Neuroanatomy and Action Potentials Quiz

Questions and Answers

Which layer of the spinal meninges is the toughest and extends to vertebra S2?

Epidural space

Dura mater (correct)

Pia mater

Arachnoid mater

The subarachnoid space is where cerebrospinal fluid circulates.

True

What is the role of the sensory receptor in a reflex arc?

To respond to a stimulus.

The thin and delicate layer adhering to the surface of the spinal cord is called the ______.

pia mater Signup and view all the answers

Match the following components of a reflex arc with their roles:

Sensory neuron = Transmits impulses to the spinal cord Integrating center = Processes information and sends a response Motor neuron = Carries impulses away from the spinal cord Effector = Responds to the motor neuron’s signal Signup and view all the answers

What is the primary function of the myelin sheath?

To insulate the nerve and speed up transmission Signup and view all the answers

An action potential will always be larger if the stimulus strength is increased.

False Signup and view all the answers

What occurs during the repolarization phase of an action potential?

Voltage-gated K+ channels open, allowing K+ to flow out of the neuron. Signup and view all the answers

The sequence leading to neurotransmission begins with the action potential reaching the axon terminal and ends with the binding of the neurotransmitter to the ______ receptor.

postsynaptic Signup and view all the answers

Match the events of neurotransmission with their sequence:

A. Action potential reaches axon terminal = 1. Neurotransmitter binds to receptors B. Ca2+ enters synaptic knob = 2. Neurotransmitter is released by exocytosis C. Neurotransmitter is released = 3. Binding of neurotransmitter opens channels D. Binding opens channels = 4. Action potential arrives at synapse Signup and view all the answers

Study Notes

Nerve Anatomy and Action Potentials

Myelin sheath insulates axons, enhancing nerve impulse speed.
Action Potentials (AP) are rapid changes in membrane potential that include depolarization followed by repolarization.
Voltage-gated Na+ and K+ channels activate in sequence during an AP.
The all-or-none principle ensures consistent impulse size regardless of stimulus strength.

Neurotransmission

99% of signal transmission in the nervous system is chemical, with 1% electrical.
Neurotransmitter release occurs at synapses via exocytosis upon action potential arrival.
Receptor binding on the postsynaptic neuron triggers channel openings.

Spinal Cord Structure and Protection

The spinal cord is encased in vertebrae and surrounded by spinal meninges: dura mater, arachnoid mater, and pia mater, which are continuous with cranial meninges.
Cerebrospinal fluid (CSF) circulates in the subarachnoid space, providing cushioning and nutrients.

Spinal Cord Functions

Reflexes are fast and involuntary reactions to stimuli, manageable through simple spinal reflex arcs or complex cranial reflexes.
A reflex arc includes a sensory receptor, sensory neuron, integrating center, motor neuron, and effector, such as muscles.

Brain Anatomy

Key brain components include the cerebrum, cerebellum, brain stem, hypothalamus, and thalamus.
The brain stem encompasses the medulla oblongata, pons, and midbrain, crucial for basic life functions.

Blood Supply and Protection

The brain consumes 20% of the body's oxygen and requires a continuous glucose supply.
Lack of oxygen for more than four minutes can lead to irreversible damage.
The blood-brain barrier (BBB) selectively allows substances like oxygen and certain drugs while protecting against harmful materials.

Cerebellum Functions

The cerebellum coordinates balance, muscle tone, and skilled voluntary movements.

Diencephalon Functions

The thalamus acts as the main relay for sensory and motor signals.
The hypothalamus regulates homeostasis, including temperature, thirst, and hormone production, and links the nervous and endocrine systems.

Cerebrum and Cerebral Cortex

The cerebrum is the largest brain region, divided into right and left hemispheres, and responsible for complex neural functions.
The cerebral cortex is involved in sensory perception, motor control, language, and higher mental functions, encompassing four major lobes: occipital, temporal, parietal, and frontal.

Memory and Learning

Memory involves processes of storing and retrieving information, engaging multiple brain regions, particularly in the limbic system and diencephalon.
Skill memory is associated with the cerebellum and basal ganglia.

Cranial Nerves

Cranial nerves I-XII serve various sensory and motor functions, including smell, vision, eye movement, taste, and autonomic regulation of organs.

Aging and Brain Development

Rapid brain development occurs in early life due to neuron growth and increased synaptic connections.
Aging results in brain mass decline and reduced synaptic activity, leading to potential decreases in brain function.

Description

Test your knowledge on nerve anatomy, action potentials, and neurotransmission with this quiz. Explore the structure and functions of the spinal cord while understanding the intricacies of nerve impulse transmission. Ideal for students studying neuroscience or advanced biology.