Central Nervous System

Central Nervous System

• Divided into 4 major sections–Brain stem–Cerebellum–Diencephalon–Cerebrum

• Cerebrospinal fluid provides protection, maintains proper ion concentration for the CNS, and provides a pathway to the blood for waste

Brain Stem

• Connects cerebrum and diencephalon to the spinal cord

• Midbrain- reflexes• Pons- breathing• Medulla oblongata- heart rate, breathing,

blood pressure• Reticular formation- arousal (comatose state)

Cerebellum• Anterior and posterior lobes• Coordination of desired movements• Regulates posture and balance• Cognitive and language processing

Diencephalon• Located between cerebral hemispheres and

above the midbrain• Contains:

– Thalamus- relay station for sensory impulses– Hypothalamus- maintains homeostasis by

regulating:• Heart rate• Temperature• Water/ electrolyte balance• Hunger• Glandular secretions• Sleep

- Epithalamus- superior and posterior tothalamus• Contains pineal gland- secretes hormone melatonin (endocrine)

Cerebrum• Divided into 2

cerebral hemispheres by longitudinal fissure

• Connected by the corpus callosum

• Convolutions- ridges of the brain (gyri)

• Sulcus- shallow groove

• Fissure- deep groove

• The Basal Ganglia (Nuclei): caudate nucleus, putamen, globus pallidus

• act as a relay station for motor impulses travelling from the cerebral cortex to the spinal cord

• The cerebral cortex interconnects with the basal ganglia, the thalamus and the hypothalamus to form the Limbic System– Controls

emotional experience and expression

Lobes of the cerebrum(higher brain function)

• Frontal• Parietal• Temporal• Occipital• Insula

• Covered in a thin layer of gray matter called the Cerebral Cortex– Motor area (mostly frontal)– Sensory area (mostly parietal)– Association areas (throughout cerebrum)

• Frontal- concentration, problem solving, planning

• Parietal- compose speech, touch sensation• Temporal understand speech, reading, music• Occipital- analyzing visual patterns

patb

can map somatosensory areas (lips and hands large area, trunk and limbs small area)

Sensory and Motor areas of the cerebral cortex (Brain Map)

Peripheral nervous system

Nerve structure-very similar tostructure of muscle!!

Link

I - Olfactory II - Optic III - Oculomotor IV - Trochlear V - Trigeminal VI - Abducens VII - Facial VIII - Auditory IX - Glossopharyngeal X - Vagus XI - Accessory XII - Hypoglassal

Spinal nerves andplexuses (tangled networks of axons)