The Human Brain
The Human Brain. IB Biology Joohee Kim Sec. III. Structure and Functions of Parts of the Brain. Cerebral Hemispheres Sensory information received from outside world is processed Controls voluntary movement Regulates conscious thought and mental activity.
The Human Brain
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Presentation Transcript
The Human Brain IB Biology Joohee Kim Sec. III
Structure and Functions of Parts of the Brain • Cerebral Hemispheres • Sensory information received from outside world is processed • Controls voluntary movement • Regulates conscious thought and mental activity
Structure and Functions of Parts of the Brain • Cerebellum • In charge of balance and coordination • Receives information from eyes, ears, and muscles, and joints about body’s movement and position
Structure and Functions of Parts of the Brain • Hypothalamus: monitors certain activities and controls body’s internal clock
Structure and Functions of Parts of the Brain • Medulla Oblongata: most inferior portion • Functions as a conduction pathway • Reflex centers for: • Regulating heart rate • Blood vessel diameter • Coughing, sneezing • Breathing • Swallowing
Structure and Functions of Parts of the Brain • Pituitary Gland: secretes hormones regulating homeostasis • Hormones are actually made in the nerve cell bodies of hypothalamus
Investigating Brain Function • Animal Experiments: including primates, surgical procedures • Parts of skull have to be removed • Animal must be kept alive • Effects on animal are observed • Ethical objections • Animal suffering and sacrifice
Investigating Brain Function • Lesions: damaged parts of the brain • Accidents, strokes, tumors can damage • Brain functions are deduced • Example: left cerebral hemisphere cause dysphasia - Inability to speak but reading, writing possible
Investigating Brain Function • Functional magnetic resonance imaging: • fMRI: technique for determining which parts of brain are activated by specific thought processes • Active parts of brain receive increased blood flow • Experimental subject is placed in scanner • High-resolution scan of brain is taken
The Pupil Reflex and Brain Death • Pupil Reflex: when bright light shines into one eye and the pupils of both eyes constrict • If unconscious patient’s pupils do not constrict when a light is shone into eye, it suggests that they have injuries serious enough to have caused brain death.
