Lecture 28 (Disorders of primary haemostasis)

Question 1 of 37

1

What does the term "haemorrhage by rhexis" mean?

Select one of the following:

A substantial tear in a blood vessel or a tear in a heart chamber --> rapid escape of a substantial
volume of blood
The escape of red blood cells one by one through minute or microscopically imperceptible defects
in vessel walls
Escape of blood from the cardiovascular system
Haemorrhage into a synovial joint

Explanation

Question 2 of 37

1

What does the term "haemorrhage by diapedesis" mean?

Select one of the following:

A substantial tear in a blood vessel or a tear in a heart chamber --> rapid escape of a substantial
volume of blood
The escape of red blood cells one by one through minute or microscopically imperceptible defects
in vessel walls
haemorrhage into the pleural cavity
The escape of blood from the cardiovascular system

Explanation

Question 3 of 37

1

❌ = haemorrhage into the pleural cavity

❌ = haemorrhage into the pericardial sac

❌ (haemabdomen or haemoabdomen) = haemorrhage into the peritoneal cavity

❌ = haemorrhage into a synovial joint

❌ = haemorrhage into urine

❌ = coughing of blood

❌ = vomiting of blood

❌ = passage of fresh blood in faeces (typically over the surface of stools)

❌ = diarrhoea containing blood

❌ = diffuse, dark red-black discolouration of faeces due to upper alimentary tract haemorrhage or swallowing of blood from the respiratory tract

❌ = bleeding from the nose

❌ = haemorrhage into the anterior chamber of the eye

Drag and drop to complete the text.

haemothorax

haemopericardium

haemoperitoneum

haemarthrosis

haematuria

haemoptysis

haematemesis

haematochezia

dysentery

melaena

epistaxis

hyphaema

Explanation

Question 4 of 37

1

❌ = tiny, pinpoint foci of haemorrhage, 1-2 mm in diameter, typically found in skin and on mucosal and serosal membranes

❌ = slightly larger haemorrhages ≥ 3 mm in diameter

❌ = larger foci of haemorrhage, 2-3 cm in diameter; usually blotchy and of irregular shape

❌ haemorrhages = linear or streaky haemorrhages, especially over serosal or mucosal membranes, as if a brush dipped in red paint has been hastily splashed across the tissues

❌ = a palpable, discrete, space-occupying mass of clotted blood within tissues, small "" are common at sites of difficult venipuncture

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petechiae

purpura

ecchymoses

paintbrush (or suffuse or suffusive)

haematoma

Explanation

Question 5 of 37

1

The gross colour of haemorrhage depends on whether the blood was arterial or venous, the volume of extravasated blood and the time elapsed since haemorrhage occurred. What colour does the bruise appear during the acute, sub-acute and chronic stages and what is the molecule causing this colouration?

In the acute phase, bruises appear ❌ due to the presence of poorly oxygenated ❌

In the subacute phase, bruises appear ❌ due to the formation within macrophages of ❌ (derived from the porphyrin component of haemoglobin)

In the chronic phase, bruises appear ❌ due to the formation of ❌ and, to a lesser extent, haematoidin +/- lipofuscin pigments

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red-blue

haemoglobin

blue-green

biliverdin and bilirubin

gold-brown

grey-black

haemosiderin

Explanation

Question 6 of 37

1

What happens to a haematoma from 5-7 days after onset?

Select one or more of the following:

They become enveloped by granulation tissue - following phagocytosis of the extravasated blood
The cavity of a haematoma is ultimately filled in by scar tissue (fibrosis)
Haemosiderin colouration of the haematoma

Explanation

Question 7 of 37

1

❌ (composed of ferritin micelles (iron + apoferritin) derived from the iron component of haemoglobin) first appears microscopically within macrophages by 24-48 hours after the onset of haemorrhage. Sufficient "" accumulation to cause gross yellow discolouration is not expected until 2-3 days after haemorrhage.

❌ is a bright golden extracellular pigment composed of precipitates of bilirubin complexed with tissue proteins

❌ is an intracellular yellow-brown pigment derived from peroxidation of phospholipids of membranes of damaged cells in the area

Drag and drop to complete the text.

haemosiderin

Haematoidin

Lipofuscin

Explanation

Question 8 of 37

1

What factor(s) determine the clinical significance of haemorrhage?
(select the answer or answers that are correct)

Select one or more of the following:

Location of haemorrhage
Rate of blood loss
Volume of blood loss

Explanation

Question 9 of 37

1

❌ (haemorrhage into tissues or body cavities) --> reutilisation of plasma
proteins and iron

❌ (e.g. from the skin or gastrointestinal, respiratory, urinary or reproductive tracts) --> if recurrent or prolonged= hypoproteinaemia and iron deficiency anaemia

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internal haemorrhage

external haemorrhage

Explanation

Question 10 of 37

1

What is the most common cause of haemorrhage in domestic animals?

Select one of the following:

Physical trauma
Ectoparasites (e.g. fleas) and endoparasites
Neoplasia
Inherited or acquired defects in primary and/or secondary haemostasis

Explanation

Question 11 of 37

1

What is the clinical sign this horse is exhibiting?

Select one of the following:

epistaxis
haemoptysis
haematemesis
hyphaema

Explanation

Question 12 of 37

1

What is the correct terminology for each of these poo/faeces samples?

Drag an answer into the correct orange point.

melaena

haematochezia

dysentery

haematuria

haematemesis

Explanation

Question 13 of 37

1

What is the correct terminology for each of these forms of haemorrhage?

Drag an answer into the correct orange point.

haemothorax

haemoperitoneum

haemoptysis

haemarthrosis

haemopericardium

hyphaema

epistaxis

Explanation

Question 14 of 37

1

How would you correctly describe each of these haemorrhagic lesions?

Drag an answer into the correct orange point.

petechiae

ecchymoses

purpura

paintbrush

haematoma

hyphaema

Explanation

Question 15 of 37

1

Below are two lists of possible "features" or "symptoms relating to primary or secondary haemostasis, which list belongs to primary haemostasis and which to secondary haemostasis?

❌
•delayed bleeding after venipuncture
•large volume bleeds
•petechiae rare
•haematomas common
•bleeding into muscles, joints and/or body cavities
•bleeding may be localised
•+/- mucosal bleeding

❌
•bleeding immediately after venipuncture
•small volume bleeds
•petechiae common
•haematomas uncommon
•bleeding from mucous membranes
•bleeding from multiple sites

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Secondary haemostasis

Primary Haemostasis

Explanation

Question 16 of 37

1

Disseminated intravascular coagulation (DIC) is a combined disorder of both Primary and Secondary Haemostasis.

Select one of the following:

True
False

Explanation

Question 17 of 37

1

Match the below words with the correct definition

❌- deficiency of platelets in the blood. Can result in bleeding into the tissues, bruising, and slow blood clotting after injury.

❌- clinical disorders of haemostasis characterised by a bleeding tendency

❌ - replacement of haemopoietic bone marrow by neoplastic tissue (e.g. leukaemia), collagen (myelofibrosis), bone (osteosclerosis) or inflammatory exudate (e.g. chronic granulomatous osteomyelitis in systemic fungal infections)

❌- platelet dysfunction

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Thrombocytopenia

Haemorrhagic diatheses

Myelophthisis

Thrombocytopathy

Thrombocytosis

Explanation

Question 18 of 37

1

Which of the below are disorders of Primary Haemostasis?

Select one or more of the following:

platelet deficiency (thrombocytopenia)
platelet dysfunction (thrombocytopathy, thrombopathy or thrombopathia)
von Willebrand’s disease (deficiency of von Willebrand factor)
damage to small blood vessels
inherited deficiency of one or more coagulation factors
decreased coagulation factor synthesis due to severe acute or chronic hepatic parenchymal disease
excessive fibrinolysis or fibrinogenolysis

Explanation

Question 19 of 37

1

Which of the below are disorders of Secondary Haemostasis?

Select one or more of the following:

excessive fibrinolysis or fibrinogenolysis
decreased coagulation factor synthesis due to severe acute or chronic hepatic parenchymal disease
decreased coagulation factor activity due to vitamin K antagonism or deficiency
inherited deficiency of one or more coagulation factors
damage to small blood vessels
platelet deficiency (thrombocytopenia)

Explanation

Question 20 of 37

1

Disorders of secondary haemostasis provoke multiple short-lived bleeds that cease once the coagulation cascade generates fibrin

Select one of the following:

True
False

Explanation

Question 21 of 37

1

What is the most common acquired haemostatic disorder in dogs and cats?

Select one of the following:

thrombocytopenia
thrombocytopathy
von Willebrand’s disease
damage to small blood vessels

Explanation

Question 22 of 37

1

What is the MOST COMMON mechanism responsible for clinically significant thrombocytopenia in cats?

Select one of the following:

Decreased platelet production
destruction of platelets
Consumption of platelets
sequestration of platelets

Explanation

Question 23 of 37

1

What is/are the most common mechanisms of decreased platelet production in cats that lead to thrombocytopenia?

Select one or more of the following:

Retroviral infection (especially feline leukaemia virus (FeLV))
Myeloproliferative or lymphoproliferative disease
Megakaryocytic hypoplasia
Hypothermia

Explanation

Question 24 of 37

1

Of the below which can cause marrow aplasia or panhypoplasia?

Select one or more of the following:

Ionising radiation
Viral infection eg. canine and feline parvovirus, FeLV, feline immunodeficiency virus (FIV), equine infectious anaemia (EIA) virus
Toxins eg. aflatoxins, stachybotryotoxin, bracken fern, benzene
Drug cytotoxicity - chemotherapeutic agents, chloramphenicol, sulphadiazine, oestrogen (dogs and ferrets), griseofulvin (cats), methimazole (cats)
Other infectious agents - late stages of infection with Ehrlichia canis and other rickettsial species
Immune mediated destruction of platelets
Massive external haemorrhage

Explanation

Question 25 of 37

1

Which is the correct order of cell lifespan (from longest to shortest)?

Select one of the following:

erythrocytes > platelets > neutrophils
erythrocytes > neutrophils > platelets
neutrophils > erythrocytes > platelets
neutrophils > platelets > erythrocytes
platelets > erythrocytes > neutrophils
platelets > neutrophils > erythrocytes

Explanation

Question 26 of 37

1

What is the most common mechanism of thrombocytopenia in dogs?

Select one of the following:

Platelet destruction
Platelet consumption
Platelet sequestration
Decreased Platelet Production

Explanation

Question 27 of 37

1

What is the most common cause of platelet destruction in dogs?

Select one of the following:

Immune-mediated destruction
Infectious viral agents
Infectious bacterial agents
Infectious parasitic agents

Explanation

Question 28 of 37

1

Platelet consumption due to formation of numerous microthrombi is typical of disseminated intravascular coagulation (DIC)

Select one of the following:

True
False

Explanation

Question 29 of 37

1

In health what percentage of platelets are located in the spleen?

Select one of the following:

30-40%
10-20%
70-80%
5-10%

Explanation

Question 30 of 37

1

In most circumstances, does sequestration of platelets cause a mild, moderate or severe thrombocytopenia?

Select one of the following:

mild
moderate
severe

Explanation

Question 31 of 37

1

Why does massive acute haemorrhage usually only cause a mild subclinical thrombocytopenia?

Select one of the following:

because of the large splenic platelet reservoir
because platelets are rapidly made in the bone marrow (faster than any form of bleed)
because of the large liver platelet reservoir

Explanation

Question 32 of 37

1

Define Thrombopathia

Select one of the following:

rare autosomal-recessive genetic form of haemophilia
rare autosomal-dominant genetic form of haemophilia
common autosomal-recessive genetic form of haemophilia
common autosomal-dominant genetic form of haemophilia

Explanation

Question 33 of 37

1

Which is the most common inherited bleeding disorder of dogs?

Select one of the following:

von Willebrand’s disease (vWD)
Glanzmann thrombasthenia
Chédiak-Higashi syndrome
inherited thrombopathia

Explanation

Question 34 of 37

1

What is the role of the large glycoprotein von Willebrand factor?

Select one of the following:

Mediates the adhesion of platelets to exposed subendothelial collagen via their surface GpIb receptors. Prevents platelets being dislodged by blood flow.
Activates the zymogen prothrombin by converting it into the serine protease thrombin
Forms a mesh, enforcing the platelet plug making it stronger
is an intracellular yellow-brown pigment derived from peroxidation of phospholipids of membranes of damaged cells in the area
Prevents the adhesion of platelets to exposed subendothelial collagen via their surface GpIb receptors and so prevents platelets being lodged in vessels during blood stasis.

Explanation

Question 35 of 37

1

Where can von Willebrand's factor expressed and/or stored?

Select one of the following:

vascular endothelial cells
megakaryocytes
subendothelial connective tissues
All of the above

Explanation

Question 36 of 37

1

Determine which is type 1, type 2 and type 3 von Willebrand's disease forms from the below lists of information

❌
- the most common form of vWD in dogs (> 90% of cases)
- all of the various multimer chains of vWf are present but in reduced plasma concentrations (< 50% of normal)
- e.g. doberman pinscher (in the not so distant past, approximately 60% of dobermans in Australia were thought to be carriers of the trait), Welsh corgis, German shepherd dogs, golden retrievers, and poodles
- may be subclinical or cause mild to moderate bleeding
- bleeding does not usually occur until the plasma vWf concentration falls below 20% of normal

❌
- there is virtually negligible vWf in plasma, with all multimers absent
- Scottish terriers (the main breed affected in Australia), Shetland sheepdogs, Chesapeake Bay retrievers and Dutch kooikers
- trauma in homozygotes --> severe haemorrhage

❌
- decreased plasma vWf concentration is associated with a disproportionate loss of the large high m.w. multimers
- can be responsible for severe haemorrhage
- rare but reported in German short-haired and wire-haired pointers
- also reported in horses

Drag and drop to complete the text.

Type 1 vWD

Type 3 vWD

Type 2 vWD

Explanation

Question 37 of 37

1

Dogs with vWD will often bleed spontaneously

Select one of the following:

True
False

	Created by Kathryn Borg about 8 years ago

DVM2 HLI (Semester 1) (Pathology (Jenny's lectures)) Quiz on Lecture 28 (Disorders of primary haemostasis), created by Kathryn Borg on 13/04/2016.

Lecture 28 (Disorders of primary haemostasis)

Question 1 of 37

What does the term "haemorrhage by rhexis" mean?

Select one of the following:

Explanation

Question 2 of 37

What does the term "haemorrhage by diapedesis" mean?

Select one of the following:

Explanation

Question 3 of 37

Drag and drop to complete the text.

Explanation

Question 4 of 37

Drag and drop to complete the text.

Explanation

Question 5 of 37

Drag and drop to complete the text.

Explanation

Question 6 of 37

What happens to a haematoma from 5-7 days after onset?

Select one or more of the following:

Explanation

Question 7 of 37

Drag and drop to complete the text.

Explanation

Question 8 of 37

What factor(s) determine the clinical significance of haemorrhage? (select the answer or answers that are correct)

Select one or more of the following:

Explanation

Question 9 of 37

❌ (haemorrhage into tissues or body cavities) --> reutilisation of plasma proteins and iron ❌ (e.g. from the skin or gastrointestinal, respiratory, urinary or reproductive tracts) --> if recurrent or prolonged= hypoproteinaemia and iron deficiency anaemia

Drag and drop to complete the text.

Explanation

Question 10 of 37

What is the most common cause of haemorrhage in domestic animals?

Select one of the following:

Explanation

Question 11 of 37

What is the clinical sign this horse is exhibiting?

Select one of the following:

Explanation

Question 12 of 37

What is the correct terminology for each of these poo/faeces samples?

Drag an answer into the correct orange point.

Explanation

Question 13 of 37

What is the correct terminology for each of these forms of haemorrhage?

Drag an answer into the correct orange point.

Explanation

Question 14 of 37

How would you correctly describe each of these haemorrhagic lesions?

Drag an answer into the correct orange point.

Explanation

Question 15 of 37

Drag and drop to complete the text.

Explanation

Question 16 of 37

Disseminated intravascular coagulation (DIC) is a combined disorder of both Primary and Secondary Haemostasis.

Select one of the following:

Explanation

Question 17 of 37

Drag and drop to complete the text.

Explanation

Question 18 of 37

Which of the below are disorders of Primary Haemostasis?

Select one or more of the following:

Explanation

Question 19 of 37

Which of the below are disorders of Secondary Haemostasis?

Select one or more of the following:

Explanation

Question 20 of 37

Disorders of secondary haemostasis provoke multiple short-lived bleeds that cease once the coagulation cascade generates fibrin

Select one of the following:

Explanation

Question 21 of 37

What is the most common acquired haemostatic disorder in dogs and cats?

Select one of the following:

Explanation

What factor(s) determine the clinical significance of haemorrhage?
(select the answer or answers that are correct)

❌ (haemorrhage into tissues or body cavities) --> reutilisation of plasma
proteins and iron

❌ (e.g. from the skin or gastrointestinal, respiratory, urinary or reproductive tracts) --> if recurrent or prolonged= hypoproteinaemia and iron deficiency anaemia