The bodys communication systems help maintain homeostasis.

A stimulus is anything that causes a response.Responses can be chemical, cellular, or behavioral.

Chemical: insulin, growth hormone, adrenaline

Cellular: White Blood cells

Behavioral: Body temperature, walking into sunlight

The nervous and endocrine systems respond to stimuli.

The nervous system controls thoughts, movement, and emotion.

The endocrine system controls growth, development, and digestion.

The nervous and endocrine systems have different methods and rates of communication.

The nervous system works quickly, using chemical and electrical signals.divided into central nervous system (CNS) and peripheral nervous system (PNS)Central: brain & spinal cordPeripheral: all other nerves

spinal chord

nerves

The endocrine system works more slowly.only chemical signalssignals move through bloodstream physically unconnected organs

receptor

target cell

not a target cell

bloodstream

hormone

Endocrine or Nervous?

Rate at which your fingernails grow?Blinking?Heart Rate?Hair growth?Knee jerk reflex?Amount of Insulin Released?

Endocrine

NervousNervousEndocrineNervousEndocrine

Neurons are highly specialized cells.

A neuron has three parts.cell body has nucleus and organelles

1

Cell body

*

dendrites receive impulses

Neurons are highly specialized cells.

A neuron has three parts.cell body has nucleus and organelles

2

dendrites

*

axon carries impulses

dendrites receive impulses

Neurons are highly specialized cells.

A neuron has three parts.cell body has nucleus and organelles

3

axon

*

Neurons have other structures to transmit signals.

Schwann cell (affected by MS)

*

synapse

Neurons have other structures to transmit signals.

Schwann cell

synapse

*

terminal

synapse

Neurons have other structures to transmit signals.

Schwann cell

axon terminal

*

Neurons receive and transmit signals.

Resting potential means no signal is being transmitted. more Na+ outside of cell more K+ inside of cell Inside of cell Outside +

*

An action potential is a moving electrical impulse.

It is generated by a stimulus.Na+ enters, and cell becomes positively charged.K+ leaves, and area of positive charge moves.

*

A chemical signal passes between neurons.

Impulse reaches terminal.

impulse

*

A chemical signal passes between neurons.

Impulse reaches terminal.

impulse

*

A chemical signal passes between neurons.

Impulse reaches terminal.

impulse

Neurotransmitters released into synapse.

*

A chemical signal passes between neurons.

Impulse reaches terminal.Neurotransmitters released into synapse.

impulse

Neurotransmitters stimulate next cell.

synapse

receptor

vesicles

neurotransmitter

*

Neuron Visual Questions (pg. 878)

1. When a neuron is at rest, what is the charge of its inner membrane?

2. What causes an area of the inner membrane to become positively charged?

3. How does an area of positive charge, or impulse, move down the axon of a neuron?

4. How is the negative charge of the axons inner membrane restored?

5. What happens when the impulse reaches the axon terminal?

6. How do neurotransmitters generate an impulse in an adjacent neuron?

The CNS and PNS pass signals between one another.

Sensory receptor generates impulse.Impulse travels on sensory neurons PNS passes impulse to CNS. CNS interprets impulse.CNS passes impulse to PNS. PNS motor neurons stimulate a response.

The CNS processes information.

The brain has three parts. cerebrum controls thought, movement, emotioncerebellum allows for balancebrain stem controls basic life functions

midbrain

pons

medulla oblongata

Brainstem

Lobes of the Brain

Frontal: responsible for personality, reasoning, judgment, coordinates speech & voluntary movementTemporal: speech interpretation & hearingOccipital: VisionParietal: Interprets information from sense of touch

The brain stem has three parts.

midbrain controls some reflexespons regulates breathing medulla oblongata controls heart function, swallowing, coughing

midbrain

medulla oblongata

pons

The spinal cord controls reflexes.

sensory neuron sends impulse to spinal cordspinal cord directs impulse to motor neuron does not involve the brain

interneuron

motor neurons

sensory neuron

The PNS links the CNS to muscles and other organs.

3 Common Technologies to study the brain

CT uses x-rays to view structure.

PET detects activity, where glucose is used, in the brain.

MRI uses magnetic fields and radio waves to view structure.

Different neurotransmitters relate to different functions.

some stimulate impulsessome prevent impulses

Normal

synapse

neurotransmitter

receptor

Addiction is the physiological need for a substance. Tolerance occurs when more drug is needed to produce an effect.Drugs might cause desensitization or sensitization.desensitization: more neurotransmitter leads to fewer receptorssensitization: less neurotransmitter leads to more receptors.

When the amount of neurotransmitter becomes abnormal, the adjacent neuron adapts.

Stimulants cause more action potentials

may increase neurotransmitter in synapsemay decrease removal of neurotransmitter in synapse

cocaine

neurotransmitter

synapse

Depressants cause fewer action potentials.

may produce neurotransmitter that prevent impulses may slow release of neurotransmitter that generates impulses

Hormones are chemical signals that influence cells activities.

produced by glandstravel through the circulatory systemaffects cells with matching receptors

target cell

hormone

receptor

not a target cell

bloodstream

There are steroid hormones and nonsteroid hormones.

Steroid hormones enter the cell. Nonsteroid hormones do not enter the cell.

nucleus

Chemical reactions

Steroid hormone diffuses through the cell membrane

Steroid hormone binds to a receptor within the cell.

The hormone and receptor enter the nucleus and bind to DNA

Steroid hormone causes DNA to make proteins.

Nonsteroid hormone binds to receptor on the cell membrane.

Receptor stimulates a second messenger with in the cell.

Second messenger starts a series of chemical reactions in the cytoplasm.

Second messenger reactions activate enzymes.

Steroid hormone

receptor

DNA

proteins

Non-steroid hormone

receptor

second messenger

activated enzymes

Endocrine glands secrete hormones that act throughout the body.

There are many glands located throughout the body.

Hormones travel through the bloodstream to cells with matching receptors.

HYPOTHALAMUS

PITUITARY

THYROID

THYMUS

ADRENAL GLANDS

PANCREAS

FEMALE GONADS :OVARIES

MALE GONADS : TESTES

The hypothalamus interacts with the nervous and endocrine systems.

The hypothalamus is a gland found in the brain.

a structure of both the nervous andendocrine systemsproduces releasing hormones,sent to pituitary glandThe pituitary gland is found below the hypothalamus in the brain.controls growth and waterlevels in blood Also produces releasing hormones

Negative feedback loops are necessary for homeostasis.

Feedback compares current conditions to set ranges.Negative feedback counteracts change.

Negative Feedback Loop

Holding breath, CO2 levels rise,

Control system forces exhale, inhale

O2 / CO2 level returns to normal

Positive feedback increases change.

Torn vessel stimulates release of clotting factors

growth hormones stimulate cell division

platelets

fibrin

white blood cell

red blood cell

blood vessel

clot

Examples of feedback loops Negative or Positive?

Your energy level decreases, stomach growls telling you need nutrition to get your energy levels back up.

The adrenaline rush you experience in dangerous situations.

You do sprints for an hour and you pass out. Your body is telling you your oxygen level is too low.

NEGATIVE

NEGATIVE

POSITIVE

Problem Solve

#1 Box 2

Box 3 Box 4

Given Situation. Is it an example of negative or positive feedback? Explain

Provide your own example

of Negative Feedback

Provide your own example of

Positive Feedback

Given Situation. Is it an example of negative or positive feedback? Explain

Problem Solve

#1 Box 2

Box 3 Box 4

When contractions start during labor, the hormone oxytocin is released into the body and causes more contractions to allow a woman to give birth.

Its a hot day and you start

to sweat.

Provide your own example

of Positive Feedback

Provide your own example of

Negative Feedback

Label the Brain/Neuron

On the brain side, label and describe the function of the following:Cerebellum, Frontal Lobe, Medulla Oblongata, Occipital Lobe, Parietal Lobe, Pituitary Gland, Pons, Spinal Cord, Temporal LobeOn the neuron, label and describe the function of the following:Axon, axon terminal, cell body, dendrites, nucleus, Schwann cell