© 2010 Delmar, Cengage Learning 1 PowerPoint Presentation to Accompany

© 2010 Delmar, Cengage Learning 2 Chapter 11 The Nervous System The Brain, Cranial Nerves, Autonomic Nervous System and the Special Senses

© 2010 Delmar, Cengage Learning 3 Introduction Brain is divided into four main parts –Brainstem: controls breathing, heartbeat rates and reactions to auditory and visual stimuli –Diencephalon: controls homeostasis –Cerebrum: controls intellectual processes and emotions –Cerebellum: maintains body posture and balance

© 2010 Delmar, Cengage Learning 4 4 The Principal Parts of the Brain

© 2010 Delmar, Cengage Learning 5 The Principal Parts of the Brain (cont’d.) Main parts: brainstem, diencephalon, cerebrum and cerebellum Protection –Cranial bones –Meninges –Cerebrospinal fluid Ventricles –Interventricular foramen

© 2010 Delmar, Cengage Learning 6 The Principal Parts of the Brain (cont’d.)

© 2010 Delmar, Cengage Learning 7 7 The Anatomy and Functions of the Brainstem

© 2010 Delmar, Cengage Learning 8 The Anatomy and Functions of the Brainstem (cont’d.) Medulla oblongata –Ascending and descending tracts –Connect spinal cord with the brain –Some tracts cross over in medulla –Reticular formation: controls consciousness –Reflex centers

© 2010 Delmar, Cengage Learning 9 Pons varolii –Connects spinal cord with brain –Connects parts of brain with each other –Helps control breathing The Anatomy and Functions of the Brainstem (cont’d.)

© 2010 Delmar, Cengage Learning 10 The Anatomy and Functions of the Brainstem (cont’d.) Midbrain –Ventral cerebral peduncles: convey impulses from cortex to pons and spinal cord –Dorsal tectum: reflex center –Controls movement of head and eyeball (visual stimuli) –Controls movement of head and trunk (auditory stimuli)

© 2010 Delmar, Cengage Learning 11 © 2010 Delmar, Cengage Learning 11 The Anatomy and Functions of the Diencephalon

© 2010 Delmar, Cengage Learning 12 The Anatomy and Functions of the Diencephalon (cont’d.) Optic tracts Mamillary bodies: memory and emotional responses Thalamus –Relay station for sensory impulses –Interpretation center for pain, temperature and touch Epithalamus: contains pineal gland

© 2010 Delmar, Cengage Learning 13 The Anatomy and Functions of the Diencephalon (cont’d.) Hypothalamus: homeostasis –Controls and integrates autonomic nervous system –Receives sensory impulses from internal organs –Controls pituitary gland and links endocrine and nervous systems

© 2010 Delmar, Cengage Learning 14 © 2010 Delmar, Cengage Learning 14 The Cerebrum: Structure and Function

© 2010 Delmar, Cengage Learning 15 The Cerebrum: Structure and Function (cont’d.)

© 2010 Delmar, Cengage Learning 16 The Cerebrum: Structure and Function (cont’d.) Cerebral cortex: gray matter surface Longitudinal fissure separates two hemispheres Gyri: folds Sulci: grooves Corpus callosum: bridge connecting two hemispheres

© 2010 Delmar, Cengage Learning 17 The Cerebrum: Structure and Function (cont’d.) Surface of the cortex –Motor areas control muscular movements –Sensory areas interpret sensory impulses –Association areas process emotions and intellect

© 2010 Delmar, Cengage Learning 18 The Cerebrum: Structure and Function (cont’d.) Cerebral hemispheres –Frontal lobe: muscle movement, moods, aggression, smell, motivation –Parietal lobe: touch, pain, balance, taste, temperature –Temporal lobe: hearing, smell, memory, abstract thought, judgment –Occipital lobe: vision

© 2010 Delmar, Cengage Learning 19 © 2010 Delmar, Cengage Learning 19 The Cerebellum: Structure and Function

© 2010 Delmar, Cengage Learning 20 The Cerebellum: Structure and Function (cont’d.) Butterfly-shaped Two partially separated hemispheres connected by vermis Functions –Coordinating muscular movements –Maintaining posture –Maintaining balance

© 2010 Delmar, Cengage Learning 21 © 2010 Delmar, Cengage Learning 21 The Autonomic Nervous System

© 2010 Delmar, Cengage Learning 22 The Autonomic Nervous System (cont’d.) Subdivision of efferent PNS Functions without conscious effort Regulates functions of internal organs Assists in maintaining homeostasis Helps deal with emergency situations

© 2010 Delmar, Cengage Learning 23 The Autonomic Nervous System (cont’d.) Sympathetic –Energy and stressful situations –Increases heartbeat and breathing rates –Neurotransmitters: acetylcholine and norepinephrine

© 2010 Delmar, Cengage Learning 24 The Autonomic Nervous System (cont’d.) Parasympathetic –Restores body to nonstressful state –Neurotransmitter: acetylcholine –Stimulates digestion, urination and defecation

© 2010 Delmar, Cengage Learning 25 © 2010 Delmar, Cengage Learning 25 The 12 Cranial Nerves and Their Functions

© 2010 Delmar, Cengage Learning 26 The 12 Cranial Nerves and Their Functions (cont’d.) (I) Olfactory: smell (II) Optic: sight (III) Oculomotor: movement of eyeball, constriction of pupil (IV) Trochlear: movement of eyeball

© 2010 Delmar, Cengage Learning 27 The 12 Cranial Nerves and Their Functions (cont’d.) (V) Trigeminal: chewing, sensations in teeth (VI) Abducens: movement of eyeball (VII) Facial: facial expression, taste, tear and salivary glands (VIII) Vestibulocochlear: equilibrium, hearing

© 2010 Delmar, Cengage Learning 28 The 12 Cranial Nerves and Their Functions (cont’d.) (IX) Glossopharyngeal: swallowing, taste, salivary glands (X) Vagus: certain muscle movements, sensory impulses (XI) Accessory: swallowing, head movement (XII) Hypoglossal: swallowing, speech

© 2010 Delmar, Cengage Learning 29 © 2010 Delmar, Cengage Learning 29 The Special Senses

© 2010 Delmar, Cengage Learning 30 The Sense of Smell Molecules in air dissolve in nasal mucus Bipolar sensory neurons transfer chemical impulse Olfactory bulbs receive impulse Impulse sent to olfactory cortex Odor variety dependent on brain interpretation

© 2010 Delmar, Cengage Learning 31 The Sense of Taste Taste buds on tongue, palate and pharynx Taste bud cell types –Exterior capsule: epithelial cells –Interior: taste cells Taste depends on chemicals dissolved in saliva Taste influenced by olfactory sensations

© 2010 Delmar, Cengage Learning 32 The Sense of Sight Eyes protected by eyelids and eyelashes Tears –Lubricate the eyes –Contain bacteriolytic lysozyme enzyme –Contain salt and gamma globulin

© 2010 Delmar, Cengage Learning 33 The Sense of Sight (cont’d.)

© 2010 Delmar, Cengage Learning 34 Animation - Vision [Insert Vision_SWF folder]

© 2010 Delmar, Cengage Learning 35 The Sense of Hearing and Equilibrium Outer ear –Auricle: external, visible, flexible part –External auditory meatus Lined with hair and ceruminous glands –Tympanic membrane: vibrates in response to sound

© 2010 Delmar, Cengage Learning 36 The Sense of Hearing and Equilibrium (cont’d.) Middle ear –Auditory ossicles: malleus, incus and stapes –Openings: oval and round windows –Eustachian tube: equalizes pressure

© 2010 Delmar, Cengage Learning 37 The Sense of Hearing and Equilibrium (cont’d.) Inner ear –Cochlea: hearing –Equilibrium Static: vestibule Kinetic: semicircular canals

© 2010 Delmar, Cengage Learning 38 The Sense of Hearing and Equilibrium (cont’d.) Structures of the ear shown in cross section

© 2010 Delmar, Cengage Learning 39 Animation - Hearing Insert Hearing_SWF folder]

© 2010 Delmar, Cengage Learning 40 Summary Named the principal parts of the brain Discussed the functions of the major parts of the brain Named the 12 cranial nerves Discussed the role of the autonomic nervous system and its divisions Described the special senses and the organs involved