Brain & Spinal Cord

Brain & Spinal Cord http://www.edheads.org/activities/brain_stimulation/

Protection of CNS • Bone • Blood-Brain Barrier • least permeable capillaries in body (allows only water, glucose, and a.a. to pass thru) • Useless against fat-soluble molecules (alcohol, nicotine, anesthesia, etc) • CSF • Ventricles - 4 chambers filled w/CSF • CSF – surrounds exposed surfaces of CNS, cushions and supports, transports nutrients, chemical messengers and waste products • Meninges – series of layers covering CNS • Protects against shock, infection, friction • Delivers O2 and nutrients to meninges, 3 Layers • Dura Mater • Outermost, Tough fibrous layer • Fused to periosteum of skull • Subdural space – lymph fluid • Arachnoid • Subarachnoid space - CSF • Pia Mater • Bonds to underlying neural tissue • Extensive circulatory supply

Main Parts of the Brain • Cerebral Hemispheres • Diencephalon • Brain Stem • Cerebellum

Cerebral Brain Structures • Gyrus – elevated ridges • Sulcus – shallow groves • Fissure – deep groove that separates large regions of the brain (ex. Longitudinal fissure separates L/R hemispheres)

Cerebral Structure • Cerebral cortex - gray matter • Cerebral White matter – nerve fibers • Corpus Callosum – connects the cerebral hemispheres • Ganglia Bodies – islands of gray matter

Cerebral Cortex • Primary sensory, motor, and association cortex • Sensory – initial site for conscious sensation • Motor • conscious control of skeletal muscles (damage causes paralysis) • Association • Integrates all sensory inputs allowing conscious perception and planning of responses • Cognition – attention, language, social behavior and other higher processes

Cerebral Hemispheres • Frontal Lobe • Parietal Lobe • Temporal Lobe • Occipital Lobe

Frontal Lobe Functions • Reasoning, planning, parts of speech, movements, emotions, problem solving • 4 functionally distinct areas • Primary motor cortex (most posterior) • Arousal/motivation (medial frontal) • Social behavior (orbital frontal) • Language comprehension (inferior lateral) • Working memory (dorsolateral) Broca’s Area – ability to speak

Parietal Lobe Functions • Posterior to central sulcus • Integrates sensory information (sensory homunolculi) • Visual spatial processing • Calculating, writing, right/left orientation • Naming and word recognition • Drawing

Temporal Lobe • Auditory Perception • Receptive component of language • Declarative and visual memory • Emotions • Olfactory area • Area of Wernicke – speech area

Occipital Lobe • Primary visual cortex • Responsible for visual processing

Diencephelon (Interbrain) • Thalamus • Relay station and controls sensory inputs to cerebral cortex • Acts w/brainstem to control state of arousal • Participates in coordination of movements • Hypothalamus (floor) • Homeostasis regulation, body temperature, appetite, thirst • Control of autonomic nervous system • Regulates secretion of hormones including control of pituitary gland • Epithalamus (roof) • Houses pineal body • CSF is formed here

Brain Stem • 3 Parts: • Midbrain • Reflex centers for vision and hearing • Pons • “Bridge” – fiber tracts • Nuclei involved in control of breathing • Medulla Oblongata • Merges w/spinal cord • Fiber tract area • Regulates hr, bp, breathing, swallowing, and vomiting • RAS (Reticular Activating System) – gray matter thru brain stem controls consciousness and wake/sleep cyles

Cerebellum • Coordination and accuracy of complex movements and balance • Procedural memory

The Spinal Cord • Controls spinal reflexes • Diameter decreases as it descends • Except at cervical enlargement • And lumbar enlargement • Central canal – filled w/ CSF • Gray matter – glial cells, cell bodies of neurons • Horns extend out into horns • White matter – myelinated and unmyelinated axons • Ascending tracts – sensory info to brain • Descending tracts – motor commands to spinal cord

What is the general name that describes the pons, medulla and midbrain? • Diencephalon • Cerebellum • Cerebrum • Brain stem

In terms of volume, the largest part of the brain is • Diencephalon • Cerebellum • Cerebrum • Brain stem • Frontal Lobe

Which lobe is primarily responsible for somatosensation? • Frontal Lobe • Parietal Lobe • Temporal Lobe • Occipital Lobe • Cerebellum • Brain Stem

Which lobe contains the primary visual cortex? • Frontal Lobe • Parietal Lobe • Temporal Lobe • Occipital Lobe • Cerebellum • Brain Stem

Damage to which lobe can produce disruptions to social and emotional behavour? • Frontal Lobe • Parietal Lobe • Temporal Lobe • Occipital Lobe • Cerebellum • Brain Stem

The auditory cortex is found in the: • Frontal Lobe • Parietal Lobe • Temporal Lobe • Occipital Lobe • Cerebellum • Brain Stem

The fluid found in the brain's cavities is called ______; this principally protects the brain from ______. • Cerebrospinal fluid; external pressure • Cerebrospinal fluid; infection • Ventricular fluid; external pressure • Blood; infection and external pressure

The _________________ serves as a protective filter that regulates the entrance of certain substances into the brain from the bloodstream. • Meninges • Bone • Gray matter • White matter • Blood-brain barrier

What is the primary function of the cerebellum? . • coordination of complex muscular movements • coordination of endocrine and nervous responses • control of digestion, circulation, and breathing movements • center of consciousness

You just finished running and your heart rate is fast as is your breathing. The part of the brain controlling basic body functions such as heart rate and blood pressure is the _______. • Cerebrum • Cerebellum • Spinal cord • Medulla Oblongata

The thalamus is responsible for which of the following functions? • connection between speech and hearing • motor coordination • control of many of the endocrine glands • integration and relay of information

The primary functions of the spinal cord involve __________. • intelligence and memory • reflex actions and communication between the brain and spinal nerves • controlling muscle activity and maintaining balance • speech, smell, taste, hearing and vision

Brain & Spinal Cord