Exam Flashcards
Please name the following structures
Please name the following structures
Please name the following structures
Please name the following structures
Please name the following structures
Please name the following structures
What is origin and insertion of masseter muscles?
Origin: Zygomatic arch
Insertion: Mandible angle and mandible ramus
What is the action of the masseter muscles?
Elevate the mandible
What is the origin and insertion of the temporalis muscles?
Origin: Temporal fossa
Insertion: Mandible coronoid process
What is the action of the temporalis?
- Elevate the mandible
- Retrude mandible
What is the origin and insertion of medial pterygoid muscles?
Origin: Maxillary tuberosity
Insertion: Medial surface of mandible angle
What is the action of the medial pterygoid muscles?
- Elevate the mandible
- Retrude the mandible
What is the origin and insertion of the lateral pterygoid muscles?
Origin: Infratemporl crest of greater wing of sphenoid bone
Insertion: Pterygoid fovea on Mandible condyle anterior neck
What is the action of the lateral pterygoid muscle?
Depression of the mandible
What does informed consent include?
- Alternatives and all options for treatment
- Information surrouding the nature and what the treatment involves
- Risks of treatment
- Pros and Cons of treatment and No intervention
- Cost of treatment
What is important to understand about culture?
Our culture helps to shape our perspective, biases and behaviours. And it is important to undrestand in order to provide better care for our patients, build rapport and follow civil and professional conduct.
What is bias?
It is an inclination or prejudice for or againts a particular group of people due to a particular characteristic they share
What is stereotyping?
Stereotyping is a process of addressing a group of people by a single characteristic or trait
What is discrimination?
It is acting on bias by trating people differently based on certain characteristics
What are the main ethical theories?
- Consequentialism - self explanatory - consequences we face because of our choices
- Deontology - ethics is about rules
- Virtue Ethics - ethics is about character
What is utilitarianism?
It is basically - greatest happiness for the greatest number. Most benefit = the best route
What are the four classic biomedical principles?
- Non-maleficence
- Beneficence
- Autonomy
- Justice
What is non-maleficence?
Cause no harm. Donwside: harm could be unavoitable and uncotrolled
What is justice?
Justice is giving another their due/what they are owed.
What is pubic health?
It is response of society to protect and promote health and to prevent illness
What is lifestyle approach?
It essentially based on the idea that healthy behaviours are shaped by social environment
A public health problem must…
- Be widespread or serious
- Sever consequences to individuals and societies
- High costs to individuals and societies
- Effective methods have to be available to prevent or reduce the impacts
Public health strategies must…
- Use evidence to support the need for intervention
- Use evidence to support the effectivness of interventions
- Have public acceptability and professional support
- Have an economic benefit
What are the three key dimensions of public health?
- Disease prevention
- Health Promotion
- Health protection
Who is involved in Public health?
- Government
- Private sector
- NGO’s (non-govenment organisation)
- All sectors of society
What is epidemiology?
Epidemiology is the study of the distribution and determinants of health-related states or event in specifed populations, and the application of this study to the control of health problems.
What is a directed acyclic graph?
It is a graph that can be used to describe the task of epidemiologly.
Essentially a C (confounding) is a cause that influences both dependent (Y) and independent variable (X)
What is descriptive epidemiology?
It is part of epidemiology that looks and tries to describe the dependent variable (Y).
Y could be anything, for example dental caries.
Descriptise epidemiology tries to find out how much caries is there in a given poopulation.
What is predictive epidemiology?
It is part of epidemiology that asseses the independent variable in order to predict potential outcomes of the dependent variable.
This aspect of epidemiology caould be used for target interventions.
What is the third task of epidemiology?
To investigate causes and corelations.
For example: does the independent variable (baby formula) really cause a dependent variable to change (dental caries in children).
What is an important distinction that needs to be made when assesing disease in an individual and population?
The causes at the individual level might be different from the causes at the populaiton level.
What are the advantages of high risk approach?
- It is beneficial for individuals
- Important in adressing the inequalities
What are the disadvantages in high risk approach?
- Does not change population levels of disease
- Issues in identifying who is at risk
- Does not change the drivers in population
Continue the phrase by Geoffrey Rose: “Instead of simply focusing on those at high risk we must consider the fact that…”
…a large number of people at a small risk may give rose to more causes of disease than the small number who are at high risk.”
What are the are the advnatages of population health approach?
- Triying to remove the reason why the disease is common
- Almost everyone benefits
What are the disadvantages of population health approach?
- May not address health inequalities
- Does not represent a large benefit to the individual
What is the best approach to health?
Combining both high-risk and the population approaches
What are the three levels of prevention and how do they evolve from population to individual?
- Primary - mostly population approach
- Secondary - mostly population with little bits of individual
- Tertiary 1 - population and individual equally
- Tertiary 2 - mostly individual
What is the common risk factor approach?
It is an integrated approach that allows multiple disciplines to target similar risk factors in order to obtain a reduction in disease prevelence in multiple systems.
E.g.
- Most oral conditions share risk factors with general health conditions
- Must focus on the social determinants of health
- Integration of high-risk and population approaches for prevention
- Inclusion of oral health prevention stratetgies in idfferent settings
What is surveillance?
It is the ongoing, systematic collection, analysis and interpretation of outcome-specific data, essential to the planning, implementation, and evaluation of public health practive, closely integrated with the timely dissemination of these data to those responsible for prevention and control
What are the types of measurnments of disease occurence?
- Counts (prevalence and incidence)
- Proportions (prevalance)
- Rates (incidence)
- Means
What is a count measurnment? Give examples of each type.
It is an amount at one point of time or over a paeriod of time
Prevelance - an estimated 1.2 million australians had diabetes in 2017-2018
Incidence - There were 2800 total new cses of type 1 diabetes in australia in 2018
What are proportions measures? Give an example.
It is a measurnment that is always expressed in %.
E.g. 4.9% of the total population had diabetes in 2017-2018
What are rates measurnment? Provide an example.
A unit of preson-time.
E.g. The incidence of type 1 diabetes remained relatively stable between 2000 and 2018, flactuating between 11 and 13 new cases per 100000 population each year
What are means? Provide an example.
Basically the average number for a given population.
E.g. Australian adults aged 15 years and over had an avergae of 11.2 decayed, missing and filled teeth in 2017-2018
What measurnment scale can we use to measure dental caries?
Teeth: DMFT (decayed, missing and filled teeth), ranges between 1 to 32 in adults, depedning on the 3rd molar included in scoring
Surfaces DMFS (decayed, missing and filled surfaces), ranges from 0 to 128 or 148. Surfaces: occlusal, lingual/palatal, mesial, distal, buccal
How is DMFT recorded?
- When carious lesion(s) or both carous lesion(s) and a restoration are present, the tooth is recorded as D
- When a tooth has been extracted due to caries, it is recorded as an M
- When permanent or temporary filling is present, or when a filling is defective but not decayed, it is counted as an F.
What does the DMFT scale able to asses?
- Severity of disease (M component)
- Access to treatment (F and D relationship)
- Delayed access to treatment (M components)
What is the Community Periodontal Index of Treatment Needs (CPITN)?
- 6 index teeth reprsenting sextants (4 first molars, one maxillary and one mandibular anterior incisor)
- Shallow and deep periodontal pockets (4-5mm and 6+mm, respectively), dental calculus and bleeding on probing
What is the disease control and prevention (CDC) and American Academy of Periodontology (AAP) periodontal disease case definition?
- Examination of six sites per tooth in all teeth present, excluding third molars
- Sever periodontal disease defined as the presence of at least 2 teeth with 6+ mm of clinical attachment loss in interporximal sites with pocket depth of 5+ mm.
What are the definitions relating to Tooth Loss?
- Edentulism: Complete tooth loss
- Functional dentition: Presence of 21 teeth or more
- Severe tooth loss: Presence of 10 teeth or less
- Mean number of missing teeth: mean number of “M” / “m” component of the DMF / dmf index
What is the global prevalence of oral conditions in the population?
Nearly half of the world population suffer disability from oral conditions
What is the prevalence of dental caries in the primary dentition (age 5 -10) in Australia?
41.7%
What is the prevalence of untreated dental caries in primary dentition age 5-10?
27.1%
What is the mean DMFT for primary dentition age 5-10?
1.3
What is the caries prevalence in the permanent dentition age 9-14?
23.5%
What is the prevalence of untrated decay in permanent dentition age 9-14?
10.9%
What is the mean DMFT for permanent dentition age 9-14?
0.7
What are the three major oral health surveys and when were they conducted?
- National Oral Health Survey - 1987-88
- The National Survey of Adult Oral Healh 2004-06
- National Study of Adult Oral Health 2017-18
In general how can we summarise the findings of the 3 oral health surveys?
- Dental Caries is highly prevalent
- Socioeconomic gradients in caries experience are profound
- Improvements in caries experience are observed over time, mainly for childer and young adults
Wht was consdered moderate periodontitis in the National Oral Health Surveys?
2 or more interproximal sights with attachment loss equal or above 4 mm on 2 different teeth,
or
2 interproximal sites with pocket depth equal or above 5mm on 2 different teeth
What was considered severe periodontitis in the National Oral Health Surveys?
2 or more interproximal site with attachment loss of 6mm or above on 2 different teeth
and
1 or more interproximal site with pocket depth of 5 mm or more
What is the prevelence of moderate or severe periodontitis?
30.1%
How can we summarise the finding of the 2017-18 survey in regards to periodontitis?
- Prevalence of periodontal disease (moderate or severe) in Australian populatio was 30% in 2017-18
- Periodontal disease was strongly associated with age
- Prevalence of periodontal disease was greater among those of lower socioeconomic background
How can we summaries the key points from the 2017-2018 survey in regards to tooth loss?
- 4% of the australian adult population are edentulous
- 10% of the australian adult population are having <21 teeth
- Socioeconomic gradient in tooth loss
What is a Calgary-Cambridge model?
It’s a model that shows a way a patient - practitioner relationship can be formed through out the conversation.
What is the ecosystem model?
It is a model, which shows different determinants of health for a patient. Shaped like a sphere.
What is a biomedical model?
It is a model that is based on a conception of health as absence of disease with aim to treat disease.
What is a biopsychosocial model?
It is a model that is based on a conception of health as a continuum of wellbeing, physical and mental health are integrated. Aim: to promote health and wellbeing, to reduce ill-health.
What are some of the patient-practitioner relationships?
- Paternalism
- Consumerism
- Mutuality
- Default
What are two essential elements of patient-centered care?
- Ethical protection of patients
- Legal protection of patients
What is rapport?
- Connection, shared understanding, put patient at ease
- Professional therapeutic relationship
Why is rapport important?
To build trust and confidence between patient & team.
What is empathy?
The ability to understand and share the feelings of another.
What type of question can we ask when obtaining a chief concern?
An open question
What type of questions can we ask when obtaining the medical history?
Closed questions
What is an effective way to provide info (what framework can we use)?
TRIM:
Timing
Relevance
Involvment
Relevance
What are the 5 principles of NHMRC?
- Patients are entitled to make own decisions abotu treatment and given adequate information
- Information provided in form and manner which help patient understand
- Doctors should give advice that patient is free to accept or reject with no coercion
- Patients should be encouraged to make their own decisions
- Patients should be frank and honest in giving info about health
What is the needle stick inury protocol in dental emergencies?
- Stop
- Place needle/sharp aside
- Take off gloves
- Wash hands with soap and water
- Dry and cover with non-stick dressing
- Apply pressure if bleeding
- Let tutor know
- Contact SADS registered nurse for risk assessment
- Write up incident report - SLS
What are the standard precautions?
- Personal hygiene pracitce
- Use of PPE
- Appropriate handling of and safe disposal of sharps
- Appropriate sterulisation of reusable equipment and instruments
What to do if a patient faints?
- DRSABCD - Danger, Response, Send for help, Airway, Breathing, CPR, Defibrillator
- Lay victim flat
- Raise legs
- Place on side (if pregnants)
Why do we use antiseptic fluid and paper towels to wipe table and benches?
- Antiseptic solutions reduce the bacterial and viral load BUT TO NOT FULLY REMOVE IT
- Paper towels are available, cheap and easy to despose
What is the difference between active vs arrested carious lesion?
Active - dull and frosty. Soft and leathery texture
Arrested - shiny
Why do caries spread laterally at the DEJ?
At DEJ, the dentine is less mineralised (path of least resistance)
What is primary and secondary caries?
Primary - begins on a tooth urface with no previous caries or restoration
Secondary - occurs on a tooth surface which has already had a lesion
What does the mandibular movement exam include?
- TMJ exam
- Opening closing paths
- Maximal Mandibular opening
- Maximum mandibular lateral movement
What does the static occlusal relationship exam include?
- Notation and morphology
- Arch Shape
- Crowding, spacing, rotations
- Axial incilation
- Occlusal curvatures and opposing contacts
- Angle’s molar classification + canin classification
- Overjet (mm)
- Overbite (%)
- Crossbite
- Mediolateral relationships
What are the steps of gingival assesment?
CCCTE:
Colour: general and pigmentations
Contour :
- Gingival margin - rounder or rolled
- Papillae - bulbous, blunted or craterd
Consistency: dense and firmly bound
Texture: Stippling
Exudate: Pus
(Remember genrelised or localised and “need to confirm clinically)
What are some of the diagnostic aids in dentistyr?
- Naked eye
- Dry field
- Good lighting
- Magnification
- Transillumination
- Bitwings
- Surface texture (explorer)
- Dyes and detectors
What are the steps to bitewing critique?
- Exposure
- Orientation of detector
- Horizontal detector position (look where is starts and ends)
- Vertical detector position (is the Mx and Md crowns equal?)
- Horizontal beam angulation (contact point overlaps)
- Vertical beam angulation (superimposition of buccla and platal cusps)
- Position of centra ray beam (cone cutting?)
- Rotational position of the collimator (Cone cutting?)
- Sharpness (sharp of blurry)
- Overall digansotic quality of image
What is ALARA?
It means as low as reasonably achiavable
What are the three key principals we use following ALARA?
- Time of exposure
- Distance from exposure
- Shield from exposure
What is radiolucency?
Radiolucency is a concept in which a material is able to be easily penetrated by the X-ray particles thus is shown as darker on an X-ray or bitwing radiograph
What is radiopacity?
It is a concept where X-ray particles are unable to fully penetrate an object, thus such object will be shown more lightly on an X-ray/bitwing radiograph.
When assesing a radigraph what are the potential steps?
- Specificity (what radigraph area you are reffering to)
- Radiolucency or radiopacity
- Extent
What are the features of the upper incisors?
- Ttrapezoidal from labila and triangular from proximal
- Ratio of crown height to MD diameter is close to 1
- Rounded distoincisal corners
- Central incisor is longer than lateral
- ROute toward the distal
What is the feature of the lower incisors?
- Prapezoidal from labial & triangular from proximal
- Smaller MD crown
- Very equal sides
- Mesio incisal half is longer on the lateral incisor
What are the key featurs of the upper canines?
- Maxillary canines are bell shaped from labial
- Very prominent cingulum and lingual ridge
What are the features of the lower canine?
- Distinct flat mesial side
- Less distinct cingulum
- Cusp tip pointed toward the mesial
What are the features of the Upper first Pre-Molar?
- 2 cusps
- Occlusal outline shape is hexagonal
- Labial cust is slightly higher then the palatal cusp
- Mesial developmental groove
What are the features of the Upper second Pre-molar?
- 2 cusps
- Both cusps are the same height
- Less destinct features
What are the features of the Lower first Pre-Molar?
- 2 cusps
- The lingual cusp is considerably smaller then the buccal cusp
- There isa transverse ridge
- There is mesiolingual developmental groove
- Crown is at 45 degress towards lingual
What are the features of the Lower second Pre-molar?
- Two or Three cusps (U and Y shape)
- Crown is not on an angle
What are the features of the Upper first Molar?
- 4 cusps
- Buckle-mesial cusp is the largest one
- Buckle-medial bulging
- 3 roots, 2 buckle & 1 palatal
- Cusp of carabeli in caucasians
What are the feature sof the upper second molar?
- Less paralellogram like comparing to the First upper molar
- 4 cusps
- Oblique ridge is smaller
What are the features of the lower first molar?
- 5 cusps
- 3 cusps
- 2 roots
- Buccal roll
What are the features of the lower second molar?
- 4 cusps
- Hot cross bun occlusal outline
- Buccal roll
What is a structure of the heart?
Heart sits in the mediastinum. Apex of the heart is at the bottom. The location between the sternum and vertebra column facilitate cardiac compression. Heart has 4 chambers (2 ventricles and 2 atria). Left side has a thicker wall as it needs higher pressure to pump the blood to the entire body. It protected by a pericardium – a fibrous tissue bag.
What is the function of the heart?
It maintains continues supply of oxygen and nutrients, immune cell transport, transport of waste and many more.
But also – heart pumps oxygen poor blood to the lungs for gas exchange, and it pumps oxygen rich blood to systemic organs and tissues
What are the 4 great vessels of the heart?
- Aorta
- Superior & inferior vena cavae
- Pulmonary artery
- Pulmonary veins
What are the two circuits of the circulatory system?
- Pulmonary circulatory system – RHS of non-oxygenated blood is moved to the lungs
- Systemic circulation – blood leaves the LHS of the heart to the tissues
What is the difference between the arteries and veins?
Veins carry the blood to the heart and arteries carry the blood away from the heart
What is a pericardium?
It is a multilayer sack (triple layer).
2 major parts:
- Fibrous pericardium – the most outer layer that is tough and inelastic, full of dense irregular CT. Used for protection.
- Serous pericardium – double layer that has a partial layer fused with fibrous pericardium and visceral layer fused with heart muscle tissue. It is the secretory part of the pericardium, and it secretes pericardial fluid that allows for heart beating without friction. Connects with simple squamous endothelium of the heart wall.
What are myocardia cells?
They are specialized muscles cells of the heart. They are arranged in spirals which improves heart performance (due to small amount shortage). They multinucleated cells (1,2 or up to 2 nuclia), branched and long. Have cross striation. Have intercalated discs.
What are the three structures related to intercalated discs?
- Fascia adherents
- Maculate adherents (desmosomes)
- Gap junctions
The intercalated discs help with cell-to-cell communication
What is the function of heart valves?
Heart valves prevent back flow. As pressure builds in the ventricles the atria-ventricular valves close preventing backflow.
What are cordae tendinae?
They small fibrous tissue connected to the papillary muscles that allow the heart valves to not convert.
What are the three types of valves in the heart?
- Righ AV valve – tricuspid valve
- Left AV valve – bicuspid
- Aortic and pulmonary valve - tricuspid
What are the coronary arteries?
They are hearts own blood supply. Myocardial infraction happens due to blockage of the coronary arteries. Heart attack patients should not have dental treatment for the next 6 months.
What is the electrical conducting system of the heart?
Cardiac muscle are autorhythmic but they need extra input for peacemaking.
SA node and the AV node which are connected by the internodal pathway.
AV node than brunches into left and right bundles of his and than into Purkinjean fibres.
This occurs with use of specialized muscle cells.
What is the structure of blood vessels?
There are three distinct layers to blood vessels:
- Tunica intima – endothelial cells
- Tunica media – smooth muscle – bigger in pressure vessels
- Tunica adventitia – elastic and collagen fibres
What is the function of blood vessels?
Blood vessels are designed to carry fluids over long distances, allow exchange of materials, immune transit and more.
What are some of the roles of the endothelial cells?
- Vasodilators production
- Antithrombotic factors
- Growth inhibitors
- Inflammation inhibitors
- Vasoconstrictors
And more
What is the structure of lymphatic vessels?
They are thin-walled capillaries, quite similar to the blood vessels. Have valves that are able to reduce the probability of backflow. They drain into subclavian veins of the heart.
What is the function of lymphatic vessels?
- Absorption of interstitial fluid
- Carry lymph
- Immune transit
- Lipid transport
How is the lymph moved in the lymphatic system?
Through the contraction of skeletal muscles
What are the 5 types of blood vessels?
- Arteries – thick wall due to muscles – pressure reservoir
- Arterioles – primary resistance function
- Capillaries – exchange of materials
- Venules – blood reservoir
- Veins – thinner wall – blood reservoir
What is the function of the elastic arteries?
They are involve in stabilization of blood flow/pressure and they recoil in diastole
What is the function of muscular arteries?
Control of blood flow to organs
Why is elastin important in muscular arteries?
Helps with recoil thus help with regulation of blood pressure
What is the function of capillaries?
Aid in exchange of materials through diffusion because they are thin walled
What are the 3 types of capillaries where do you find them?
- Continuous – fat, muscle and nervous system – tight junctions
- Fenestrated – intestinal villi, endocrine glands, kidney glomeruli - fenestrations
- discontinuous capillary – liver, bone marrow, spleen – larger spaces
What are the 4 specialization we should keep in mind when talking about the function of the heart?
- Arrangement of muscle fibers
- Unique connections between individual cells
- Specialization of muscle cells into contractile and non-contractile functions
- Specialization of muscle proteins
What are some of the function of the intercalated discs?
- Action potential spreads form cell to cell
- Nervous innervation rate of action potential
- Specialization of cells according to function
What are the two types cardiomyocytes?
- Contractile cells -99%
- Autorhythmic cells – conduct action potentials
Explain the pacemaker cell activity on a cellular level in 5 steps.
- The membrane potential continues to repolarize
- This triggers an opening of funny channels that allow inward flow of sodium. Closure of potassium channels also occurs which restricts the outflow of potassium
- T-type Ca2+ channels open
- Threshold is reached, the peak is achieved through opening of Ca2+ L-type channels
- At the peak, potassium channels reopen, causing potassium outflow, this results in repolarization of the cell
At what rate can each of the components of the conducting part of the electrical activity of the heart creates beats?
- SA node – 70-80 BPM
- AV node – 40-60 BPM
- Bundle of His – 0
- . Purkinje fibers – 20-40
What are the 4 steps of electrical spread in the heart?
- An action potential initiated at the SA node first spread through both atria
- The spread is facilitated by two specialized atrial conduction pathways, the interatrial and internodal
- The AV node is the only point where an action potential can spread from the atria to the ventricles
- From the AV node, the action potential spreads rapidly throughout the ventricles, hastened by a specialized ventricular conduction system consisting of the bundle of His and Purkinje fibers
Describe the action potential in contractile myocytes in 4 steps.
- The rapid rising phase of the action potential in contractile cells is the result of Na+ entry on opening of fast Na+ channels at threshold
- Early, brief repolarization after the potential reaches its peak is because of limited K+ efflux and inactivation of the Na+ channels
- The prolonged plateau phase is the result of slow Ca2+ entry on opening of L-typeCa2+ channels and reduction of K+ efflux due to close of K+ transient channels
- Rapid falling phase is the result of K+ efflux due to opening of voltage-gated K+ channels
Why is cardiac output is important?
- Delivery of oxygen
- Removal of waste
- immune transport
- Transport of nutrients and more
What is cardiac output?
The volume of blood ejected by the ventricles per minute – about 5 L of blood per minutes
What is the equation for cardiac output?
CO = SV (ml/beat) x HR (beats/min)
What is the Stroke volume?
It is the volume of blood ejected from the ventricles per beat
What is heart rate?
The number of times heart beats per minuet.
What happens to CO during sympathetic stimulation?
Sympathetic stimulation (e.g. nervous patient) causes increase in cardiac output due to increase firing of the SA node which increase the heart rate and thus according to the cardiac output, increases cardiac output.
What is the key difference between an untrained individual and an elite athlete in terms of the cardiac output?
Cardiac output in elite athletes is much higher because elite athlete’s cardiovascular system has a higher stroke volume due to expansion of the heart.
What are the changes in ventricular filling associated with changes in heart rate?
Ventricular filling decreases as the heart rate increases. This occurs due to decreased amount of time for filling between beats.
So why do my legs swell up when I go for a run?
The consensus idea is that not all vascular beds are fully open at rest – for the sake of conserving energy and blood pressure. When the sympathetic stimulation occurs, that triggers relaxation of precapillary sphincters which are structures that are limiting blood flow to the entire blood capillary bed. This increases the volume of blood in the skeletal muscles thus making your legs look swollen.
What are the events of the cardiac cycle?
- Systole – contraction
- Diastole – relaxation
- Repolarization
- Refractoriness – no other beat is able to be produced
- Relaxation
- Contraction
- Spread of action potential
- Depolarization
What is tachycardia?
High heart rate
What is extrasystole?
Premature ventricular contraction – reduces cardiac output
What are the 5 events of mechanical cardiac cycle?
- Passive filling – diastole
- Atrial contraction – forcefully pushing the blood into the ventricles
- Isovolumetric Ventricular contraction – AV valves close thus creating pressure in the ventricles
- Ventricular contraction – ventricles contract pushing the blood out into great vessels
- Isovolumetric ventricular relaxation – end of cycle – heart is relaxed and blood is being pumped in (a bit of blood stays back)
What are the intrinsic controls pf the heart create?
Auto-rhythmic activity which a spontaneous activity that is caused by funny sodium channels
What are some of the extrinsic controls of the heart rate?
- Parasympathetic stimulation – decreases heart rate – rest and digest
- Sympathetic stimulation – increase heart rate – flight or fight
- Hormonal influences – increases heart rate
What is Bainbridge reflex?
As venous return increases, there is an increase in artrial stretch which causes an increase in heart rate. Thus higher blood volume due to fluid retentions causes higher heart rate.
What is the equation for stroke volume?
End diastolic volume – end systolic volume = stroke volume
What is normal blood pressure?
120/80
What is MAP?
Mean arterial blood pressure or simply your blood pressure.
What is the equation for MAP?
MAP = Heart rate x Stroke Volume x TPR
Why is pressure kept within tolerance limits?
Because if:
- Blood pressure is low it limits the perfusion of blood to vital tissue
- Blood pressure is high it cause increased workload on heart, vascular damage therefore organ damage.
How is blood pressure regulated?
Blood pressure is regulated through both sort term and long term mechanisms
Why does little movement cause a decrease in Venus return?
The skeletal that are contracted during still movement are squeezing onto the veins which due to their structure are creating a pool of blood.
What are some of the factors that control TPR?
- Arteriolar radius
- Blood viscosity
What is postural intolerance?
It is a type of hypotension (low blood pressure). The blood is getting pulled on the lower extremities thus reducing the pressure around the brain. This reduction in pressure causes less oxygen to get to the brain and brain shuts down.
What is the compliance of elastic arteries?
Compliant arteries are arteries that are able to recoil. In older individuals compliance is lower meaning that aorta is enable to expand and recoil meaning there is lower blood pressure.
What are the major resistance vessels of the body?
Arterioles
Why is it important to regulate blood pressure using arterioles?
Arterioles are important for peripheral resistance because they are able to maintain blood pressure that smaller capillaries are able to tolerate and not burst.
What is the Law of LaPlace?
T=PxR or wall tension = pressure x radius. Thus reducing the radius of arterioles we increase blood pressure.
What are the two baroreceptors of the body related to blood pressure?
- Aortic arch baroreceptor
- Carotid sinus baroreceptor
What is the function of the baroreceptors?
Baroreceptors are able to fire signals to the heart (sympathetic stimulation) that are able to change cardiac output and cardiac function.
What are the ANP and BNP?
They are hormones that are released upon stretch in the heart. These hormones can cause kidneys to lose more sodium thus decreasing blood volume and decreasing blood pressure.
What is the differences between the baroreceptor response and the macula dense response?
The baroreceptors response is usually very rapid while the macula dense regulated response is usually slower.
What is the difference between microbiota and microbiome?
Microbiome = genetic material of microbes
Microbiota = Ecological community of commensal, symbiotic & pathogenic microorganisms.
What is the immune system?
Immune system – is a series of cells tissues, proteins and other that act together to counter act foreign bodies.
Why is it important for dental professionals to understand immunity?
- Due to advancements in medicine, people can now survive once fatal diseases
- Many oral diseases have an immune component (e.g. periodontal disease)
- Current and future therapeutics may have an impact on the function of immune system thus on oral health
- Systemic and Oral diseases are interrelated and are both dependent on appropriate function of the immune system
What is a pathogen?
Pathogens – are agents that cause or generate disease. Such as bacteria, viruses, fungi, dust mites, pollen.
What is an antigen?
Antigen – a substance that has the ability to provoke an immune response. Could be pathogenic/ not pathogenic.
What is the mode of action of an APC?
- The antigen is detected y a special receptor on the APC
- The antigen is engulfed through phagocytosis of the APC
- It is processed and then displayed on the surface of the cell’s membrane of the APC through a special antigen presenting proteins
- The presented antigen could bind with the receptor on T lymphocytes to activate them
What is an antibody?
Antibody – a glycorptoein that is produced and secreted by plasma cells and B lymphocytes (restricted thod). Also serve as receptors on B lymphocytes.
What are the classes of antibodies?
MADGE – IgM, IgA, IgD, IgG, IgE
What is a structure of the immunoglobulin?
Y shape, have variable and constant domains
What is the function of each immunoglobulin?
IgA – Found in mucous, saliva, tears and breast milk. Protect those sites against pathogens
IgD – Part of the B cell receptor. Responsible for basophils and mast cells activation.
IgE – Protects against parasitic worms. Responsible for allergic reactions
IgG – Secreted by plasma cells in the blood. Able to cross the placenta into the fetus.
IgM – May be attached to the surface of a B cell or secreted into the blood. Responsible for early stages of immunity.
What are the three functions of the antibodies?
- Neutralization
- Tag
- Activating antigen killing proteins
Why is immune system important for dental health professionals?
- Due to advancements in medicine, people can now survive once fatal diseases
- Many oral diseases have an immune component (e.g. periodontal disease)
- Current and future therapeutics may have an impact on the function of immune system thus on oral health
- Systemic and Oral diseases are interrelated and are both dependent on appropriate function of the immune system
What is a pathogen?
Pathogen is an agent that is able to cause or generate dieseas?
What is an antigen?
An antigen is a substance that has the ability to provoke an immune response. This could be pathogenic/not pathogenic
What is an immunoglobulin?
An immunoglobulin is also know is an antibody. It is a glycoprotein that produced by pklasma cells and somewhat by B lymphocytes.
Antibodies also act as receptors on B lymphocytes.
What are the three functions of the antibody?
- Neutralisation - physical blockage of the antigen
- Tag - antibodies act as “tags”, that are able to signal phagocytic bacteria to perform phagocytosis of the molecule antibodies attach to.
- Activating antigen killing proeins - self-explanatory
What is an APC?
ACP is an antigen presenting cell.
It is a cell that is able to process the antgien and present it to other cells.
It could also trigerr further immune reponse by releasing cytokines.
What are some of the common antigen presenting cells?
- Dendritic cells
- Macrophages
- Langerhans cells
- B lymphocytes
What is the mode of action of an ACP?
- Antigen is detected by a special receptor on the ACP
- The antigen engulfed through phagocytosis of the ACP
- It is processed and then displayed on the surface of the ACP cell membrane through special antigen presenting protein
- The presented antigen could bind with the receptor on T lymphocyts to activate them
What are cytokines?
Cytokines are the chemicals of immunity. They are repoduced by activated cells and are able to change the behaviour of other cells.
What is a strucutre of immunoglobulins?
Y shape, have variable and constant domains
What is the function of IgA?
It is found in mucous, saliva and tear. Protect those sites from pathogens
What is the function of IgD?
It acts as a B cell receptor. Responsible for basophil and mast cells activation
What is the function of IgE?
Protection against paracitic worms. Important in allergic reactions.
What is the function of IgG?
Secreted by plasma cells in the blood. Able to cross the placenta into the fetus.
What is the function of IgM?
Responsible for early stages of immunity.
What are the two types of lymphatic organs?
- Primary - generator organs - red bone marrow and thymus
- Secondary - immune and other functions - lymphoid vessels, lymph nodes, spleen and follicles.
What are the lymphatic vessels?
They are thin walled ubes lined with endothelium and surorunded by thin layer of smooth muscles. Carry lymph. Terminate near the subclavian artery.
What is the spleen?
Spleen is the organ of the secondary lymphati system. it has 2 functions filtering blood form the ntigen and removal of old red blood cells
What is the thymus?
It is an organ of the primary lymphatic system that is used for development/maturation of T lymphocytes. It has a plae center with activated T lymphocytes.
What are lymph nodes?
They are organs of the secondary lymphatic system that are used for antigen presentation.
What are lymphoid follicles?
They are organs of the secondary lymphatic system that are situated under the epithelium for protection from ferieng invaders
What is the waldeyer’s tonsilar ring?
It is a series of tonsillar tissue that forms a ring around the oral cavity in addition to the lymphatic between each of the 3 major tonsils. Main function - to provide protection aginst harmuf substances and pathogens that may enter the body through the nose and mouth.
What are MALT?
MALT - mucosa associated lymphoid tissue.
WHat are the two major areas of immunity?
Innate - non-specific immunity
Acquired - specific immunity
What are the main defence mechanisms of the innate immune system?
- Physical barriers (epithelium and saliva for example)
- Chemical barrier (proteins in saliva)
- Cellular components (neutrophils, mast cells, macrophages etc.)
What are the main defensive mechanisms of the adaptive immune system?
- Humoral (memory B lymphocytes and plasma cells)
- Cellular (T lymphocytes, NK cells and NK T cells)
What are the main differences between the innate and adaptive defense systesms?
Innate system is considerably faster, less specific and unable to amplify it’s efficiency upon repeated antigen presentation.
Addaptive system is slower, more specific and able to amplify it’s efficiency upom repeated antigen presentation.
What is oponization?
It is a process of marking an antigen for phagocytosis
What are PRR?
PRR are the pattern recognition receptors, they are receptors that identify potential pathogens.
What do you know about neutrophils?
They are a cell with a many shaped nuclei - respond by chemotaxis from chemokine release and use diapedesis to get to the site of tissue injury - release granules - have an antimicrobial effect.
What do you know about macrophages?
Macrophages are a form of a monocyte - used for phagocytosis and antigen presentsation - Use PRR receptors
What do you know about eosinophils?
They are a type of granulocyte - kill large parasites - contain large number of enzymes
What are mast cells?
They are cells that contain potent substances - cells that induce chemotaxis - one of the most important signaling cells in inflamation
What are dendritic cells?
They are cells that have similar function to macrophages and actually have similar origin - act as messengers and antigen presenters
What are natural killer cells?
They are a non-T and a non-B lymphocyte - they recognise infected or transformed cells through the MCT II recpetor - f a cell does not have an MHC receptor it must be killed
What are the 7 steps of phagocytosis?
- Chemotaxis and adherence of microbe to phagocyte
- Ingestion of microbe via phagocytosis
- Formation of a phagosome
- Fusiion of phagosome with lysosome to form a phagolysosome
- Digestion of the ingested microbe by enzymes
- Formation of residual body containing indigestible material
- Discharge of waste materials
What are the 4 important aspects of phagocytosis?
- MHC receptors used for recognition
- Receptor - ligand engagement that induces cytoskeletal and membrane remodeling
- Perticle engulfment
- Destruction
What is inflamation?
Inflamation is an innate immune response that is protective, non-specific and results in a series of interrelated events.
What are the three goals of inflamation?
- Isolate, detsroy or inactivate
- Remove debris
- Prepare for healing
What are the 4 cardinal signs of inflamation?
Redness, Swelling, Heat, Pain
What causes the redness in inflamation?
It is caused by increased blood flow tp the area - which increases the number of red blood cells - red blood cells are red because of albumin
What causes swelling in inflamation?
It is caused by increased leakage of protein rich fluid om the tissue are due to increased capillary permeability as a result of vasodialation.
What causes heat in inflamation?
Heat is caused by increased blood flow to the area - this increase in heat increases the metabolic rate of cells
What causes pain and loss of function in inflamation?
The pain is caused by increased leakage of protein rich fluid into the tissue that aggrevates the nerve endings - specifically pain is a result of pressure receptors being hypersensetive to touch
What is the sequence of event during inflamation?
- Brief vasocontriction
- Vasodialation - mediated by mast cells
- Increased vasuclar permeability - to small proteins not cells (cause of edema is due to release of water due to colloid osmotic prssure)
- Transmigration - chemotaxis and increased cell wall permeability allw=ows for extravasion and leukocyte migration
- Phagocytosis
- Healing
What are the two components of aquired immunity?
- Cellular - production of Suppressor, Cytotoxic and Helper T cells. This is targeted for desctructionn of already infected body cells
- Humoral - B cells differentiate into plasma cells and B memory cells
How can the aquired immune system eliminate the pathogen?
- Antibodies - derived from plasma cells
- Cytotoxic cells - attack directly or discharge granules
What happens during the lymphocyte activation?
- Antigen are processed by the phagocytes
- They are presented on modified MHC II and I receptors
- MHC II receptor is able to bind with CD4+ T lymphocyte and creat a Helper T cell which than continue the cascade to activate B cells
- MHC I receptor is able to bind with CD8+ T lymphocyet and creat Supressor and Cytotoxic T lymphocytes
What are the steps of CD4+ cell activation process?
- Foreign antigen phagocytes, killed & processed by the APC
- ACP presents processed fragment
- This is done via MHC II molecule (epitode) on the membrane surface of the APC
- Epitode binds with TCR on naive CD4+ T lymphocyte
- This causes activation of the naive CD4+ T lymphocyte and creates a T helper cell
- T helper is able to bind with a B lymphocyte and cause it to transform into either B memory cell or plasma cell
How do vaccines work?
Vaccines are able to present the antigens in weakened form in order go through the acquired immunity response to create sophisticated Plasma Cells that can produce specifc antibodies for the antigen, in order to eliminate the antigen faster when it is presented in the system next time.
What is herd immunity?
It is a refrence to the population where 70-80% of people are vaccinated. This reduces person-to-person transmission, thus this protects the unvaccinated individuals.
What is an autoimmune diseases?
It is a condition where bodies own antibodies develop specificity towards the bodies own tissue. This is due to defects in the aquired immune system.
What are the four allergy specification?
Type I - immediate response (anaphylaxis)
Type II - Transfusion (hours)
Type III - Immune complexes (days)
Type IV - Delayed (weeks)
What is Type I hypersensitivity?
It is an excessive immune response to harmless antigen. Involved are mast cells (degranulation processes caused by binding with IgE), B cells and T helper cells.
What are the steps of Type I hypersentivity?
- Antigen is processed as usual and Plasma cells are created with a speicifc IgE antibody
- IgE antibody binds with a mast cells and act as a receptor
- If the antigen apprearce again and binds with IgE receptor on the mast cell it will cause degranulation
What is the resident flora?
Resident floral conssts of relativley fixed type of microorganisms regularly found in the oral cavity at a given age. It reastablishes quickly.
What is transient flora?
It is a group of bacteria that consists of non-pathogenic or potentially pathogenic microorganisms that inhabit the oral cavity for hours/day. They do not establish themselves permenantly.
So how does transient flora replace resident flora?
The resident flora can be disturbed or the host resistance can change. This will cause the transient microorganisms to colonize the freed niches, proliferate and produce disease.
Why do bacteria colonise teeth?
Because teeth are solid and non-shedding surfaces and that is why bacteria prefer to colonize them.
What are the 6 major niches for bacteria in the oral cavity?
- Tongue
- Tonsils
- Hard, non-shedding surfaces
- Gingival Sulcus
- Mucosa
- Saliva
What is the gram system and how does it separate bacteria?
Gram system separates the microorganisms in 2 distinct groups
- Gram positive - blue in clour - min bacteria in periodontal bacteria
- Gram negative - pink in colour - contain LPS - major driver of inflamatory reaction
What are the stpes of sulcus colonization?
- Early colonization from gram positive cocci microorganism
- Secondary colonization by gram positive and negative rods
- Late colonization by gram negative rod and motile bacteria
- Microbial succession – dominance of microorganisms
What happens to the aerobic/anerobic transition during the colonization of the sulcus?
The bacteria transition from mostly aerobic at the early colonization to mostly anaerobic. This happens due to the fact that as bacteria grow – the biofilm also grows, meaning that the aerobic bacteria that get covered by the biofilm transition to an anaerobic state due to lack in oxygen.
What are the physical barrier system in the sulcus?
- Epithelial desquamation – constant shedding of the epithelial cells does not allow the bacteria to attach to those surfaces
- Saliva flow – pick up and moves the bacteria
- Soft tissue movement – moves the biofilm
- Mastication – moves the biofilm
What are the chemical barriers in the sulcus?
- Saliva – has antibacterial action – Immunoglobulin A, lysozymes, lactoperoxidase
- Antimicrobial Peptides – peptides stored in saliva, used for destruction of bacteria and more
What is GCF?
GCF is gingival crevicular Fluid. It is the transudate or exudate of the periodontal tissues collecting sulcus. It has 4 functions: 1. Cleansing the sulcus 2. Antimicrobial function 3. Antibody activity 4. Cell adhesion.
What are the two theories of GCF source?
Theory 1: Increased permeability due to inflammation in the capillaries near the sulcus.
Theory 2: Fluid is in a form of transudate due to osmotic gradient. And upon inflammation becomes an exudate.
What is the function of Junction Epithelium in the periodontal defense system?
The junction epithelium has a very fast turn over rate, meaning it is constantly shedding. This results in inability for the bacteria to attach to junction epithelium. Also the shedding of cells outside the sulcus, physically pushes bacteria that are floating around the sulcus (this occurs with help of Gingival Crevicular Fluid).
What are PMNs?
Polymorph nuclear Neutrophils (neutrophils)
How are neutrophils move into the oral cavity?
Through junction epithelium. They have three modes of action: 1. Phagocytosis 2. Granulation 3. NETosis (neutrophils extracellular traps – extinction of chromatin in the extracellular space that kills bacteria)
What is the definition of periodontal health?
Periodontal health should be defined as a state free from inflammatory periodontal disease that allows an individual to function normally and not suffer any consequences as a result of past disease.
What is pristine periodontal health?
It is defined as total absence of clinical inflammation and physiological immune surveillance on a periodontium with normal supports
What is clinical periodontal health?
It is defined as absence or minimal levels of physiological immune surveillance or clinical inflammation in periodontium with normal support
What are the functions of the respiratory system?
- Protection of respiratory surfaces – such as water loss, temperature, microorganisms and particulate matter
- Sound production
- Olfactory input – smell
- Blood pH regulation
What is the importance of the elastic and collagen components of the lungs?
They allow for sthrength and passive recoil (elastic fibres).
What are the two divisions of the respiratory system?
- Upper respiratory tract – nose, nasal cavities, paranasal sinuses and pharynx
- Lower respiratory tract – larynx, trachea, bronchial tree and lungs
What are the two functional divisions of the respiratory system?
- Conduction part – involved with transfer of gases – nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles
- Respiratory part – respiration mechanisms – respiratory bronchioles, alveolar ducts and alveoli
Histologically, how does the respiratory tract changes as we travel from the conducting part to the respiratory part?
The epithelium lining of the respiratory tract changes due to change in function mainly:
- Height of the epithelium changes – changes occur to the height of the cells, as we travel down to the respiratory part cells become more vertically challenged
- The complexity of the epithelium changes – there are less cells of different types present in the epithelium lining as we travel from the conduction to respiratory part of the respiratory tract.
How can we describe the function of the ciliated cells in the respiratory tract?
Muco-ciliary escalator
What type of epithelium is present in the upper part of the airway?
A pseudo-stratified ciliated epithelium
What type of epithelium present in the parts of the airway that come in contact with food?
A stratified squamous epithelium
What type of epithelium is present in the lower respiratory tract?
A pseudo-stratified ciliated epithelum
What type of epithelium is present in the bronchioles?
Simple cuboidal
What type of epithelium is present in the gas exchange area?
Simple squamous epithelium
What are the 5 cells of respiratory epithelium?
- Pseudostratified columnar ciliated
- Mucous goblet
- Brush
- Basal
- Small granule
What is the function of pseudostratified columnar cells?
They are the most common cell in the respiratory tract. There function is to be the muco-ciliary escalator.
What is the function of the goblet cell?
To produce mucus.
What is the function of the brush cells?
We don’t know but they are there.
What is the function of the basal cell?
They act as stem cells
What is the function of small granule cells?
They act as enteroendocrine (release hormones) cells.
What are the major functions of conduction portion of the respiratory tract?
- Moisten / humidify – serous & mucous secretion
- Warm & humidify – vein network
- Trap dust / allergens – mucus
- Move trapped particles – muco-ciliary escalator
What is the function of an epiglottis?
It prevents the entry of food from the pharynx to the larynx.
What are the three function of the larynx?
- Prevent air entry to oesophagus
- Prevent food/liquid entry to lower respiratory tract
- Allow phonation
What are anatomical significance of the trachea?
- The C shape hyaline cartilage which provides structure
- The muscle and ligament on the posterior surface which allows for contraction and change in shape of the cartilage and prevention of over extension.
What type of cartilage present on the bronchus?
Irregular shaped hyaline cartilage.
At which point does the transition between the conduction and respiratory part of the respiratory system occur?
This occurs when terminal bronchioles brunch into respiratory bronchioles.
What is the pleura?
It is a double serous membrane with collagen and elastic CT. 2 layers – visceral and parietal.
What are the three different types of bronchioles?
- Larger bronchioles
- Terminal bronchioles
- Respiratory bronchioles
What are the types of cells within the alveoli?
- Type 1 alveolar cell – flat cell that is used in the blood gass barrier
- Type 2 alveolar cell – produces surfactant
- Alveolar macrophage – typical macrophage function – protection by engulfing pathogens and antigens
What are the structural part of the alveolar and what are their functions?
- Respiratory bronchioles – carry gasses to and from the alveolar sacs, connect the alveolar sacs together.
- Alveolar sacs – sac like collection of alveoli
- Alveolar ducts – connect the alveoli together
- Alveoli – respiratory conducting part that have a direction connection to blood gas barrier.
What are the functions of the club cells?
- Produce one component of surfactant
- Bronchiolar progenitor cells
- Immune system regulation
- Environmental protection function (thru use of GAGs, enzymes and other substances).
What is the structural importance of basement membrane in alveolar gas exchange?
In order to achieve the optimal diffusion of gasses – the distance between the alveolus and the capillaries need to be minimized.
This is done by fusing the basement membrane of the alveolar septum and the endothelium (capillaries) into 1 shared basement membrane. This means that instead of traveling through 2 seprate membrane, the gas only needs to diffuse through 1 basement membrane, which induces a higher rate of gas exchange between the alveoli and capillaries.
What is the function of type II pneumocyte?
Their function is to synthesize and release surfactant. The surfactant is able to reduce the alveolar surface tension and prevent alveolar collapse during expiration.
What connective tissue provide support to the alveoli?
- A few fibroblasts
- Reticular fibers
- Collagen fibers
- Elastic fibers (elastic recoil)
What is asthma and what are the potential implication for dental treatment it may cause?
Asthma – a chronic inflammation of the bronchioles.
Potential relation to oral health include:
• Increased caries development
• Reduced saliva flow
• Changes in oral mucosa
• Orofacial abnormalities
Why do dentist need to know about the respiratory system?
- Mouth if part of the upper respiratory system thus dental procedures can impede airflow
- LA and sedation can alter respiratory function
- Potential to cause of respiratory episodes
- Clients pre-existing respiratory conditions could interact with dental procedures
What are the function o the respiratory system?
- Homeostasis of oxygen and carbon dioxide
- Homeostasis of pH
What is cellular respiration?
It is a metabolic process in cells. Cells use oxygen for metabolism and excrete carbon dioxide.
What is external respiration?
It is the exchange of oxygen and carbon dioxide between atmosphere and cells of body. It has 4 steps.
What are the 4 steps of external respiration?
- Ventilation or gas exchange between the atmosphere and air sacs in the lungs
- Exchange of oxygen and carbon dioxide between air in the alveoli and the blood in the pulmonary capillaries
- transport of oxygen and carbon dioxide by the blood between the lungs and the tissues
- Exchange of oxygen and carbon dioxide between the blood in the systemic capillaries and the tissue cells
So what is the point of the cartilage in the trachea and larynx and why don’t we have in lower respiratory portion of the respiratory tract?
Cartilage provides structure to the upper airways which prevents if from deflating or collapsing when large forces are apply in respiration in order to have ultimate flow of gases.
The alveoli need an ability to stretch for ultimate gas exchange thus having cartilage around them will be counterintuitive. Rather they have elastic tissue for recoil.
What protect the lungs entry?
The laryngeal muscle that can open/close are able to provide protection for the glottis thus protecting the lungs from potential pathogens.
What are the 4 major aspects in terms of mechanics of breathing?
- Muscle of respiration involved
- Elastic properties of the lungs
- Elastic properties of the chest wall
- Airway resistance
What are the major muscles used in passive inspiration?
These muscles contract every inspiration and their relaxation causes passive expiration.
- Diaphragm
- External intercostal muscles
What are the major muscles used in forceful inspiration?
On top the diaphragm and the external intercoastal muscles we also have the:
- Sternocleidomastoid muscles
- Scalenus muscles
What muscles are used in active expiration?
Following muscle contract only during active expiration
- Abdominal muscles
- Internal intercoastal muscles
What are the 3 important pressure to consider?
- Atmospheric pressure (pressure outside) – 760 mm Hg
- Intra-alveolar pressure (pressure in the alveoli) – 760 mm Hg
- Intrapleural pressure (pressure in the first cavity where the intrapleural fluid is) – 756 mm Hg
Why is the pressure in the alveoli and the atmosphere the same at rest?
Because, technically, the alveoli and the atmosphere are connected through the airway thus are they display the same pressure at rest.
What is Boyle’s law?
It states that pressure of any gas varies inversely with the volume of the said gas. Basically if the same amount of gas is put in a contain with volume x, another with volume 2x and another with volume 4x, the container x will have 2 timer the pressure than container 2x and 4 times the pressure then container 4x.
What are the 5 steps of inspiration?
- Diaphragm and external intercostal muscles contract
- Thoracic cage expands up and out
- Lungs expand
- This causes a drop in intrapulmonary pressure
- This cause a drop in intra-alveolar pressure thus movement of air from the atmosphere to the alveoli
What are the 6 steps of expiration?
- Diaphragm and external intercostal muscles relax
- Thoracic cage moves in and down
- Lung’s recoil toward pre-inspiratory size
- Air in lungs compressed
- Pressure rises above atmospheric
- Air flows out of the lungs down the pressure gradient
What is compliance?
Compliance is the effort required to expand the lungs. Some factors may reduce compliance thus making is hard to breathe. Some things, such as elastic connective tissue that facilitate alveolar recoil, increases elastic compliance.
What is surface tension?
Surface tension is a force that make it hard for the alveoli to expand. Basically there are water molecules on the epithelium lining of the alveoli which create the “air-water interface”, but those water molecules are more strongly attracted to each other than the air thus are able to resist the pulling apart while the alveoli expand.
How can we overcome the surface tension?
Through use of a surfactant released by type 2 alveolar cells. Surfactant can be released through tubular myeline. It reduces the attraction between the hydrogen bonds of the water molecules thus reducing their resistance to separation while the alveoli expand resulting in an increase in pulmonary compliance.
What effects bronchodilation?
- Neural (sympathetic drive)
- Chemical (increase carbon dioxide)
- Hormonal (adrenaline)
What effects bronchoconstriction?
- Neural (parasympathetic)
- Chemical (reduction in carbon dioxide)
What is the anatomical dead space?
It is the air remaining in the airways that cannot participate in gas exchange – around 150ml.
What is alveolar ventilation?
It is the volume of air exchanged between the atmosphere and alveoli per min.
What is the difference between the alveolar and pulmonary ventilation?
The pulmonary ventilation includes the entirety of the gas injested by a person while alveolar ventilation only includes a part of the gas that is exchanged in the alveoli (pulmonary volume – dead space)
What is the significance of dead space?
It is basically constant. Thus if a person has shallow breathing that does not create tidal volume that exceeds the dead space value, they won’t actually perform alveoli respiration.
How do gasses move across the blood gas barrier?
Through net diffusion. Thus following appropriate gradients, gases move from area of high concentration to the area of low concentrations until dynamic equilibrium is reached. Note: particles can still move even if equilibrium is reached (hence why it is called dynamic equilibrium).
How are lungs specialized for diffusion?
Through used of hundreds and millions of alveoli that can expand, lungs are able to create high surface area which following Fick’s law is great for diffusion of substances.
How is partial pressure calculated?
Percentages of the gas times by the total atmospheric pressure.
Why is the partial pressure of oxygen slightly lower in the lungs than in the atmosphere?
Because as air passes through the nasal cavity and the mouth it get saturated with water molecules creating water vapor, thus total pressure of air coming in is altered lowering the oxygen partial pressure.
Also the fresh air that comes in contact and mixes with dead space air thus lowering partial pressure of oxygen even further.
So how does partial pressure help with diffusion?
Partial pressure in different mediums drive diffusion as the gasses will move down their partial pressure gradients. For example, the partial pressure in the alveoli upon inspiration is higher than the alveolar capillaries – thus oxygen moves into the capillary. It travels down the circulatory system and reaches target tissue which has lower partial oxygen pressure than the capillary – thus oxygen moves from the capillary into said tissue.
Carbon dioxide follows a similar blue print but in reverse.
What is the role of the Pre-Botzinger complex?
It is thought to be a pacemaker center of the respiratory system
What is the function of the pneumotaxic center?
Fires signals to DRG to reduce breathing
What are the components of the GIT and what is there function?
Oral Cavity – biting, chew, swallow
Pharynx & esophagus – transport
Stomach – mechanical disruption (via muscular contraction); chemical digestion
Small intestine – chemical & mechanical digestion & absorption
Large intestine – absorption of electrolytes & vitamins
Rectum and anus – storage and excretion
What is the basic structure of the GIT?
- Mucosa
- Submucosa
- Muscularis
- Serosa
What type of junction is connected between epithelial cells in the GIT?
Tight junctions
What is the muscularis externa?
It is a layer of muscles that are present in the GIT that are composed of mostly smooth muscles and sometimes skeletal muscles.
What is the autonomous smooth muscle function?
Autonomous smooth muscle function – internal pacemaker activity – initiated of the interstitial cells of Cajal
What are intrinsic nerve plexuses?
Intrinsic nerve plexuses – myenteric plexus between the two layers of the muscularis – submucosal plexus – both used to regulate local action
What are the three layers of the stomach histologically?
- Cardia – narrow circular band – mostly secretory cells that produce mucous & lysozymes
- Fundus and body – has fundic glands and most of acid producing cells
- Pylorus – very deep gastric pits – secrete mucus & lysozymes
What are mucous cells of the GIT and what is there significance?
- Mucous surface cells – produce insoluble mucous
- Mucous neck cells – produce thinner and more soluble mucous – irregular shape cells
Both mucous cells produce mucous, a special coating that helps with protection of the stomach as well as not allowing the gastric juice to damage the stomach and “self-digest”.
What are parietal cells and where are they found?
Parietal cells are mainly found on the upper parts of gastric glands. Bright pink (eosinophilic). Resting or active. Secrete H+ and Cl- which combine to form HCl. Also secrete intrinsic factor for B12 absorption.
What are chief (zymogenic) cells?
They are cells that are mainly found in lower regions of glands. Synthesis protein. Have granules that contain inactive pepsinogen. Produce lipase.
What are the enteroendocrine (and paracrine) cells?
They are cells found in neck and base of gastric gland. Fundus of stomach secretes serotonin. Body of stomach secretes histamine. Pylorus of stomach secretes gastrin and somatostatin.
What are the three areas of the small intestine?
Duodenum (5%), jejunum (40%) and Ileum (60%)
What are the enterocytes?
They are tall columnar cells with oval nucleus. Contain microvilli and function to absorb nutrients and secrete enzymes.
What are Paneth cells?
They are cells located in base of crypts. They contain lysozyme which has antibacterial activity.
What are duodenal glands?
They are a part of MALT and are situated in the lamina propria of the small intestine.
What are the two functions of the pancreas?
- Endocrine function – pancreatic islets – produce insulin, glucagon and somatostatin - pale
- Exocrine function – groups acinini grape like clusters – form lobules separated by septa – majority of the pancrease – composed of serous cells containing zymogen granules
What are the four types of papillae?
- Vallate – taste buds on the lateral surface
- Fungiform (mushroom) – taste buds on the apical surface
- Foliate (leaf shape) – taste buds on the lateral surface
- Filiform – does not contain taste buds
What is the location of the olfactory epithelium?
The top of the nasal cavity.
What are the three types of cells that are located in the olfactory epithelium?
- Olfactory cells
- Supporting cells
- Basal cells
How do we achieve haemosatasis in 4 steps?
- Vascular spasm/local vasocontriction - the cut vessels immediately contrict to slow blood flow and minimise blood loss
- Formation of a platelet plug via adhesion, activation & aggregation of platelets:
a. von Willebrand factor adheres to the exposed endoepethilial collagen, creating sites which allow platelets to bind forming a platelet plug - than platelets release factors that aggregate other platelets
b. Thromboxane A2 - major component produced by platelets - involved in platelet aggregation adn vasocontriction
c. ADP is also produced by platelets - it stimulates release of prostocyclin and nitric oxide which can limit platelet aggregation - platelets plug size control - Blood coagulation = transformation of blood from liquid to solid gel
a. Platelets are stimulated to relase prothrombin activator which converts the plasma protein prothrombin into the enzyme, thrombin
b. Thrombin converts the plasma protein fibrinogen into threads of the protein fibrin which wind around the platelet plug to form a framework of fibres - this holds the plug and other blood cells in the blood vessel
c. Platelets in the clot begin to shrink - tightening the clot - Clot dissolution occurs via:
a. TPA, a protein on endothelial cells activates the conversion of plasminogen to plasmin
b. Plasmin breaks down clots by breaking down the fibrin netwrok
c. Macrophages & phagocytic WBCs then phagocytose the debris
What are the three zonas of the adrenal gland cortex?
- Zona glomerulosa
- Zona fasciulata
- Zona reticularis
Show all elements of the diagram
Show all elements of the following diagram
Which 2 structures are technically fuzed together in the juxtaglomerular aparatus?
The afferent arteriole and the distal tubule
What are the juxtaglomerular granular cells, what is their location and function?
- Granular cells are specialised smooth muscle cells
- Found primarily on the afferent arteriole
- Function: synthesise, store and secrete renin
What are the three layes of the glomerular barrier that facilitate filtration?
- Lumen of the capilaries
- Basement membrane
- Lumen of Bowman’s capsule
What is bowman’s capsule hydrostatic pressure?
It is the pressure that oposes filtration due to the fact that the bowman’s capsule already has some liquid in it, so the liquid pushes in the opposing direction to the filtration
What is plasma colloid osmotic pressure?
It is a pressure that is excereted by large protein molecules that keeps the water and deisolved substances within vascular system
What are podocytes?
They are cells that cover basal lamina of the bowman’s capsule
What is the countercurrent multiplier mechanism?
It is a mechanism by which desscending and ascending loops of henley are able to creat an osmotic gradients thus release more water and ions into the medula respectivley
Describe the aldosterone triggered process in the cellular wall of the distal tubule in 5 steps.
- Aldosterone binds with cytoplasmic receptor
- Initiation of transcription
- Synthesis of new protein channels
- Modulation of existing channels
- Modified and new channels are able to reabsorb more Na+ and secrete K+
Please name the following
Please name the following
- Root - protect the pulp
- Sharpeys fibres - connect the cemntum and the alveolar bone
- Periodontal ligament - connection of tooth to alveolar bone and armatisation
- Alveolar bone - bone function
Please name the following
