1. The Human Brain Ranges from 750 cc to 2100 cc Contains almost 98% of the body’s neural tissue Average weight about 1.4 kg (3 lb)

3. Motor Cortex Sensory Cortex Frontal Lobe Parietal Lobe Temporal Lobe Occipital Lobe Cerebellum Reticular Activating System Spinal Cord 12 3 4 5 6 7 8 9

4. three layers of meninges around the brain and spinal cord.

5. 1. Cerebrum –Largest part of brain –Controls higher mental functions –Divided into left and right cerebral hemispheres –Surface layer of gray matter (neural cortex) Neural Cortex –Also called cerebral cortex –Folded surface increases surface area –Elevated ridges (gyri) –Shallow depressions (sulci) –Deep grooves (fissures)

6. 2. Cerebellum –Second largest part of brain –Coordinates repetitive body movements –2 hemispheres –Covered w/ cerebellar cortex 3. Diencephalon –Located under cerebrum and cerebellum –Links cerebrum with brain stem 4. Mesencephalon Also called midbrain Processes sight, sound, and associated reflexes Maintains consciousness

7. Figure 14–5a The Diencephalon Integrates sensory information and motor commands Thalamus, epithalamus, and hypothalamus Pineal Gland in posterior epithalamus –Secretes hormone melatonin Thalamus Post Office –Filters ascending sensory information for primary sensory cortex

8. thalamus(80 % of diencephalon), hypothalamus, & epithalamus.

9. Brain Structure: Hindbrain Hindbrain (Old Brain) (Reptilian Brain) –Spinal cord, lower brain stem, and cerebellum Medulla Oblongata –Located where the spinal cord enters the skull –Breathing, posture

10. Brain Structure: Hindbrain Cerebellum –Extends from rear of hindbrain –Motor control Pons –Bridge in hindbrain –Sleep and arousal

11. Brain Structure: Midbrain Midbrain –Between midbrain & forebrain –Relays information between the brain and eyes/ears Reticular Activation System RAS –Stereotyped patterns of behavior –Walking, sleeping, automatic functions Basal ganglia Starting and stopping voluntary movements

12. Brain Structure: Limbic System Instinctual Brain Limbic system –Plays an important role in both memory and emotion Amygdala –Discrimination of objects and emotion Angry Amy Hippocampus –Storage of memories – BIG Campus Library!

13. Brain Structure Hypothalamus –Monitors eating, drinking, sex, temperature –Helps direct the endocrine system through the pituitary gland –Involved in emotion, stress, and reward

14. 8 Functions of the Hypothalamus 1.Provides subconscious control of skeletal muscle 2.Controls autonomic function 3.Coordinates activities of nervous and endocrine systems 4.Secretes hormones: ADH(Antidiuretic) & OT (Oxytocin) 5.Produces emotions and behavioral drives: –the feeding center (hunger) –the thirst center (thirst) 6.Coordinates voluntary and autonomic functions 7.Regulates body temperature: 8.Controls circadian rhythms (day–night cycles):

15. Sensory Areas Postcentral gyrus of parietal lobe: –receives somatic sensory information (touch, pressure, pain, vibration, taste, and temperature) Primary sensory cortex: –surface of postcentral gyrus Visual cortex: –information from sight receptors Auditory cortex: –information from sound receptors Olfactory cortex: –information from odor receptors Gustatory cortex: –information from taste receptors Central sulcus separates motor and sensory areas

17. Neocortex.. NEWBRAIN Occipital lobe..SIGHT –Back of the head –Vision Temporal lobe –Just above the ears –Hearing,Speech

18. Neocortex Frontal lobe –Behind the forehead –Purposeful control of voluntary muscles –Intelligence, Cognition Parietal lobe –Top of the head, toward the rear –Processing bodily sensations –Motor Cortex –Somatosensory Cortex

19. Left Hemisphere Language, Linear, Logical Right Hemisphere Radical, Religious, Random, Roundabout ways Corpus Callosum

21. Brain Protection and Support Physical protection: –bones of the cranium –cranial meninges –cerebrospinal fluid Biochemical isolation: –blood–brain barrier Cranial Meniges - 3 layers: –dura mater –arachnoid mater –pia mater Is continuous with spinal meninges Protects the brain from cranial trauma

22. 4 Breaks in the BBB 1.Portions of hypothalamus: –secrete hypothalamic hormones 2.Posterior lobe of pituitary gland: –secrete hormones ADH and oxytocin 3.Pineal glands: –pineal secretions 4.Choroid plexus: –where special ependymal cells maintain blood–CSF barrier

23. Brain Damage Plasticity –The brain’s capacity to modify and reorganize itself following damage Collateral sprouting –Axons of healthy neurons adjacent to damaged cells grow new branches Substitution of function –Damaged region’s function is taken over by another area, or areas, of the brain Phineas Gage

25. Studying the Brain Electroencephalograph (EEG) –Records the electrical activity of the brain Computer-assisted axial tomography (CAT scan) –3D imaging obtained from X rays of the head Magnetic resonance imaging (fMRI) –Magnetic field around the body PET Positron Emission Tomograpy Color images of “hot & cold” actions

26. The Endocrine System Endocrine Glands Release their chemical products, called hormones, directly into the bloodstream Pituitary gland –Controls growth and regulates other glands Adrenal glands –Play an important role in our moods, energy level, and ability to cope with stress Thyroid Gland –Growth Gonads – Sex Characteristics

27. Autonomic nerves (in blue)--sympathetic and parasympathetic--regulate much of the body without our conscious knowledge. Sympathetic nerves branch from spinal nerves (in white) and form a chain of ganglia that sends fibers to the organs. Parasympathetic nerves, including the important vagus, usually reverse the action of sympathetic ones.