Higher Human Biology Unit 3 Neurobiology & Communication KEY AREA 1: Divisions of the Nervous System & parts of the brain

Reminder from N5 Biology! Discuss these questions with a study buddy or your group 1.What is the nervous system? 2.What is the CNS? 3.What are the 3 main parts of the brain? 4.What is a reflex action? 5.What makes up the reflex arc? 6.What is a synapse? 7.What is the Endocrine System? 8.What are Hormones? 9.Where do Hormones have an effect? 10.What is Homeostasis? 11.Why is it important that our Glucose, Water & Body Temperature are controlled? 12. Which parts of our brain help to control blood water concentration and temperature?

Higher Human Biology We are going to build on the knowledge and skills that you developed during N5 and will learn about the following Neurobiology key areas : - Key Area 1 - Divisions of the nervous system & parts of the brain Key Area 2 - Perception and memory Key Area 3 - The cells of the nervous system and neurotransmitters at synapses Key Area 4 - Communication and social behaviour

Neurobiology & Communication Learning Intentions KEY AREA 1 - Divisions of the nervous system & parts of the brain a) Structure & function of the Central Nervous System (CNS) b) Structure & function of the Peripheral Nervous System (PNS) and the Somatic Nervous System (SNS) c) Functions of the medulla and cerebellum in the central core of the brain d) Functions of the limbic system e) Functions of the cerebral cortex in receiving information, coordinating voluntary movement and making decisions in light of experience f) Localisation of brain functions including sensory and motor areas and association areas

1a) Structure & function- Central Nervous System (CNS) The nervous system is made up of the:- BrainSpinal CordNervesSense Organs Structural division of the nervous system: - Central Nervous System (CNS) (Brain & Spinal cord) Peripheral Nervous System (PNS)(Nerves) Peripheral nerves contain a sensory pathway made of sensory nerves and a motor pathway made of motor nerves Sensory pathways carry nerve impulses from receptors (e.g. skin) to the CNS The brain analyses the information and sends nerve impulses along motor pathways to effectors (e.g. muscles) which then bring about a response e.g. muscle contraction

1b) Structure & function-Central Nervous System (CNS) responses receptors effectors Nerve impulses carried by sensory neurons in sensory pathways Nerve impulses carried by motor neurons in motor pathways CNS stimuli

1c) Peripheral Nervous System(PNS) & SomaticNervous System(SNS) Somatic Nervous System (SNS) contains sensory and motor neurons which control the voluntary movement of skeletal muscles SNS brings about some involuntary actions (e.g. reflex response) but majority of actions are under voluntary control (e.g. picking 4 favourite chocolates out a large box of chocolates) Autonomic Nervous System (ANS) regulates the internal environment by controlling structures and organs (e.g. heart, blood vessels, bronchioles) This control is involuntary because it works automatically without the person’s conscious control being involved The sympathetic and parasympathetic systems of the ANS are antagonistic, meaning that they affect many of the same structures but in opposite ways in order to maintain a stable internal environment

1d) Peripheral Nervous System(PNS) & Somatic Nervous System(SNS) Divisions of the Nervous System Structural & Location Division Functional Division

1e) Peripheral Nervous System(PNS) & Somatic Nervous System(SNS) Antagonistic Methods of the Sympathetic and Parasympathetic System in response to a man chasing you! Sympathetic SystemParasympathetic System Type of response“fight or flight”“rest and digest” Response occurs At start of event when sensory nerves stimulated At end of event when excitement is over Heart RateIncreasesReturn to normal Blood PressureIncreasesReturn to normal Blood supply Increased supply at muscles Decreased supply at gut/skin Return to normal Peristalsis increases Nervous perspirationIncreasesReturn to normal Characteristics Thudding heart White face with fear Clammy armpits and hands Return to normal Adrenaline(epinephrine)ProducedNot produced ResponseFight or run away!Return to normal to help body conserve resources and store energy

1f) Autonomic Nervous System - antagonistic nature

1g) Peripheral Nervous System(PNS) & Somatic Nervous System(SNS) Sympathetic & Parasympathetic balance each other – body rarely at extremes

1h) Fight or Flight ‘Fight or flight’ – sympathetic nervous system sends more impulses than the parasympathetic in order to prepare the body to use energy quickly Heart rate and blood pressure increase and blood supply diverted to skeletal muscles Nervous perspiration increases Epinephrine production stimulated After the ‘fight or flight’ situation has passed the parasympathetic nervous system takes over briefly to calm you down

1i) Rest and digest After the ‘fight or flight’ situation has passed the parasympathetic nervous system takes over briefly to calm you down Heart rate and blood pressure drop Rate of peristaltic contractions increase Blood re-diverted back to intestines

1j) The Brain The brain is composed of 3 interconnected layers : - The central core - Medulla(breathing, heart rate ) &Cerebellum (balance, coordination, posture) The limbic system - Hypothalamus The cerebral cortex- Outer layer of the cerebrum

1k) Functions of the Limbic System The limbic system is found in the cerebral cortex The function of the limbic system is to:- Process information to form long-term memories Regulate emotions (e.g. anxiety, fear, aggression) Influence biological motivation (e.g. hunger, thirst, sex drive) The limbic system contains the hypothalamus The hypothalamus is connected to the pituitary gland, and acts as a link between the nervous system and the hormonal (endocrine) system

1l) Functions of the Cerebral Cortex The cerebral cortex is the centre of conscious thought; it also recalls memories and alters behaviour in light of experience The cerebral cortex is the outer layer of the cerebrum and is split into two halves called the cerebral hemispheres. The left hemisphere processes information from the right visual field and controls the right side of the body The right hemisphere processes information from the left visual field and controls the left side of the body The left and right hemispheres are connected by a large bundle of nerve fibres called the corpus callosum. The corpus callosum transfers information between the two hemispheres

1m) Localisation of Brain Function The cerebral cortex is the centre for conscious thought and contains 3 types of localised functional areas: - Sensory(receives sensory impulses from receptors e.g. skin) Association(analyses, interprets & take decisions) Motor(sends motor impulses to muscles e.g. move hand) Each cerebral hemisphere consists of distinct areas which have a particular function to perform e.g. speech motor area, auditory area, visual area Interconnections between each area occur due to tiny nerve fibres. This allows for sophisticated perception of a situation and the ability to make an integrated response. There are areas of the cerebral cortex that are responsible for higher mental processes such language, personality, imagination, creativity, conscience and intelligence

Neurobiology & Communication Questions KEY AREA 1 - Divisions of the nervous system & parts of the brain 1.Testing Your Knowledge 1Page 208 Q’s Testing Your Knowledge 2Page 219Q’s What you should knowPage 219Q Quick Quiz