Neuroanatomy 2: Nervous System Organization, Spinal Cord & Reflexes

Flashcards covering the organization of the nervous system, spinal cord anatomy, and reflex arcs, including their components and functions.

What are the two major subdivisions of the nervous system?

The Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

What are the components of the Central Nervous System (CNS)?

The brain and spinal cord.

What is the primary function of the Central Nervous System (CNS)?

It serves as the integrative and control center of the body.

What are the components of the Peripheral Nervous System (PNS)?

Cranial nerves, spinal nerves, and ganglia.

What is the primary function of the Peripheral Nervous System (PNS)?

It serves as the communication line between the CNS and the rest of the body.

What are the two main functional divisions of the Peripheral Nervous System (PNS)?

The Sensory (Afferent) division and the Motor (Efferent) division.

Which functional division of the PNS conducts impulses from receptors to the CNS?

The Sensory (Afferent) division.

Which functional division of the PNS conducts impulses from the CNS to effectors (muscles and glands)?

The Motor (Efferent) division.

Which type of neuron is sensory, afferent or efferent?

Afferent neurons are sensory.

Which type of neuron is motor, afferent or efferent?

Efferent neurons are motor.

What are the two main divisions of the Motor (Efferent) division?

The Somatic Nervous System and the Autonomic Nervous System (ANS).

What is the Somatic Nervous System responsible for?

It conducts impulses from the CNS to skeletal muscles, allowing for voluntary control.

What is the Autonomic Nervous System (ANS) responsible for?

It conducts impulses from the CNS to cardiac muscle, smooth muscle, and glands, regulating involuntary functions.

What are the two subdivisions of the Autonomic Nervous System (ANS)?

The Sympathetic division and the Parasympathetic division.

What is the primary role of the Sympathetic division of the ANS?

It mobilizes body systems during activity, preparing for 'fight or flight' responses.

What is the primary role of the Parasympathetic division of the ANS?

It conserves energy and promotes 'housekeeping' functions during rest, known as 'rest and digest'.

Which ANS division dilates pupils, increases heart rate, and inhibits digestive activity?

The Sympathetic division.

Which ANS division constricts pupils, slows heart rate, and stimulates digestive activity?

The Parasympathetic division.

What is the general organization of white matter and gray matter in the spinal cord?

White matter is found superficially, while gray matter forms a deep, H-shaped core.

What is white matter primarily composed of?

Myelinated and unmyelinated axons.

What is gray matter primarily composed of?

Neuron cell bodies, unmyelinated axons, dendrites, neuroglia, and interneurons.

Where does sensory information enter the spinal cord?

Sensory information enters via the dorsal roots.

Where do motor commands exit the spinal cord?

Motor commands exit via the ventral roots.

What are spinal reflexes?

Simple behaviors produced by the CNS spinal cord that occur without direct involvement of higher brain centers.

What are the five basic components of all reflex arcs?

Receptor, Sensory neuron, Integration center, Motor neuron, and Effector.

In a reflex arc, what is the role of the receptor?

It is the site of stimulus action.

In a reflex arc, what is the role of the sensory neuron?

It transmits afferent impulses from the receptor to the CNS.

In a reflex arc, what is the role of the integration center?

It is a monosynaptic or polysynaptic region within the CNS where the sensory neuron synapses with other neurons.

In a reflex arc, what is the role of the motor neuron?

It conducts efferent impulses from the integration center to the effector organ.

In a reflex arc, what is the role of the effector?

It is a muscle fiber or gland cell that responds to efferent impulses by contracting or secreting.

What is the Crossed-Extensor Reflex?

A reflex that involves a withdrawal reflex in one limb (flexion) and compensatory extension in the opposite limb to maintain balance.