Unit 4 - Sensation & Control Flashcards
What are the two main parts of the nervous system?
The central nervous system & the peripheral nervous system
List and describe the parts of a neuron.
The cell body contains the nucleus and other cell organelles.
Dendrites extend from the cell body and receive nerve impulses from other neurons.
The axon is a long extension of the cell body that transmits nerve impulses to other cells.
What do motor neurons do?
Motor neurons carry nerve impulses from the brain and spinal cord to muscles and glands
What is myelin and the myelin sheath?
The axon of many neurons has an outer layer called a myelin sheath (see Figure above). Myelin is a lipid produced by a type of a glial cell known as a Schwann cell. The myelin sheath acts like a layer of insulation, similar to the plastic that encases an electrical cord
Define resting potential and action potential.
Resting potential: The difference in electrical charge across the cell membrane when the a neuron is resting
Action potential: A nerve impulse is a sudden reversal of the electrical charge across the membrane of a resting neuron. The reversal of charge is called an action potential.
What is a synapse?
The place where an axon terminal meets another cell is called a synapse. (space between neurons)
Name the organs of the central nervous system.
Brain & spinal cord
Which part of the brain controls conscious functions such as reasoning?
cerebrum
What are the roles of the brain stem?
connects the rest of the brain with the spinal cord and passes nerve impulses between the brain and spinal cord. It also controls unconscious functions such as heart rate and breathing.
Sam’s dad was in a car accident in which his neck was broken. He survived the injury but is now paralyzed from the neck down. Explain why.
Spinal cord was damaged and is not able to send messages from the brain to the rest of the body.
Compare and contrast the somatic and autonomic nervous systems.
Both part of the Motor division of PNS
The somatic nervous system (SNS) controls mainly voluntary activities that are under conscious control.
other involuntary activities not under
conscious control are the responsibility of the autonomic nervous system (ANS).
What are the two divisions of the autonomic nervous system?
sympathetic nervous & parasympathetic nervous systems
What is the role of the sympathetic division?
sympathetic division deals with emergency situations. It prepares the body for “fight or flight.
Explain how the nervous system is linked with the endocrine system.
The hypothalamus is actually part of the brain,, but it also secretes hormones. Some of its hormones “tell” the pituitary gland either to secrete or to stop secreting its hormones. In this way, the hypothalamus provides a link between the nervous and endocrine systems
List five of the major glands of the endocrine system.
Hypothalamus, pituitary gland, thyroid gland, parathyroid gland, pineal gland, pancreas, adrenal glands, gonads
