PSYCHOLOGY

Neural and Hormonal Systems

True or False?1. A small amount of brain tissue from a

person cannot be distinguished from that of a monkey.

2. The human brain produces its own natural opiates.

3. Some one can write but be unable to read.

4. Electrically stimulating a cat’s brain at a certain point can cause the animal to cower in terror in the presence of a small mouse.

5. Some people have had their brain cut in half with no apparent ill effect.

What does your skull tell us about you?

Demostration: take your hands and feel your skull/head

What do you notice?

Phrenology

Franz Gall - phrenologist Bumps on skull reveal mental abilities & character traits

Not very scientific However it did highlight the presumed function of specific brain regions

Neural Communication

Biological Psychology branch of psychology concerned with the links between biology and behavior

some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists

Neuron

Neuron a nerve cell the basic building block of the nervous system

Neural Communication Dendrite (listen)

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

Axon (speak) the extension of a neuron, ending in branching terminal fibers, through which messages are sent to other neurons or to muscles or glands

The insulator

Myelin [MY-uh-lin] Sheath a layer of fatty cells encasing the fibers of many neurons

enables vastly greater transmission speed of neutral impulses

Neuron

Axon terminals - where message leaves axon

Synaptic gap - space the message jumps across from the axon terminal to the next dentrite

Neural Communication Synapse [SIN-aps] (Sherrington)

junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

tiny gap at this junction is called the synaptic gap or cleft

Neurotransmitters chemical messengers that traverse the synaptic gaps between neurons

when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether it will generate a neural impulse

Neural Communication

Neural communication

How does a neuron fire a message?

Neural Communication

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

Threshold the minimum level of stimulation required to trigger a neural impulse

How does a neuron fire a message?

For Action potential a Threshold has to be reach:The + sodium ions (partiers) around the axon have to be excited

There has to be more partiers (excitatory) then party poopers (inhibitory) for the message to be sent down the axon

Neural impulse - Action potential

1. Resting potential (polarized neuron; - potassium inside, + sodium outside)

1. Excitatory (+ sodium, partiers - gas pedal) vs Inhibitory (- potassium, party poopers -brake)

2. All or nothing response• Reach threshold for action potential

3. Depolarization (+sodium come into the axon)• Selectively permeable - gate opens

4. Refractory period (recharging, +sodium move back out)

Neural Communication

Cell body end of axon

Direction of neural impulse: toward axon terminals

Neural communication

Where does a neural impulse begin? Know the order of transmission

How does one neuron communicate to another? Be able to explain the process

Neural comm.

Know names of neurotransmitters and their functions & malfunctions - see chart in book

Should also know whether they inhibit or excite

Neural Communication

Neural Communication

Acetylcholine [ah-seat-el-KO-leen] a neurotransmitter that, among its functions, triggers muscle contraction

Endorphins [en-DOR-fins] “morphine within” natural, opiate-like neurotransmitters

linked to pain control and to pleasure

Agonist vs Antagonist

Agonists - excite / mimicAntagonists - inhibit / block

Neural Communication

Neurotransmitter molecule

Receiving cellmembrane

Receptor site onreceiving neuron

Agonist mimicsneurotransmitter

Antagonistblocksneurotransmitter

Reuptake

Reuptake - neurotransmitters that don’t get absorbed by the receiving neuron go back to the sending neuron

Neural Communication

Neural Communication

Serotonin Pathways Dopamine Pathways

3 kinds of neurons

1. Sensory Neurons neurons that carry incoming information from the sense receptors to the central nervous system

2. Interneurons CNS neurons that internally communicate and intervene between the sensory inputs and motor outputs

3. Motor Neurons carry outgoing information from the CNS to muscles and glands

The Nervous SystemNervous System

the body’s speedy, electrochemical communication system

The Nervous System

Nerves neural “cables” containing many axons

part of the peripheral nervous system

connect the central nervous system with muscles, glands, and sense organs

The Nervous System

Central(brain and

spinal cord)

Nervoussystem

Autonomic (controlsself-regulated action of

internal organs and glands)

Skeletal (controlsvoluntary movements of

skeletal muscles)

Sympathetic (arousing)

Parasympathetic (calming)

Peripheral

2 parts of nervous system

Central Nervous System (CNS) the brain and spinal cord

Peripheral Nervous System (PNS) the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body

PNS

Skeletal or Somatic Nervous System the division of the peripheral nervous system that controls the body’s skeletal muscles

PNS

Autonomic Nervous System (think automatic)the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart)

a. Sympathetic Nervous System division that arouses the body, mobilizing its energy in stressful situations

b. Parasympathetic Nervous System division that calms the body, conserving its energy

The Nervous System

The Nervous System

The Nervous System Reflex

a simple, automatic, inborn response to a sensory stimulus

Skinreceptors

Muscle

Sensory neuron(incoming information)

Motor neuron(outgoing information)

Brain

Interneuron

Spinal cord

Neural Networks

Neural Networks interconnected neural cells

with experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results

computer simulations of neural networks show analogous learning

Inputs Outputs

Neurons in the brain connect with one

another to form networks

The brain learns by modifyingcertain connections in response to feedback

The Endocrine System Endocrine System the body’s “slow” chemical communication system

a set of glands that secrete hormones into the bloodstream

Endrocrine system

Hormones Slow & long lasting chemical messengers that travel through the blood

Endocrine System

Pituitary Gland (the master gland) under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands

Endrocrine system

Adrenal [ah-DREEN-el] Glands a pair of endocrine glands just above the kidneys

secrete the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline), which help to arouse the body in times of stress