Chapter 10 - The Human Nervous System Flashcards
Describe homeostasis.
- Regulation of internal conditions of an organism to maintain optimum conditions for function, in response to internal and external conditions.
Give 3 examples of a control system.
- Receptors
- Effectors
- Coordination centres
Describe the functions of the receptor.
- Detecting change (stimuli) in the external or internal environment.
Describe the function of the effector.
- Muscles initiating a response to the stimulus.
What does the coordination centre do?
- Receives and processes information from receptors.
Give 3 examples of internal conditions controlled by homeostasis.
- Body temperature
- Water levels
- Blood glucose concentration
How does the nervous system protect you from danger?
- It uses electrical impulses to enable you to react to you surroundings.
RQP - Describe an experiment to measure the reaction time of a person. [6]
- Ruler drop test [1]
- Assistant holds the ruler above your hand [1]
- Top of the thumb in line with 0cm [1]
- Assistant drops the ruler [1]
- Catch as soon as possible [1]
- Record the distance the ruler dropped, from 0cm to top of your thumb. [1]
Describe the pathway the nervous system takes to enable a reaction.
Stimulus - Receptor - Coordinator - Effector
Describe what a reflex is.
- Automatic and rapid responses to prevent harm.
State the 3 neurones involved in enabling reflexes.
- Sensory neurone
- Motor neurone
- Relay neurone
State the reflex pathway
Stimulus - Receptor - Sensory Neurone - Relay Neurone - Motor Neurone - Effector - Response
What is synapse?
- A gap between neurones which carry the electrical impulses.
State the function of the cerebral cortex.
Contains conscious thought, including emotion, decision making and memory.
What does the medulla do inside the brain?
Controls heart rate and breathing and subconscious thought.
Give the function of the cerebellum.
Enables balance and muscle coordination.
What is the function of the pituitary gland?
Release of hormones and control of the menstrual cycle.
Give 2 ways which scientists can use to study damaged areas of a patients brain.
Electrical brain stimulation.
MRI scans.
Describe the pathway of light through the eye. [5]
Light enters via pupil/cornea through aqueous humour. [1]
Lens focuses light. [1]
Retina detects focused light. [1]
Message passed through blind spot to optic nerve. [1]
Optic nerve delivers message to brain. [1]
What is the function of the iris?
Controls size of eye and amount of light entering the eye.
State the functions of the ciliary muscles and suspensory ligaments.
Changes shape of lens to fine focus light on retina.
Describe what someone will be affected by when they are diagnosed with myopia.
Explain a method of treatment.
Distant objects are blurred, but close objects are in clear focus.
Use glasses with concave lens to spread light out from distant objects before the eye is reached.
Describe hyperopia.
Give a possible treatment.
Clear focus on distant objects, but close objects appear blurred.
Use of glasses with a convex lens to bring the light together before the eye is reached.
Evaluate the use of contact lenses to help a patient with an eye defect. [6]
Points for:
You can play sports much easier. [1]
Lenses are comfortable [1]
Made of flexible material [1]
Points against:
Short lifetime [1]
Need removal every night [1]
Need storage in sterile solution [1]
Describe the process of applying a replacement lens.
Give 1 positive and negative of using replacement lens.
Adding another lens in the eye to correct the visual defect.
P - Corrects the visual defect permanently.
N - Possible damage to retina and/or infections.
