Topic 7

Question 1

Define Hypermia

Answer 1

This is due to an increased of blood flow to an organ or tissue due to vasodilation of either the arteries and veins. the blood flow is excessive

or the blood vessel is blood which will cause an accumulation of blood in that tissue or organ

Question 2

What are the types of hypermia

Answer 2

Active hyperaemia happens when there’s an increase in the blood supply to an organ. This is usually in response to a greater demand for blood — for example, if you’re exercising.

Passive hyperaemia is when blood can’t properly exit an organ, so it builds up in the blood vessels.

It is also divided in physiological and pathological. For pathological hyperaemia it has 2 subdivisions neurogenic and metabolic. Neurogenic again has further subdivisions, neurotonic and neuroparalytic

Question 3

What are the causes of hyperaemia

Answer 3

Exercise. Your heart and muscles need more oxygen when you’re active. Blood rushes to these organs to supply extra oxygen. Your muscles need up to 20 times their normal supply of blood during a workout.

Heat. When you’re running a high fever or it’s hot outside, extra blood flows to your skin to help your body release heat.

Digestion. After you eat, your stomach and intestines need more blood to help them break down foods and absorb nutrients.

Inflammation. During an injury or infection, blood flow to the site increases.

Menopause. Women who are in menopause often have hot flashes, which causes a rush of blood to the skin — especially of the face, neck, and chest. Blushing is a similar response.

Release of a blockage. Hyperemia can happen following ischemia, which is poor blood flow to an organ. Once ischemia is treated, blood rushes to the area.

Question 4

What are the causes of Venous hyperaemia (mainly blockage)

Answer 4

Etiological factors of venous hyperemia:
are those, which narrow the lumen of veins. They may be exogenous and endogenous. They are:
• obstruction of veins with a thrombus or an embolus;
• compression of veins by a tumor, enlarged internal organ (for example, uterus),
exudate in the region of inflammation;
• compression of veins by exudative pleuritis, hemothorax, pneumosclerosis, em ­
physema;
• cardiac left- or right-ventricular failure;
• professional overloading (maintaining vertical position for a long time);
• genetic predisposition to venous congestion (weakness of the venous elastic ap­paratus, low tonus of the smooth muscle elements of the vascular wall).

Question 5

How is venous hyperemia caused

Answer 5

This is due to a lack of oxygen and substrates develop.this results in atrophic and dystrophic changes. The blood viscosity will therefore will increase as well as the permeability. this is linked to oedema . Basically this causes congestion.

This causes dilations of small blood vessels.

atrophic and dystrophic tissue

Hypoxia

enlargement of organs or tissues due to swelling

thrombus

Sclerosis (abnormal hardening of tissues)

metabolic disorder

Question 6

Define Ischemia

Answer 6

deficient supply of blood to a body part (as the heart or brain) that is due to obstruction of the inflow of arterial blood (as by the narrowing of arteries by spasm or disease)

Question 7

List the three types of Ischemia

Answer 7

compressive Ischemia= and object blocking the. arteries i.e. tumour fatty deposits

Obstructive Ischemia= Due to narrowing of the blood vessel. Because of embolisms(obstruction of artery due to lot or an air bubble) or atherosclerotic process

Angioplastic Ischemia= reduction in the vasomotor task, Promote vasoconstriction. This is short term. Maybe due to physical factors(cold,mechanical and injuries) chemical agents, biological, reflexes and emotional factors.

Factors which contribute to Angioplastic Ischemia depends on the permeability of smooth muscle cell membranes for N a+, Ca2+, K+and Cl” ions. Neurogenous a-adrenergic, histaminergic, serotoninergic, dopaminergic mechanisms also matter.

Angiotensin II is one of the most potent vasoconstrictors. It effects smooth muscle cells directly causing depolarization as a result of increased Na+permeability. When Na+ions accumulate in the muscle fibers of vessels, their sensitivity to vasoconstrictors (cate­ cholamines, vasopressin and angiotensin) increases.
Endothelium injury results in its inability to produce relaxing factors (NO). This leads to spastic reactions.
Angiospastic ischemia may have a conditioned reflex nature. Ischemia leads to oxygen deficiency (hypoxia).

Question 8

Side effects to Ischemia

Answer 8

Necrosis

Dystrophy

Blood flow reduced

local hypothermia

reduced organ size

paleness of the ischemic region

pain

Paresthesia (sensitivity disorder, tingling )

Organ function failure

Question 9

Define stasis

Answer 9

This is a reduce amount of blood flow to the capilleries, small arteries and veins

Question 10

What are the 2 different types of Stasis

Answer 10

True stasis capillaries and Ischemic (complete stop of blood inflow) to the venous

Blood stasis is a term used by some Eastern medical practitioners meaning that the blood is not flowing or circulating as optimally as it could to all parts of the body. It is considered to be one of the major causes of pain.

Question 11

Outline what is True Stasis (Capillaries)

Answer 11

This is due to pathological changes in the capillaries or abnormality flow of blood within this vessels. Blood flow will therefore become stagnant and homogenised. This will lead to cell death and dystrophy

Question 12

What are the etiological factors of true stasis

Answer 12

Physical (Cold, burn) chemical and biological

Question 13

Outline Ischemic and Venous stasis

Answer 13

This is a combination of a blockage or narrowing of the blood vessels which will promote reduce blood flow. This maybe due to artery spasm, compression or occulation.If these factors are not eliminated then this may develop to true stasis

Question 14

Define Thrombosis

Answer 14

Thrombosis occurs when blood clots block your blood vessels. There are 2 main types of thrombosis:

Venous thrombosis is when the blood clot blocks a vein made from thrombus or any material. Veins carry blood from the body back into the heart.
Arterial thrombosis is when the blood clot blocks an artery. Arteries carry oxygen-rich blood away from the heart to the body.

Thrombosis occur when there is reduce blood flow and there is a damage to that vessel. or factors which increase blood coagutivity i.e. oestrogen

Question 15

List the process of thrombosis

Answer 15

1. The extrinsic pathway is activated rapidly (within seconds) following tissue damage. Damaged tissue releases a complex of chemicals called thromboplastin or tissue factor, which initiates coagulation. The intrinsic pathway is slower (3–6 minutes) and is triggered when blood comes into contact with damaged blood vessel lining (endothelium).

Due to the damaged wall of the blood vessels this attracts platelets to stick to the wall of the vessels initiating serotonin to be released this causes vasoconstriction

2. Platelets readily conjugate to the affected area and form a platelet plug this is completed in 6 minutes
3. Prothrombin activates thrombin to convert fibrinogen to fibrin. Fibrin matures the blood clot and makes it stronger than the platelet plug.
4. The process of removing and healing a clot is called Fibrinolysis. Plasminogen found in the clot is converted to the enzyme plasmin and this breaks down fibrin and thus causes phagocytes to finally remove them

Question 16

What is an embolism

Answer 16

An embolism is a blocked artery caused by a foreign body, such as a blood clot or an air bubble. The body’s tissues and organs need oxygen, which is transported around the body in the bloodstream.