biological bases of behavior

phrenology

a pseudoscience that bumps on the skull revealed mental ability and personality.

The Nervous System

a network of cells, organs, and chemicals that work together to produce thoughts, actions and behaviors.  

central nervous system

• Consists of the brain and the spinal cord. 

• It is the main control center of the body—it takes in sensory information, organizes and synthesizes this input, then provides instructions for motor output to the rest of the body

Glial Cells

provide support and protection for neurons in the central and peripheral nervous systems.

the brain

• THE Core of the Nervous System

• Takes information from sense, makes “sense” out of them, makes decisions and sends the refined information to muscles and other parts of the body.

The Spinal Cord

A long bundle of Neurons; the pathway for messages sent by the brain to the body and from the body to the brain. 

The Spinal Cord

• A network of nerves strands that branch off from the left and right sides of the spinal cord through openings between each vertebra on the spinal canal. 

• These nerve pairs spread throughout your body to deliver commands from your brain and spinal cord to and from parts of your body.

peripheral nervous system

The sensory and motor neurons that connect the central nervous system to the rest of the body. 

somatic nervous system

Enables voluntary control of our skeletal muscles. 

afferent neurons

sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain

efferent neurons

motor neurons that carry neural impulses away from the central nervous system and towards muscles to cause movement.

sensory (afferent)

send impulses to the brain and spinal cord

motor (efferent)

send impulses away from the brain and spinal cord

interneuron

found only in the cns and can be sensory or motor; the more complex the required action, the greater the number of interneurons involved.

automatic nervous system

Automatically regulates the glands, use of muscles, internal organs and blood vessels, pupil dilation, digestion, and blood pressure.

sympathetic nervous system

arouses and expands energy.  Accelerates heart beat, raises blood pressure and slows digestion.  FIGHT OR FLIGHT RESPONSE. (excitatory)

parasympathetic system

The calming agent of the Sympathetic Nervous system.  Lowers major fight or flight functions. (inhibitory)

neurons

Specialized cell in the Nervous system that receives and sends messages within that system.

dendrites

receive messages from other cells

terminal branches of axon

form junctions with other cells

axon

passes messages away from the cell body to other neurons, muscles, or glands.

cell body

the cell’s life support center

neural impulse

(action potential) electrical signal traveling down the axon

myelin sheath

covers the axon of some neurons and helps speed neural impulses

nucleus

Located in the Cell body and contains the genetic material and DNA in the form of chromosomes.

the cell body

connects to the dendrites, which bring information to the neuron, and the axon, which sends information to other neurons.

axon

the long, spider-thin, tail-like structures found on neurons (nerve cells). Each neuron has a nerve body, dendrites, and axons, all of which are used to send information throughout your body. It carries signals (electric voltages) between the dendrites and it’s terminal.

node of ranvier

e spaces between the myelin coating on the neuron's axon. allow an action potential to propagate quickly down an axon.

Schwann’s Cells

produce the myelin sheath. involved with the speeding of action potential.

myelin sheath

a fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulating layer. Helps protect the Axon and send messages faster.  

dendrites

Branch-like structures that receive messages and conduct impulses toward the cell body.

axon terminals

(located at the end of the neuron) The function of the axon terminal is to transmit a neurotransmitter from one   neuron to another. The neurotransmitter is released from the end of the axon of one neuron and binds to the dendrites of the target neuron.

action potential

All-or-none electrical signal that is conducted along nerve axons.

resting potential

The inside of a neuron are negatively charged which mean that they have a low change of firing.

selectively permeable

the axon’s surface is selective about what is allowed inside the axon. (bouncer at the club)

depolarization

When positive ions enter the cell

hyperpolarization

When negative ions enter the cell

refractory period

a period of inactivity after a neuron is fired.  (santa on dec. 26th)

excitatory

triggers the neuron’s response

inhibitory

stops a neuron from responding

synapse

A small junction that connects the axon terminals of one neuron to the dendrites of another neuron.

electrical impulse to neurotransmitter

shot through the axon is converted to chemical energy into a Neurotransmitter at the synapse.

neurotransmitters

the brain chemicals that communicate information throughout our brain and body.

neurotransmitters

The brain uses it to tell your heart to beat, your lungs to breathe, and your stomach to digest.  They can also affect mood, sleep, concentration, weight, and can cause adverse symptoms when they are out of balance.