Unraveling the Wonders of the Nervous System

• Human Regulation and Reproduction
• Further Education (Key Stage 5)

Unraveling the Wonders of the Nervous System

Learning Objective

Understand the organization of the nervous system, including its components, functions, and dysfunctions.

What do you already know about the nervous system?

Central and Peripheral Nervous Systems

The CNS includes the brain and spinal cord, while the PNS comprises nerves and ganglia outside the CNS.

CNS

• Made up of brain and spinal cord

• Grey and white matter

• Grey matter – non-myelinated nerve cells and cell bodies

• White matter – myelinated nerve fibres

Central Nervous System

Peripheral Nervous System

Which nervous system comprises nerves and ganglia outside the CNS?

1. Autonomic Nervous System
2. Somatic Nervous System
3. Peripheral Nervous System
4. Central Nervous System

Where are the nerves and ganglia outside the brain and spinal cord located?

1. Somatic Nervous System
2. Autonomic Nervous System
3. Central Nervous System
4. Peripheral Nervous System

Which part of the nervous system includes the brain and spinal cord?

1. Central Nervous System
2. Autonomic Nervous System
3. Somatic Nervous System
4. Peripheral Nervous System

Neuron and Glial Cells

Neurons are excitable cells that transmit information, while glial cells support and protect neurons. Myelinated neurons have a fatty layer, enabling faster transmission.

Transmission of Action Potentials

Action potentials are the basis of neural communication, and saltatory conduction increases the speed of transmission in myelinated neurons.

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What is an action potential?

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Depolarization in an action potential refers to the change in membrane potential towards a more positive value.

Correct definition of depolarization.

Depolarization is unrelated to membrane potential.

Depolarisation is a change towards a more negative value.

01:20

What type of channel allows the depolarisation in an action potential?

Water

Sodium

Helium

Disney

Transmission at Synapses

Neurotransmitters are chemical messengers that your body can't function without. Their job is to carry chemical signals (“messages”) from one neuron (nerve cell) to the next target cell. The next target cell can be another nerve cell, a muscle cell or a gland. 

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what types of synaptic neurons are at each side of the synaptic cleft?

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What causes the vesicles to release the neurotransmitters?

Stimuli Detection

Receptor cells and sense organs detect stimuli, initiating neural signals for processing.

Stimuli Detection

1. Mechanoreceptors: They provide information about mechanical changes in the environment and respond to physical force such as pressure (touch or blood pressure), movement, and stretch.

Tactile receptors: Provides information regarding touch and vibrations 

Baroreceptors: Detects changes in pressure

Proprioceptors: Detects the position of joints

Stimuli Detection

2. Photoreceptors: They respond to light. In the human eye, photoreceptor cells are located in the retina. There are two types of photoreceptor cells: cones and rods.

3. Thermoreceptors: They respond to temperature changes. They are accessible nerve endings situated in the skin, liver, and skeletal muscles. Cold thermoreceptors are 3.5 times more common than heat receptors.

4. Chemoreceptors: They respond to dissolved chemicals during sensations of taste and smell. They can also detect changes in internal body chemistry, such as blood variations and PH. Taste buds are an example of chemoreceptors.

5. Nociceptors: They respond to various stimuli associated with tissue damage. The brain interprets pain.

What type of receptor detects the position of limbs and body parts?

1. Proprioceptors
2. Thermoreceptors
3. Baroreceptors
4. Chemoreceptors

What do chemoreceptors detect in the body?

1. Temperature variations
2. Body movements
3. Pressure changes
4. Chemical stimuli such as changes in pH or concentration

Which receptors are responsible for sensing temperature?

1. Chemoreceptors
2. Baroreceptors
3. Proprioceptors
4. Thermoreceptors

What do mechanoreceptors detect?

1. Temperature variations
2. Chemical changes
3. Body position
4. Physical deformation or mechanical pressure

Which type of receptor detects changes in pressure?

1. Chemoreceptors
2. Baroreceptors
3. Proprioceptors
4. Thermoreceptors

Autonomic Nervous System

The ANS regulates involuntary processes and is divided into sympathetic and parasympathetic divisions, utilising different neurotransmitters.

4. Which division of the autonomic nervous system is responsible for rest and digest functions?

1. Parasympathetic nervous system
2. Somatic nervous system
3. Sympathetic nervous system
4. Central nervous system

1. What is the function of the sympathetic nervous system?

1. Regulate digestion
2. Prepare the body for fight or flight response
3. Maintain homeostasis
4. Control voluntary movements

Voluntary and Non-Voluntary Reflexes

Reflex actions involve afferent (inwards) and efferent (outwards) pathways, with interneurons playing a crucial role in processing reflex responses.

Review and Discussion

Summarize key concepts and engage in a class discussion to reinforce learning.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.

What is your favourite photo that you have taken this week?