Human Regulation

Regulation:• The life process by which the human body

responds to its changing (inside and outside) environment.

• Constant adjustments made as a result of the changing environment help maintain…

HOMEOSTASIS!

Regulation:

1. Nervous System

2. Endocrine System

Main Function:

Responds to internal and external stimuliby controlling and coordinating functions throughout the body

Our nervous system allows us to feel pain and react to it!

Consists of: brain, spinal cord, nerves and sense organs

Sense Organs: Eyes, Skin, Ears, Nose & Tongue

2 Divisions of the Nervous SystemCentral Nervous System

(CNS)

• brain & spinal cord• Main control center of body

Peripheral Nervous System

(PNS)

• nerves extending throughout body

• Gathers & delivers info to and from the CNS

Peripheral Nervous System (PNS)

All of the Organs the PNS controls!!!

Neurons carry messages called impulses back and forth between the

peripheral nervous system and the central nervous system.

Impulse in a Neuron

dendrites

cell bodyaxon

synapse(space)

signal directionONE WAY

nucleus

terminal branches

signal directionONE WAY

Impulse in a Neuron

axon

synapse(space)

signaldirection

myelin coating

Axon is coated with insulation made of myelin cells (Lipids)

With myelin…signal hops from node to node at 330mph! (vs. only 11mph)

Multiple Sclerosis immune system attacks myelin coating

loss of signal

synapse

Because neurons never touch, chemical signalers called neurotransmitters must travel through the space called synapse between two neurons.

Neurotransmitters

Synapse (gap)

The message is transferred when RECEPTORS receive neurotransmitters.

Receptors:• Protein• Shape Specific!

Drugs/Poisons

• Stimulants - Speed up production and release of neurotransmitters (Caffeine)

• Depressants – block formation of neurotransmitters. (Pain Killers)

Which cell (X or Y) shows the receptor molecules?

What would a drug that interferes with communication between these two cells look like?

Sensory

Neuron

Interneuron

Motor Neuron

Sensory Neuron

Interneuron

Motor Neuron

Muscle Contracts

Synapse

Synapse

Synapse

3 Types of neuronssensory neuron(from senses)receive stimulus

interneuronCNS

motor neuron(to effector – muscle/gland)produces response

Motor Neurons

Axons branching out to muscle fibers

Fun facts about neurons• Most specialized cell

in animals• Longest cell

– blue whale neuron• 10-30 meters

– giraffe axon• 5 meters

– human neuron• 1-2 meters

Nervous system allows for 1 millisecond response time

Nervous system allows for 1 millisecond response time

Simplest Nerve Circuit – Reflex Arc

1.Receptor

2.Sensory

Neuron

3.Interneuron

4.Motor Neuron

5.Effector

1

2 3

45

A reflex is an involuntary

response that is processed in the spinal cord not

the brain.

Reflexes protect the body before the brain knows

what is going on.*faster because they don’t

have to travel to brain!

Reflex Arc

Watch Again!!!

1.Receptor

2.Sensory

Neuron

3.Interneuron

4.Motor Neuron

5.Effector

1

2 3

45

brain

Spinal Cord

Cerebellum

Cerebrum

Medulla Oblongata

Brain- Receives 20% of blood pumped by heart- Is the major user of glucose in the body

Consists of 3 Parts:1. Cerebrum2. Cerebellum3. Medulla (Brain

Stem)

What does the brain use glucose for?

Higher Brain: Cerebrum • 2 hemispheres:

– left controls the right side of body– right controls the left side of body

Cerebrum Functions

frontal

temporal

• Regions specialized for different functions4 Lobes

1. frontal• speech,

control of emotions

2. temporal• smell, hearing

3. occipital• vision

4. parietal• speech, taste

reading

occipital

parietal

Cerebellum• Found in back part of head under the cerebrum

• coordination of smooth, steady and efficient MOVEMENT• BALANCE, equilibrium and posture

• If damaged can result in jerky movement, loss of coordination and balance

Brain Stem (Medulla)

• Medulla Oblongata• basic body functions

– breathing – heartbeat– digestion – swallowing – vomiting – coughing– blinking

• HOMEOSTASIS

CNS Protection• Bone: Skull, Vertebrae

• Cartilage disks found

between vertebrate

absorb shock

• Meninges (protective membrane) cover the brain and spinal cord

• Cerebral Spinal Fluid surrounds Brain and Spinal Cord. Acts like a watery cushion!

When homeostasis is distrupted!

Cerebral Palsy: A group of birth disorders characterized by disturbances of motor functions.

Polio: A viral disease of the CNS that can cause paralysis.

Prevented by immunization!

Meningitis – an inflammation, caused by bacteria, of the membranes that surround the brain and spinal cord. Can be fatal.

Symptoms: severe headache, stiff neck

Concussion:The Brain is a soft organ

• protected by your hard skull• surrounded by spinal fluid (cushion that keeps

your brain from banging into your skull)

Hard hit/fall=Brain crashes into your skull=Damaged Brain