MasteringAandP: Chapter 7

What is the first event of an action potential?

Sodium gates open and the membrane depolarizes.

Which of the following can adversely affect brain development in the fetus?

alcohol

What cells of the nervous system are responsible for anchoring neurons to their blood vessels and controlling the extracellular fluid concentrations of potassium and neurotransmitters?

astrocytes

Which of the following conditions would result from damage to the cerebellum?

ataxia

What part of a neuron receives signals and sends a message to the cell body?

dendrite

Let's consider a scenario in which the resting membrane potential changes from −70 mV to +70 mV, but the concentrations of all ions in the intracellular and extracellular fluids are unchanged. Predict how this change in membrane potential affects the movement of Na+. The electrical gradient for Na+ would tend to move Na+ __________ while the chemical gradient for Na+ would tend to move Na+ __________.

out; in

Which of these parts of the brain is correctly matched with its region?

thalamus; diencephalon

What cranial nerve pair supplies many organs in the ventral body cavity?

vagus nerves

In flaccid paralysis, muscles atrophy because they are not receiving neural stimulation. Damage to which specific part of the spinal cord would cause flaccid paralysis?

ventral root

Which of these is a sympathetic effect?

Blood vessels constrict.

The concentrations of which two ions are highest outside the cell?

Na+ and Cl−

What produces cerebrospinal fluid (CSF)?

choroid plexus

The blockage of cerebrospinal fluid (CSF) outflow in the brain can cause accumulation of fluid, resulting in cranial enlargement in infants. This condition is called __________.

hydrocephalus

Which of these is an effect of the parasympathetic nervous system?

increases peristalsis within the stomach and small intestines

What could result if a spinal nerve is severely damaged?

loss of sensation and flaccid paralysis of the area served by the nerve

What part of the brain do we use when initiating skeletal muscle movement?

primary motor area

What ion depolarizes the membrane when it diffuses into the axon of a neuron?

sodium