Central nervous system

Question 1

stimuli

Answer 1

• physical or chemical changes
• light
• temperature
• sounds
• atmospheric pressure
• blood pH
• blood pressure
• tension in muscles

Question 2

CNS

Answer 2

• brain
• spinal chord
• process information from senses
• keep functioning organs, reflexes
• directs our thoughts and feelings

Question 3

CNS protection

Answer 3

• protected and nourished by connective tissue membranes called meninges
• cerebro-spinal fluid acting as a cushion
• enclosed in a bony case (cranium and vertebral coloumn)

Question 4

cerebrum

Answer 4

• ‘cap’ in the cranium
• gyrus (convolution)
• sulcus (groove)
• largest part of the brain
• split into two parts by a longitudinal fissure
• 4 cavities known as ventricles in the brain filled with cerebro-spinal fluid
• outer 3mm of the cerebrum forms the cerebral cortex (grey matter, cell bodies and neurons)
• white matter (myelinated nerve fibres)
• voluntary movements (motor area)
• senses (sensory ares, interpret impulses from sense organs - hearing, tasting, smelling, sight, skin sensation)
• association cortex (higher mental activities - memory, perception, language and consciousness)
• one hemisphere will always be dominant

Question 5

cerebellum

Answer 5

• behind and below the cerebrum
• 2 hemispheres
• ‘tree of life’ due to grey matter surrounding branched system of white matter
• co-ordinates voluntary muscle actions (complicated ones)
• partly responsible for muscle tone
• helps maintain posture and balance (using information from inner ear)

Question 6

hypothalamus

Answer 6

• below the thalamus and above the pituitary gland
• controls the autonomic system (important in maintaining homeostasis)
• centre of emotional response
• controls functioning of pituitary gland (secreting ADH, release of hormones)

Question 7

medulla oblongata

Answer 7

• lowest part of the brainstem
• when passes through foramen magnum, is known as spinal chord
• pathway for impulses
• reflex centre (controlling, breathing, heartbeat, blood pressure - vasodilation, vasoconstriction widening and narrowing of blood vessels - swallowing)
• sneezing, coughing, hiccoughing and salivating

Question 8

hemisphere and lobes

Answer 8

• frontal lobe (top left, memory, motor function, problem solving etc…)
• temporal lobe (bottom left, auditory perception, perception and recognition, speaking and understanding written verbal material, memory)
• parietal lobe (top right, sensation, reading, undertsadning special relationships, integrating sensory input, knowing left from right)
• occipital love (bottom right, vision and or visual processing, association and integration)
• hemispheres are left and right (left provides analysis and logic; right is creativity and intuition)

Question 9

corpus collosum

Answer 9

• myelinated nerve fibres form corpus callosum (body; white)

- provides communication between the cerebral hemispheres

Question 10

spinal chord

Answer 10

• elongated rod of nervous tissue
• vertebral column (back bone)
• vertebrae (33 individual bones stacked on top of each other)
• vertebral canal (hollow tube formed in the column
• discs of cartilage (between vertebrae to stabilise and allow from bending)
• spinal chord (runs in vertebral canal, made up of nervous tissue)
• central canal (runs through spinal chord and filled with spinal fluid)
• grey matter (H-shaped centre)
• white matter (surrounds grey matter)
• central canal (centre of grey matter)
• spilt by a dorsal and ventral groove
• spinal nerves enters and leaves at every vertebrae
• dorsal root (enters grey matter)
• ventral root (leaves grey matter)
• ganglion formed by a collections of neuron cell bodies in dorsal root
• pathway for impulses
• primitive reflex actions (spinal reflexes)