Brain Notes II DIENCEPHALON n Thalamus n n

Brain Notes II

DIENCEPHALON n Thalamus n n Relay station for sensory impulses to cerebral cortex Plays a role in emotions, memory, awareness and cognition

n Hypothalamus – “master gland” n n n Controls regulation eating & drinking Controls body temperature Regulation of consciousness, emotional and behavior, diurnal (circardian) rhythms – synchronizes day-night cycle

n Limbic System n Emotional aspects of behavior & aids in memory

BRAIN STEM n Connects spinal cord to diencephalon n Parts of Midbrain n Cerebral peduncles n Corpora quadrigemina n Reflex center for movement in response to sound & visual stimuli

n Pons n Connects spinal cord with brain & links parts of brain with one another by way of tracts (nerve fibers within the CNS) n Aid in control of breathing

n Medulla Oblongata n Regulates: n Cardiac center – heart rate n Vasomotor center – constricts blood vessels n Respiratory center – rate and depth of breathing

n Other centers coordinate swallowing, vomiting, coughing, sneezing & hiccuping.

n Reticular Formation n Responsible for maintaining consciousness & awakening from sleep

CEREBELLUM n Vermis –”worm” n White matter tracts are called “arbor vitae” tree of life. n Cerebellar peduncles – connect cerebellum to other parts of brain

n Coordination, balance, and posture n Damage would show loss of muscle tone and inaccurate movements

PROTECTIONS & COVERINGS n The CNS is protected by: n Bone – cranium and vertebral column n Meninges – 3 connective tissue layers Dura mater – most outer n Arachnoid mater – “spiderweb” middle n Pia mater – inner n

MENINGES n Dura mater n Outermost layer n Dense, irregular C. T. with many blood vessels and nerves n Attached to periosteum n Meningitis – inflammation of meninges

n Arachnoid mater n Spider web-like collagen and elastic fiber n Thin membrane that lacks blood vessels n Subdural space – fluid filled area between dura and subarachnoid maters

n Pia mater n Innermost, nearly transparent layer; has many nerves & blood vessels n Follows contours of brain & spinal cord n Subarachnoid space – area between arachnoid & pia mater; filled with cerebrospinal fluid