Lecture Quiz 4: Nervous System and Muscle Anatomy, Key Brain Structures and Their Functions

Central Nervous System (CNS)

The part of the nervous system that includes the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that includes cranial nerves, spinal nerves, and peripheral nerves.

Sensory (afferent)

The division of the PNS that carries sensory information to the central nervous system.

Motor (efferent)

The division of the PNS that carries motor commands from the central nervous system to the muscles.

Somatic (voluntary)

The subdivision of the motor division of the PNS that controls voluntary movements.

Autonomic (involuntary)

The subdivision of the motor division of the PNS that controls involuntary functions.

Sympathetic

One of the divisions of the autonomic nervous system that prepares the body for 'fight or flight' responses.

Parasympathetic

One of the divisions of the autonomic nervous system that promotes 'rest and digest' activities.

Neuron

A specialized cell that transmits nerve impulses.

Dendrites

The part of a neuron that receives signals.

Cell body (soma)

The part of a neuron that contains the nucleus and integrates signals.

Axon

The part of a neuron that sends signals away from the cell body.

Axon terminals

The part of a neuron that releases neurotransmitters.

Resting membrane potential

The electrical potential difference across the membrane of a neuron at rest, about -70 mV.

Action potential

A rapid reversal of membrane potential that travels down the axon.

Saltatory conduction

The process where action potentials jump between nodes of Ranvier in myelinated axons.

Neurotransmission

The process that occurs at the nerve terminal where Ca²⁺ enters, vesicles release neurotransmitters, which bind to receptors on the next neuron.

Common neurotransmitters

Acetylcholine, dopamine, serotonin, norepinephrine, GABA, glutamate.

Meninges

Protective membranes that include dura mater, arachnoid mater, and pia mater.

Cerebrospinal fluid (CSF)

Clear fluid cushioning the CNS; made in choroid plexus, circulates in ventricles & subarachnoid space.

Blood-brain barrier

A selective barrier that protects the brain from toxins/pathogens.

Cerebrum

The part of the brain responsible for thinking, sensation, movement, and memory.

Cerebellum

The part of the brain responsible for balance, coordination, and fine motor control.

Brainstem

The part of the brain responsible for autonomic functions like breathing and heart rate; includes midbrain, pons, and medulla.

Thalamus

The relay station for sensory information.

Hypothalamus

The part of the brain that regulates homeostasis, hormones, body temperature, and hunger.

Corpus callosum

The structure that connects the two hemispheres of the brain.

Pineal gland

The gland that secretes melatonin, which regulates sleep.

Regions of the spinal cord

Cervical, thoracic, lumbar, sacral.

Cauda equina

A bundle of spinal nerves below the spinal cord end.

Dorsal root of the spinal cord

The entry point for sensory (afferent) information.

Ventral root of the spinal cord

The exit point for motor (efferent) signals.

Cervical injury

May cause quadriplegia.

Thoracic/lumbar injury

May cause paraplegia.

Origin in muscle anatomy

The fixed attachment point of a muscle, usually proximal.

Insertion in muscle anatomy

The movable attachment point of a muscle, usually distal.

Action of a muscle

The movement it produces when it contracts.

Rotator cuff muscles

Supraspinatus, Infraspinatus, Teres minor, Subscapularis (SITS muscles).

Hamstrings

Biceps femoris, Semitendinosus, Semimembranosus.

Quadriceps

Rectus femoris, Vastus lateralis, Vastus medialis, Vastus intermedius.

Location of quadriceps

Anterior thigh.

Location of hamstrings

Posterior thigh.

Corpus Callosum

Connects left and right cerebral hemispheres; facilitates interhemispheric communication.

Striatum

Part of the basal nuclei; involved in motor control and reward-related behaviors.

Pineal Gland

Secretes melatonin; regulates circadian rhythms (sleep-wake cycles).

Corpora Quadrigemina

Reflex centers for vision (superior colliculi) and hearing (inferior colliculi).

Substantia Nigra

Produces dopamine; involved in movement control (damaged in Parkinson's disease).

Pons

Relays information between the cerebrum and cerebellum; aids in breathing regulation.

Medulla

Controls autonomic functions like heart rate, breathing, and blood pressure.

Amygdala

Processes emotions like fear, anger, and pleasure; involved in memory formation.

Occipital Lobe

Primary center for visual processing.

Frontal Cortex

Involved in higher cognitive functions like decision-making, reasoning, and voluntary motor activity.

Prefrontal Cortex

Responsible for personality, planning, judgment, and impulse control.

Broca's Area

Controls speech production (usually in the left hemisphere).

Wernicke's Area

Responsible for language comprehension (usually in the left hemisphere).