Anatomical References • References are made assuming a mammalian animal (such as a rat) on four legs. • For humans, assume they are on hands & knees. • Toward the nose – forward, front: • Anterior • Rostral • Toward the tail – backward, rear: • Posterior • Caudal
Anatomical References (Cont.) • Direction pointing up from the back (spine): • Dorsal (like a shark’s fin) • Direction pointing down from the belly: • Ventral • The line running down the center of the nervous system is the midline. • Close to the midline is medial. • Far from the midline is lateral (side)
Anatomical References (Cont.) • Some references describe relations between structures: • The nose is medial to the eyes. • The eyes are medial to the ears. • Structures on the same side are ipsilateral. • Structures on opposite sides are contralateral.
Kinds of Sections (Slices) • Midsagittal plane – a slice that splits the brain into two equal halves from front to back between the eyes (along longitudinal fissure). • Sagittal planes – slices parallel to midsagittal. • Horizontal plane – a slice parallel to the ground passing through both eyes and ears. • Coronal plane – a slice perpendicular to the ground and the sagittal plane.
Parts of the CNS • Cerebrum – largest part of the brain. • Split into two hemispheres along the longitudinal (sagittal) fissure. • Cerebellum – behind the cerebrum, controls movement. • Brain Stem – the stalk supporting the cerebrum and cerebellum, relaying information from the spinal cord. • Controls vital functions (breathing, heart rate)
Peripheral Nervous System • Somatic PNS – includes all the spinal nerves that control movement and collect sensory information from skin, muscles, joints. • Autonomic NS (Visceral PNS) – innervates internal organs, blood vessels, glands. • Heart rate, smooth muscles of intestine • Afferent – toward the CNS • Efferent – away from the CNS
Imaging Techniques (Scans) • Viewing the structure of the brain: • CT or CAT – computed tomography (uses x-ray) • MRI – magnetic resonance imagery (uses magnetic field) • Viewing brain activity (functioning): • PET – positron emission tomography (measures radioactive substance in blood flow) • fMRI – functional MRI (uses magnetic detection of blood flow)
Neocortex • The terms cortex and neocortex are used interchangeably when referring to humans. • Only mammals have neocortex. • Neocortex is used for different things in different species. • Evolution has its greatest impact on the size and function of the neocortex. • Localization of functions to areas of the brain is referenced to Brodmann areas.