Brain Notes II

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

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

Limbic System Emotional aspects of behavior & aids in memory

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

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

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

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

Reticular Formation Responsible for maintaining consciousness & awakening from sleep

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

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

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

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

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

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