The Brain WALT That there are distinct areas of the brain That each area has a different function

27.5.2 Structure of The Brain Longitudinal section through a human brain

Regions and Functions of the Brain - The brain is divided into 3 regions: the forebrain, midbrain & the hindbrain

1. The Forebrain The cerebrum is divided into two cerebral hemispheres connected by nerve fibres The surface is folded to increase the surface area for increased co-ordination This is the centre for thinking, memory, reasoning, imagination, learning & voluntary actions

Map of the major regions of the cerebral cortex and their functions

Areas of the brain sensory areas receive impulses from the receptors; removal of these areas results in loss of the senses motor areas send impulses to the effectors; if these areas are damaged, no responses will be evoked; association areas correlate impulses from different receptors and assist in producing the appropriate responses

The Midbrain This includes the optic lobes for vision The floor is the hypothalamus essential for homeostasis: main controlling region for the autonomic nervous system; two centres (sympathetic & parasympathetic); controls complex patterns of behaviour such as feeding, sleeping; monitor composition of blood; acts as an endocrine gland

The Hindbrain The cerebellum: a centre for muscular co ordination and body balance The medullar oblongata: This is the reflex centre for controlling involuntary actions such as breathing, heartbeat, swallowing, coughing, sneezing, and salivation; Any damage of the medulla oblongata may lead to death

Internal Structure of the Brain -The grey matter: This is the outer layer of the brain and consists of nerve cell bodies only -The white matter: This is inside the brain and consists of nerve fibres only Remember--This is the reverse of the medulla oblongata & spinal cord, the distribution of grey and white matters is the reverse with the grey matter inside and the whiote matter outside

Comparison of Endocrine and Nervous Systems Endocrine system Communication: chemical messengers or hormones Communication: by nervous impulses Transmission: by blood stream Transmission: by nerve fibres Target organ receives message Effector receives message Transmission: relatively slow Transmission: very rapid Effect: widespread Effect: localized Response: slow Response: rapid Response is often long-term Response is short-lived Effect: permanent & irreversible Effect: temporary and reversible