The nervous system

HBS3B

The central nervous system

Protective structures

The Central Nervous System consists of the B______ and S____________ c__________ As they are very delicate and vital organs they are protected by three layers – b________, membranes called m___________ and f________ called c_________________________ Protective structures of the brain and spinal cord include: Bone s______________ or c_____________ protects the b___________ v____________________ protect the s_____________________ Membranes m_______________ consist of ___ layers – The layer that contains the blood vessels is _____________ Fluid c____________________ is found It contains Its functions include

Protective structures

The Central Nervous System consists of the Brain and Spinal cord As they are very delicate and vital organs they are protected by three layers – bone, membranes called meninges and fluid called cerebrospinal fluid (CSF) Protective structures of the brain and spinal cord include:

Bone

skull or cranium protects the brain vertebrae protect the spinal cord

Membranes

meninges consist of 3 layers – a tough outer layer, a middle layer made of loose fibres and a thin inner layer The layer that contains the blood vessels is the inner layer

Fluid

Cerebrospinal fluid is found within the meninges and ventricles surrounding the brain It contains nutrients & oxygen as well as wastes for disposal Its functions include protection, support and transport

The brain - structures

Show the location of a convolution, a sulcus a fissure and a hemisphere on the diagram below Label the diagram below H I

The brain - structures

Show the location of a convolution, a sulcus, a fissure and a hemisphere on the diagram below Label the diagram below convolution sulcus H I fissure A – medulla oblongata B – pons varolii C – pituitary gland I – hypothalamus E – cerebrum/cerebral cortex F – cerebellum G – spinal cord H - thalamus hemisphere

The cerebrum

the cerebral cortex is ______________________________________________________ and is involved in basal ganglia are found ___________________________________________________ and are convolutions are _________________________________________________________ which fissures are _____________________________________________________________ the longitudinal fissure is ___________________________________________________ It divides the cerebral cortex into ___ hemispheres – the __________________________ the two hemispheres not identical, eg the left side controls and the right side controls there are ___ lobes plus the i____________, which is found _______________________________________ tracts are _______________________________________________________________ There are ____ types of tracts – sensory areas in the cerebral cortex __________________________________________ motor areas in the cerebral cortex ___________________________________________ association areas in the cerebral cortex _______________________________________

Cerebrum

The cerebrum

the cerebral cortex is the outer layer of the cerebrum, made up of grey matter basal ganglia are found deep in the brain below the white matter and are made of grey matter Convolutions are folds in the surface which increase which surface area Fissures are deep downfolds separating convolutions of hemispheres The longitudinal fissure is the fissure that separates the cerebrum into two halves It divides the cerebral cortex into 2 hemispheres – the left and the right.

The two hemispheres not identical, eg the left side controls language, and the right side controls musical and creative abilities There are 4 lobes – frontal, temporal, occipital and parietal, plus the insula, which is found deep inside the brain Tracts are bundles of myelinated nerve fibres There are 3 types of tracts the brain or spinal cord – tracts that connect areas within the same hemisphere, tracts that connect the 2 hemispheres and tracts that connect the cerebrum to other parts of Sensory areas in the cerebral cortex interpret impulses from receptors Motor areas in the cerebral cortex control muscle movements Association areas in the cerebral cortex are concerned with intellectual and emotional processes (eg thinking, memory, etc)

The cerebellum

This is found and is responsible for It receives information from 1.

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The cerebellum

This is found at the rear of the cerebrum and is responsible for balance, posture and coordination of muscle movements It receives information from 1.

Cerebral cortex 2.

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Semicircular canals of inner ear Utricles and saccules of inner ear Eyes Pressure receptors in the skin Stretch receptors in the muscles and joints

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This is found and is responsible for 1.

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The hypothalamus

Hypothalamus

The hypothalamus

This is found in the middle of the brain, just above the pituitary gland and is responsible for the regulation of Autonomic nervous system – heart rate, blood pressure, secretion of digestive juices, movement of alimentary canal, diameter of eye, etc 1.

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Body temperature Food and water intake 3.

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Patterns of waking and sleeping Contraction of urinary bladder Emotional responses – fear, anger, aggression, pleasure and contentment Secretion of hormones and control of endocrine system by control of pituitary gland

The medulla oblongata

This is which is found It contains 1. Cardiac centre which 2. Respiratory centre which 3. Vasomotor centre which It also has centres that control All the centres of the medulla oblongata are influenced and controlled by higher centres of the brain, particularly the h________________________ In the brain, the grey matter is on the o___________ and the white matter is on the i_______

Medulla oblongata

The medulla oblongata

This is a continuation of the spinal cord which is found just above where the spinal cord enters the brain.

It contains 1. Cardiac centre which controls rate and force of contraction of the heart 2. Respiratory centre which controls rate and depth of breathing 3. Vasomotor centre which controls diameter of blood vessels It also has centres that control reflexes of swallowing, sneezing, coughing and vomiting All the centres of the medulla oblongata are influenced and controlled by higher centres of the brain, particularly the hypothalamus In the brain, the grey matter is on the outside and the white matter is on the inside

Studying the brain

Scientists have found out what different parts of the brain do by studying: brain waves – - measured by responses to changes in blood flow during effects of b_______ damage in a_____________

Brain studies

Studying the brain

Scientists have found out what different parts of the brain do by studying: • brain waves – changes in electrical patterns in the cortex - measured by electroencephalograms • responses to specific electrical stimulation • changes in blood flow during different types of activity • effects of brain damage in people after injury or disease • Animal experiments

The spinal cord

This is In the spinal cord, the _________ matter is on the outside and the _________ matter is on the inside.

The

central canal

is and contains The myelinated fibres of the white matter are divided into _____ tracts The ascending tracts are The descending tracts are Functions of the spinal cord include

The spinal cord

This is a cylindrical structure that is about 44 cm in length In the spinal cord, the white matter is on the outside and the grey matter is on the inside.

The

central canal

is a small hole in the centre of the cord and contains cerebrospinal fluid The myelinated fibres of the white matter are divided into 2 tracts The ascending tracts are sensory axons taking impulses to the brain The descending tracts are motor axons taking impulses away from the brain Functions of the spinal cord include carrying sensory impulses to the brain and motor impulses away from the brain as well as integrating spinal reflexes.

1 – dorsal root ganglion (cell body of sensory neuron) 2 – mixed (spinal) nerve 3 – ventral root (motor neuron) 4 – white matter 5 – dorsal root (sensory neuron) 6 – grey matter