Human Biology 107 Exam 3 Practice

In the axon, the nerve impulses travels:

• toward the cell body
• away from the cell body.
• bidirectionally toward and away from the cell body.
• toward the dendrites.

Dendrites

• may be several feet in length.
• are always myelinated.
• are found only in the CNS
• are solely responsible for nervous conduction.
• carry impulses toward a cell body

Which part of the brain contains centers for the heartbeat and respiration?

• medulla oblongata
• hypothalamus
• cerebellum
• cerebrum
• pons

The largest portion of the human brain is the:

• cerebrum
• cerebellum.
• medulla oblongata
• pons
• brain stem

Which description best fits the central nervous system (CNS)?

• consists of the brain and spinal cord, located in the midline of the body
• consists of the brain and spinal cord, connecting the muscles and the brain
• consists of the spinal cord, located in the midline of the body
• consists of the brain and spinal cord, located on the edges of the body
• transmits sensory impulses to the PNS and motor impulses to the brain

Which of the following produces myelin in the peripheral nervous system?

• sodium-potassium pumps
• Schwann cells
• myelin
• nodes of Ranvier
• oligodendrocytes

All of the following statements concerning myelinated axons are true except

• action potentials are generated only at the nodes of Ranvier
• myelin decreases the speed of nerve impulse conduction.
• action potentials “jump” as they travel along the axon.
• myelinated axons occur in both the CNS and the PNS.
• both oligodendrocytes and Schwann cells make myelin.

Saltatory conduction occurs when

• sodium levels are highest on the outside of the axonal membrane
• sodium gates open
• resting potential fails to be reset
• neurotransmitters cross the synaptic cleft
• an action potential jumps from node to node.

Which of the following is correctly associated?

• midbrain—coordinates smooth and coordinated motions
• cerebellum—reflex centers for visual, auditory, and tactile responses
• cerebrum—reflex centers for visual, auditory, and tactile responses
• pons—regulates breathing rate
• thalamus—regulates heartbeat and blood pressure

Which of the following is true about the cerebellum?

• It is the largest part of the human brain
• It is covered by a thin gray layer.
• The two cerebral hemispheres are connected by the corpus callosum.
• Association areas integrate information from different lobes.
• It maintains posture and balance and coordinated, voluntary movements.