chapter 37: neurons and nervous system Flashcards
In humans, the central nervous system consists of the _____, which is housed in the _____ and the ______, which is housed in the _____.
a.
spinal cord; vertebral column; sensory neurons; limbs
b.
brain; vertebral column; spinal cord; skull
c.
brain; skull; spinal cord; vertebral column
d.
peripheral nervous system; limbs; brain; skull
c.
brain; skull; spinal cord; vertebral column
What unique structural adaptations are found in the mammalian brain that allowed mammals to become adept at higher mental activities?
a.
A higher degree of crevasses and folds in the neocortex that increases the surface area of the brain
b.
An increased number of blood vessels that increases the vascularization of the brain
c.
A more direct connection to the spinal cord for faster conduction of neural impulses
d.
A cranium that will protect the brain from damage
a.
A higher degree of crevasses and folds in the neocortex that increases the surface area of the brain
Which of the following statements about an action potential is not true?
a.
Repolarization occurs when potassium leaves the axon.
b.
There is a rapid change in polarity from about -70 mV to about +35 mV during depolarization.
c.
Depolarization occurs when sodium gates open and allow sodium ions to enter the axon.
d.
Potassium gates open after the sodium gates and allow potassium ions to leave the cell.
e.
An action potential takes 2 to 5 seconds.
e.
An action potential takes 2 to 5 seconds.
Neurotransmitters are molecules that cross the synaptic cleft and
a.
Always excite the postsynaptic neuron
b.
Integrate the pre-synaptic action potential
c.
Always inhibit the postsynaptic neuron
d.
Either excite or inhibit the postsynaptic neuron
d.
Either excite or inhibit the postsynaptic neuron
What portion of the brain provides reasoning to keep us from acting out strong feelings?
a.
Reticular activating system
b.
Pineal gland
c.
Brain stem
d.
Limbic system
d.
Limbic system
What are characteristics of invertebrate nervous system?
lack neurons and individual cells respond
3 things that Information gathering from the environment by a vertebrate is aided by:
- Paired eyes, ears, and olfactory structures
- Cephalization: concentration of nervous tissue in the anterior head region
- Bilateral symmetry with a vast increase in the number of neurons
How are vertebrate nervous systems organized?
-Many more neurons than invertebrates
-Brain controls nervous system
1. Hindbrain
2. Midbrain
3. Forebrain
what are the two divisions of the nervous system
central nervous system and peripheral nervous system
What allows mammals to become adept at higher mental activities?
A higher degree of crevasses and folds in the neocortex that increases the surface area of the brain
two kinds of nervous tissue
neurons and neuroglia
three parts of a neuron
- cell body
- dendrites
- axons
what are the different types of neurons
sensory, motor, and interneuron
what is a sensory neuron
take sensory information from the environment and sends the signal to the brain
what is a motor neuron?
communicate information from the brain to tissue and organs throughout the body, allowing for movement
what is an interneuron?
make up the majority of neurons in the body
essentially the “middle man”, transmitting information between sensory and motor neurons
play a key role in learning, memory, and planning
how does the transmission of nerve impulses work
Movement of unequally distributed ions
Voltage: electrical potential difference between two points
what is resting potential
-Membrane potential -70 mV (millivolts)
-Ion distribution
-Axon cytoplasm also contains large, negatively charged particles!
-Sodium-potassium pump
what is action potential
-Rapid change in polarity
-Transport Na+ & K+
-An action potential is generated only after a stimulus larger than the threshold!!
-2 milliseconds
what is depolarization (action potential)
Inside of a neuron becomes positive because of the sudden entrance of sodium ions
-70 mV to 35 mV