Introduction to clinical sciences Flashcards
What is the definition of acute inflammation?
the initial and often transient series of tissue reactions to injury
What is the definition of chronic inflammation?
the subsequent and often prolonged tissue reactions following the initial response
What are the principal causes of acute inflammation? (5)
- Microbial infections
- hypersensitivity reactions
- physical agents (trauma, heat, cold)
- chemicals (acid, alkali)
- tissue necrosis
What is a hypersensitive reaction?
An inappropriate or excessive immune reaction which damages tissues
What are the four key macroscopic appearances of acute inflammation?
Rubor, calor tumor and dolor. Redness, heat, swelling and pain
Why does the skin turn red in acute inflammation?
Dilation of small blood vessels near to the area
Why does the inflamed area become warmer?
Dilation of blood vessels in the area which delivers warm blood to the area
Why does the inflamed area swell?
Due to the oedema
Why does the inflamed area hurt?
Oedema stretches the overlying skin and the pus under pressure in the abscess cavity. Some chemical mediators such as bradykinin, prostaglandins and serotonin induce pain
Why is there loss of movement in the inflamed area?
Pain consciously and reflexively reduces movement. Swelling may immobilise tissue
What is essential for the histological diagnosis of acute inflammation?
The presence of the neutrophil polymorph
What are the three processes involved in acute inflammation?
Changes in vessel calibre and flow
Increased vascular permeability
The formation of a fluid exudate and emigration of neutrophil polymorphs into the extravascular space
What is the triple response to injury as described by Lewis in 1927?
Flush, flare, wheal
What are the proteins in the exudate?
immunoglobulins, coagulation factors and fibrinogen
What are the 5 things that endogenous chemical mediators cause?
- vasodilation
- emigration of neutrophils
- chemotaxis
- increased vascular permeability
5, itching and pain
Which type of vessel clears the oedema when acute inflammation is reaching an end?
The lymphatics
What are the 6 beneficial effects of acute inflammation?
- Dilution of toxins
- Entry of antibodies
- Transport of drugs such as antibiotics
- Fibrin formation to trap microorganisms
- Delivery of nutrients and oxygen
- Stimulation of the immune response
What is the life span of a neutrophil?
1-3 days
What are macrophages derived from?
Blood monocytes
What are the 3 harmful effects of acute inflammation?
- Digestion of normal tissue
- Swelling
- The inflammatory response can be inappropriate
What are the 4 conditions that favour resolution of acute inflammation?
- Minimal cell death and tissue damage
- Occurrence in an organ or tissue that has regenerative properties
- Rapid destruction of the casual agent
- Rapid removal of fluid and debris by good local vascular drainage
What is suppuration?
The formation of pus
What makes up pus?
Living, dying and dead neutrophils, bacteria, cellular debris, globules of lipid.
What are the 6 primary causes of chronic inflammation?
- Infective agent is resistant to phagocytosis and the intracellular killing
- Endogenous materials
- Exogenous materials (asbestos)
- Some autoimmune diseases
- Specific diseases e.g. ulcerative colitis
- Primary granulomatous disease
What type of inflammation do foreign bodies provoke?
Granulomatous inflammation it’s a type of chronic inflammation.
What is the definition of inflammation?
A reaction to injury or infection involving cells such as neutrophils and macrophages
Which type of cell is first on the scene in the case of acute inflammation?
Neutrophil polymorphs
Which type of cell produces antibodies?
Lymphocytes
Which type of cell produces collagen?
Fibroblasts
What are the 4 drugs frequently used to treat inflammation?
Aspirin, ibuprofen, steroid creams, corticosteroids.
Where are stem cells found in the skin?
The basal layer
What is granulation tissue?
Capillary loops and myofibroblasts
What causes wound contraction?
The contraction of myofibroblasts in the granulation tissue
What is a thrombus?
a solid mass of blood constituents formed within the vascular system in life
What is Virchow’s triad?
Abnormalities of the vessel wall; abnormalities of the blood flow; abnormalities of the blood constituents
What is an embolism?
Mass of material in the vascular system that is able to become lodged within the system and block it
What is infarction?
The ischaemic death of tissue within the living body
What is the difference between resolution and repair?
If a tissue is resolved it is now undamaged or has regenerated. If a tissue has repaired then it is still damaged.
When can a wound heal by 1st intention?
When the edges can be brought edge to edge
What is the gap in a 1st intention wound filled with?
Firstly blood and fibrin (scab). Fibroblasts then come in and fill it with collagen
When does a wound heal by 2nd intention?
When there is a chunk of tissue missing, the edges cannot be brought together.
What fills a second intention wound during repair?
Firstly granulation tissue (capillary loops and myofibroblasts) and then epithelium grows in from the perimeter of the wound. Collagen fills a large part of the wound, making the scar.
What is the definition of repair?
Replacement of damaged tissue by fibrous tissue.
What is fibrosis of neural tissue called?
Gliosis
Which types of cells cannot regenerate?
Brain, heart and spinal cells
Which types of cells can regenerate? (6)
Hepatocytes, blood cells, pneumocytes, skin epithelium, gut epithelium and osteocytes.
What does fibrin travel as in the blood and why?
Fibrinogen. It is inactive so prevents random clotting.
What is the definition of a thrombus?
A solid mass of blood constituents formed within a vascular system during life
How does an ECG suggest an MI?
ST elevation
What are the three components of Virchow’s triad?
Change in vessel wall, change in blood constituents, change in blood flow.
How does smoking increase the risk of thrombosis?
Cigarette smoke kills endothelial cells causing a change in the vessel wall and exposing collagen. Ingesting CO increases the production of RBCs therefore increasing BP- change in blood constituents.
How do you prevent thrombosis?
Low dose aspirin. It prevents platelet aggregation.
What is an embolus?
A mass of material in the vascular system which is able to become lodged and block it
How do you prevent an embolus?
Low dose heparin and elastic stockings
What is end artery supply?
When only one artery supplies an organ.
What are the main chemical carcinogens?
Polycyclic aromatic hydrocarbons, aromatic amines, nitrosamines, azo dyes, alkylating agents.
Which tumour is commonly associated with exposure to polycyclic aromatic hydrocarbons?
Lung and skin cancer
Which tumour is commonly associated with exposure to aromatic amines?
Bladder cancer
Which tumours are often associated with nitrosamines?
Gut cancers
Which tumours are often associated with azo dyes?
Bladder and liver cancer
Which tumour is often associated with alkylating agents?
Leukaemia
Which virus is thought to cause some carcinomas of the cervix?
HPV (human papillomavirus)
What are the host factors in carcinogenesis?
Race, diet, constitutional factors (gender, inherited risks), premalignant lesions, transplacental exposure.
What are the common problems caused by benign tumours?
- Obstruction
- Pressure on neighbouring structures
- Production of a hormone
- Transformation into a malignant neoplasm
- Anxiety
What is Sjögren’s syndrome?
A syndrome characterised by dryness (eyes, mouth, vagina, skin). It is an autoimmune disease.
What is graves disease?
An autoimmune disease that results in hyperthyroidism
What is hashimoto’s thyroiditis?
An autoimmune disease that results in hypothyroidism
What is erythromycin?
An antibiotic which increases gut motility. It is used to treat bacterial infections such as respiratory tract infections, skin infections, chlamydia, pelvic inflammatory disease, syphilis.
What is in an atheroma?
Central lipid core, cap of fibrous tissue, arterial endothelium
What are the 4 main risk factors for atheroma formation?
- Cigarette smoking
- High BP
- Diabetes
- Hyperlipideama
How do you prevent atheroma formation? (medication)
Low dose aspirin
What is the definition of atherosclerosis?
The formation of focal elevated regions (atheromas)
When does atherothrombosis occur?
When an atheroma becomes dislodged
Do atheromas form in veins?
No because veins do not have the same sort of turbulent pressure.
Where (in the arterial architecture) do atheromas have the tendency to form?
In bifurcations
What is the MOST important risk factor for atherosclerosis?
Hypercholostorolaemia
Why is Chlamydia a risk factor for atheroma formation?
causes inflammation init
What are the 5 stages of atheroma formation?
- Injury to the endothelium of the artery wall
- Tissue response
- Forms a small thrombus like plaque (microthrombus)
- Process repeats
- All of these small plaques accumulate to form one occluding plaque.
What are the two main problems that can arise from atheroma formation?
Ischaemia
Embolism
Which complication of atherosclerosis can cause tissue ischaemia?
Progressive lumen narrowing to high grade plaque sclerosis
Which complication of atherosclerosis can cause small infarctions in organs?
Embolism in distal arterial bed
Which complication of atherosclerosis can cause massive retroperitoneal haemorage?
Ruptured abdominal atherosclerotic aneurysm
What is the definition of apoptosis?
The physiological cellular process in which a defined and programmed sequence of intracellular events which lead to the death of the cell without the release of products which are harmful to surrounding cells.
What are the 5 stages of apoptosis?
- Apoptosis activated
- Blebbing
- Formation of small, round cells
- Ingested by phagocytes
- Phagocytosis
What is the type of apoptosis which occurs during embryogenesis?
Morphogenic apoptosis
What type of apoptosis occurs in the differentiation of tissues?
Histological apoptosis
What is the extrinsic pathway of apoptosis triggered by?
Detachment from the extracellular matrix, withdrawal of growth factors, specific signals from other cells.
What is the intrinsic pathway of apoptosis triggered by?
DNA damage, failed mitosis
What is the definition of necrosis?
The death of tissues following the bioenergetic failure and loss of plasma membrane integrity
What does necrosis induce?
Inflammation and repair
What are examples of causes of necrosis? (3)
Ischaemia, metabolic and trauma
What are the 3 types of necrosis?
Coagulative, colliquative and caseous
What is Coagulative necrosis?
Occurs in most organs, firm pale area, ghost outlines on microscopy
What is colliquative necrosis?
Occurs in the brain, dead areas are liquidfied
What is caseous necrosis?
Seen in TB, pale yellow and semi solid.
What is the definition of carcinogenisis?
The transformation of normal cells to neoplastic cells through permanent genetic alterations or mutations
What is the difference between oncogenic and carcinogenic?
Oncogenic is tumour causing and carcinogenic is cancer causing
What percentage of cancer risk is environmental?
85%
Which 3 things increase the risk of liver cancer?
Hep B, hep C and mycotoxins (toxins produced by a fungus)
What are the 5 classes of carcinogens?
- Chemicals
- Viral
- Ionising and non-ionising radiation
- Hormones, parasites and mycotoxins
- Miscellaneous
Give 4 examples of chemical carcinogens
- Polycyclic aromatic hydrocarbons
- Aromatic amines
- Nitroamines
- Alkylating agents
Which cancer can a mutation on chromosome 5 cause?
Polyps in colon
Which cancer can be caused by mutation on chromosome 3?
Retinoblastoma
What is the definition of tumour?
Any abnormal swelling
What is the definition of neoplasm?
A lesion resulting from autonomous or relatively autonomous growth of cells which persists after the initiating stimulus has been removed
What are the two types of cells which are found in a neoplasm?
- Neoplasmic cells- usually monoclonal
- Stroma cells- basement membrane, fibroblasts, extracellular matrix, immune cells, and vasculature. These keep the neoplasmic cells alive
Which size of neoplasm doesn’t need to undergo angiogenesis?
Neoplasms under 2mm in diameter.
What are the two methods of classifying neoplasm?
- Behavioural: benign or malignant
2. Histological: cell of origin
What is a fibroid?
A benign neoplasm of smooth muscle
What are the 7 features of benign neoplasms?
- Localised
- Non-invasive
- Low mitotic activity
- Close resemblance to normal tissue
- Circumscribed or encapsulated
- Normal nuclei
- Rarely necrosed.
What are the 7 features of malignant neoplasms?
- Invasive
- Metastases
- Rapid growth rate
- Variable resemblance to normal tissue
- Poorly defined or irregular border
- Hyperchromic, pleomorphic nuclei
- Necrosis
What is a papilloma?
A benign tumour of non-glandular, non-secretory epithelium
What is an adenoma?
Benign tumour of glandular, secretory epithelium
What is a carcinoma?
Malignant tumour of epithelium/ of epithelial cells
What is an adenocarcinoma?
Malignant neoplasm of epithelium of glandular or secretory epithelium
What is a lipoma
Benign tumour of adiposites
What is a chrondroma?
Benign tumour of cartilage
What is a rhabdomyoma?
Benign striated muscle tumour
What is a leiomyoma?
Benign smooth muscle tumour
What is a neuroma?
A benign neoplasm of nerve cells
What is a sarcoma?
A malignant neoplasm of connective tissue. E.g. liposarcoma. leiomyocsarcoma
How do you grade tumours?
The greater the differentiation, the higher the grade.
What are the exceptions to the naming rule of -oma being a benign tumour?
- Granuloma
- Myletoma
- Tuberculoma
How do you name a malignant tumour?
Suffix sarcoma
How do you name a benign tumour?
Suffix -oma
What are the 3 exceptions to the sarcoma rule?
- Melonoma- malignant neoplasm of melanocytes
- Mesothelioma- malignant tumour of mesothelial cells
- Lymphoma- malignant neoplasm of lymphoid cells
What is the definition of a carcinogen?
A carcinogen is an environmental agent participating in the causation of tumours
How do you name the benign tumour of squamous cells?
Squamous cell papilloma
How do you name the malignant tumour of squamous cells?
Squamous cell carcinoma
How do you name the benign tumour of transitional epithelium?
Transitional cell papilloma
How do you name the malignant tumour of transitional epithelium?
Transitional cell carcinoma
How do you name the benign tumour of basal cells?
Basal cell papilloma
How do you name the malignant tumour of basal cells?
Basal cell carcinoma
How do you name the benign tumour of glandular tissue?
Adenoma
How do you name the malignant tumour of glandular tissue?
Adenocarcinoma
How do you name the benign tumour of smooth muscle?
Leiomyoma
How do you name the malignant tumour of smooth muscle?
Leiomyosarcoma
How do you name the benign tumour of striated muscle?
Rhabdomyoma
How do you name the malignant tumour of striated muscle?
Rhabdomyosarcoma
How do you name the benign tumour of blood vessels?
Angioma
How do you name the malignant tumour of blood vessels
Angiosarcoma
How do you name the benign tumour of bone?
Osteoma
How do you name the malignant tumour of bone?
Osteosarcoma
How do you name the benign tumour of mesothelium?
BENIGN mesothelioma
How do you name the benign tumour of synovium?
Synovioma
How do you name the malignant tumour of synovium?
Synovisarcoma
How do you name the B cell lymphoma associated with the Epstein-Barr virus?
Burbitt’s lymphoma
What is Ewig’s sarcoma?
Malignant tumour of the bone in children and teenagers
What is Hodgkin’s lymphoma?
The maligant lymphoma. The presence of Reed-Sternberg cells
What is Kapose’s sarcoma?
Malignant neoplasm derived from vascular endothelium
What is a teratoma?
Neoplasm formed of layers representing all 3 germ layers: ectoderm, mesoderm and endoderm
What is a carcinoma in situ?
A tumour which has not broken through the membrane?
How does Vinblastine work?
Anti-microtubule agent, prevents division in cancer
What are the three routes of metastasis?
Haematogenous: through the blood
Lymphatic
Transcoelomic: through the body wall into the abdominal and chest cavity
What are the 11 stages of metastasis?
- One cell mutates
- Cancer cell divides rapidly
- Replacement of normal cells with cancer cell
- Not yet broken through a membrane (carcinoma in situ)
- Invade through the basement membrane to external tissue
- Produces enzymes to chew through basement membrane
- Invades extracellular matrix
- Lymph tubes/ vessels (intrvastion)
- Avoid being by lymphocytes
- Move to another site extravastion
- Angiogenesis