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
