THE PERIPHERAL NERVOUS SYSTEM EMILY BEAUMONTMCALLEN RECAP CHOOSE

THE PERIPHERAL NERVOUS SYSTEM EMILY BEAUMONT-MCALLEN

RECAP • CHOOSE THE TASK YOU WISH TO COMPLETE FROM THE 3 COLOURS. • IF YOU COMPLETE YOUR CHOSEN TASK IN THE GIVEN TIME, MOVE ONTO THE NEXT COLOURED TASK. • NEXT TIME CHOOSE THE MORE DIFFICULT TASK FIRST.

AIMS AND OBJECTIVES • AIM: EXPLORE THE STRUCTURE AND FUNCTION OF THE PERIPHERAL NERVOUS SYSTEM. • OB 1: IDENTIFY AND DESCRIBE THE STRUCTURES OF THE PERIPHERAL NERVOUS SYSTEM • OB 2: EXPLAIN FUNCTIONS OF THE PERIPHERAL NERVOUS SYSTEM • OB 3: COMPARE AND CONTRAST THE SIMILARITIES AND DIFFERENCES IN THE CNS AND PNS

NERVOUS SYSTEM REVIEW Nervous System Central Nervous System Brain Peripheral Nervous System Autonomic Spinal Cord Sympathetic Somatic Parasympathetic

PERIPHERAL FUNCTIONS BRAIN • MAIN FUNCTION: • TO RELAY INFORMATION FROM THE BRAIN AND SPINAL CORD TO THE NERVES SCATTERED AROUND THE REST OF THE BODY AND FROM YOUR BODY BACK TO YOUR SPINAL CORD AND BRAIN. CRANIAL NERVES CERVICAL NERVES (8 PAIRS) SPINAL CORD THORACIC NERVES (12 PAIRS) LUMBAR NERVES (5 PAIRS) SACRAL NERVES (5 PAIRS) COCCYGEAL NERVES ( 1 PAIR)

AUTONOMIC (PERIPHERAL) • THE PNS IS SPLIT INTO SECTIONS ACCORDING TO HOW THE BODY REACTS. • THE AUTONOMIC PNS DEALS WITH INVOLUNTARY RESPONSES TO STIMULI TASK: CAN YOU NAME SOME ANIMAL REACTIONS THAT ARE INVOLUNTARY RESPONSES TO STIMUL?

INVOLUNTARY RESPONSES • THE AUTONOMIC IS SPLIT AGAIN INTO TYPES OF INVOLUNTARY RESPONSES. THE NERVES INVOLVED IN THE AUTONOMIC PERIPHERAL SERVE ALL THE SAME ORGANS AND BODY STRUCTURE BUT CAUSE OPPOSITE EFFECTS. • SYMPATHETIC NERVOUS SYSTEM-FIGHT OR FLIGHT RESPONSES • PARASYMPATHETIC NERVOUS SYSTEM-RESTING AND DIGESTING RESPONSES. • TASK: COMPLETE THE TABLE WITH SPECIFIC ANIMAL SCENARIOS WITH WHICH INVOLUNTARY RESPONSES WOULD THE BODY USE.

SYMPATHETIC NERVOUS SYSTEM • WHAT BIOLOGICAL AND BEHAVIOURAL REACTIONS MAY THE BODY PERFORM IN EMERGENCY AND STRESSFUL SITUATIONS? • MANY ANTELOPE (AND OTHER ANIMALS) ‘DROP THEIR LOAD’ –DEFECATE • HEART RATE INCREASE • MUSCLE TWITCHING TO READY THE BODY TO RUN • BREATHING RATE INCREASE • PUPILS DILATE. These involuntary reactions are also known as reflex actions controlled by a ‘REFLEX ARC’ –This means that is momentarily bypasses the brain so that the body can react very quickly before you or the animal is consciously aware.

PUPIL TEST • I AM GOING TO TURN OFF THE LIGHTS. • CLOSE YOUR EYES AND COUNT TO 10. • WHEN THE LIGHTS COME ON, LOOK TO THE PERSON NEXT TO YOU AND ESTIMATE THE SIZE CHANGE IN THEIR PUPILS. (IN MILLIMETRES)

PRE-LONGED EXPOSURE TO NEGATIVE STIMULI • IN ANIMALS PRE-LONGED EXPOSURE TO NEGATIVE STIMULI THAT CAN CAUSE AUTONOMIC SYMPATHETIC NERVOUS RESPONSES CAN CAUSE DAMAGE PHYSICALLY AND PSYCHOLOGICALLY. • CAN YOU NAME TWO TYPES OF LONG TERM BEHAVIOURS THAT’S ANIMALS DISPLAY WHEN THEY HAVE BEEN EXPOSED TO THESE NEGATIVE STIMULI TOO LONG? Stereotypical behaviour Learned helplessness

CAN THIS AFFECT HUMANS TOO? • WE MAY NOT ALWAYS REALISE THIS BUT WE ARE OFTEN EXPOSED TO SITUATIONS THAT CAN CAUSE US STRESS. • IN SOME PEOPLE THIS CAN LEAD TO BEING PHYSICALLY AND PSYCHOLOGICALLY AFFECTED (THIS MAY ALSO INCLUDE A GENETIC OR OTHER BIOLOGICAL PRE-DISPOSITION) • ANXIETY AND DEPRESSION ARE PSYCHOLOGICAL DISORDERS THAT ARE CONNECTED TO PRE-LONGED ENVIRONMENTAL EXPOSURE TO NEGATIVE STIMULI. • IF YOU FEEL THAT YOU HAVE IDENTIFIED WITH ANY OF THESE ISSUES PLEASE VISIT THE MIND WEBSITE AND/OR SPEAK TO YOUR GP, STUDENT SUPPORT SERVICES.

PARASYMPATHETIC NERVOUS SYSTEM • MAIN FUNCTION: • TO STORE ENERGY, • SOMETIMES KNOWN AS THE ‘RESTING AND DIGESTING’ STAGE • INVOLVED IN MAINTAINING HOMEOSTATIC EQUILIBRIUM TO MAINTAIN; • A STABLE BLOOD PRESSURE • HEART RATE • RESPIRATORY RATE • METABOLIC REACTIONS INVOLVED IN THE DIGESTIVE SYSTEM.

VOLUNTARY RESPONSES • THIS IS CONTROLLED BY YOUR SOMATIC NERVOUS SYSTEM (WITHIN THE PERIPHERAL) Decision making, Voluntary behavioural responses. e. g. Toileting, eating etc.

• RECAP NEURONS, SYNAPSES AND NEUROTRANSMITTERS NEURONS-THE CELLS THAT MAKE UP THE NERVOUS SYSTEM. (THERE ARE DIFFERENT TYPES DEPENDING ON THEIR FUNCTION. SYNAPSES-GAPS BETWEEN NEURONS. NEUROTRANSMITTERS-CHEMICAL RECEPTOR MOLECULES THAT TRAVEL ACROSS SYNAPSES TO DELIVER SIGNALS TO THE NEXT NEURON IN THE LINE.

APPLY YOUR KNOWLEDGE • COMPLETE THE DIAGRAM WITH HOW THE NERVOUS SYSTEM CAN AFFECT THE STRUCTURES IN THE BODY. • COMPARE AND CONTRAST THE CENTRAL NERVOUS SYSTEM TO THE PERIPHERAL NERVOUS SYSTEM.