A&P nervous system

What does the nervous system consist of?

The brain, spinal cord and peripheral nerves

What does the CNS consist of?

The brain and spinal cord

What does the PNS consist of?

All of the nerves outside the brain and spinal cord

What is the function of the nervous system?

To detect and respond to changes inside and outside of the body. Works with the endocrine system and coordinates and controls vital aspects of the body function and maintain homeostasis

What are the two types of nervous tissue?

Neurons and neuralgia

Myelinated neurons

Neurons with large axons that are surrounded by a myelin sheath which speeds up the transmission of electrical signals

Unmyelinated neurons

Axons embedded in one Schwann cell. Speed of transmission of nerve impulses are slower

What is a nerve?

Consists of numerous neurons collected into bundles

What are synaptic vesicles?

Contain transmitter substances that will be released into the synaptic cleft and inhibit or excite the next neuron

What are neurotransmitters?

Chemical/electrical information that is transported from the axon terminal of one neuron to the dentrite of the next neuron

What are the types of glial cells in the CNS?

Macroglia, microglia and astrocytes

What is a dendrite?

Where the neuron receives a signal

What is a Schwann cell?

It makes up the myelin sheath

What are the nodes of Ranvier?

The gaps between the myelin sheath

What do afferent nerurons do?

Carry information into the CNS

What is efferent nerouns?

Carry information away from the CNS

What is a nerve impulses created by?

A change in the voltage across the wall of an axon, caused by the movement of ions in and out of the neuron

What is the PNS comprised of?

Sensory, motor, automatic, voluntary, sympathetic and parasympathetic divisions

What is a synapse?

The site where a nerve cell communicates with another cell

Where is cerebrospinal fluid made?

In the ventricles of the brain

What are neurons?

Nerve cells

Where is the Dura Mater of the brain found within?

Meninges

When looking at a cross section of the spinal cord, where is the grey matter?

Located at the centre of the cord

Where do nerve impulses pass?

From the dendrites, along the axon, to the synapses

What is the long portion of a nerve cell that’s transmit the impulses called?

Axon

Where does a nervous impulse in a neuron begin?

In the dendrite

Why does ‘white matter’ appear pale?

Because the neurons are myelinated

What are the brain stem functions mainly concerned with?

Homeostatic mechanisms

What is neuroglia?

Tissue which supports and nourishes neurons

Where does a nervous impulse in the neuron begin?

Denrite

What do astrocytes do?

Regulate blood flow, maintain the composition of fluid that surrounds the neuron and regulates communication between neurons at the synapse

What do microglia do?

Remove dead cells and other debris

What do the oligodendrocytes do?

Same function as Schwann cells - produce myelin

What happens at a chemical synapse?

An action potential triggers the pre synaptic neuron to release neurotransmitters

What happens at an electrical synapse?

Ions flow directly between cells

What is the brain stem made up of?

The midbrain, pons, and medulla oblongata.

How many pairs of cranial nerves are there?

12 pairs that emerge directly from the brain.

How many pairs of spinal nerves are there?

31 pairs that emerge from the spinal cord.

What are the 3 basic functions of the nervous system?

Motor, sensory and automatic

What are the 3 higher functions of the nervous system?

Cognition, emotion, and consciousness. These functions are performed by parts of the brain.

What are the two parts of the autonomic nervous system?

Sympathetic and parasympathetic.

What does the ANS consist of?

Efferent neurons in the PNS that do specific jobs to regulate involuntary bodily functions.

What 3 different types of cells do the ANS control?

Smooth muscle, cardiac muscle, and glands.

Where does the sympathetic nervous system start?

It starts in the thoracic and lumbar regions of the spinal cord.

Where does the parasympathetic nervous system start?

Either in the brain stem or the sacral spinal cord.

What does the sympathetic nervous system do?

It prepares the body for fight or flight responses, increasing heart rate, dilating airways, and inhibiting digestive processes.

What does the parasympathetic nervous system do?

It promotes rest and digestion, lowering heart rate, constricting airways, and stimulating digestive processes.

What is the meninges?

The protective membranes covering the brain and spinal cord, consisting of three layers: dura mater, arachnoid mater, and pia mater.

What is the cerebral spinal fluid?

A clear fluid that surrounds and cushions the brain and spinal cord, providing protection, nutrient delivery, and waste removal.

What is the medulla?

The medulla is a part of the brainstem that controls vital autonomic functions such as heart rate, breathing, and blood pressure.

What is the pons?

The pons is a part of the brainstem that connects the medulla to the midbrain and plays a key role in regulating sleep, respiration, and relaying signals between different parts of the brain.

What is the midbrain?

The midbrain is a part of the brainstem involved in vision, hearing, motor control, sleep/wake cycles, and temperature regulation.

What is the cerebellum?

The cerebellum is a part of the brain located at the back of the head, responsible for coordinating voluntary movements, balance, and motor learning.