physiology of CNS wk 8 - important

What are the two main types of cells in nervous tissue?

Neurons and neuroglia (glial cells).

What is the function of myelination in the nervous system?

Myelination speeds up the conduction of electrical impulses along axons.

What is the role of the sodium-potassium pump?

It maintains the concentration gradients of sodium and potassium ions across the neuronal membrane.

What occurs during depolarization in an action potential?

Sodium ions rush into the cell, making the inside more positive.

What is the all-or-nothing principle of action potentials?

An action potential either occurs completely or not at all, depending on whether the threshold is reached.

What neurotransmitter is primarily involved in muscle activation at the neuromuscular junction?

Acetylcholine.

What are synapses?

The junctions between two neurons where neurotransmitters are released.

What distinguishes excitatory neurotransmitters from inhibitory neurotransmitters?

Excitatory neurotransmitters depolarize the postsynaptic neuron, while inhibitory neurotransmitters hyperpolarize it.

How do sensory neurons transmit information to the central nervous system?

Sensory neurons carry information about stimuli from sensory receptors to the spinal cord and brain.

What is the function of the autonomic nervous system?

It regulates involuntary functions such as heart rate, digestion, and respiratory rate.

What is homeostasis in the context of the nervous system?

The maintenance of stable internal conditions in the body in response to changes in the external environment.

What is proprioception?

The body's ability to sense its position and movement in space.

What type of pain is associated with tissue damage?

Nociceptive pain.

What is the function of GABA in the nervous system?

GABA acts as the main inhibitory neurotransmitter, calming neural activity.

What happens during repolarization in an action potential?

Potassium ions rush out of the cell, making the inside more negative again.

What are the roles of astrocytes in the central nervous system?

They provide structural support, regulate blood-brain barrier, and contribute to the nutrient supply.

What is the effect of norepinephrine?

It promotes alertness and concentration.

What does the term 'decussation' refer to in neuroanatomy?

The crossing over of nerve fibers from one side of the body to the other.

What is the primary function of the thalamus?

It acts as a relay station for sensory information going to the cerebral cortex.

How does saltatory conduction differ from continuous conduction?

Saltatory conduction occurs in myelinated axons, where the action potential jumps between nodes of Ranvier, making it faster.

What type of neuron directly innervates skeletal muscles?

Lower motor neurons.

How are action potentials propagated along myelinated neurons?

Action potentials jump from node to node (Nodes of Ranvier) in a process called saltatory conduction.

What is an example of an excitatory neurotransmitter?

Acetylcholine.

What is the role of the sympathetic nervous system?

It prepares the body for 'fight or flight' responses.

What causes the sensation of pain to be perceived?

The activation of nociceptors by harmful stimuli.

What is the difference between upper motor neurons and lower motor neurons?

Upper motor neurons originate in the brain and project to lower motor neurons, which connect to muscles.

What are the primary functions of the peripheral nervous system?

It carries sensory and motor information to and from the central nervous system.

What neurotransmitter is involved in mood regulation and happiness?

Serotonin.

What is the purpose of reflex arcs?

To provide fast, automatic responses to stimuli without involving conscious thought.

What type of sensory neurons are responsible for detecting temperature?

Thermoreceptors.

What does the term 'afferent' refer to?

Nerve fibers that carry information toward the central nervous system.

What is the role of microglia in the nervous system?

They act as the immune defense by clearing debris and dead cells.

What is the effect of neurotransmitters binding to their receptors on the postsynaptic neuron?

They can cause either depolarization (excitatory) or hyperpolarization (inhibitory) of the postsynaptic cell.

What changes occur to potassium and sodium during an action potential?

Sodium enters the neuron during depolarization and potassium exits during repolarization.

What is the relationship between the nervous system and the endocrine system?

Both are communication systems in the body, but the nervous system operates rapidly while the endocrine system operates more slowly.

What function do Schwann cells perform in the peripheral nervous system?

They form the myelin sheath around peripheral nerves.

Which neurotransmitter is primarily involved in sleep and wakefulness?

Serotonin.

What type of pain is associated with nerve damage?

Neuropathic pain.

How does the body interpret the difference between various sensory intensities?

By the frequency of action potentials; higher intensity leads to higher frequency.

What type of receptors respond to mechanical stimuli?

Mechanoreceptors.

What is the significance of the blood-brain barrier?

It protects the brain from potentially harmful substances in the bloodstream.

What is a motor unit?

A motor neuron and all the muscle fibers it innervates.

What happens to muscle fibers when they receive an excitatory signal at the neuromuscular junction?

They undergo depolarization and contract.

What is acetylcholinesterase?

An enzyme that breaks down acetylcholine in the synaptic cleft, ending its action.

How does a lesion in the spinal cord affect sensory and motor function?

It can lead to loss of sensation and motor control below the level of injury.

What is the role of the somatosensory cortex in the brain?

It processes sensory input from various parts of the body.

What kind of information do sensory afferent neurons carry?

They carry sensory information from the body to the central nervous system.

How can understanding neurotransmitters help in the treatment of mental health disorders?

Targeting neurotransmitter levels can help alleviate symptoms of depression and anxiety.

What is the primary role of the autonomic nervous system?

Regulation of involuntary bodily functions.