Your Nervous System Central Nervous System Explain CNS

Your Nervous System Central Nervous System

Explain CNS Relays messages l Processes information l Analyzes information l

Parts of CNS 1. 2. The ____________

Protections l l 1. 2. 3. 4. Skull and Vertebrae 3 protective layers called ________(outer layer): consists of connective tissues, blood vessels, and nerves. _________(middle layer): elastic and weblike ______(inner layer): contains nerves and blood vessels. _____________ l l a clear watery liquid separates the middle and inner layers Acts as shock absorber exchange of nutrients between blood and nervous system

Section 35 -3 Cerebrum Thalamus Pineal gland Hypothalamus Cerebellum Pituitary gland Pons Medulla oblongata Spinal cord

The Brain l l The brain is the control center of the body It is about ___ of your body weight and uses 20% of your body’s ______

Parts of the Brain l Divided into four parts l l _____________

Cerebrum 1. l l l _____ part of the brain – Learning and Senses 2 hemispheres- Right and Left Connected by the __________ Right side controls- left side Left side controls – right side of body Four sections - LOBES 1. _____ Lobe 2. _____ Lobe 3. _____ Lobe 4. ______ Lobe

Gray Matter vs. White Matter _____– Absence of myelin in masses of neurons accounts for the gray matter of the brain – Cerebral Cortex l _____- Myelinated neurons gives neurons a white appearance – inner layer of cerebrum l

Cerebral Cortex l 3 types of functional areas: 1. Motor 2. Sensory 3. Association Control voluntary motor functions Allow for conscious recognition of stimuli Integration

Cerebellum l l l Second largest located below the cerebrum at back of skull This part is responsible for the _______________

Diencephalon l l Forms the central core of the forebrain 3 paired structures: l l l _____________ All 3 are gray matter

Thalamus l l _____ of the diencephalon Sensory relay station where sensory signals can be edited, sorted, and routed. Also has profound input on motor and ____ function. Not all functions have been elucidated.

Hypothalamus l Functions: l Autonomic regulatory center l l l ______________ l l l Involved in fear, loathing, pleasure Drive center: hunger ______________ Regulation of food intake l l Influences HR, BP, resp. rate, GI motility, pupillary diameter. Can you hold your breath until you die? Contains a satiety center Regulation of water balance and thirst Regulation of sleep/wake cycles Hormonal control l l Releases hormones that influence hormonal secretion from the anterior pituitary gland. Releases oxytocin and vasopressin

Epithalamus l l l Above thalamus Contains the pineal gland which releases _____ (involved in sleep/wake cycle and mood). Contains a structure called the habenula – involved in food and water intake

Brain Stem l Connects the brain to spinal cord l The Two Regions act as “switchboard” l _________"reptile brain"– Controls heart rate, breathing rate, and flow of blood through the blood vessels. l Also anger and aggression come from this part of the brain

Brain Stem l ______ – Relays signals between the cerebrum and the cerebellum l It also controls sleep and consciousness, breathing, bladder control, hearing, equilibrium, taste, swallowing, eye movement and the secretion of saliva and tears.

Lateralization l The fact that certain activities are the almost exclusive domain of one of the 2 hemispheres. l In most people, the left hemisphere has a more control ___________________. l While the right hemisphere is geared towards musical, artistic and other creative endeavors. l Most individuals with left cerebral dominance are __________.

Cross Section of the Spinal Cord Section 35 -3 Gray matter Spinal nerve Central canal White matter Meninges

Spinal Cord _________________ l 31 pairs of spinal nerves l Reflexes processed directly by spinal cord l Reflex – quick, automatic, unconscious responses l l Result of reflex arcs – shortest nerve pathways