Anatomy & Physiology

Anatomy & Physiology Study Guide • Cerebrospinal fluid (CSF) protects delicate neural structures, supports the brain, and transports nutrients, chemical messengers, and waste products. • Cerebrospinal fluid is produced at the choroid plexus, reaches the subarachnoid space through the lateral and median apertures, and diffuses across the arachnoid granulations into the superior sagittal sinus. • The blood–brain barrier (BBB) isolates neural tissue from the general circulation. • The blood–brain barrier is incomplete in parts of the hypothalamus, the pituitary gland, the pineal gland, and the choroid plexus. The medulla oblongata, which is continuous with the spinal cord, contains vital centers: • The medulla oblongata connects the brain and spinal cord. It contains relay stations, such as the olivary nuclei, and reflex centers, including the cardiovascular and respiratory rhythmicity centers. • The reticular formation begins in the medulla oblongata and extends into more superior portions of the brain stem. The pons contains nuclei and tracts that carry or relay sensory and motor information: • The pons contains sensory and motor nuclei for four cranial nerves; nuclei that help control respiration; nuclei and tracts linking the cerebellumwith the brain stem, cerebrum, and spinal cord; and ascending, descending, and transverse tracts. The cerebellum coordinates learned and reflexive patterns of muscular activity at the subconscious level: • The cerebellum adjusts postural muscles and programs and tunes ongoing movements. The cerebellar hemispheres consist of the anterior and posterior lobes, the vermis, and the flocculonodular lobe. • The superior, middle, and inferior cerebellar peduncles link the cerebellum with the brain stem, diencephalon, cerebrum, and spinal cord, and interconnect the two cerebellar hemispheres. The mesencephalon regulates auditory and visual reflexes and controls alertness: • The tectum (roof of themesencephalon) contains the corpora quadrigemina (superior colliculi and inferior colliculi). The tegmentum contains the red nucleus, the substantia nigra, the cerebral peduncles, and the headquarters of the reticular activating system (RAS). The diencephalon integrates sensory information with motor output at the subconscious level: • The diencephalon is composed of the epithalamus, the hypothalamus, and the thalamus. • The hypothalamus can control somatic motor activities at the subconscious level, control autonomic function, coordinate activities of the nervous and endocrine systems, secrete

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