Module 4 Responding to the environment 2.4.6 Organising the nervous system

Learning Outcomes To understand the structure of the human brain Label the gross structure of the human brain (Grade E - D) Outline the function of the cerebrum, cerebellum, medulla oblongata, hypothalamus and pituitary gland (Grade C –B) Describe the role of the brain and nervous system in coordinated muscular movement (Grade B – A) 4

Starter A) Sensory areas B) Association areas C) Motor areas Compare input with previous experiences in order to interpret what the input means and judge an appropriate response Sends impulses to effectors (muscles and glands) Receives impulses indirectly from the receptors A) Sensory areas B) Association areas C) Motor areas A3, B1 and C2

Gross Structure of Brain http://www.youtube.com/watch?v=snO68aJTOpM Use a balloon as a model of the draw on the sections and label Use page 228

Regions of the Brain

Regions of the brain Hindbrain Midbrain Medulla oblongata – controls vital functions such as heart and ventilation rates, peristalsis and blood pressure Cerebellum – controls balance and muscle coordination Midbrain Small in mammals Contains nerve fibres that connect fore and hindbrain

Regions of the brain Forebrain Cerebrum – controls the bodies voluntary behaviour, reasoning, personality and memory Thalamus – relays sensory information from the sense organs to the correct part of the cerebellum Hypothalamus – receives sensory information (body temp, blood solute concn)

Cerebral hemispheres The cerebrum is the largest part of the brain it is divided into 2 halves (hemispheres) The two halves are quite separate except for the corpus callosum, (a bundle of 200 million neurones which run between the two halves) The left cerebral hemisphere controls the right side of the body and visa versa

Cerebral hemispheres The cerebral hemispheres have an outer layer the cerebral cortex which contains the nerve cell bodies (grey matter) and an inner area containing nerve fibres (white matter) The cerebral cortex is highly folded and so has a large surface area. The cortex is the most complicated, fascinating and least-understood part of the brain.

Functional areas

Functional areas Mapping of the Somatosensory area reflects sensitivity. Mapping of the Motor area reflects mobility. Association areas are the link between the two and are involved in thinking, reasoning, decision making, memory, emotion and learning.

Mapping of Somatosensory area Motor area

Parts of Brain Structure Description Function Cerebrum Cerebellum Medulla oblongata Hypothalamus Pituitary gland

Cerebrum Cerebellum Medulla oblongata Pituitary Gland Hypothalamus Structure Description Function Cerebrum Largest part of brain, 2 hemispheres connected via corpus callosum, surface is thin layer of nerve cells known as the cerebral cortex-highly folded Higher brain functions (e.g. conscious thought & emotional response, ability to override some reflexes, reasoning, judgement) Cerebellum Neurones carrying impulses to motor areas (contains over half of all nerve cells in brain) Coordinated motor response: balance, fine movement: (voluntary muscle movement initiated in cerebrum) but fine muscle control requires significant nonconscious operation ‘autopilot’ Medulla oblongata Found at the base of the brain, at the top of the spinal cord Controls non-skeletal muscles e.g cardiac and respiratory centre Hypothalamus Found beneath the middle part of brain Controls autonomic nervous system and endocrine glands. Homeostasis e.g. temperature, osmoregulation, hormones Pituitary Gland Small gland found at base of brain, below but attached to hypothalamus. Two lobes – anterior and posterior. Endocrine gland, anterior lobe produces and secretes many hormones - control many other glands. Posterior stores and releases hormones made in the hypothalamus. (eg ADH)

Other areas

Starter D, B,C

Task Complete exam question (brain exam question)

Plenary Use cards to play snap with the part and function of the brain

Learning Objectives Success Criteria To understand the structure of the human brain Label the gross structure of the human brain (Grade E - D) Outline the function of the cerebrum, cerebellum, medulla oblongata and hypothalamus (Grade C –B) Describe the role of the brain and nervous system in coordinated muscular movement (Grade B – A) 22