2. • Nerve impulses have a domino effect. Each
neuron receives an impulse and must pass it
on to the next neuron and make sure the
correct impulse continues on its path.
Through a chain of chemical events, the
dendrites (part of a neuron) pick up an
impulse that's shuttled through the axon and
transmitted to the next neuron. The entire
impulse passes through a neuron in about
seven milliseconds — faster than a lightning
strike. steps
3. Here's what happens in just six easy
steps
• Polarization of the neuron's membrane:
Sodium is on the outside, and potassium
is on the inside.
• Resting potential gives the neuron a
break.
• Action potential: Sodium ions move inside
the membrane.
4. • Repolarization: Potassium ions move
outside, and sodium ions stay inside the
membrane.
• Hyperpolarization: More potassium ions
are on the outside than there are sodium
ions on the inside.
• Refractory period puts everything back to
normal: Potassium returns inside, sodium
returns outside.
5. SYNAPSES
The coordination of cellular activities in animals is usually considered to
involve
• an endocrine system: where the response is to
hormones: chemicals secreted into the blood by
endocrine glands and carried by the blood to the
responding cell.
• a nervous system: response to electrical impulses
passing from the central nervous system to
muscles and glands.
6. SYNAPSE CONSIST
• a presynaptic ending that contains
neurotransmitters, mitochondria and
other cell organelles
• a postsynaptic ending that contains
receptor sites for neurotransmitters
• a synaptic cleft or space between the
presynaptic and postsynaptic endings.
8. SENSORY RECEPTORS
• a sensory receptor is a structure that
recognizes a stimulus in the internal or
external environment of an organism. In
response to stimuli the sensory receptor
initiates sensory transduction by creating
graded potentials or action potentials in the
same cell or in an adjacent one.
9. FUNCTIONS
• RECEPTION, which is the ability of a cell to absorb stimuli of
energy
• TRANSDUCTION is the conversion of stimulus energy into a
change in membrane potential of a receptor cell
• AMPLIFICATION is responsible for strengthening stimulus
energy, and can occur in either accessory structures, or as a
part of transduction.
• TRANSMISSION which conducts impulses to the central
nervous system
• INTEGRATION is the process of information and begins as
soon as information starts to be received
11. INTERORECEPTORS
• Neurological receptors that receives
information from the internal environment
• Examples blood pressure, pH and O2 of the
blood, body temperature, blood glucose and
GIT distension
