Physiology lab #3

Stimulus received---> Stimulus is strong enough to reach threshold---> VG Na+ channels are going to open---> Na+ rushes into the cell---> rapid depolarization---> Peak of A.P.---> VG Na+ channels close & VG K+ channels open---> K+ rushes out of the cell---> causes repolarization--->RMP---> Some VG K+ channels remain open---> causes hyperpolarization---> VG K+ channels close---> Na+ K+ ATP pump (3 Na+ out of cell & 2K+ in the cell)---> True RMP (Homeostasis)

-70mV

• K+= -90mV
• Na+= 60-65 mV

Through synapses and neurotransmitters

• No Threshold
• Can sumate
• No refractory period

• IPSP- causes hyperpolarization which inhibits and A.P,
• EPSP- causes depolarization which allow A.P.

Are produced by the visual association areas of the parietal and occipital lobes and predominate when the subject is relaxed and awake but has eyes closed.

Are strongest from the frontal lobes and reflect the evoked activity produced by visual stimuli and mental activity

Emitted from the cerebral cortex and are seen in awake infants. Common in adults during deep sleep, the presence if delta waves in an awake adult indicates brain damage

• Emitted from the temporal and occipital lobes; are common in newborn infants and sleeping adults
• In awake adults generally indicate severe emotional stress.

Nerve cell consists of 3 regions---dendrites, cell body, axon

Voltage will be measured across the axon membrane

Maintained by unequal distribution of ions on the two sides of the membrane.

Momentary reversal and reestablishment of the resting potential

increase in amplitude as the voltage increase

when stimulating voltage reaches a sufficient level to become depolarized

Potential difference reduced (become more positive)

Return to resting membrane potential (become more negative)

More negative than RMP, requires active transport (Na/K ATP pump)

a neuron does not fill or fires maximally

• Functional connection between a neuron and another neuron or effector cell
• Transmission in one direction only