ex

If acetylcholinesterase became mutated and nonfunctional, what would be the immediate result?

Acetylcholine would build up in the synaptic cleft. Correct

Which of the following muscles is in the medial compartment of the thigh?

Adductor longus

What term best describes the relationship between the pronator quadratus and supinator?

Antagonists

Which statement about the nervous and endocrine systems is true?

Both systems are dedicated to maintaining stable internal conditions by detecting and responding to stimuli.

What is the ability of muscle cells to shorten called?

Contractility

Which one of these muscles helps to open the mouth (depress the mandible)?

Digastric

What is the opposite of presynaptic inhibition?

Facilitation

Acetylcholine has which effect on the postsynaptic neuron?

Ligand-gated sodium ion channels open, and sodium diffuses in.

During depolarization, which of the following statements about voltage-gated ion channels is true?

Na+ gates open before K+ gates.

Which cells form myelin in the spinal cord?

Oligodendrocytes

Which of the following is most likey to cause a rapid depolarization?

Opening of sodium channels

Which of the following is an accurate comparison of skeletal muscle to smooth muscle?

Smooth muscle contracts and relaxes more slowly.

What happens as a result of ion flow at a presynaptic terminal?

Synaptic vesicles migrate to the plasma membrane and release acetylcholine.

Where do most local potentials form in a neuron?

The dendrites

Which of the following statements about the resting membrane potential is true?

The exterior of the cell has a net positive charge, and the interior has a net negative charge.

What happens when acetylcholine stimulates its receptors in the neuromuscular junction?

The permeability of the sarcolemma to Na+ increases.

The resting membrane potential is negative due to which of the following?

There are more negatively charged particles on the inside of the membrane than on the outside.

Indicate the summative effect that brings the initial segment closest to threshold.

Two EPSPs in proximity to each other Correct

An action potential arriving at the presynaptic terminal causes what to occur?

Voltage-gated calcium ion channels open, and calcium ions diffuse into the cell.

Which of the following contains overlapping thick and thin filaments?

a band

Raising an arm to one side of the body to stop a taxi is an example of __________ of the shoulder.

abduction

Substances that cause facilitation of a neuron ____________________________.

cause the neuron to fire that may not fire under the same circumstances in the absence of the facilitator Correct

. A resting membrane potential of -70 mV indicates that the ________________.

charges lining the inside of the plasma membrane are negative compared to the charges lining the outside Correct

The opening of __________ gates produces an __________.

chloride; IPSP

In a neuron, the opening of sodium gates typically leads to __________.

depolarization of the plasma membrane

The occipital and frontal bellies of occipitofrontal are connected via the __________.

galea aponeurotica

Which of the following are effectors?

glands

Graded potentials result from the opening of ________________.

ligand-gated channels Correct

Why does depolarization occur?

more Na+ diffuse into the cell than K+ diffuse out of it

The rectus abdominis is a __________ muscle, while the rectus femoris is a __________ muscle.

parallel; bipennate

An inhibitory postsynaptic potential results from the opening of____________________.

potassium and/or chloride channels Correct

Why does repolarization occur?

potassium ions continue to diffuse out of the cell after the inactivation gates of the voltage-gated sodium ion channels begin to close.

When doing a pushup, your shoulders __________ as your body is pushed upward.

protract

Normally, sodium and potassium leakage channels differ because ___________________.

sodium ions diffuse through leakage channels into the cell, but potassium ions diffuse through leakage channels out of the cellCorrect

In skeletal muscle, the term that describes the alternating light and dark bands is ___________.

striations

The __________ division tends to prepare the body for action.

sympathetic

The joint between the L2 and L3 vertebrae is a __________.

symphysis

The least movable joints are _____________ joints.

synostosis

The protein that acts as a calcium receptor in skeletal muscle is __________.

troponin

The __________ division carries signals to the smooth muscle in the large intestine.

visceral motor