the brain and cranial nerves ch. 19. major brain subdivisions cerebrum diencephalon – hypothalamus...
TRANSCRIPT
Major Brain Subdivisions
• Cerebrum• Diencephalon
– Hypothalamus and Thalamus
• Brain Stem – Midbrain, pons, medulla
oblongata
• Cerebellum
Cerebrum• Processes:
– motor control, thoughts, judgment, problem solving, memory, and language
• Left & Right Hemispheres– longitudinal fissure
separates hemispheres– Gyri: elevated ridges– Sulci: shallow grooves– Fissures: deeper grooves
Cerebrum• Corpus callosum:
– Bundle of axon fibers that enables communication between the hemispheres
• Cerebral cortex: outermost area of brain– cell bodies of cerebral
neurons (gray matter)• White matter:
– Made of fiber tracks carrying impulses to or from the cortex
Diencephalon
Consists of:• Thalamus
– Translates information for interpretation by cerebral cortex
• Hypothalamus– Translates electrical
signals into hormones
Brain StemConsists of:• Midbrain
– connects the pons below with the cerebrum above
• Pons– means bridge– motor and sensory fiber
tracts connecting or bridging the brain to the lower CNS
• Medulla oblongata– lowest brain stem region.
It is composed mainly of fiber tracts
Cerebellum
• Function:– Coordination and
integration of sensory input and motor control (controls balance and equilibrium)
Meninges• Brain and Spinal cord are protected by 3
connective tissue membranes– Dura Mater– Arachnoid Mater– Pia Mater
Cerebral Spinal Fluid • Fluid
– inside the brain found in ventricles– Outside the brain is found in arachnoid layer
• Prevent brain from collapsing in on itself• Shock absorption
Cranial Nerves
• Twelve pairs of cranial nerves arise from the brain
• They have sensory, motor, or both sensory and motor functions
• Each nerve is identified by a number (I through XII) and a name
Functions of NervesI. Olfactory - sense of smellII. Optic - visionIII. Oculomotor Nerve - movement of eyelid and eyeball, constriction of
pupil and accommodation of lens for near visionIV. Trochler Nerve - movement of eyeballV. Trigeminal - chewing (motor) and sensoryVI. Abducens Nerve - lateral movement of eyeballVII. Facial Nerve - Facial expression, taste, tearsVIII. Vestibulocochlear Nerve - hearing, equilibriumIX. Glossopharyngeal Nerve - taste, swallowing, speechX. Vagus Nerve - taste, swallowing, talkingXI. Accessory Nerve - swallowing, SCM, trapezius muscles (neck muscles)XII. Hypoglossal Nerve - tongue movement
Some Say Marry Money But My Brother Says Big Brains Matter Most
Mnemonics for Cranial Nerves
1) On occasion our trusty truck acts funny --very good vehicle anyhow
2) Oh oh oh to touch and feel very green vegetables ah