Biol 121 lecture introduction 23rd feb :

Pass program
Little groups * Learning notes topics discussions * Informal * opens Friday 27th feb 5.00

Studies:
How the body works
Anatomy
Gross anatomy – internal structures
Microscopic anatomy- study of cells, study of tissues (microscope)
Physiology- cellular physiology – e.g. nerves and muscle fibres
Integrative physiology- different tissues and organs, functions e.g. cardiovascular
Levels of organisation e.g. tissues, organs, organ systems organism levels

Go through link called echo – access lecture recordings
My unit- weekly feedback quiz
Biology and chemistry lessons
Textbook folder mastering a&p

Lecture d 3rd week on a Tuesday
Labour day (Monday) good Friday

Assessments
In class tests (30%)
Quiz a (10 %) quiz b (20%)
Worksheet questions (30%)
Final exam 40%

See unit outline for due dates, methods, extensions

Quiz a
Week 3 (early feedback)
30 mins to complete
Opens 3pm Tuesday 10th
Closes 3am Thursday 12th

Quiz b
Week 7 semesters
Week 3 up to lecture 16 (muscles)
60 mins marked out of 50

Worksheet questions (30%) due week 11 of sem
Set of questions provided online in week 8
Week 1-10
Final exam
Mix mcq and sa
Material from whole semester
Higher weighting of 11 &12

Feedback about progress:
Quizzes weekly
Review assessments

EIP

BIOL 121 TUTORIAL 1 CHEMISTRY:
Reading: pages 53-61 notes

* Science of structure that deals with matter. * Defined as anything that takes up space and has mass. * Smallest units of matter = atoms * Everything is composed of atoms. * Atoms are composed of subatomic particles inc ( protons +) neutrons (neutral) (electrons -) * Atoms contain = numbers of protons + electrons * Number of protons = atomic number * Electrons travel around nucleus at high speed ( in the electron cloud) * Negatively charge electron is atteacted to positively charged proton * Element is a pure substance composed of atoms of only one kind. * Each element inc all atoms that have same number of protons + atomic number * 92 elements exist in nature * each element has a chem symbol * elements of human body ? * atoms of the same element whose nuclei contain same number of protons, but diff number of neutrons are called ISOTOPES. * Diff isotopes of an element have the same chemical properties, except the basis of mass. * Mass number= total number of protons + neutrons in the nucleus – used to design isotopes * Some isotopes nuclei are unstable, break down and radiate is measureable amts (radioisotopes) ( breakdown p= radioactive decay) * Mass numbers are useful as they tell us the number of subatomic particles of the nuclei of diff atoms ( do not tell actual mass of atom) * Atoms participate in chem reactions in fixed numerical ratios. * Atoms are electrically neutral every positive proton is balanced with a negative electron * Elements that do not participate readily in chem process are inert. Eg helium neon and argon have filled outermost energy levels. * Those with unfilled energy levels are reactive eg hydrogen. * When chemical bonds occur the result is a new chemical eg compounds or molecules. * Compound = pure chem substance made up of two or more atoms * Molecule = atoms held together by covalent bonds * Ionic bonds form between ions. (atoms or molecules that carry electrical charge cations + anions- * Ions have unequal number of protons and electrons * Covalent bonds (single + double) * Nonpolar and polar ^ * Hydrogen bond is the attraction between … * States of matter (solid,liquid,gas) * Molecular weights (is the sum of the atomic weights of its component atoms. * Kinetic energy – e on motion * Potential energy- stored e * types of reactions decomposition,( breaks a molecule smaller) synthesis (assembles smaller molecules into larger ones) exchange( parts of the reactants are shuffled to produce new products) reversible

WEEK 1 LECTURE B CELLS AND TISSUES:
Cells- structural unit of life – made of atoms and molecules
Body is made of cells
Humans are multicellular
Similar cell groups together as tissues
Many tissues form organs
Organs work together as a system

Cell- functional unit of life
Take in nutrients, oxygen, remove wastes, repair grow and reproduce, sense and react to changes, (feeding, respiration, excretion, reproduction, irritability)
Drugs are made to modify cell structure and functions
Diseases often affect structure and function also

Cells- very small – bigger than atoms
Over 100 different types of cells in body
Most 10 -15 micrometres in size
Largest cell is = ovum ( sperm is smallest)
Nanometer (measure organells

Cell shapes – red blood cell, ( carry oxygem) nerve cell, ( longest cell in body) epithlatel cell , smooth muscle cell, (eg intestines and uterus sperm cell ( head filled with digestive enzymes to digest cell membrane, only cell that has a tail has to make lashing movement
Structure and function go hand in hand

Skin cells are flat and form layers for COVERING AND PROTECTION
Nerve cells have long axons for TRANSFERRING ELECTRICAL IMPLUSES
Muscle cells are made of moveable proteins for CONTRACTION
Sperm cells are streamlined with long tails for SWIMMING
PARTS OF A CELL: 1. CELL MEMBRANE OR PLASMA MEMEBRANE ( FLUID WITHIN THE CELL AND OUTSIDE THE CELL 2. ICF ITRACELLCULLAR FLUID ECF INTERCELLULAR FLUID
STRUCTURE OF CELL MEMBRANE (fluid mosaic model)
1. Double layer phospholipids
2. Protein float in the membrane
3. Cholesterol in between
2. CYTOPLASM (CYSTOSOL + ORGANELLS (little organs)
3. NUCLEUS (MOST IMPORTANT CONTROL CENTRE)

phospholipids
Hydrophilic phosphate heads
Hydrophobic lipd tails

Proteins
Peripheral or integral proteins
Some are receptors others enzymes
Some form channels gates or pumps

Functions of cell membrane
Maintains the composition of ICF + ECF
Determines movement of substances into and out of cells
Communicates with other cells

Selective permeability
Lets some substances in and out of cells
Due to structure of membrane
Some molecules are too large to fit through normsal protein channles eg glucose
Use a special carrier protein to move them through the membrane
Facilitated diffusion

Lipid soluble – can cross double membrane by simple diffusion
Water soluble – ions and water pass through special protein channels/gates/pumps
By diffusion osmosis or active transport

The cytoplasm
Composed of cytosol jelly like (water in constant motion)

ORGANELLES AND THERE FUNCTIONS:
Rough endoplasmic - MEMBRANOUS- transports protein
Smooth er – MEMBRANOUS – synthesis of fats eg testes
Golgi apparatus – MEMBRANOUS- packaging secretion for internal external use
Lysosomes-MEMBRANOUS – digestion of bugs
Mitochondria yes powerhouse
Ribosomes- yes protein synthesis
Peroxisomes –no – breakdown of fats
Cytosketon no- structural support
Cytoskeleton microvilli – no – increase surface area
Nucleus – control centre- contains dna org into chromosomes

Tissue – group of similar cells for a specific function
Epithelial tissue – protection lining – absorption – avascular * no blood vessels grow rapidly – classified by- shape and num of layers single many ( simple ,stratified) psedostrassified single layer but uneven sides
Connective tissue – most abundant support tissue, insulation few cells matrix in larger filled in spaces eg fluid gel fibrous, some are vascular some aren’t
Muscle tissue –allows movement keeps joints stable ,produces heat
Skeletal, smooth, cardiac vii
Neural nerve tissue – neurons neuroglia (support cells for comm

Week 1 lecture c skin and membranes:
Membranes of the body:
Physical barriers /cover parts of body:
Consists of
Epithelium + supporting connective tissue
4 types of membranes
Mucous
Serous – parietal( outer) and visceral (inner) layers
Cutaneous – skin (sub ( under skin)
Synovial
Pericardial fluid for protection as always moving
THE SKIN CUTENOUS MEMBRANE
Parts of the intergumary system:
Skin - largest organ
Thickness
Most part 1-2 mm

Functions of skin
Protection or water loss, uv radiation
Regulation :(body temp) homstatis
Perception of stimuli : Temperature,touch, pain, pressure.
Excretion eg sweating
Synthesis of vit d
Absorbtion eg drugs

Structure of skin Two layers: outer epithelial layer- epidermis Deep supporting layer dermis ( papillary and radicular) Subcutaneous layer+ fat beneath dermis (not part of skin hypodermis) not associated Epidermis is avascular Obtains nutrients and oxygen from the dermis Epidermis – several cell types: Basal cells - mitosis Keratinocytes (most numerous become keratinised) Melanocytes- produces melanin (dark pigment) exposes self to sun meloncites become reactive meanin increases not number of melocites Dermis Dense tough connective tissue Contain collagen and elastic fibres Carries blood, nerves, sensory receptors, hair follicles Under surface merges into hypodermis Two major regions papillary and reticular Blood supply to skin Amt of blood in dermis controls skin colour Dilated blood vessels flushed (erythema) Constricted blood vessels pale (pallor) Low level of oxygenated blood bluish colour (cyanosis) ( Yellow colour represents kidney disease – jaundice Nerve supply to the skin: Dense network of nerves in skin Some carry sensorty info From receptors to cns From sensory pathways Some control of blood flow and secretion from glands From cns to effectors Accessory organs of the skin: Glands: Sweat glands- eccrine sweat glands – common Apocrine sweat gland-gives rise to body ador – hair follicles Sebaceous (oil glands) Usually connected to hair Softens and lubricates hair and skin Blockade of these causes pimples Enhances water resistance of skin Hair: Shaft – above skin Root –hair follicles Nails: solid plates dead cells Sensory function of skin Pain receptors (nocieptors) Temperature receptors (thermo receptors) Mechanoreceptors (touch pressure vibration Temperature regulation Thermo receptors detect change in temperature If tem is below 37 degrees vasoconstriction less heat lost Goose bumps and shivering produce heat Skin changes with age : Thinning epidermis Age spots Wrinkles – smoking, sun Grey hair – hair loss BIOL LECTURE: MAY YAO: HOMEOSTATIS: Comes from greek word homois “ similar” Body maintains a relatively stable environment Constant fluctuation monitored by out body – influenced by internal and external factors. (int: infection, disease) Eg cruise control in a car Why do we need to maintain homeostasis: Optimal condition for cells to function Cells constantly need nutri, oxy,optimal temp and removal of waste. Similar to humans needing enough sleep, diet,excersise,relaxation. How does our body maintain a relatively stable internal environment despite influenced by internal and external factors? Using various systems within our body. ( all work together to maintain homeostatis) All systems page 8 ( systems within the body that help maintain) Blood pressure: Cardiovascular Urinary system Endocrine Nervous system Systems that help maintain : Blood glucose Muscular system – stores glucose ( glycogen) Urinary system Endocrine system Digestive system

Calcium levels: Skeletal system Endocrine system two hormones Digestive system Intenmentary system vit d Internal environ is at contant fluctuations by ex or int factors Monitored by body Various body systems work together- maining a steady state ( homeostasis) If not maintainsed Blood pressure - hypertension Blood glucose levels - diabetes Calcium lrvels – osteoporosis Blood pressure 120/80 – 140-90 Blood ph 7.35-7.45 Body temp 36.5-27.2 Fast glucose levels 4-6 mol/l how does body maintain homeostasis through feedback system cycle of events evaluated changed if required re monitored revaluated components involved in feedback system: body response to stimulus two types negative feedback- negate changes initiated by stimulus positive feedback- can enhance change initiated by stimulus negative: does opposite of what stimulus is doing to body main feedback used to regulate changes in body homeostatic range is brought back to norm state eg body temp teg

* E.g.body temp = Our body responds by trying tobody temp 
 * E.g.body temp = Our body responds by trying tobody temp 
 Positive feedback: Enhances when stimulus is doing to the body Body is moved away from homeostasis until event clashes Used to speed up processes Infrequently used – only dangerous or stressful process must be completed to restore homeostasis Stretch in cervix = Our body responds by 
releasing chemicals thatStretch in cervix 
 Blood clotting = Our body responds by 
releasing chemicalsblood clotting occurs in childbirth and hamestasis , accelerates a process to restore homeostatis homeostatis is a state of dynamic equilibrium , can be chanlleged by internal or external factors. Homostatic range are monitored by receptors, systems in our body work together to maintain homeostasis MICROBIOLOGY: WHAT IS IT? Organisms that too small to see without a microscope/ Harmful? Not all detrimental to health and environ Decomposition Fixing nitrogen in soil Normal flora on our skin Focus on infectious in this lecture 5 clases: viruses.bacteria,protozoa,fungi yeast and moulds VIRUSES: *not alive ( do not have capability to reproduce ) VERY SMALL – No cellular structures Protein capsules containing nucleic acid (rna or dna) Eg chicken pox rabies HIV OBLIGATE INTRACELLULAR PARASITES ( need to find another cell to reproduce) Can only grow within cell Must use host machinery to reproduce Eukaryotes (cells e.g. worms fungi) prokaryotes ( e.g. bacteria, smaller) EUKARYOTES: True nucleus Organelles some are endosymbiosis bacteria) Cell walls (plants /fungi) Mostly multicellular Plants Fungi Animals PROKARYOTES: No nucleus No membrane bound organelles Cell wall present Mostly unicellular BACTERIA: Prokaryotes Small bigger than virus Rigid cell walls Capable of independent survival Mostly unicellular Can be motile (move) Eg salmonella tb Key differences Shapes Staining Gram positive (purple) or negative (red) can rule out different groups of bacteria Penicillin (gram negative not going to help) only gram positive Very helpful narrowing down type of bacteria the person has. PROTOZOA Eukaryote Bigger than bacteria Single celled They move Eg malaria

Fungi: Eukaryote Single or multicelled Cell wall present Produce spores (may \cause the problem) Eg ringworm HELMINTHGS: Eukaryotic (animals) Multi celled, have own organ systems Microscopic stage in life cycle Eg tapeworm, hookworm, heartworm Less likely to effect people living in melb Bacteria growth requirements Temperature – 10 and 39 Ph usually optimal close to neutral ( grow bw 6-8) Water – prefer moist enviro Nutrients Chemical requirements – carbon nitro,sulpar. Organic growth factors: Vitamins amino acids Time: May divide once every 20 mins Competition – different bacteria compete for space + nutrients Usually one wins: other dies Oxygen: Obligate aerobe – must have oxygen- tb (prefers lungs) Obligate anaerobe – no oxygen - tetanus (penetrating wounds) Facultative anaerobe – prefers oxy but can survive without – (gut) NORMAL FLORA: LIVE IN / ON US Bacteria Anywhere contact with outside Skin nose/mouth Gut mostly g rods Normal flora: Do things for us Eg vit k digestion KEEP BAD GUYS AWAY – Can be consequence when flora is interrupted eg antibiotics OPPORTINISTIC PATHEGENS – if you cut skin- bacteria may get into wound- Sterization/ disinfection Sterilisation: killing removal of all Disinfection: reduction to safe level Chemical agents: bactericidal (killed ) bacteriostatic ( stopping for reproduces) different concentrations Soap detergents: vigorous hand washing Chlorine (bleach) iodine Acids alkalis (PH EG in food or soaps ) Hydrogen peroxide Alcohols Formaldehyde Sterilisation/disinfection Physical: DRY HEAT MOIST HEAT Pasteurisation Freezing Uv lights Filtration Radiation Infectious disease: Requirements: A pathogen Virulence Suffienct dose Portal of entry and exist Susceptible host eg hiv Prevent these: prevent infection Pathogenicity: The ability to cause disease: Virulence: How bad is it Pathogenic properties: Adherence Fimbriae on bacteria Attach to receptors Help colonisation Invasiness into tissues Eg produce digestive enzymes PATHEOGENIC PROPERTIES EVASION: avoid detection / attack by immune Eg within cell tb Antigenic variation: influenza Toxins- poisonous Endotoxins: part of cell wall Exotoxins: secreted into host tissues tetanus Portal of entry and exist Skin wounds cuts Susceptible: Children elderly Or someone who is hiv + Mode of transmission Cotact: bw host and source Direct: body contact: Indirect: through fomites, tap handles, money Droplet: cough sneeze speck Via vehicle from air water food Via vectors living agents: Eg mosquitos and malaria Controlling infectious disease: Interfere with at least one of: Presence of pathogens Virulence Sufficient dose Port of entry and exist Susceptible host PHARMCOLOGY: STUDY OF DRUGS Actions and effects on living systems Health professionals- informed about medications How it works What it does to body Effects Interaction Drug: any substance or product that is used or intended to be used to modify or explore physiological systems or pathological states for the benefit of the recipient Any substance that acts on living tissues Potency – the amount of chemical required to produced a derived effect Sources of drug: Micro-organisms Humans and animals Minerals or mineral products Substances in lab Plants

Name of drugs: (nomenclature) Chemical name (chem formulation) Generic – group or family Approved – become familiar with using *** based of chem formula non proprietary or generic Trade- - brand name – should be written with capital generic must know! Eg asprins amoxicillin ( penicillin) generic brand prescribing – cheaper option – same drug- no flash advertising drug classification therapeutic use eg cost , eg antidepressant : routes of drug admin and drug formulation route oral- tablet, syrup topical – cream ointment Intranasal, drops, spray parenteral , solutions injections transdermal- patches oral drug ad: natural, uncomplex,removable dis: slow response, irregular absorption eg tablets: compressed in powder, sugar coated, disc shaped Excipient (inert binding material eg starch doesn’t act on body ) Sustained realse prep- bit of drug – resin- drug- etc When it dissolved then drug resin –slow release Controlled release : ( fancier verson) ^ Enteric coated prep: (tabs that don’t dissolve in stomach, only in intestines) Capsules hard gel, soft gel, Oral liquid: syrups, linctus Sublingual drug administration: applying drug under tongue Better absorbtion Avoids the gi tract Topical drug admin Local effects Rectal drug Ad: difficulties swalling , nausea Dis : prob with self admin Eg suppository solid drug Enema liquid topical Parenteral drug admin Drugs given by injection, solutions must be sterile, Ad alternate, quick, Dis admin, invasive, unrecoverable Eg Subtacultanoeus inject – under skin Intra inject – muscle belly Intravenous inject vein Direct into blood Avoid absorption Result in faster drug action Drug dosage: Amt and frequency Aim to achieve effects whilst avoiding toxicity May be fixed , variable maximum dose repeated Taken with food Factors influence dosage of drug: Body weight Body fat comp Body water comp Smoking Pregnancy Age Disease Other drugs Therapeutic range: Ranges of drug concentrations that should work without being toxic Minimum effective concentration Min toxic concentration Therapeutic index: Calculated by giving a large number of mice a drug that finding out at what dosage do 50% of them show an effective response and what dosage do 50% of them show toxicity. Measure of drug safety Bigger index the safer the drug Volume of distribution: Theoretical volume that determines distribution of drug b/w blood and rest of body When drug remain wholly in plasma When it remains in one tissue Used to determined dose Eg alcohol – men and women Drug clearance: Ability of an organ or the body o eliminate the drug. Livers and kidneys- get rid of drugs Drug half-life time: time for the plasma or blood concentration of drug to decrease by ½ Determines Duration of action Time taken to reach stead state Dosing frequency What is pharmacokinetics how body acts on drugs What determines drug absorption? Nature of absorption Chemical structure of drug Getting drug into plasma- need to cross cell membrane – except IV Drug distribution Transfer of drug between locations eg blood Many drugs exist in circulatory system bound to plasma proteins Only free drugs expert pharmacological effects Drug metabolism Enzymes modification of drug molecules. ( get rid of drug) Start of elimination process Metabolism of drugs by the liver renders (not lipid soluble) Bioavailability: Amt of drugs that are available to the body to produce a therapeutic effect. Expressed as a % Drug excretion – going outside of body eg kidneys roll Other routes Breast milk Breath Pharmacodynamics: studies of the biological and therapeutic effects of drugs how drugs act on out body. Drugs act on DNA Act via a chemical reaction Drugs act by binding to protein molecules Receptors large groups of proteins that are drug targetd Chemical signalling- bw and within cells What is a ligand Molecules that bind to receptors Types families: Membrane bound Insulin Cytoplasm Steroids How do drugs act on receptors Binding to receptors on cell membrane or inside cell Lock and key analogy (specific) Either bind as an antagonist agonist Agonist and antagonist Binds to a receptors and produces the same response as the endogenous ligand (from within) Full or partial Antagonist Bind to receptor and blocks access of endogenous ligand Blockers **

Week 3 LECTURE D: The lymphatic (immune system) Structure made of lymphocytes scattered connective tissue Tubes around the body Functions: Drained excess fluid + proteins from tissues > back to blood circulation Transports fats and vitamins from gut. liver ( digestion) Responsible for immunity/resist from disease Components: Immune cells Lymph tissue Lymph vessels Lymphatic organs + tissues Immune cells: ( white blood cells) Lymphocytes- kep players Produced from the same precursor cell in the bone marrow Mature in bone marrow or thymus ( b t cells ) Lymphocytes subdivided into t cells, b cells, nk cells Cytotoxic t (killer cell) Helper t cells (helps all immune cells to do job ) Suppressor t cells (supress immunity) Memory t cells (attack pathogens) B cells( antibody making factories) Plasma cells Nk cells( natural controlling whole body destroying pathogens in tissues)

Lymph (fluid) Contains lymphocytes + macrophages+ enemies they seek and destroy Foreign cells (microbes) Foreign proteins Cancer cells Plasma proteins and rbc usually not found Organs: Lymph flows through tubes from tissues to venous system Lymphatic capillaries Lymphatic vessels (trunks + ducts) Circulation Blood plasma (from capillaries) Interstitial/tissue fluid Lymphatic capillary Lymph vessels, trunks + ducts Blood plasma (vein at base of neck) Lymphatic capillaries: Capillaries that begin as blind ended tubes Structure similar to blood capillaries One layer of endothelial cells supported by basement membrane Structure helps to let fluid in but not out Fluid inside is called lymph Lymph capillaries in intestinal villi = lacteals Lymph vessels ( similar to veins) Thin walls Resemble veins > more valves Have lymph nodes at intervals Respiratory and muscular pumps promote flow of lymph towards large veins/heart Lymph ducts: Vessels unite to form 2 thoracic ducts Right side head,arm,chest, empty into right lymphatic duct Left side and lower body empties into main thoracic duct (largest vessels) Lymph from ducts flow into left & right subclavian veins Lymphatic organs and tissues Primary: red bone marrow , thymus Secondary Spleen Lymph nodes Diffuse tissue : Tonsils, adenoids + payers patches

Primary lymphatic organ 1 : Red bone marrow In flat bones, end of long bones , contain( hematopoietic stem cells) Produces + matures b cells and make pre t cells ( lymphocytes) Secondary organ 2 Thymus gland (in mediastinum Large in infancy Max size 70 g Atrophy T cells mature here Thymus makes thymosin hormones for dev secondary lymphatic organ 1 Lymph nodes Along lymph vessels Multiply lymphocytes ( their job) Filter lymph afferent vessels Foreign matter trapped in fibres Efferent vessel leaves node with cleaner lymph Spleen (secondary lymphatic organ Between stomach and diaphragm Lymphoid tissues MALT (MUSCOSA ASSOCIATED LYMPHOID TISSUE) Eg tonsils BODY DEFENCES: LECTURE B WEEK 3 Antigen: Anything foreign to use: Microbes Protein from other species Horse serum, dust mite, cat hair, pollen Transplanted tissue Defence: Invaders target is your tissues Sp protect the tissues First line defence – all outside stop entry of antigen Second line -stop if already in tissue Third line – the final weapon

Portals on entry and exit for microbes: Mouth gut or longs Nose Eye Urethra Vagina Anus skin/mucosa Defending the portals against pathogens Physical protection Chemical protection Biological protection Body defences: Non-specific- Specific – First line – non specific Aim keep invaders out Eg skin, flushing urine, lysozyme (physical +chemical) Innate inborn Second line defence- non-specific Any invader inside is unwelcome Recognise invaders have entered flight them all in same way Phagocytosis, fever, inflammation Phagocytosis Wbc patrol body looking for invaders Attracted to the site by chemotactic Destroy and clean up Neutrophils, macrophages Natural killer (nk cells) INFLAMMATION Localised response Damaged cells send chem messages Body responds with inflammation This process supported by phagocytosis Role of inflammation Destroy + removes agent ( immune response Limits effects of injurious agent Cleans up dead tissues and debris Repairs or replaces damaged tissues Promotes healing ( essential for healing) STAGES OF INFLAMMATION: VASODLIATION Increased BV diameter More blood to wound Cells, chemicals leave blood into tissues Remove toxic products dead cells 2 phagocyte migration Phagocytosis Cell eating Neutrophils arrive first chemotaxis – attracted to sites more mad e- leucocytosis short lived, die early monocyte come next once in tissue turn into macrophages very big dead phagocytes+ damaged tissues = pus purulent = full of pus 3 repair: reapir cannot occur until injurious agent is removed inflammation is necessary Signs of inflammation Redness - vasodilation Pain – chemical discharge Heat Swelling Loss of function fever Systemic response- all over the body all system effected Temperature regulator in hypothalamus is reset body tries to attain this new higher level if prolonged ( dangerous) fever good in short term Antimicrobial chemicals Interferon – works against virus’s 2 sources white cells own cells which have viruss Complement – group of proteins all of these support immune cells THIRD LINE THE LAST RESORT Need to know weak pints of the enemy and plan attack Specific immunity Third line is humoral immunity Found in ( body fluids) Differs from non specific It is specific ( only one target) Lock and key Bug/antigen= lock antibody= particular kkey to open( kill it) Each key can open 1 lock the key ( the workers) in humeral immunity it is antibody b cells makes hand grenade which kills b cells doesn’t directly touch antigen in cells mediated immunity the t cell is the key t cell strangles the antigen/bug with bare hands third line defence uses b and t lymphocytes from stem cell in bone barrow b cells make antibody ( immunoglobulin) work against ( microbes / toxins that circulate in blood and body fluids) Antibodies: 5 classes: IGM– big lasts short time made in new infection IGG – memeory antibody – quicky made in further infection smaller IG A – ON LINING SURFACE IN BLOOD IG E – ACTIVE IN ALLERGIES ( PARASITE PROTECTION) IG M

SPECIFIC and memory : two significant characteristics EACH B CELL OR T CELL IS PROGRAMMED TO ACT AGAINS ONE INVADER ONLY Measles antibody will stop you from getting measles again Measles antibody is no use against mumps virus Humeral immunity It has memory Every different target with cause fighter to be made Who will remember And react instantly next time it sees the same enemy Cell mediated immunity T cells Cell kills direct Work against: microbes, fungi , transplanted tissue, cancer cells

Lecture c nerves: Brain & nerves control body’s functioning’s Damage may disease or death Many drugs affect/impair enhance nervous function Disease may affect it too Functions: 3 major functions Sensory – knows what is happening Integration – makes decisions ( receives,process,compares,responds) Motor- does something about it (response) Divisions of the nervous system: Central nervous system Cosists of the spinal cord and brain Peripheral nervous system Includes all neural tissues outside cns Divisions of the PNS ; Afferent: ( sensory info) Brings sensory info to cns from receptors in peripheral tissues and organs. Efferent existing the cns ( motor command) Somatic nervous system Controls voluntary and involuntary ( reflexes) muscle skeletal; contractions. Autonomic nervous system Parasympathetic & sympathetic divisions Controls subconscious actions, contractions of smooth muscles( digestive tract) and cardiac muscles and glandular secretions. Hostology Neural tissues contains two kids of cells 1 neurons- cells that send and receive signals neuroglia -cells to support and protect neurolgia smaller & more support protect nerve cells maintain homeostasis insulation- not all are insulated (nurons) phagocytosis- eats maintain potassium balance make and circulate fluid nerve regeneration neurons: basic functional unit structure of neurons: cell body, short branched dendrites, long single axon cell body nucleus (genes) organelles dendrites: highly branched receives input from other neurons axon: long carries electrical signals away from cell body to other neurons axon terminals some swell – synaptic end bulbs synaptic vesicles>( little swellings) release nurons: the synapse: presynapitic cell * neuron that sends messages postsynaptic cell cell that receives messages the synaptic cleft small gap separating the presynaptic membrane and post synaptic membrane. Neurotransmitters: Chem Excite or inhibit the impulse (message received, end of axon, released chem in gap, they bind to next cell) Drugs may mimic, enhance or dampen down these Neurotransmitter examples: Adreline Serotonine - depression Endorphins- Are released from terminal Trigger a response Then are degraded Nerve structure: Nerves Many cells lie together Cell bodies look like a swelling Their axons are called nerve fibres Budles of fibres: In the CNS CALLED TRACT PNS CALLED NERVE COLLECTION OF CELL BODIES Cns nucleus – can be inside a cell containing genes Pns gaglion Myelin sheath Made by glial cells Fatty white sheath around axon Electrically insulates axon Increases speed of transmission (Salutatory conduction) white matter= my eliminated grey matter= unmyelinated lecture a week 4: NERVE PHYSIOLOGY: RESTING MEMBRANE POTENTIAL: EXCELLULAR FLUID AND INTRACELLULAR FLUID (cystol) Concentration gradient of ions (potassium, sodium) Cells have selective permeable membranes Many more leaking potassium channels than sodium Membrane permeability higher to potassium Polarisation: At rest More sodium on outside More potassium and protein ions inside Outside is more positive than inside Inside is more negative than outside Difference ( potential) across the membrane is -70 mv ( volts) State is maintained: the polarised state –able to leap into action Action potential: When membrane potential changes the balance changes Net balance goes from -70 to 30 But must go back again The signal that makes it happen is called action potential Signal ( message is repeated every step along the way Called propagation Nerve impulse: Action potential is progated along a nerve ( dendrite or axon Dendrite can transmit an action potential But only axon can generate start one Depolarisation: Membrane has channels for some ions May be always open or may be gate d Some gates are controlled by voltage Signal opens sodium gate> sodium rushes in > more permeable to sodium Inside is now more positive So not – 70 mv difference but 30 mv No longer polarised More sodium in becomes more positive !! * 60 voltage gate/channel open > sodium comes into cell until +30 mv > back to rest by closing sodium voltage channels > potassium voltage channels open to bring down to -70 > leaves cell becoming more negative (ACTION POTENTIAL TRASNMITTING SIGNAL) DEPOLIRISARION – MEMBRANE BECOMES LESS NEGATIVE REPOLIRISATION- MEMBRANE BECOMES MORE NEGATIVE HYPERPOLISATION- over shoots MORE NEGATIVE THAN RESTING MEMBRANE POTENCIAL Sodium pump: Trys to restore things Balance of sodim and potassium on either side must be regained Refractory periods: Time when membrane is closed for business Impossible for another impulse to start when sodium gates are open Absolute refractory period After that ( until back to -70 mv) Can do so only with a very strong stimulus Relative refractory period- Nerve nerve transmission Synapse: Junction b/w 2 nerves or neve & effector ( muscle) pre and post synaptic cell Nuerotransmitters released from terminal ( chemicals) Trigger a response ( carry message across gap) `1 action potential arrives and depolarises the synaptic terminal extracellular calcium enters the synaptic terminal, triggering th exocytosis aCH binds to receptors and depolarises the postsynaptic membrane ach is removed by AchE