Revision for 1020

• - Made up of a lipid bilayer which prevents solutes from entering the cell through diffusion
• - contains specialised receptors
• - keeps the cell shape
• - acts as a barrier

• - Functions as the the transport system of the cell
• - moves proteins and other substances around the cell
• - also is involved with synthesising of proteins

Smooth and Rough ER (Rough has ribosomes attached)

Make proteins

- Modifies proteins that are given to them when the golgi appartus and endoplasmic reticulum fuse together

Provide cell with energy through aerobic respiration

- eat foreign particles within the cell as self-defence

• - Stores genetic material
• - cell division
• - regulating cell function

• - Ribosome and protein production
• - Storage of genetic material - Chromatid - DNA Helix with proteins which form chromosomes.

- consists of the all the viscous material within a cell and keeps everything in shape and place

• - Bacterial
• - Plant
• - Yeast
• - Mammalian

• - Diffusion: passive form of transport involving water
• - Active transport: mediated by carries or channels
• - Endocytosis: uptake of particles that dont fit through the cell membrane
• - Phagocytosis: ingestion of particles
• - Exocytosis: release of large particles out of a cell

Found at polar regions of the cell and serve a purpose in cell division

Hair like structures on the cell that wave in a co-ordinated way

Propellar system used for movement of the cell

Cardic cells - lots of mitochondrion cells so the cells never get tired - need lots of energy

Sperm cells- have flaggelae for movement within the fallopian tubes

Salivary Glands - contain heaps of ER, ribosomes and have a prominent GA to produce he secretion of saliva

• - Epithelium
• - Nervous
• - Muscle
• - Connective

Epithelium consists of sheet of cells that are joined together. It does not contain any blood vessels but is rick in nerves.

• Functions:
• = protects us from injury -> can regenerate and detect potential threats i.e. fire, burning - nerves tell us to pull hand away from flame
• = Gas exchange and absorption of nutrients
• = Secretes lubricants

• - Simple Squamous: sacs of lungs
• - Simple cuboidal: kidneys
• - Simple columnar: digestive organs
• - Stratified squamous: skin, vagina
• - Stratified cuboidal: lines sweat gland ducts
• - Stratified columnar: mammary glands

Consists of intracellular substances, fibres and cells.

Its main function is to support and connect other tissues. It also binds them to the skeleton

Types: Adipose tissue, bone, cartilage, blood, areolar connective tissue

Muscle tissue is composed of specialised cells which are able to contract or shorten in length and subsequently relax again to move the body.

• 3 Types:
• - Smooth: no cross striations and is involuntary
• - Striated or Skeletal: voluntary under somatic nerve control with striations
• - Cardiac: involuntary with striations

Nervous tissue is highly specialised and its main function is to transmit impulses from one part of the body to another.

It has a effective relaying system to provide appropriate and fast responses to stimuli

If muscle tissue did not work together with nervous tissue, muscles would not be able to contract - they are under voluntary control.

• - To be able to see what kind of envrionment the patient has inside their mouth and why
• - Certain bacteria = create oral diseases and thrive in certain environments, dentists and microbiologists can get to the bottom of patients diseases

Entamoeba gingivalis

Examples: Bacteria, Fungi and Protozoa

• - Nuclear Material is separated form the cytoplasm
• - Reproduce by binary fission (Externally)
• - Either Prokaryotes or Eukaryotes

Example: Viruses

• - Needs a host, cannot produce its own energy
• - Genetic material is either DNA or RNA
• - NO cytoplasm
• - reproduce by disassembling genetic material and reassembling new generation of viruses inside the cell

• - DNA is floating around the cytoplasm (single, circular, double stranded)
• - divide by binary fission
• - transfer of genetic material is by conjugation, transduction or transformation
• - Energy is produced through the cytoplasmic membrane
• - contains 70s ribosomes
• - peptidogylcan cell wall flaggelae
• - has a that contains the protein flaggellin

• - DNA is enclosed within its own membrane
• - cells divide by mitosis
• - transfer of genetic material is by sexual reproduction
• - contains membrane bound organelles
• - contains 80s ribosomes
• - some have polysaccharide cell walls of either cellulose or chittin

- Binary fission: is asexual reproduction which cell replicates own DNA and then divides into two daughter cells that are exactly the same as the parent cell

- Lytic Cycle: Attachment, Penetration, Replication, Assembly and Exit *if virus not enveloped, when it exits the cell it ruptures the wall and causes the cell to die.

- Mitosis: One parent, DNA replicate = 2 daughter cells each with half of original chromosomes and then they divide again and are fertilized

• - Conjugation: through direct cell to cell contact or a bridge like connection e.g. pillus
• - Transduction: Uses a vector to transfer material
• - Sexual Reproduction: parent cell, DNA replicates (2 daughter cells), chromatids are pulled apart and separated so 4 daughter cells come about and then are fertilized.

• - Nucleoid - one single circular chromosome
• - Ribosomes
• - Cytoplasm: semi permeable, used for energy production, synthesis of cell precursors and secretion of enzymes and toxins
• - Storage granules for energy

• - gives rigidity and shape
• - is permeable to small molecules
• - almost all contain a peptidoglycan layer ( difference of how big of a layer they have is between Gram + and Gram - bacteria)
• - some contain outer layer of a lipopolysaccharide layer which contains endotoxins

• - Diagnostic tool used for identification of unknown bacteria.
• - Was developed by Hans Christian Gram in 1882
• - By using crystal violet, iodine, an alcohol wash and safranin on a piece of cell wall we can tell by the colour (pink or purple) whether or not the bacteria is gram negative or positive -> can then use a decision tree to identify it

• - Gram+ (purple) Bacteria contain more of a peptidoglycan layer and a smaller S- protein layer
• - Gram - (pink Bacteria contain a small peptidoglycan layer and a lipopolysaccharide layer.

• - attaches to host cells
• - protects it from phagocytic engulfments
• - is a reserve of nutrients/ protection

• - morphology/ shape
• - cellular arrangement
• - cell wall structure.. etc.

Normal oral flora is a diverse group of organisms that live within the oral cavity without causing any harm or without disturbing the rest of the oral flora in the mouth.

• - crowding of the teeth: reduces cleaning efficiency
• - presence of diseases: changes oral environment and therefore the flora within it
• - amount of fermentable carbohydrates consumed: the stickyness and abrasive-ness of them
• - Medication and immunosuppressants
• - amount of saliva that is present to clear out the oral cavity
• - general health of patient - illness changes diet and hygiene practices

• - acts as a buffering system
• - maintains the pH
• - clears the oral cavity
• - lubricates the hard and soft tissues
• - acts as a nutrient source - remineralises enamel
• - provides the tooth with a pellicle (thin layer of salivary glycoproteins)

A complex microbial community found on tooth surfaces.

It is comprised of living, dead and dying bacteria that is embedded in a matrix of polymers mainly derived from saliva.

• - Streptococci mutans
• - Streptococci mitis
• - Streptococci salivarius
• - Streptococci anginosus

• - Actinomyces
• - Prevotella
• - Porphyromonas
• - Fusobacterium
• - Veillonella

• 1. Gram positive cocci attach to pellicle
• 2. bacteria reproduce
• 3. new bacteria attach onto already attached bacteria cells
• 4. keeps reoccurring until it is a mature biofilm
• 5. during this all extracellular matrix of salivary glycoproteins are being embedded into the biofilm

Calcified mature plaque - usually found around salivary gland ducts.

• - Is the localised destruction of the tissues of the tooth by fermentation of dietary carbohydrates.
• - It is a chronic endogenous infection (caused by changes within the normal oral flora)

*Cavitation can occur when plaque micro-organisms metabolise dietary carbohydrates and produce acid which demineralises the tooth structure.

• 1. "White Spot" lession -> chalky white spot on tooth that can be remineralised to become inactive
• 2. Cavitation -> no longer reversible and an intervention must occur to prevent the cavity from becoming bigger.

• 1. Host Factors
• - tooth structure: enamel quality, fluoride, morphology
• - Saliva: composition, flow rate, buffering and remineralising capacity
• 2. Diet
• - frequency of intake of carbohydrates and the form of it
• - sugary and acidic foods drop the pH of the oral environment - take up to an hour to remineralise again by the acid diffusing out and saliva creating the buffering effect.
• - repeated and frequent composition is bad
• 3. Time
• - carious process consists of periods of destruction and repair
• 4. Plaque Micro-organisms
• - Streptococcus mutans is involved with enamel lessions and loves low pH's. It can also rapidly metabolise sugars and can produce intracellular polysaccharides which act as their own food storage.
• - Lactobacili is involved in progression of the lession into the dentine
• - Actinomyces is involved in root caries
• - Veillonella is also commonly found to be involved but not 100% sure

The Stephan curve describes the change in pH the oral cavity experiences after the intake of dietary carbohydrates. it takes 15 minutes to recover and return to a normal pH.

This hypothesis believes that one or more specific bacterial groups are principally involved in caries i.e. Streptococcus mutans.

Believes their is a heterogeneous mixture of non-specific bacteria (lots of different bacteria that can cause the disease).

Believes that the intake of sugar affects the oral environment which changes the growth of certain nasty bacteria in the mouth.

- They can be used to establish the numbers of certain bacterias within the oral cavity e.g. Streptococcus mutans

• - Access to the habitat/ oral cavity
• - Adherance - stick to the surface or bacteria already there and
• - Growth - must have the desired environment to grow

• - A disorder of the supporting structures of the teeth including gingivae, periodontal ligament and alveolar bone.
• - Two Catergories: Gingivitis and Periodontitis

• Gingivitis:
• - Is a reversible inflammation that involves the marginal gingivae.

• Periodontitis:
• - Where the inflammation extends deeper into the periodontium.
• - is characterised by the loss of attachment of the tooth and alveolar bone loss
• - Irreversible

• - Plaque is necessary
• - Environment of the oral cavity need to be desirable
• - Time - long process
• - Host Susceptibility - host must be susceptible
• - Key Microorganisms need to be present.

• 1. Plaque starts to accumulate
• 2. Gram positive bacteria present
• 3. Population of Gram negative bacteria overcome population of Gram positive

*Normally only Gram positive cocci.

• Gingivitis: more Gram positive rods (Actinomyces) and Gram negative organisms
• Periodontitis: More Gram negative organisms found subgingivally.

Based on the accumulation of plaque being the sole cause.

This however does not explain how some people have lots of plaque and no disease and others have little plaque but heaps of disease.

Is the result of the overgrowth of one or a small group of a specific organism.

• Includes Three Factors:
• 1. Specific pathogens are presents
• 2. Conditions in the oral cavity are optimal
• 3. Host is susceptible

*Plaque causes inflammation

• - Host defence systems
• - Virulence factors of bacteria i.e. do they have fimbriae to attach to tissues

• 1. Spirochaetes
• 2. Aggregatibacter actinomycetemcomitans

* Difficult to define the species involved as they are difficult to culture and obtain and different sites may have different pathogens. Also sometimes opportunistic species grow at the same time and are often in small numbers but are very aggressive.

• 1. Initial - few neutrophils and lymphocytes
• 2. Early Lesion - 4-7 days plaque accumulation and formation of dense lymphoid cell infiltration i.e. swelling
• 3. Established - Lymphoid infiltrate characterised by plasma cells - loss of connective tissue and junctional epithelium (2-3 weeks)
• 4. Advanced Lesion - loss of alveolar bone and widespread manifestations of inflammation and tissue damage.

• Endogenous:
• - come from within the natural environment. Are controlled by host response.

• Exogenous:
• - are not apart of the normal oral flora and need to be completely removed from the oral cavity via antibiotics.

• 1. presence of the pathogens
• 2. Local environment is encouraging it
• 3. host is susceptible

Homeostasis describes the the body state where all internal conditions are in balance with eachother.

• 1. Receptor
• 2. Control Centre - receives and processes
• 3. Effector

Result = Homeostasis.

• Negative Feedback System:
• - reverses or negates the change e.g. shiverring when cold to get warm again
• - minimizes the change to keep within normal limits.
• - e.g. blood pressure

• Positive Feedback System:
• - is where the response enhances the change in the original condition
• - e.g. breast feeding

Different people have different homeostatic set points which allows there to be some range of normal when looking at, for example, body temperatures. Can change due to gender, race, general health and natural environment.

*If the balance between host defences and pathogen virulence - infection can occur.

• - Innate or Natural (Uses phagocytic cells)
• - Learned or Adaptive (More Specific to certain infections/ diseases and uses lymphocytes)

• - Is our inbuilt, native and natural immunity to resist infection.
• - has cellular and humoral components

• Cellular: involves neutrophils, macrophages, natural killers and eosinophils
• Humoral: Complement system and lysosomes or acute phase response

• - It is a biochemical series of chemical reactions that helps clear pathogens from an organism.
• - it enhances the uptake of a particle and can active various cells, participate in regulation of antibody responses and can manufacture those that make cells burst (Osmotic lysis).
• - Has alternative and Lectin pathways - classical pathway is a mechanism of the adaptive humoral immunity

*Acute phase responses involves looking at the concentration changes of plasma proteins during infection. Looks at C-reactive proteins (Activates the classical pathway in the absence of an antibody) and Serum Amyloid

• T-cells:
• - have markers on their cell surface (CD Antigens)
• - can be divided into two sub groups -> CD4 and CD8 cells
• - CD4 cells produce soluble factors and help T and B cells
• - CD8 cells kill virus infected cells (Cytotoxic T cells)
• -make mediators and kill virus infected cells

• B- cells :
• - make antibodies

Have cells that have been educated for specific recognition of their targets.

• Primary lymphoid organs are in the bone marrow and the thymus
• Secondary lymphoid organs include the spleen, lymph nodes etc.

- Programmed cell death and unplanned accidental cell depth respectively.

• 1. Epithelial cells - first like of defence to block entry of micro-organisms
• 2. pathogens damage epithelium and since they are damaged they are "activated" which means chemokines and cytokines are then released
• 3. Chemokines guide lymphocyte cells to area and cytokines change the morphology of the epithelial cells so permeability is reduced. Also trigger release of phagocytic neutrophils via IL2. --> Inflammation is caused (Heat swelling redness and pain)
• 4. Phagocytes then come to infection and neurtrophils and monocytes phagocytose micro-organisms

Produces more cells with a specific antigen to help fight disease.

Direct the response of T cells to foreign antigens and can present the foreign particles to them.

• Class I:
• - all cells express MHC I
• - regulation of immune responses to intracellular parasites
• - activates normal T cells: CD8

• Class II:
• - regulation of immune responses to extracellular parasites
• - not all cells express it
• - activates CD4 T cells.

It increases - affinity maturation

it must be processed within the cell and loaded onto the MHC Molecules

it is a way of producing a number of different receptors with difference specifities.

*Diversity is obtained by altering the way in which genes are combined.

So they can recognize self .

• - Lines the oral cavity
• - moist lining

• Functions:
• - protection of underlying tissues from trauma
• - Sensation - contains specialised nerve endings so can detect touch pain and pressure to furthure protect the tissues from damage
• - Secretion - lubrication of the tissues so they can rub over each other freely and easily without causing harm.

• Epithelium
• Lamina Propria
• Submucosa - has fat, glands, vascular and muscular tissue
• *Between the Epithelium and Submucosa is where the Lamni Propria lies - it has projections in the epithelium which contain fine nerve fibres (rete pegs)

• Attached Gingiva
• Hard palate
• It attaches to the mucoperiosteum - directly to bone.