© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE NERVOUS SYSTEM: THE BRAIN, CRANIAL NERVES, AUTONOMIC NERVOUS SYSTEM, AND THE SPECIAL SENSES Chapter 11

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE PRINCIPAL PARTS OF THE BRAIN

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Principal Parts of the Brain (cont’d.) Main parts: brainstem, diencephalon, cerebrum and cerebellum Protection –Cranial bones –Meninges –Cerebrospinal fluid

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Principal Parts of the Brain (cont’d.) Ventricles –Interventricular foramen

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Principal Parts of the Brain (cont’d.)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE ANATOMY AND FUNCTIONS OF THE BRAINSTEM

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy and Functions of the Brainstem (cont’d.) Pons varolii –Connects spinal cord with brain –Connects parts of brain with each other –Helps control breathing

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE ANATOMY AND FUNCTIONS OF THE DIENCEPHALON

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy and Functions of the Diencephalon (cont’d.) Epithalamus: contains pineal gland Hypothalamus: homeostasis –Controls and integrates autonomic nervous system –Receives sensory impulses from internal organs –Controls pituitary gland and links endocrine and nervous systems

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE CEREBRUM: STRUCTURE AND FUNCTION

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Cerebrum: Structure and Function (cont’d.)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE CEREBELLUM: STRUCTURE AND FUNCTION

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Cerebellum: Structure and Function (cont’d.) Butterfly-shaped Two partially separated hemispheres connected by vermis Functions –Coordinating muscular movements –Maintaining posture –Maintaining balance

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE AUTONOMIC NERVOUS SYSTEM

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Autonomic Nervous System (cont’d.) Sympathetic –Energy and stressful situations –Increases heartbeat and breathing rates –Neurotransmitters: acetylcholine and norepinephrine

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Autonomic Nervous System (cont’d.) Parasympathetic –Restores body to nonstressful state –Neurotransmitter: acetylcholine –Stimulates digestion, urination and defecation

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE 12 CRANIAL NERVES AND THEIR FUNCTIONS

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE SPECIAL SENSES

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Sense of Sight Eyes protected by eyelids and eyelashes Tears –Lubricate the eyes –Contain bacteriolytic lysozyme enzyme –Contain salt and gamma globulin

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Sense of Sight (cont’d.)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Animation – Vision Click Here to Play Vision Animation

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Sense of Hearing and Equilibrium (cont’d.) Inner ear –Cochlea: hearing –Equilibrium Static: vestibule Kinetic: semicircular canals

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Sense of Hearing and Equilibrium (cont’d.) Structures of the ear shown in cross section

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Animation – Hearing Click Here to Play Hearing Animation

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. 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

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Summary (cont’d.) Described the special senses and the organs involved