Unit 3 – Key Area 1 Divisions of the nervous system and parts of the brain

KA 1: Divisions of the nervous system and parts of the brain (a) CNS Central Nervous System (f) Localisation of brain functions The Nervous System (b) PNS Peripheral Nervous System (e) Cerebral Cortex (c) Medulla and Cerebellum (d) Limbic System

N5 Revision The Nervous System Multi-cellular organisms are made of trillions of specialised cells that work together to ensure survival of that organism. Internal communication is needed to bring this about this co-operation is provided by the nervous system.

The Nervous System Made of 3 parts: Brain Spinal Cord N5 Revision The Nervous System Made of 3 parts: Brain Spinal Cord Nerves – (Peripheral NS) The CNS is connected to all parts of the body by the nerves Central Nervous System or CNS N5 only note

The Brain Control centre of CNS Protected by skull N5 Revision The Brain Control centre of CNS Protected by skull Adult brain – 1.3 – 1.4 kg Newborn brain – 350 – 400g 2% of adult weight in healthy individual 100 billion neurons

Cerebrum Cerebellum Medulla Spinal Cord N5 Revision You could colour code the different parts ….. Spinal Cord

Part of brain Function Cerebrum Cerebellum Medulla N5 Revision Part of brain Function Cerebrum Cerebellum Medulla Controls breathing and heart rate Enables conscious thought, memory, learning and intelligence Controls balance and muscular coordination

Flow of information CNS STIMULI RESPONSE e.g. touch/light N5 Revision Flow of information CNS SENSORY NERVES MOTOR NERVES RECEPTORS (e.g. sense organs) EFFECTORS (e.g. muscle & glands) STIMULI e.g. touch/light RESPONSE e.g. movement/ hormone release

Motor neurone Harmful stimulus from a hot object N5 Revision Sensory neurone Synapse Relay neurone Response: arm muscles contract and hand withdraws Motor neurone Effector: muscles of the arm Harmful stimulus from a hot object

Nervous System: N5 Revision What 2 parts of the body make up the central nervous system (CNS) Name the 3 types of neurons present in the nervous system. What is the purpose of a reflex action. Brain and spinal cord. Sensory, relay and motor neurons. To protect the body from harm.

A 4) The following diagram shows a human brain. Which letter indicates the site of memory and conscious responses? A

B 5. The diagram below shows a section through the human brain. Which labelled part co-ordinates movement and balance? B

C 6. The diagram below shows a human brain. Which letter shows the site that controls heart rate and breathing rate? C

7. Which of the diagrams below identifies neurons and the direction of travel of nerve impulses?

8. The following stages occur in a reflex action. 1 The effector produces a response. 2 A sense organ is stimulated. 3 An impulse passes along a sensory neurone. 4 An impulse passes along a motor neurone. The correct order of the stages is A 2, 3, 4, 1 B 2, 1, 4, 3 C 1, 2, 3, 4 D 3, 4, 1, 2.

9. The diagram below shows neurones connecting the eye with the central nervous system. Which line in the table below identifies correctly the types of neurones and the direction of impulses which travel along them?

10. The pathway for a reflex arc involves the following. 1. Central nervous system 2. Sensory neurone 3. Motor neurone Which of the following correctly represents the pathway of a reflex arc? A 1 > 2 > 3 B 1 > 3 > 2 C 2 > 1 > 3 D 2 > 3 > 1