The Brain Ch. 7c

The Brain Functional Anatomy –Cerebral Hemispheres –Diencephalon –Brain Stem –Cerebellum

Cerebral Hemispheres Anatomy –Most superior part of the brain –Fissures separate parts of the Cerebrum 2 hemispheres (left and right) 4 lobes each –Frontal Lobe –Parietal Lobe –Occipital Lobe –Temporal Lobe

Cerebral Hemispheres Physiology –Frontal Lobe Language comprehension Voluntary movement –Parietal Lobe Somatic Sensory Area –Occipital Lobe Visual –Temporal Lobe Auditory (hearing) Olfactory (Smell)

Cerebral Hemispheres Broca’s Area –Junction of temporal, parietal & occipital lobes –Speech area

Cerebral Hemispheres Sensory and Motor functions –Perception and control are crossed Left Brain senses and controls right side of body Right Brain senses and controls left side of body

Diencephalon Diencephalon (interbrain) –Thalamus –Hypothalamus Regulates body temperature, water balance, metabolism Regulates emotions such as appetite, sex, pain, pleasure –Pituitary Gland

Brain Stem Midbrain –Sends messages into and out of the brain –Vision and Hearing reflexes Pons –Breathing Control Medulla oblongata –Control: heart rate, blood pressure, breathing, swallowing, vomiting, etc. Reticular formation –Controls Asleep/Awake

Cerebellum Inferior and Dorsal to the Occipital Lobe Functions: –Timing for Skeletal muscle activity –Balance –Equilibrium –Monitors body position

Protection of Central Nervous System Meninges Cerebrospinal Fluid Blood-Brain Barrier

Meninges 3 layers of connective tissue protecting CNS –Dura Mater Means “tough or hard mother” Outer most layer - thick and tough –Arachnoid Mater Means “spider mother” Middle layer - web-like –Pia Mater Means “gentle mother” Innermost layer

Cerebrospinal fluid Watery “broth”, like blood plasma Forms watery cushion around brain and spinal cord –Protection from injury and trauma Is made from filtered blood Circulates and renews at a constant rate

Blood-Brain Barrier Least permeable capillaries feed nervous system Prevents serious chemical imbalances Prevents disease from passing into CNS Some substances still easily pass into brain –Alcohol –Nicotine –Anesthetics

Brain Dysfunctions Concussion –Slight injury: dizzy, briefly lose consciousness Contusion –Brain tissue destruction: coma –Progression of brain injury/healingProgression of brain injury/healing Cerebral Edema –Brain Swelling Cerebrovascular Accident –Blood circulation to brain is stopped: clot, ruptured blood vessel. Brain tissue dies