unit 2: biological bases of behavoir

What do phrenology and biological psychology have in common?

They share a focus on the links between the brain and behavior

When a neuron fires an action potential, what does the information travel through and in what order?

Dendrites, cell body, axon

How does our nervous system allow us to experience the difference between a slap and a tap on the back?

Stronger stimuli cause more neurons to fire and to fire more frequently than happens with weaker stimuli

What happens in the synaptic gap?

Neurons send neurotransmitters across this tiny space between one neurons terminal branch and the next neurons dendrite or cell body

Neuron

A nerve cell; the basic building block of the nervous system

Cell body

The part of a neuron that contains the nucleus; the cell’s life-support center

Dendrites

A neurons branching extensions that receive and integrate messages, conducting impulses towards the cell body

Axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands

Myelin

A fatty tissue layer encasing the axons of some neurons; enables greater transmission speed as neural impulses hop from one node to the next

Glial cells

Cells in nervous system that support, nourish, and protect neurons; also help learning, thinking, and memory

Action potential

A neural impulse; a brief electrical charge that travels down an axon

Threshold

The level of stimulation required to trigger a neural impulse

Refractory period

pause occurs after a neuron has fired; action potentials cannot occur until the axon returns to resting state

All-or-none response

A neurons reaction of either firing or not firing

What is reuptake?

occurs when excess neurotransmitters are reabsorbed by the sending neuron. Can also drift away or broken down by enzymes

Serotonin, dopamine, and endorphins are all chemical messengers called ___

Neurotransmitters

What is the function of Acetylcholine (ACh)

Enables muscle action, learning, and memory

What are examples of malfunctions of Acetylcholine?

With Alzheimer’s disease, ACh-producing neurons deteriorate

What is the function of dopamine?

Influences movement, learning, attention, and emotion

What is the malfunction of dopamine?

Oversupply linked to schizophrenia, while an under supply is linked to Parkinson’s disease

What is the function of serotonin?

Affects mood, hunger, sleep, and arousal

What is the malfunction of serotonin?

Under supply linked to depression.

What is the function of norepinephrine?

Helps control alertness and arousal

What is the function of GABA(gamma-aminobutyric acid)?

A major inhibitory neurotransmitter

What is the malfunction of GABA???

Under supply linked to seizures, tremors, and insomnia

What is the function of glutamate?

A major excitatory neurotransmitter involved in memory

What is the malfunction of glutamate?

Oversupply can overstimulate the brain, producing migraines or seizures

What is the function of endorphins?

Neurotransmitters that influence the perception of pain or pleasure

Agonist

A molecule that increases a neurotransmitters action

Antagonist

A molecule that inhibits or blocks a neurotransmitters action

Motor neurons

Carry outgoing messages from the CNS to muscles and glands

Sensory neurons

Carry incoming messages from sensory receptors to the CNS

Interneurons

Communicate with the CNS and process information between incoming and outgoing messages

What bodily changes does your ANS direct before and after you give an important speech?

your ANS sympathetic division will arouse you, then your parasympathetic division will calm you

Reflex

A simple, automatic response to a sensory stimulus, such as the knee-jerk response

How does information flow through your nervous system as you pick up a fork?

1. CNS systems hungry brain activates and guides your arm and hand via peripheral nervous systems

2. As fork is picked up, brain process info from your sensory nervous system to guide the fork

3. Function cycle starts with sensory input, processes through CNS, and finishes motor output

Why is the pituitary gland called the “master gland?”

Responds to signals from the hypothalamus, pituitary releases hormones that trigger other endocrine glands to secrete hormones, which influence brain and behavior

How are the nervous and endocrine systems alike?

Both produce chemical molecules that act on the body’s receptors to influence our behavior and emotions

How do the nervous and endocrine systems differ?

The endocrine system secretes hormones in the bloodstream, meaning that its slower than the nervous system (however, it’s messages linger longer than the nervous system)

Why are psychologists concerned with human biology?

We are biopsychosocial systems