Structure of the Nervous System

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What happens when a nerve cell is stimulated with a stimulus below the threshold value?

The nerve cell will generate a response

An action potential will occur

The stimulus will be transmitted along the axon

No action potential will occur (correct)

What is the main function of a nerve cell?

To transmit sensory and motor impulses as well as action potentials (correct)

To transmit motor impulses

To transmit action potentials

To transmit sensory impulses

How do impulses get transmitted between two neurons in the central nervous system?

Through the cell body of the neurons

Through the axons of the neurons

Through special junction areas between the neurons (correct)

Through the dendrites of the neurons

What happens when the stimulus starts from the cell body of a neuron?

It is transmitted along the neuron's axon, creating electrical potential changes in the cell body of another neuron Signup and view all the answers

How is the transmission of the stimulus along the axon similar to?

The flow of electric current through a cable Signup and view all the answers

What happens when the transmitter substance released from the axon end binds to the membrane of another neuron?

Stimulation of another neuron or cell occurs Signup and view all the answers

What is the primary function of the pia mater?

To nourish the brain tissue with its abundant vascular network Signup and view all the answers

What is the primary role of the peripheral nervous system?

To connect the central nervous system to the body's organs and parts Signup and view all the answers

What is the primary difference between the somatic and autonomic nervous systems?

The somatic system ensures harmony with the outside world, while the autonomic system maintains internal balance Signup and view all the answers

What is the primary function of the arachnoid mater?

To act as a thin, non-permeable membrane between the dura mater and pia mater Signup and view all the answers

What is the primary difference between cranial nerves and spinal nerves?

Cranial nerves exit the skull, while spinal nerves exit the vertebral column Signup and view all the answers

What is the primary function of the cerebrospinal fluid in the subarachnoid space?

To provide a protective cushion for the central nervous system Signup and view all the answers

Which part of the body does the lumbar plexus innervate?

Lower extremities Signup and view all the answers

Which nerves form the sacral plexus?

L5 and S1 Signup and view all the answers

Where are the receptors of the somatic system typically found?

Skin, joints, muscle spindles, tendons Signup and view all the answers

How do somatic sensory neurons transmit stimulus to the spinal cord?

Via afferent nerves Signup and view all the answers

What happens to the frequency of action potential as stimulus intensity increases?

Increases Signup and view all the answers

Where in the brain does the somatosensory cortex reside?

Parietal lobe Signup and view all the answers

Which of the following statements accurately describes the classification of the nervous system based on organ groups?

The somatic nervous system is responsible for voluntary skeletal muscle control, while the visceral (autonomic) nervous system controls involuntary functions like smooth muscle, heart, and gland activity. Signup and view all the answers

What are the two main structural elements that form the nervous system?

Neurons and neuroglia (glia cells) Signup and view all the answers

What is the primary function of dendrites in a neuron?

To receive and carry impulses from the environment and other neurons to the pericarion (cell body) Signup and view all the answers

Which of the following statements accurately describes the function of the axon in a neuron?

The axon is the single and long extension of the pericarion that transmits nerve impulses to other nerve cells, muscle tissue, or gland cells. Signup and view all the answers

Which of the following statements accurately describes the pericarion (cell body) of a neuron?

The pericarion is the mass of cytoplasm around the nucleus, together with the nucleus, in a neuron. Signup and view all the answers

What is the primary role of neuroglia (glia cells) in the nervous system?

To provide structural support and nourishment for neurons Signup and view all the answers

What is the primary function of the motor endplate in the muscle-nerve junction?

To bind with acetylcholine released from the motor neuron Signup and view all the answers

Which of the following accurately describes the role of acetylcholine in the muscle contraction process?

Acetylcholine is released from the synaptic vesicles of the motor neuron and binds to receptors on the motor endplate Signup and view all the answers

What is the sequence of events that leads to the release of calcium ions from the sarcoplasmic reticulum during muscle contraction?

Acetylcholine binds to receptors → sodium ion entry → action potential → calcium ion release Signup and view all the answers

What is the role of the synaptic cleft in the muscle-nerve junction?

It is the space between the motor neuron terminal and the motor endplate where neurotransmitters are released Signup and view all the answers

Which of the following statements about the structure of the motor neuron terminal is correct?

The motor neuron terminal is branched, and the branches enter the synaptic clefts Signup and view all the answers

What is the primary function of the T-tubules in the muscle contraction process?

To propagate the action potential from the sarcolemma into the muscle fiber Signup and view all the answers