The Amazing Brain

•Weighs about 3 pounds

•Major portions:•Cerebrum•Diencephalon•Cerebellum•Brainstem

•Made of about 100 billion neurons

The Amazing Brain•Cerebrum•Largest portion•Higher mental functions

•Diencephalon•Processes sensory input

•Brain Stem•Coordinates and regulates visceral activities

•Cerebellum•Coordinates muscle movements

Cerebrum•Largest portion•2 cerebral hemispheres•connected by CORPUS CALLOSUM

•Many convolutions to increase surface area

Cerebrum

•Divided into lobes •Frontal lobe•Parietal lobe•Temporal lobe•Occipital lobe

Cerebrum

•Performs higher brain functions•Interpreting sensory info•Coordinating muscle movement•Intelligence & personality

CerebrumSpecial areas control different functions

A. Primary Motor Area(Frontal Lobe)

• Controls motor impulses

B. Frontal Association Area(Frontal Lobe)

• Thinking, planning, emotions, behavior

CerebrumC. Premotor Area

(Frontal Lobe)• Behavior planning• Muscle movement for

various actions

D. Frontal Eye Field(Frontal Lobe)

• Coordinates voluntary eye movements

CerebrumE. General Interpretive Area

a.k.a. Wernicke’s Area (Temporal Lobe)

• Recognition of written and spoken language

F. Broca’s area (Temporal Lobe)

• Coordinates muscles that create speech

CerebrumG. Somatosensory area

(Parietal Lobe)• Limb position, touch

sensations

H. Visual Area(Occipital Lobe)

• Sight• Identification of things

we see

Hemisphere Dominance

• Both cerebral hemispheres function in receiving and analyzing sensory input and sending motor impulses to the opposite side of the body.

• Most people exhibit hemisphere dominance for the language-related activities of speech, writing, and reading.

Hemisphere Dominance

• 90% of the population exhibits left hemisphere dominance• Some are right hemisphere dominant• Some have equal dominance in both hemispheres

• The non-dominant hemisphere specializes in nonverbal functions and controls emotions and intuitive thinking.

Frontal Lobe Higher level functions: emotions, reasoning, problem solving, judgment, movement, creativity

Parietal Lobe Somatosensory Info: touch, pain, taste, pressure

Temporal Lobe Hearing and language

Occipital Lobe Vision

Ventricles•Interconnected cavities w/in cerebrum & brainstem•Filled with CSF

Diencephalon

•Area between cerebral hemispheres

•Thalamus•Hypothalamus•Limbic System•Glands

Diencephalon

•Thalamus = Switchboard

•Directs impulses from spinal cord to correct location in brain

Diencephalon

Hypothalamus:•Heart rate & blood pressure• Body temp.• Water/salt balance• Hunger/weight• Movements & secretions ofstomach & intestines• Hormone secretion• Sleep & wakefulness

Diencephalon

•LIMBIC SYSTEM –emotions & expression

•AMYGDALA•Recognizes facial expressions•Assesses situation and responds

•Primitive decision-making center•Emotions

Diencephalon

•LIMBIC SYSTEM

•HIPPOCAMPUS•Memory•Spatial navigation

Brainstem

•Connects cerebrum & spinal cord •Parts:•Pons- breathing rate

•Medulla Oblongata-•Heart rate, BP, Sneezing, coughing,vomitting

Cerebellum

•coordinates skeletal muscle activity

•balance

•equilibrium

•maintains posture