6. Responding to the Environment (Humans)

1. Core Content

Introduction

The nervous system (involving nerves) and endocrine system (involving hormones) are two components that help us respond to the environment.

Human nervous system

The need for a nervous system in humans:

• Reaction to stimuli (stimuli can be external and internal)

• Coordination of the various activities of the body

Central nervous system

The brain and spinal cord are protected by meninges

Location and functions of the following parts:

• Brain

- Cerebrum

- Cerebellum

- Corpus callosum

- Medulla oblongata

• Spinal cord

Peripheral nervous system

Location and functions of the peripheral nervous system (cranial and spinal nerves)

Autonomic nervous system

Location and functions of the autonomic nervous system (sympathetic and parasympathetic sections)

Structure and functioning of a nerve

Functions of sensory and motor neurons

Structure and functions of parts of sensory and motor neurons, using diagrams: nucleus, cell body, cytoplasm, myelin sheath, axon and dendrites

The simple reflex arc

Definition of reflex action and a reflex arc

Structure of a reflex arc and functions of each part, using a diagram: receptor, sensory neuron, dorsal root of spinal nerve, spinal cord, interneuron, motor neuron, ventral root of spinal nerve, effector

Functioning of a simple reflex action, using an example)

Significance of a reflex action

Significance of synapses

Disorders of the CNS

Causes and symptoms of the following disorders of the nervous system:

• Alzheimer's disease

• Multiple sclerosis

Receptors

Functions of receptors, neurons and effectors in responding to the environment

The body responds to a variety of different stimuli, such as light, sound, touch, temperature, pressure, pain and chemicals (taste and smell). (No structure and names necessary except for names of the receptors in the eye and ear.)

Human eye

Structure and functions of the parts of the human eye, using a diagram

Binocular vision and its importance

The changes that occur in the human eye for each of the following, using diagrams:

• Accommodation

• Pupillary mechanism

The nature and treatment of the following visual defects, using diagrams:

• Short-sightedness

• Long-sightedness

• Astigmatism

• Cataracts

Human ear

Structure of the human ear and the functions of the different parts, using a diagram

Functioning of the human ear in:

• Hearing (include the role of the organ of Corti, without details of its structure)

• Balance (include the role of maculae and cristae, without details of their structure)

Cause and treatment of the following hearing defects:

• Middle ear infection (the use of grommets)

• Deafness (the use of hearing aids and cochlear implants)