Oral Anatomy 3 Flashcards
Blood
- A fluid connective tissue
- The substance which form transport system of the body.
- PH 7.4
Function of blood
- Transport - Oxygen and carbon dioxide, Nutrients to the tissue, waste to excretory organ, hormones from endocrine glands to their target gland/ tissue.
- Maintain body temperature
- Forms the clotting mechanism
- Help immunity - transporting antibodies to the area of infection.
Blood Volume
- Average human being 5.6Litres blood
- 8% of total body weight
- 1 Litre in the arterial system
- 1 litre in the capillary system
- 3 litres in venous system
Blood composition
- 55% Plasma
- 45% Cells ( 41% Red blood cells , 4% white blood cells)
Plasma
- Straw coloured fluid
- 90-93% water
- Rest - Plasma protein, Clotting factors, Mineral salts, Nutrients, waste products, Hormones, Antibodies, Gases
Plasma function
- Salt and proteins imported in maintaining balance of water in tissues and in blood - in balance results in oedema
- Caries nutrients from alimentary canal to body tissues
- Carries waste eg. Uric acid to kidneys and CO2 to lungs for excretion
- Carries antibodies e.g immunoglobulins involved in immune response
Blood cells
- Erythrocytes- Red blood cells
- Leucocytes - White blood cells
- Thrombocytes - Platelets
1- Erythrocytes
- Biconcave , circular
- Non - Nucleated
- Developed in 9days
- life span 120. Days
- 7 microns in diameter , 2 micron in diameter
- Formed in red bone marrow
- Contain Haemoglobin - involved in transportation of oxygen around body .
Leucocytes
- Larger than erythrocytes
- In fewer number
- Nucleated
Types of Leucocytes
- Granulocytes
- Agranulocytes
1- Granulocytes
3 Types : Neutrophils, Eosiniphils, Basophils
- Granule in cytoplasm
- 75% of white cell count
- 1-2 day life span
- 12-15 microns in diameter
- Development 2 weeks
1a - Neutrophils
- 70% white cells
- 4-5 lobed nucleus in N or S shape
- Phagocytose bacteria
- Attracted to area of infection by chemotaxis
- Lysosome granules degrade ingested material
1b- Eosinophils
- 4% white cell count
- Bi- lobed nucleus
- Neutralise histamine released in allergic reactions
- Histamine cause vasodilation and increase permeablity vessels
1c-Basophils
- 1% white blood cells
- Kidney shaped bi- lobed nucleus
- Called mast cells when in tissue
- Contain histamines and heparin granules
- Promotes entry of blood into inflamed tissue - allows movement of antibodies and phagocytes.
2-A Granulocytes
- No granules in cytoplasm
- 25% white cell count
- Life span 2-3 days
- 2 types Lymphocytes and monocytes
2a- Lymphocytes
- 23% white cell count
- 8-12 microns in diameter
- Large nucleus
- Formed in bone marrow - Transported by blood to lymphoid tissue to be activated to respond to antigens.
- Effector cells destroy specific antigens.
- Memory cells remain in lymphoid tissues to pass on capabilities to subsequent generations (immunity )
2b- Agranulocytes - Monocytes
- 2% of white cell count
- Large monoculear cells
- 18 microns in diameter
- Circulated in blood stream for two days then migrate into tissues to become macrophages
- Phagocytes bacteria , cellular debris , cancer cells and dead and dying cells .
2c- Thrombocytes
- 2-4 microns in diameter
- 8-11 day life span
- Originates in red bone marrow
- Non- Nucleated
- Granules in cytoplasm
- Involved in haemostasis and coagulation
Immunology
- The defence system of body
- Two lines of defence - Natural immunity and Acquired immunity
A- Natural immunity
- First line of defence
- Non specific
- No memory
- Acts in same way at each exposure
E.g Skin, tears, cough reflex, Saliva, Stomach acid
B- Acquired immunity
- Second line of defence
- Highly specific
- Has memory
- Capable to defence in repeated exposure
- Two system : Cell mediated and Humoral immune system
- Work together in balance to mount an appropriate response to challenge.
Cell mediated immunity
- T- lymphocytes by thymus glands
- released into circulation.
- Respond to specific antigen no matter what encounter
- Antigen must be presented to the T- Lymphocyte by antigen presenting cell. Like Macrophage - Phagocytoses antigen and displays fragment of it own cell membrane.
- When contact is made produce 3 cells
- Memory cell- created to respond to future contact with same antigen
- Cytotoxic cells- attach to target cell and produce toxin to destroy it
- Helper cells - Work with B- lymphocytes to produce anitbodies can not be produced without simulation from T- cells
- Produce cytokines - Support cytotoxis cells
Humoral Immunity
-B - lymphocytes processed in bone marrow
- Exist fixed in lymphoid tissues
- Produce proteins called Antibodies which bind to and destroy target specific antigens
- Antigen do not need to be presented
- Once antigen detected , Help comes T- Lymphocyte, B- Lymphocyte enlarges and divide into 2 : Plasma cells - secrets antibodies into blood . Memory cells- Cell remain in the body to respond in future encounter with same antigen
-
Antibodies
- Bind to antigens- Label them for destruction by other cells
- Neutralise bacterial toxins
- Activate complement - system of protein aids immunity , increases chemotaxis/ phagocytosis.
Immunisation
- Memory cells form basis of immunisation
- Vaccine (antigen) given to induce small immune response
- Body then recognise antigen and produce antibodies to fight it.
- Booster given as antibody levels fall unless antigen encountered again.
- Presence of memory cells rapidly induces greater secondary response
Oral cavity
-Saliva
- Mucosa
- Crevicular fluid
Oral Cavity Immune response
- Salivary ImmnogolinA (IgA) presented attached to bacteria to oral mucosa
- If antigen penetrates mucosa , Phagocytoses by macrophages in sub- mucosa, these stimulate T- helper cells to initiate immune response.
- Neutrophils - Migrate from blood vessels into gingival crevice and on into mouth.
- Increases in presence of Perio
Bones of the skull
Relationship of anatomical structure
- The human body divided into 3 planes
- 1- Sagittal / Median plane - body split vertically
2- Transverse plane - Across body
3- Coronal plane - Vertical plane at right angles to sagittal / median plane.
Position of body structure
- Anterior or ventral
- Posterior or dorsal
- Superior
- Inferior
Median plan - Medial and lateral
- Lateral being further away from midline
The Skull
It protects :
- The brain
- The organs of special sense
- The cranial part of the respiratory and digestive systems
- Provide attachment for many muscles of the head and neck.
- Composed of 28 bones
- Structure of the skull can be divided into 2 areas : Cranial skeleton and facial skeleton
Cranium
Composed of 8 bones
1 frontal bone
2 Parietal bones
1 occipital bone
2 temporal bones
1 sphenoid
1 ethmoid
1Frontal
- Forms the forehead, roof of the nasal cavity and orbits
2Parietal
- Form sides and roof of the Cranium
1 Occipital
Back of head
2Temporal
Side of head
Sphenoid
- Forms middle portion of base of the cranium
Ethmoid (eye)
- Light bone at the base of skull, helps to form the orbits eye and nose
Superior aspect of skull
- Convex covered with 3 sutures
- Coronal - divides frontal from parietal
- Sagittal- Centre of skull front to back
- Lamboid - Divided parietal and occipital
Anterior aspects of skull -
- Forms the facial skeleton
- Many bones are pieced together by sutures, except the mandible which is movable joint
Anterior aspects of skull -
- Maxilla (2)
- Nasal (2)
- Mandible (1)
- Lacrimal (2)
- Zygomatic (2)
-Palatine (2) - Vomer
- Inferior Turbinates (2) part of maxilla connect with ethmoid
Feature of the Anterior Aspect
- Supra- orbital Foramen
- Infra- orbital foramen
- Anterior Nasal spine
- Orbit
- opening in the orbit
Supra - Orbital Foramen
- Transmission of the ophthalmic division of the 5th cranial nerve
Infra - Orbital Foramen
- Transmission of the. Terminal branches of maxillary division of the 5th cranial nerve
Anterior Nasal Spine
- Anterior nasal spine of maxilla
Orbit
4 walls
- Roof - Frontal and lesser wing of sphenoid
Floor - Maxilla
- Medial - Lacrimal and parts of maxilla , ethmoid and sphenoid
- Lateral - Zygomatic and greater wing of sphenoid
Opening of orbit
- Optic Foramen
- Superior orbital fissure
- Inferior orbital fissure
- Naso Lacrimal duct
Lateral Aspect of Skull
- Ramus of mandible
- External Auditory Meatus
- Mastoid process
- Styloid process
- Glenoid fossa
- Articular Eminence
- Temporal Fossa
Ramus of Mandible
- Condyle for articulation in the glenoid fossa (front one )
- Coronoid process for muscle attachment. ( back one)
Mastoid Process
- Air filled
Styloid process
- Attachment of stylo- Glossus and stylo- hyoid muscle
- Attachment of stylo- hyoid and stylo- mandibular ligament
Glenoid fossa
- Articulate with condyle of mandible
What protect dislocation of TMJ ?
Articular eminence - Anterior to Glenoid fossa
Temporal Fossa
- Origin for temporalis muscle
Inferior Aspect of skull
- Horizontal process of maxilla (paired)
- Horizontal process of palatine Bone (paired )
- Incisive Foramen
- Greater palatine Foramen (paired )
Horizontal process of maxilla
- Anterior 2/3rd of hard palate
Horizontal process of palatine Bone
- Posterior 1/3rd of hard palate
Incisive Foramen
- Posterior to central incisors (terminal branches from the spheno- palatine ganglion.
Greater Palatine Foramen (paired)
- Palatally to upper first molar
- Passage for branches of the spheno- palatine ganglion
Middle part
- Situated from the posterior border of the palate to the Foramen magnum contains
- Medial Pterygoid plate
- Lateral Pterygoid plate
- Pterygoid Hamulus
- Infra Temporal crest of the greater wing of the sphenoid Bone.
- Carotid canal
- Foramen Lacerum
- Glenoid Fossa
- Stylomastoid Foramen
Infra temporal crest of the Geater wing of sphenoid Bone
- Foramen ovale - Passage for mandibular division of 5th cranial nerve
-Foramen Spinosum - passage for middle meningeal artery and nervous spinosus
Passage for Carotid artery ?
- Carotid canal
Passage for blood vessels
- Foramen Lacerum
Which part articulate mandibular condyle
- Glenoid fossa
Passage for 7th cranial nerve?
Stylomastoid Foramen
Posterior part
- Foramen Magnum (passage for medulla oblongata)
- Occipital Condyle (paired) articulates with atlas vertebrae
-Jagular Foramen ( passage of Jagular vein and the 9th, 10th and 11th cranial nerve) - Posterior condylar canal.
-External occipital Protuberance- slightly roughened for muscle attachment.
Feature of anterior cranial fossa
-Orbital plate of frontal bone (above the orbit)
-Cribriform plate of the Ethmoid Bone.
- Crista Galli.
- Lesser wing of the sphenoid Bone.
Feature of the Mid Cranial Fossa
- Optic Foramen - Passage of optic nerve
- Hypophyseal Fossa (Sella turcica) - Optic chiasma and pituitary gland
- Foramen Rotundun
- Foramen Ovale
- Foramen Spinosum
- Foramen Lacerum
- Petrous Portion of Temporal Bone
- Internal Auditory meatus
Feature of Posterior cranial Fossa
- The largest and deepest fossa - Foraman magnum
- Jagular Foramen (paired)
- Hypoglossal canal ( 12 cranial nerves )
