Nervous System

Question 1

Resting potentional

Answer 1

All cells

Na+/K+ ATPase pumps sodium ions out of the cell and potassium into the cell.

Negative voltage of -70 mVolts across plasma membrane

Question 2

Action potential

Answer 2

Wave of electrochemical info moving through axons and muscle tissue

When membrane voltage becomes less negative than resting potential, voltage-gated sodium channels open and sodium comes into the cell, causes depolarization of the membrane, the channel closes again.

Depolarization in one section triggers channel opening on next section.

In myelinated neurons, action potential jumps from one node of ranvier to the next

Size is always the same, increase in frequency to indicate strength

Question 3

Refractory period

Answer 3

Upper limit on the frequency of action potentials

Question 4

Synapses

Answer 4

Gap between neuron and target cell

Membrane potential is converted to chemical signal (neurotransmitter)

Neuromuscular junctio - specialized synapse, releases acetylcholine (ACh) into synaptic cleft which binds to receptors. Receptors open sodium channels, triggering action potential that contracts the muscle cell

Question 5

Turn of synaptic neurotransmitter

Answer 5

1. Diffusion
2. Enzymatic inactivation (ACh)
3. Reuptake into cells by transporters (adrenaline)

Question 6

Somatic

Answer 6

Voluntary; acts on skeletal muscle

Question 7

Autonomic

Answer 7

Involuntary; targets glands, smooth muscle, and heart

Consists of sympathetic and parasympathetic systems

Question 8

Sympathetic nervous system

Answer 8

Fight-or-flight
Increases heart rate
Increases breathing
Lowers digestive rate
Causes pupil dialation

Norepinephrine is primary neurotransmitter

Question 9

Parasympathetic nervous system

Answer 9

Rest-and-digest 
Lowers heart rate
Does not affect breathing
Increase digestive rate
Does not cause pupil dilation

Vegas nerve is principle nerve

ACh primary neurotransmitter

Question 10

Thalamus

Answer 10

Nervous impulses and and sensory information are related and integrated en route to and from the cerebral cortex by this region

Question 11

Hypothalamus

Answer 11

Controlled by visceral and homeostatic functions such as hunger, thirst, pain, temperature regulation, and water balance

Question 12

Cerebellum

Answer 12

Muscle activity coordinated and modulated

Question 13

Pons

Answer 13

Relay center for cerebral cortical fibers en route to cerebellum

Question 14

Medulla oblongata

Answer 14

Breathing, heart rate, and gastrointestinal activity

Question 15

Reticular activating system

Answer 15

Network of neurons in brain stem processes signals and sensory inputs and transmits them to cortex and other regions. Regulates brain activity

Question 16

Dorsal horn

Answer 16

Entrance point for sensory nerve fibers or efferent neurons

Question 17

Ventral horn

Answer 17

Contains cell bodies of motor or efferent neurons