Anatomy Lab - nervous system

What is a neuron?

A neuron is a nerve cell.

What is a nerve fiber?

A nerve fiber is a long axon.

What is a nerve?

A nerve is a collection of axons in the peripheral nervous system (PNS).

What are the three main functions of the nervous system?

Sensation, Integration, and Motor functions.

What are the two main divisions of the nervous system?

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

What do visceral organs receive innervation from?

Visceral sensory fibers and motor fibers of the autonomic nervous system.

What innervates the limbs and other somatic body regions?

Motor fibers of the somatic nervous system and somatic sensory fibers.

What do arrows in nervous system diagrams indicate?

The direction of nerve impulses.

What are the four types of sensory and motor fibers in the PNS?

1. Somatic sensory

2. Visceral sensory

3. Somatic motor

4. Visceral motor

What does the cerebrum do?

Initiates movement, regulates temperature, and handles higher-level processing.

What structures are housed in the diencephalon?

The thalamus, hypothalamus, and epithalamus.

What is the function of the cerebellum?

It smoothes and coordinates body movements.

What are the vital functions of the brainstem?

Breathing, sleep, and heart rate.

What is the function of the midbrain?

Acts as a relay system and transmits information, especially for hearing and vision.

What does the pons do?

Relays and regulates signals.

Which cranial nerves attach to the pons?

Cranial nerves V (5), VI (6), and VII (7).

What is the medulla oblongata responsible for?

• Decussation of the pyramids

• Houses cardiac, vasomotor, and medullary respiratory centers

• Attaches to cranial nerves VIII (8), IX (9), X (10), and XII (12)

What are gyri (or gyrus)?

Folds or bumps in the brain.

What are fissures (or fissure)?

A deep sulcus in the brain.

What are sulci (or sulcus)?

A shallow furrow or groove in the brain.

What is the main function of the meninges?

To protect the brain and spinal cord.

What are the three meninges layers?

Dura mater, Arachnoid mater, and Pia mater.

What does the dura mater do?

It is the strongest meninge; houses the drainage system to let blood leave the brain and cerebrospinal fluid (CSF) to enter.

What does the arachnoid mater do?

Contains CSF and cushions the brain.

What does the pia mater do?

Houses blood vessels to the brain and contains CSF.

What are the three partitions formed by the meningeal dura mater?

• Falx cerebri

• Falx cerebelli

• Tentorium cerebelli

What is the purpose of these partitions?

They subdivide the cranial cavity and limit movement of the brain within the cranium.

What are the three main functions of the spinal cord?

• Sensory and motor innervation of the body below the head (via spinal nerves)

• Provides a two-way conduction pathway between body and brain (via white matter tracts)

• Serves as a major center for reflexes (via gray matter integration)

What is the conus medullaris?

The “cone” of the spinal cord; its caudal (lower) end.

What is the cauda equina?

A collection of nerve roots at the inferior end of the vertebral canal.

What is the filum terminale?

A long filament of connective tissue extending from the inferior spinal cord to the coccyx.

What is the function of the spinal cord meninges?

To protect the spinal cord.

What causes spinal cord enlargements?

Increased neural tissue in specific areas.

What is a nerve plexus?

A network of nerves formed by ventral rami only.

How many nerve plexuses are there in the human body?

Four.

What are the four nerve plexuses?

• Cervical plexus

• Brachial plexus

• Lumbar plexus

• Sacral plexus