Patho Week 4 Flashcards
3 method of infection of T.B
1- inhalation: most common in human T.B and it effect lung
2- ingestion : in bovine T.B , affect tonsils and intestine due to ingestion of un pasteurized milk
3- skin inoculation : due to handing infected material as meat
When does exudative tissue reaction in TB occur
It’s happened when a large number of tuberculosis reach the serous membranes and meninges of a sensitized individual ( the tissue contain sensitized T lymphocytes )
The action is characterised by excess serous inflammatory fluid exudate . The exudate is clear – and contains fibrinogen and large number of lymphocyte and the small number of epitheliod and lang hans giant cell
3 Fate of primary complex
1- Healing : in mild infection
Small lesion heal by complete fibrosis
Bigger one heals by capsulation followed by dystrophic calcification
Spread (3)
Direct spread ; Macrophages and tissues fluid carry the bacili to surrounding areas
Hameatogenous spread (3)
Small number of bacilli : destroyed by reticuloendothelial system
Moderate number of bacilli : settle in one favorable site cause isolated organ tuberculosis
Large number; results from opening of caseous focus through a large vessel : forming a small uniform tuberculous lesion this known as miliary tuberculosis
Intracanalicular spread
3- Encapsulation and reactivation
4 early lesion features of bilharziasis
1- hyperemia
2- inflammatory edema
3- petechial haemorrhage
4- granularity of mucosa
Bilharziasal sandy patches
Bilharziasal sandy patches
Larger number of ova are trapped in the sub mucosa followed by calcification and fibrosis
The overlining mucosa undergo pressure atrophy and ischemia to vascular compression
3 causes of bilharzial ulcer and its description
Mucosal damage by large number of ova penetrating the mucosa associated with inflammation ,necrosis and mucosal shedding
shedding of the atrophic mucosa over an area of sandy patches
Ulceration of polyp
Sharp edges , granular floor , firm base
2 fate of scar
1- Hyalinosis
2- Calcification
5 local factors affecting repair
Severity and extent of tissue damage
Type of damaged cell
Blood supply
Presence or absence of bacteria
Presence or absence of foreign body
4- general factors affecting repair
1-Age
2-Nutrients :
Protein
Vitamins CAD
Vitamin C for synthesis of connective tissue and bone
Vitamin A for healthy epithelium
Vitamin D for bone formation
3-GlucoCorticoid and cytotoxic drugs delay healing
4-Endocrine gland disease as diabetes millilitres delay the healing
One example and the 3 steps of healing by first intention ( primary unoin of wounds
Surgical wound
1- clot formation :
Fibrin : form a meshwork that serves to hold the tissue together
Fibronectin : temporary adhesive material
2- Inflammation
Mild acute inflammation
No suppuration nor fever nor leukocytosis
3- Epithelization
The basal cell layer of epidermis proliferate to meet at center
The cells divide to form the whole thickness
Dremal appendage don’t regenerate
The remnants of the clot at the surface called scab
4 situations of healing by secondary intention
Gaping wounds ( gun shot , abscess )
Oral surgery
Serious burns
10 complications of healing
1-Chronic Ulcer
2- sinus : blind ended tract
3- fistula
4- keloid
5- contracture
6- infection
7- weak scar
8- dehiscence
9- Implantation ( epidermoid cyst )
10- malignant transformation
What is virchow tria
The causes of thrombus
1- endothelial damage
2- change in blood composition
3- stasis
2 examples of stasis and 4 change the composition of blood
The slowing of blood flow in the heart as in
1- mitral stenosis
2- varicose vein
1- increase fibrinogen in pregnancy
2- increase platelets in operation
3- increase RBCs -> increase viscosity-> stasis
4- increase WBCs
Mechanisms of thrombus
Platelets leave the bloodstream agglutinate and adhere to damaged endothelium they form laminae which are arranged vertical to the bloodstream and called lines of zhan
Soon fibrin accumulate around them
2 types of thrombophlebitis and example for each
3 examples of phlebothrombosis
1- septic thrombophlebitis : appendicular vein in case of appendicitis
2- aseptic thrombophlebitis :
Caused by factor other than bacteria as trauma or radiation
1- thrombosis in varicose vein due to stasis
2 - Thrombosis in calf vein deep Venus thrombosis in chronic cardiac patient confined to bed stasis and compression of calf muscle
3-Thrombosis in pelvic and femoral veins after labour or operation
Fate of thrombi
Septic thrombi : fragments by proteolytic enzyme into septic embolism-> pyaemia
Aseptic thrombi
Small : is absorbed
Large
1- organization ( fibrosis )
2- Organization & canalization
3- calcification
4- fragmentation
Compare between thrombus and blood clot according to
1- attachments
2- texture
3- moisture
4- color
5- lines of zhan
Clot in stagnat blood due to formation of fibrin from fibrinogen
Clot is : soft , moist , loosely attached, red or yellow, no lines of zhan
Thrombus : friable and dry , firmly attached, pale or red , yes lines of zhan
6 types of Embolism
1- Detached thrombi
2- Fat embolism
3- Air embolism
4- tumor embolism
5- parasitic embolism
6- Amniotic embolism
3 Sites of embolism of detached thrombi
1- Pulmonary embolism , source: leg and pelvic veins after prolonged recumbency and major pelvic operation
2- Systematic embolism : from the left side of heat to systemic circulation
3- Portal embolism: from portal vein to liver
Effect of thromboembolism depends on 3
What is the effect of pulmonary embolism
1- size of embolus
2- nature ( septic, aseptic)
3- state of collaterals
In pulmonary embolism
1- large embolism: Right sided heart failure
2- Medium sized : if the lung is healthy-> no effect
If the lung is congested-> lung infarction
3- small size: no effect
Mechanism of formation of pyeamic abscess
1- Sever pyogenic infection
2- Septic thrombophlebitis
3- fragmented of septic thrombus
4- Septic embolism
5- impaction
6- Multiple small pyaemic abscess
3 causes of Air embolism and 3 of fat embolism
1- injury in large neck vein -> the air sucked by negative pressure
2- Surgery in cardiothorax lesions-> the air enter
3- Caisson disease ( decompression sickness)
1- bone fracture and crush limb injury
2- trauma in adipose tissue
3- Major surgery
4 Causes of Acute ischemia and 2 effects
1- Thrombosis , embolism
2- Surgical ligature
3- Twisting of the pedicle of a movable organ as ovary
4- Arterial spasm ( ergot poisons)
Effect depend on state of collateral
1- if end artery or poor collateral-> infarction and gangrene
2- if good collateral-> no effect
3 causes of chronic ischemia and 2 effect
1- Atherosclerosis
2- Pressure on artery due to enlarged lymph node
3- End arteritis as in chronic inflammation
If poor collateral
1- pain on exercise: angina pectoris
2- cellular degeneration: atrophy followed by fibrosis
3 reaction of infarction and 2 fate of it
1- fever
2- leukocytosis
3- elevated serum enzymes as transaminse in myocardial infarction
Small infarction
Necrotic tissue removed by macrophages, granulation tissue fills the defect followed by fibrosis
Large infarction
Gets surrounded by fibrous capsule and its substance may show dystrophic calcification
