The synapse between a motor neuron and a muscle fibre, utilizing the neurotransmitter acetylcholine.

Sarcoplasmic reticulum

The organelle that releases calcium inside a muscle cell.

Sarcolemma

The membrane of a muscle cell.

Reflex

An automatic response to a stimulus, such as the withdrawal reflex for painful stimuli.

Stretch reflex

A monosynaptic reflex, like the knee-jerk reflex, detected by muscle spindles.

Polysynaptic reflex

A reflex involving multiple synapses, such as the withdrawal reflex.

Gray matter

Part of the nervous system containing neuron cell bodies.

White matter

Part of the nervous system containing myelinated axons.

Dorsal (posterior) horn/root

Structures of the spinal cord associated with carrying or processing sensory information.

Ventral (anterior) horn/root

Structures of the spinal cord associated with carrying or processing motor commands.

Dorsal root ganglion

A cluster of sensory neuron cell bodies located outside the spinal cord.

Conus medullaris

The anatomical end of the spinal cord.

Cauda equina

A bundle of spinal nerves extending from the end of the spinal cord.

Filum terminale

A structure that anchors the spinal cord.

Ascending tracts

Nerve pathways that carry sensory information to the brain; examples include dorsal columns, spinothalamic, and spinocerebellar tracts.

Descending tracts

Nerve pathways, such as the corticospinal tract, that carry motor commands from the brain to control voluntary movement.

Spinothalamic tract

An ascending tract responsible for carrying pain and temperature information.

Dorsal columns

Ascending tracts that carry information regarding fine touch, vibration, and proprioception.