Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connects the brain with the spinal cord Contains relay stations and reflex centers Olivary nuclei- Relay information to the cerebellar cortex about somatic motor commands as they are issued by motor centers at higher levels. Medulla oblongata

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cardiovascular and respiratory rhythmicity centers. -Cardiovascular Centers- Adjust heart rate strength of cardiac contractions, and flow of blood through peripheral tissues. -Respiratory Rhythmicity Centers- Set the basic pace for respiratory movements. Activity is regulated by inputs from the apneustic and pneumotaxic centers of the pons. Reticular formation begins in the medulla oblongata and extends into more superior portions of the brainstem. -Reticular formation- Diffuse network of gray matter that extends the entire length of the brain stem. Medulla oblongata, continue

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.7 The Diencephalon and Brain Stem Figure 14.7a, b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.7 The Diencephalon and Brain Stem Figure 14.7c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.8 The Medulla Oblongata and Pons Figure 14.8a, b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.8 The Medulla Oblongata and Pons Figure 14.8c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Pons contains: Sensory and motor nuclei for four cranial nerves Nuclei that help control respiration Nuclei and tracts linking the cerebellum with the brain stem, cerebrum, and spinal cord Ascending, descending and transverse tracts The pons

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.8 The Medulla Oblongata and Pons Figure 14.8a, b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.8 The Medulla Oblongata and Pons Figure 14.8c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Adjusts postural muscles and tunes on-going movements Cerebellar hemispheres Anterior and posterior lobes (separated by the primary fissure) Vermis- Narrow band of cortex along the midline; separates the cerebellar hemispheres. Flocculonodular lobe- Lies between the roof of 4th ventricle and the cerebellar hemispheres and vermis. Superior, middle and inferior cerebellar peduncles link cerebellum with brain stem, diencephalon, cerebrum, and spinal cord Interconnects the two cerebellar hemispheres The cerebellum

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.9 The Cerebellum Figure 14.9a

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.9 The Cerebellum Figure 14.9b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The tectum (roof of mesencephelon) contains the corpora quadrigemina (two pairs of sensory nuclei called the superior and inferior colliculi). Nuclei process visual and auditory sensations. The mesencephalon contains many nuclei Red nucleus has numerous blood vessels receives information from cerebrum and cerebellum issues subconscious motor commands that affect upper limb position and background muscle tone. The mesencephalon

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings - Substantia nigra: Nucleus that lies lateral to the red nucleus - Gray matter in this region contains darkly pigmented cells - Regulates activity in the basal nuclei - Basal nuclei: Nuclei of the cerebrum that are important in the subconscious control of skeletal muscle activity. - Cerebral peduncles: Nerve fiber bundles on the ventrolateral surfaces of the mesencephalon. - Cerebral peduncles contain: 1). Descending fibers that go to the cerebellum via the pons 2). Descending fibers that carry voluntary motor commands issued by the cerebral hemispheres. -RAS headquarters: Specialized component of the reticular formation. - Stimulation of the mesencephalic portion of the RAS makes one more alert and attentive. The mesencephalon, continue

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Mesencephalon Figure 14.10a, b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithalamus- The roof of the diencephalon superior to the third ventricle. Anterior portion has an extensive area of choroid plexus that extends through the interventricular formation into the later ventricles. Posterior portion has the pineal gland (endocrine; secretes hormone melatonin). Hypothalamus- Floor of diencephalon; has centers involved subconscious regulation of visceral functions, emotions, drives, and coordination of neural and endocrine functions. Thalamus- Walls of the diencephalon. Functions as the final relay point for ascending sensory information that will be projected to the primary sensory cortex. Coordinates the activities of the cerebral cortex and basal nuclei. The diencephalon is composed of

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Thalamus Figure 14.11a, b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Controls somatic motor activities at the subconscious level Controls autonomic function Coordinates activities of the endocrine and nervous systems Secretes hormones (i.e. ADH). Produces emotions and behavioral drives Coordinates voluntary and autonomic functions Regulates body temperature Coordinates circadian cycles of activity The hypothalamus

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.12a Figure The Hypothalamus in Sagittal Section

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 14.12b Figure The Hypothalamus in Sagittal Section