1. Nervous System …the brain…

2. Nervous System …the brain… Section of the brain SubsectionSizeFunction Brain Stem Medulla oblongata3cm -Cardiac Centre (heart rate/force) -Respiratory Centre (breathing rate/depth) -Vasomotor Centre (blood vessel dilation) -Controls swallowing, sneezing, coughing & vomiting Pons Varolii3cm -Bridge between spinal cord and brain Midbrain2cm -Bridge between cerebrum and lower brain/spinal cord -Control of head reflex in response to audio/visual -Involuntary control of muscle tone

3. Section of the brain SubsectionSizeFunction Diencephalon Hypothalamus1.5cm Regulates: - Autonomic nervous system: - heart rate, blood pressure, secretion of digestive juices, movements of AC, diameter of pupil in the eye etc. - Endocrine system: - regulates metabolism, growth, reproduction & response to stress -body temp -food water intake -day-night cycles -contraction of urinary bladder -emotional responses: fear, anger, aggression, pleasure & contentment Thalamus 2 sections, 3cm each - receiving centre for senses (minus smell) before Cerebrum and emotional state Cerebellum-4cm - Controls posture, balance and coordinates skilled movements - Aids in learned motor skills Nervous System …the brain…

4. Section of the brain SubsectionSizeFunction Cerebral Cortex Frontal Lobe (motor & sensory area) 2-4 mm thick -Voluntary Control of skeletal muscles and perception of olfactory stimuli Parietal Lobe (sensory area) -Conscious perception of touch, pressure, vibration, pain, temperature and taste Occipital Lobe (sensory area) -Conscious perception of visual stimuli Temporal Lobe (sensory area) -Conscious perception of auditory stimuli Association areas-Integration and processing of all sensory data; processing and initiation of motor activities, memory Integrative Centers-Direct extremely complex motor activities & perform complex analytical function Nervous System …the brain…

5. Nervous System Peripheral Nervous System

6. Nervous System Peripheral Nervous System Cranial Nerves: 12 pairs of nerves arising from brain (eg optic nerve, auditory nerve) most mixed, some single. Spinal Nerves: 31 pairs of mixed nerves each joined to the spinal cord by two roots. 1. Ventral Root: axons of motor neurons with cell bodies in grey matter of spinal cord 2. Dorsal Root: axons of sensory neurons with cell bodies in small swelling on dorsal root (dorsal root ganglion) Nerve fibres carrying msgs to/from CNS & groups of nerve cell bodies (ganglion)

7. Nervous System Peripheral Nervous System Afferent (sensory) Division: Efferent (motor) Division: Divisions: Somatic (voluntary) Division: Autonomic (involuntary) Division: Sympathetic (preparation) Division: Parasympathetic (maintenance) Division:

8. Nervous System Spinal reflexes Reflex Arc or Spinal reflex arc: Receptor: Sensory Neuron: Synapse: Reflex is a rapid, automatic response to a change in the internal / external environment (homeostasis) Motor Neuron: Effector: