The Nervous System Lesson

The Nervous System

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Nervous System

• The nervous system controls your emotions, movements, thinking, and behavior

• Dived into two parts:

  The Central Nervous System (CNS)- includes the brain and spinal cord and The Peripheral Nervous System (PNS)- made up of all of the other nerves in the body
  

• The PNS is connected with the CNS so that the two systems can communicate quickly and efficiently.

• The PNS is divided into two parts: AUTONOMIC and SOMATIC

Peripheral Nervous System

• The PNS is divided into two parts:

  
  

• Somatic- controls voluntary muscles (legs and feet while you walk, for example)

• Autonomic- controls the involuntary muscles (heart and lungs, for example)

Multiple Select

The autonomic system controls your eyes and kidneys

• True

• False

• The autonomic system can be divided into two parts:

• Sympathetic-alerts the body and helps it get “energized” to respond to a stressor: speeds up our breathing and heart rate and prepares for the fight or flight response

• Parasympathetic-calms us down and returns heartbeat and breathing to normal levels

Brain Cells (Neurons)

Neurons are the cells that make up most of your brain and nervous system. They have a very special job, and are designed to work in a very specific way. Each Neuron has lots of little arms (dendrites) that receive messages from other neurons' axon and nerve endings (tail). This allows the nerve cells to quickly pass signals throughout your body.

Neurons

• Neurons are the long, thin cells of nerve tissue along which messages travel to and from the brain

• They send signals to and from the brain whenever the cells are stimulated and send a signal from other neurons.

  
  

Neurons “fire” with the all-or-none principle: When a neuron fires, it does so at full strength and if the neuron is not stimulated past the minimum, it does not fire at all 

Parts of a neuron: Dendrites

• At the “top” of a neuron, extending out from a center, are the branch-like structures called “dendrites.”

• These reach out and connect to the ends of other neurons, and receive impulses from them.

• 
  

Parts of a neuron: Soma

• The soma or cell body is at the center of the dendrites and contains the nucleus

• If enough energy is sent from the dendrites to the cell body, it will cause the nerve to “fire.”

• 
  

Parts of a neuron: Axon

• The axon is the elongated portion of the neuron

• It connects the “top” (soma) to the “bottom” of the neuron, the terminal branches.

• When a neuron “fires,” the impulse is sent along the axon.

Parts of a neuron: Myelin Sheath

• The myelin sheath is a fatty covering that some axons have to help insulate and speed along the electrical impulses that occur within the axon.

• Not all neurons have a myelin sheath

• 
  

Multiple Choice

Where is the nucleus located?

• Axon

• Dendrites

• Soma

• Myelin Sheath

In some neurological disorders, the myelin can become damaged, causing the neurons to fire more slowly, or less consistently. An example is Multiple sclerosis (MS)

Parts of a neuron: Axon Terminal

• The axon carries impulses from the cell body towards the axon terminals

• Axon terminals release neurotransmitters to stimulate the dendrites of another neuron

• They are located at the end of the axon

Fill in the Blank

The _________ is at the top of the neuron and receives neural impulses

Neural Communication

• Neurons only fire “one way” – from the soma down the axon to the terminal buttons. Communication throughout the nervous system, then, must be a “two-way street.”

  
  

Neurons called afferent neurons carry information to the brain from sensory organs like eyes, ears, nose, and skin

Neural Communication

• Neurons called efferent neurons carry orders away from the brain out to the rest of the body. When you walk, move exercise, or interact with your environment, efferent neurons coordinate the movements

• 
  

Multiple Choice

Our nervous system helps us...

• Transport nutrients and get rid of waste.

• Absorb oxygen & clean our blood.

• Transport information around the body.

Multiple Choice

Select the three main parts of the nervous system.

• Muscles, spinal cord and nerves.

• Spinal cord, brain and nerves.

• Muscles, senses and brain.

Fight or Flight?

Have your ever been really scared? Think of walking through a haunted house... Did you feel anxious? Scared? Was your heart beating faster than normal? Were you more aware of things happening around you? This is your nervous system in "fight or flight" mode.

Fight or Flight

When you're scared, your nervous system goes into its' Fight or flight mode, which is designed to prepare your body to either fight, or run (flight). Your heart rate increases, you might start sweating, you're more aware of things happening around you, you feel anxious, and your mind starts racing. Your body is preparing itself for a fight or a flight.

Multiple Choice

The left side of your brain controls the _______ side of your body.

• Right

• Left

• Front

• Back

Multiple Select

What are the main parts of the neurons to send and receive information (2 parts)?

• nucleus

• axon

• dendrite

• myelin sheath

• Node of Ranvier

The Peripheral Nervous System

The PNS is made up of all nerves outside of the CNS.

The PNS carries information to and from the CNS to the rest of the body, such as limbs and organs

The PNS is divided into two parts.

The somatic and automatic nervous system

The Somatic Nervous System

• Controls voluntary skeletal muscle movements.

• Eg. waving or reaching out to take an object

The Autonomic nervous system

• Controls involuntary actions - happen without conscious control.

• Examples include: heartbeat, digestion, respiration, salivation and perspiration.

• This system maintains your body's internal environment (homeostasis).

The Autonomic nervous system has two parts.

The sympathetic and parasympathetic division - which work together to maintain balance in the body.

Sympathetic

• Prepares you for action!

• eg. speeds up your heart rate

Parasympathetic

• Calms you down

• eg. slows down the heart rate.

Multiple Choice

The slowing of your heartbeat is part of the

• sympathetic division

• parasympathetic division

Multiple Choice

increased heart rate is part of the

• sympathetic division

• parasympathetic division

Multiple Choice

The _____part of the autonomic nervous system is active during resting.

• sympathetic
• parasympathetic
• somatic
• peripheral

Multiple Choice

What does the somatic system do? (the somatic system is part of the Peripheral Nervous System)

• It speeds up functions of the body ready for fight or flight

• it slows down functions of the body ready for rest and digest

• It consists of all the neurons outside of the Central Nervous System

• It is used for actions that you control (reaching out and grabbing something) and sensing stimuli

Multiple Choice

You see a friend and wave, which part of you PNS is causing this?

• Somatic

• Autonomic

• Sympathetic

• Parasympathetic

Multiple Choice

Alexa is presenting a project in front of her class. She starts sweating and her heart rate increases. This is an example of the autonomic nervous system, sympathetic division.

• True

• False

Multiple Choice

Which one coordinates the inner organs?

• somatic nervous system

• autonomic nervous system

The Brain

• The processing centre of the body - mainly concerned with survival.

• Your brain is a soft heavy organ, protected by a tough skull.

• The brain is home to your memories, personality and thought process.

Lobes of the brain

The cerebrum or outer section of your brain is divided into four lobes or sections which have specific functions.

The frontal Lobe

• Located at the front of the brain.

• Functions include emotions, reasoning, movement and problem solving.

The Parietal Lobe

• Manages the perception of senses.

• Including taste, pain, pressure, temperature and touch.

The Temporal Lobe

• Located in the region near your ears.

• Deals with the recognition of sounds and smells.

The Occipital Lobe

• Located at the very back of the brain.

• It is responsible for various aspects of vision.

Multiple Choice

What does your occipital lobe do?

• Processes your hearing

• Processes your vision

• Contains your personality

• Processes your sense of touch

Multiple Choice

What does the parietal lobe do?

• Processes your hearing

• Processes your vision

• Contains your personality

• Processes your sense of touch

Multiple Choice

What does the frontal lobe do?

• Processes your hearing

• Processes your vision

• Contains your personality

• Processes your sense of touch