NEW Unit 3 NAR Revision Higher Human Biology

Divisions of the nervous system and parts of the brain Cerebral Cortex Personality, intelligence, imagination Recalls memories, motor control Medulla Regulates breathing

Memory Information can be transferred from short term memory into long term memory by; • Rehearsal - repeating information over and over • Organisation- information is grouped into categories • Elaboration of meaning – additional information is added Information can be lost from short term memory if it is displaced due to new information entering STM

Contextual Cue A contextual cue is a “memory trigger” which aids the retrieval of information. Contextual cues relate to the time that the memory was first encoded.

Cells of the nervous system Motor cell Cell Body Dendrite Myelin sheath insulates the axon and so speeds up the rate of nerve transmission

Neurotransmitters diffuse across the synapse from the neuron to the target effector (e. g. muscle).

Non-Specific Defence • Mast cells are a type of white blood cell which is present in most tissues, surrounding blood vessels and nerves. • Mast cells release histamine which causes the inflammatory response. • Histamine causes vasodilation and increased capillary permeability

Phagocytes are cells which will engulf and digest pathogens. Once the pathogen is inside the phagocyte, lysosomes fuse with the vesicle, digesting the bacterium. VIDEO

Specific Defences • Lymphocytes have receptors that are specific to one antigen

Clonal Selection Receptor

Clonal Selection • Lymphocyte Y undergoes cell division because the antigen is complementary to its receptor

Antibody action The binding of the antibodies causes the • inactivation of the pathogen (or the toxin it produces) and • pathogen to become more susceptible to phagocytosis

Herd immunity is where a large % of a population have been immunised against a particular disease, they can offer protection to non immune individuals… This is because their chance of coming into contact with an infected individual is minimal. Threshold is the percentage of the population who need to be immunised by the vaccine to offer protection for people who are not vaccinated.

Problem Solving • • Selecting information, predicting Calculating percentages, averages Analysing information Drawing conclusions from experimental data REMEMBER!!!! Read the questions carefully and bring a CALCULATOR and RULER Good luck