1.1 Human nervous system

1.1 Human nervous system

By KASMAWATI Moe

​A student is able to:

1. Explain parts involved in the movement  of impulses from the affector to  the effector.  

2. The pathways of impulses in  voluntary and  involuntary  actions. 

Nervous System

• The nerve cell (neuron) is the building block of the nervous system. The nervous system is responsible for transmitting signals around your bodys.

• The signals are releases of electricity that travel down a string of nerve cells.

• We can think of the nerve cells like power lines, the electrical signal travels down the nerve cell, along the elongated Axon before passing to the next connected nerve cell at the Axon Terminal.

Two Divisions of the Nervous System

• The central nervous system (CNS) contains your brain and spine.

• The peripheral nervous system (PNS) contains the nerves that run throughout your body (feet, legs, etc.) that all branch from the CNS

Multiple Choice

What do we call the long "tail" like part of the neuron, that is responsible for continuing the electrical signal?

• Dendrite

• Soma

• Axon

Multiple Select

The Central Nervous System is made up of which TWO parts?

• Brain

• Arms

• Legs

• Spine

Ways to divide the functions of the nervous system.

• Motor vs. Sensory

• Automatic vs. Voluntary

Motor vs. Sensory

• One function of the nervous system is sensation—receiving information about the environment to gain input about what is happening outside the body (or, sometimes, within the body). The sensory system recognizes stimulus (changes in the outer or internal environment).

  The senses we think of most are the “big five”: taste, smell, touch, sight, and hearing. Those five are all senses that receive stimuli from the outside world, but there are outer stimuli to sense from the internal environment like the stretch of an organ wall.

Motor vs. Sensory

• The motor nervous system produces a response to the stimuli received by sensory structures. An obvious response would be the movement of muscles, such as withdrawing a hand from a hot stove, but there are broader uses of the term.

Somatic nervous system vs Autonomic nervous system

• The somatic nervous system is associated with the senses and any motor nerves associated with skeletal muscle movement. So pumping iron is an example of the somatic nervous system. Jumping when you are scared when someone surprises you is another example.

• The autonomic nervous system is responsible for the involuntary control of your body. For example you don't direct your sweat glands to start sweating, that would be apart of the autonomic nervous system.

Multiple Select

Identify the 2 labels that could apply to the nervous system response below. You smash a fly with your hand.

• Motor

• Sensory

• Autonomic

• Somatic

Multiple Select

Identify the 2 labels that could apply to the nervous system below. The muscles of your stomach move to begin digesting food.

• Sensory

• Motor

• Autonomic

• Somatic

Multiple Select

Identify the 2 labels that could apply to the nervous system below. You smell Grandma's cooking and you start to drool.

• Somatic

• Autonomic

• Sensory

• Motor

Nervous System

How the Brain and Spinal Cord Work

The Nervous System

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 The Peripheral Nervous System (PNS)- made up of all of the other nerves in the body

• 
  

Multiple Select

What are the two parts of the nervous system

• Central

• Peripheral

• Axios

• Upper

• 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

Multiple Choice

What is the largest part of the brain

• Medulla

• Cerebellum

• Cerebrum

• Oblagata

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 Choice

The cerebrum is the _________ part of your brain

• Smelling

• Tasting

• Wasting

• Thinking

Multiple Select

The autonomic system controls your eyes and kidneys

• True

• False

Multiple Choice

The cerebrum also controls your __________________.

• Muscles

• Heart

• Liver

• Bones

• The autonomic system can also 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

Multiple Choice

The cerebellum is the small part of the brain that controls your _____________.

• Thinking

• Balance

• Heart

• Lungs

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.

• 
  

Multiple Choice

What is the brain stem (medulla) connected to?

• Phalanges

• Stop Lights

• Spinal Cord

• Sternum

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 

Multiple Select

The brain stem (medulla) controls the following

• Heart Rate

• Breathing

• Food Digestion

• Running

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.

• 
  

Multiple Choice

What does the Amygdala control?

• Emotions

• Speed

• Jumping Ability

• Strength

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.”

• 
  

Multiple Choice

What produces a chemical in your brain that helps you learn?

• Video Games

• Lounging on the couch

• Exercise

• Sitting in a desk

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

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Poll

Are we feeling comfortable with the basics of the nervous system and neurons?

• Yes

• No