Nervous System Anatomy and Function

<p>31 spinal nerve pairs and 12 cranial nerve pairs. (D)</p> Signup and view all the answers

<p>Hippocampus (C)</p> Signup and view all the answers

<p>Cervical, thoracic, lumbar, and sacral regions, arranged from superior to inferior. (A)</p> Signup and view all the answers

<p>Carrying sensory information from the body to the CNS. (B)</p> Signup and view all the answers

<p>Options A and C (C)</p> Signup and view all the answers

<p>Neurons generate electrical signals for communication, while glial cells support neurons and regulate the ECF composition. (D)</p> Signup and view all the answers

<p>The sympathetic division prepares the body for emergency situations, while the parasympathetic division is dominant during 'rest and digest.' (A)</p> Signup and view all the answers

<p>Myelin insulates axons, increasing the speed of action potentials. (D)</p> Signup and view all the answers

<p>Brain and spinal cord (C)</p> Signup and view all the answers

<p>Oligodendrocytes form myelin in the CNS, while Schwann cells form myelin in the PNS. (A)</p> Signup and view all the answers

<p>Axons deliver information, and dendrites receive information. (C)</p> Signup and view all the answers

<p>Supporting neurons metabolically (D)</p> Signup and view all the answers

<p>Serving immune function (B)</p> Signup and view all the answers

<p>Numerous EPSPs from various presynaptic terminals causing a total depolarization of 15 mV at the initial segment. (A)</p> Signup and view all the answers

<p>The duration of the neurotransmitter's action on the postsynaptic receptors. (C)</p> Signup and view all the answers

<p>By modifying the amount of neurotransmitter released from neuron B, leading to either presynaptic inhibition or facilitation at the synapse with neuron C. (C)</p> Signup and view all the answers

<p>Inward movement of sodium ions (Na+). (B)</p> Signup and view all the answers

<p>It breaks down ACh in the synaptic cleft, reducing its availability to bind to postsynaptic receptors. (A)</p> Signup and view all the answers

<p>Large Na+ influx and minimal K+ efflux. (B)</p> Signup and view all the answers

<p>Prolonged stimulation due to increased neurotransmitter concentration in the synapse. (A)</p> Signup and view all the answers

<p>Neuron A releasing a neurotransmitter that blocks voltage-gated calcium channels on neuron B's axon terminal, reducing neurotransmitter release onto neuron C. (C)</p> Signup and view all the answers

<p>A stronger stimulus results in a higher frequency of action potentials. (B)</p> Signup and view all the answers

<p>Voltage-gated $Na^+$ channels are inactivated and cannot be opened until the membrane potential is repolarized. (A)</p> Signup and view all the answers

<p>They block voltage-gated $Na^+$ channels, preventing depolarization. (C)</p> Signup and view all the answers

<p>Passive spread of depolarization under the myelin sheath, with action potentials generated only at the Nodes of Ranvier. (A)</p> Signup and view all the answers

<p>Increases velocity, due to decreased axial resistance. (D)</p> Signup and view all the answers

<p>They drive the membrane potential farther from the threshold, decreasing the likelihood. (C)</p> Signup and view all the answers

<p>Refractory periods of the membrane. (D)</p> Signup and view all the answers

<p>The ability to skip sections of the axon via saltatory conduction. (D)</p> Signup and view all the answers

<p>Nicotinic receptors are permeable to both $Na^+$ and $K^+$, while muscarinic receptors primarily affect intracellular signaling cascades via G proteins. (C)</p> Signup and view all the answers

<p>Active reuptake by the axon terminal and enzymatic degradation (A)</p> Signup and view all the answers

<p>Increased heart rate and bronchodilation. (C)</p> Signup and view all the answers

<p>Slow in onset and diffuse, influencing multiple neural circuits. (A)</p> Signup and view all the answers

<p>Serotonin (B)</p> Signup and view all the answers

<p>They release one or more neuropeptides, often alongside other neurotransmitters. (D)</p> Signup and view all the answers

<p>Reduced anxiety and muscle relaxation. (D)</p> Signup and view all the answers

<p>They mediate long-term potentiation (LTP), a cellular mechanism underlying learning and memory. (A)</p> Signup and view all the answers

<p>The somatic division controls voluntary movements and always leads to excitation, while the autonomic division can be either excitatory or inhibitory and innervates involuntary targets. (C)</p> Signup and view all the answers

<p>Release of glucose to provide more energy. (B)</p> Signup and view all the answers

<p>Reduced gland secretion. (B)</p> Signup and view all the answers

<p>Nicotinic receptors. (D)</p> Signup and view all the answers

<p>A filtrate of the blood, circulating through the ventricles and spinal cord before being reabsorbed. (D)</p> Signup and view all the answers

<p>Cessation of function and eventual cell death due to lack of glucose and oxygen. (A)</p> Signup and view all the answers

<p>It selectively allows essential nutrients to enter, while the brain depends on a constant supply of glucose. (B)</p> Signup and view all the answers

<p>Synapse with a postganglionic neuron within the trunk at the same level, ascend or descend within the trunk to synapse at another level, or pass through the trunk to synapse in a collateral ganglion. (C)</p> Signup and view all the answers

ACh receptors that are ligand-gated and allow Na+ & K+ to pass.

ACh receptors that couple with G proteins, affecting various cellular responses.

Enzyme responsible for the rate-limiting step in catecholamine synthesis from tyrosine.

Neurotransmitters made from tyrosine including dopamine, norepinephrine, and epinephrine.

Neurons that release epinephrine (E) or norepinephrine (NE).

A neuromodulator made from tryptophan, involved in mood and sleep regulation.

Glutamate and aspartate, the major excitatory neurotransmitters in the CNS.

Neuropeptides like endorphins that bind to opioid receptors, providing pain relief.

Minimum depolarization needed to trigger an action potential.

Excitatory postsynaptic potential; causes depolarization in neurons.

Inhibitory postsynaptic potential; causes hyperpolarization in neurons.

A gradual increase in membrane potential toward the action potential threshold.

Interaction between axons that can enhance or inhibit synaptic transmission.

A major neurotransmitter in the PNS involved in muscle activation.

Enzyme that breaks down ACh in the synapse to terminate its action.

Substances that alter neurotransmitter release or breakdown at synapses.

The brain and spinal cord, responsible for processing information.

Nerves and nerve fibers that connect the CNS to the rest of the body.

Basic units of the nervous system that generate and transmit electrical signals.

Support cells in the CNS that assist and protect neurons, making up 90% of CNS cells.

A fatty substance formed by oligodendrocytes and Schwann cells that insulates axons and speeds up signal transmission.

Part of a neuron that receives signals from other neurons.

Long projections of neurons that carry action potentials away from the cell body.

CNS: Oligodendrocytes, Astroglia, Microglia; PNS: Schwann cells.

The membrane potential needed to trigger an action potential, typically about 15mV less negative than resting potential.

Action potentials either occur fully or not at all; there is no partial action potential.

The period during which a second action potential cannot be generated, crucial for recovery.

A gas that acts as a neurotransmitter, influencing blood flow and neural signaling.

An enzyme activated by NO that produces cGMP, influencing various cellular functions.

The time during an action potential when no second action potential can occur, regardless of stimulus strength.

A brief period after the absolute refractory period when a stronger stimulus can trigger a second action potential.

Central Nervous System, consisting of the brain and spinal cord.

Nerve fibers covered with myelin, allowing faster propagation of action potentials via saltatory conduction.

Peripheral Nervous System, which includes spinal and cranial nerves.

A cluster of neuron cell bodies in the PNS, acting as relay points.

A specialized junction where neurons communicate; can excite or inhibit postsynaptic neurons.

A type of synapse that increases the likelihood of an action potential in the postsynaptic neuron.

A group of neuron cell bodies located in the CNS, involved in processing information.

Involved in emotion, learning, appetite, sex, and endocrine integration.

Part of the autonomic nervous system that controls gastrointestinal functions.

Controls voluntary movements via single neurons from the CNS to skeletal muscles.

Regulates involuntary actions through a two-neuron chain to effector organs.

Part of the autonomic system that prepares the body for 'fight or flight' responses.

Part of the autonomic system that promotes 'rest and digest' functions.

Receptors for ACh include nicotinic and muscarinic types affecting muscles and neurons.

A selective permeability barrier that protects the brain from potentially harmful substances in the blood.

Fluid that cushions the brain, flows through ventricles and spinal cord, and is reabsorbed into blood.