Patho Week 4

Question 1

3 method of infection of T.B

Answer 1

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

Question 2

When does exudative tissue reaction in TB occur

Answer 2

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

Question 3

3 Fate of primary complex

Answer 3

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

Question 4

4 early lesion features of bilharziasis

Answer 4

1- hyperemia
2- inflammatory edema
3- petechial haemorrhage
4- granularity of mucosa

Question 5

Bilharziasal sandy patches

Answer 5

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

Question 6

3 causes of bilharzial ulcer and its description

Answer 6

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

Question 7

2 fate of scar

Answer 7

1- Hyalinosis
2- Calcification

Question 8

5 local factors affecting repair

Answer 8

Severity and extent of tissue damage

Type of damaged cell

Blood supply

Presence or absence of bacteria
Presence or absence of foreign body

Question 9

4- general factors affecting repair

Answer 9

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

Question 10

One example and the 3 steps of healing by first intention ( primary unoin of wounds

Answer 10

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

Question 11

4 situations of healing by secondary intention

Answer 11

Gaping wounds ( gun shot , abscess )
Oral surgery
Serious burns

Question 12

10 complications of healing

Answer 12

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

Question 13

What is virchow tria

Answer 13

The causes of thrombus

1- endothelial damage
2- change in blood composition
3- stasis

Question 14

2 examples of stasis and 4 change the composition of blood

Answer 14

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

Question 15

Mechanisms of thrombus

Answer 15

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

Question 16

2 types of thrombophlebitis and example for each

3 examples of phlebothrombosis

Answer 16

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

Question 17

Fate of thrombi

Answer 17

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

Question 18

Compare between thrombus and blood clot according to
1- attachments
2- texture
3- moisture
4- color
5- lines of zhan

Answer 18

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

Question 19

6 types of Embolism

Answer 19

1- Detached thrombi
2- Fat embolism
3- Air embolism
4- tumor embolism
5- parasitic embolism
6- Amniotic embolism

Question 20

3 Sites of embolism of detached thrombi

Answer 20

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

Question 21

Effect of thromboembolism depends on 3

What is the effect of pulmonary embolism

Answer 21

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

Question 22

Mechanism of formation of pyeamic abscess

Answer 22

1- Sever pyogenic infection
2- Septic thrombophlebitis
3- fragmented of septic thrombus
4- Septic embolism
5- impaction
6- Multiple small pyaemic abscess

Question 23

3 causes of Air embolism and 3 of fat embolism

Answer 23

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

Question 24

4 Causes of Acute ischemia and 2 effects

Answer 24

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

Question 25

3 causes of chronic ischemia and 2 effect

Answer 25

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

Question 26

3 reaction of infarction and 2 fate of it

Answer 26

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