Y1: Term 4: Cognition

*complex communication system that uses nerve impluse to communicate.

*NS works closely with Endocrine system to regulate and maintain cell function and homeostasis

Function is to control and co-ordinates cell activity throughout the body. 

• *consists of brain and spinal cord
• *acts as the integrating and command centers of the NS.

• *includes all neural tissue outside the CNS
• *deliver sensory infomation to the CNS
• *Carry motor commands to the peripheral tissues and systems
• *consists of nerves that acts as communicating lines
• *nerves carry impulses from sensory receptors (skin) to CNS and from CNS to appropriate muscles and glands.

*cells of the nervous system  specialized to transmit messages throughout the body

• consists of:
• *sensory (afferent) neurons that conduct impulses to spinal cord and brain
• * Motor (efferent) neurons that conduct impulses away from spinal cord or brain toward muslces and glands

Neurotransmitters are the chemicals which allow the transmission of signals from one neuron to the next across synapses

An action potential is part of the process that occurs during the firing of a neuron. During the action potential, part of the neural membrane opens to allow positively charged ions inside the cell and negatively charged ions out. This process causes a rapid increase in the positive charge of the nerve fiber. When the charge reaches +40 mv, the impulse is propagated down the nerve fiber. This electrical impulse is carried down the nerve through a series of action potentials.

Afferent (sensory) division > carries sensory info from PNS sensory receptors to CNS

Efferent (motor) division> Carries motor commands from CNS to PNS muscles and glands

Regulates and control skeletal muscel contractions

*third division of  autonomic NS, meshwork of nerve fibers that innervate the viscera.

Regulates and controls internal organs by involuntary control

>Sympathetic division - Prepares the body to deal with immediate threat, stimulating fight and flight response.

>Parasympathetic division - Co-ordinates the body's resting activities to maintain homeostasis. Has a relaxing effect Eg, rest and digest

• Structures:
• Frontal lope
• Parietal lope
• Temporal lobe 
• Occipital lobe
• Insula

Function: Integration, movement and senses such as touch and pressure

• Contain a sensory map of the body
• Able to compare, evaluate and responds to bits of information and then integrate then in a whole picture

• *located between cerebrum and midbrain
• *consists of: 
• Thalamus- serves as a major relay station for sensory inpulses on their way to the cerebral cortex

Hypothalamus- small but functionally important area of the brain.

Pineal gland regulates the body's biological clock

• *located below the posterior portion of the cerebrum
• *second largest part of brain
• *contains more neurons than the rest of the NS, transverse fissure separates the two parts of the brain

• Function:
• Fine Movement Coordination
• Balance and Equilibrium
• Muscle Tone

*perform senosory, motor, and reflex functions

*Spinothalamic tracts is important sensory tracts that pass through the brainstem

• *Pons contains pneumotaxic centers that help regulate respiration
• *Midbrain contains centers for certain cranial nerve reflexes
• *Medulla oblongata
• lowest part of the brainstem. Attached to spinal cord.

• Functions:
• *provides a supportive, protective cushion. 
• * Resevoir of circulating fluid monitored by the brain to detect changes in the internal enviroment

permits the passage of essential substances while excluding unwanted material.

The three membranous layers that surround the brain

• *Pia mater
• *Arachnoid mater
• *Dura mater

space between each layer are potential spaces.

• *main pathway for information connecting the brain and peripheral NS.
• *located in the vertebral foramen and made up of 31 segments

• *8 Cervical
• *12 thoracic
• *5 lumbar
• *5 Sacral
• *1 coccygeal

• *produce spinal reflexes without any input from the brain
• *They are automatic, no conscious effort
• *protective mechanism
• *can be influence by thought and emotion Eg touching hot oven.

A spinal reflex is an automatic, rapid response to a stimulus. The action is involuntary and occurs without any involvement of thought or the brain

*offer quick and simple way to vertify cognitive function and screen for cognitive loss*tests orientation, attention, calculation