Anatomy and Physiology of the Brain

Brain

• The brain is divided into 3 different areas with the same embryonic origin.– Forebrain– Midbrain– Hindbrain

Forebrain

• Has 2 Hemispheres• Divided into 4 lobes– Parietal lobe– Frontal lobe– Temporal lobe– Occipital lobe

Forebrain

• Gyrus (gyri) = folds• Sulcus (sulci) = inside

the gyrus• Lateral Fissure• Central sulcus• Preoccipital notch• Parieto-occipital sulcus

Forebrain Areas

• Both hemispheres (primary areas)– Primary motor cortex– Primary sensory cortex– Primary auditory area– Primary visual cortex

• Only in dominant hemisphere ( secondary areas)– Exner’s area – controls hand movement for writing– Broca’s area - controls larynx and tongue for speech– Wernicke’s area – main processing centre for spoken language– Supramarginal language area – interprets visual symbols as written

words– Angular gyrus language area

Forebrain Areas

Forebrain

Midbrain

Midbrain

• Passes motor output from the cerebral cortex to the Pons and sensory input from the spinal cord to the thalamus

• Controls movement

Hindbrain

• Made of 3 parts– Medulla oblongata– Pons– Cerebellum

Hindbrain

• Medulla oblongata– Passes sensory input and motor output between

other parts of the brain and spinal cord• Pons– Passes impulses from one side of the cerebellum to

the other and between the medulla and midbrain• Cerebellum– Compares intended movements with what is actually

happening to smooth and coordinate movement.

Brain stem

• Made of 3 parts– Midbrain– Pons– Medulla oblingata