Description

Source: Kawasakidiseasefoundation

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Context

Recently a stand up comedian revealed his son was suffering from a rare disease called Kawasaki disease.

About Kawasaki Disease

Kawasaki Disease (KD) is an acute, self-limiting illness that predominantly affects children under the age of 5. It is characterized by inflammation of blood vessels (vasculitis) and can lead to serious complications if left untreated.

Characteristics

Primarily affects children under 5 years.

Slightly more common in boys than girls.

Most cases occur in Asia particularly Japan but it is found worldwide.

More common in late winter and early spring.

Causes

Exact Cause: Unknown but suspected triggers include:

Viral or bacterial agents.

Genetic Factors (Predisposition in families).

An abnormal reaction to an environmental trigger.

Symptoms

Presence of fever lasting more than 5 days along with at least four of the following five symptoms:

Conjunctivitis (Bilateral, non-purulent redness of the eyes).
Lymphadenopathy (Swelling of lymph nodes typically in the neck).
Oral Changes.
Extremity Changes:
- - Swelling and redness of the hands and feet.
  - Peeling of the skin around the nails in later stages.

Treatment

Intravenous Immunoglobulin (IVIG): Standard treatment to reduce inflammation and prevent coronary complications.

Aspirin.

About Blood Vessels

Type of Blood Vessel	Structure	Function	Examples
Arteries	Thick, muscular and elastic walls; narrow lumen.	Carry oxygenated blood away from the heart (except pulmonary arteries).	Aorta, Coronary arteries, Pulmonary artery
Arterioles	Smaller branches of arteries; thinner walls with smooth muscle.	Regulate blood flow and pressure by vasodilation and vasoconstriction.	Precapillary arterioles
Capillaries	Single-cell-thick walls; no muscle layer; very narrow lumen.	Exchange of gases, nutrients and waste products between blood and tissues.	Capillaries in lungs, muscles, intestines
Venules	Thin-walled vessels formed from capillaries; contain some smooth muscle.	Collect deoxygenated blood from capillaries and transport it to veins.	Postcapillary venules
Veins	Thin walls with less muscle; larger lumen; contain valves to prevent backflow of blood.	Carry deoxygenated blood toward the heart (except pulmonary veins).	Vena cava, Pulmonary veins
Vasa Vasorum	Small blood vessels that supply the walls of larger blood vessels.	Provide nutrients and remove waste for the outer layers of large arteries and veins.	Found in the walls of aorta and vena cava

Comparison of Arteries, Capillaries and Veins

Feature	Arteries	Capillaries	Veins
Wall Thickness	Thick and muscular	Very thin (single layer of cells)	Thin, less muscular
Lumen Size	Narrow	Extremely narrow	Wide
Presence of Valves	Absent (except pulmonary artery)	Absent	Present
Blood Flow	Away from the heart	From arteries to veins	Toward the heart
Pressure	High	Low	Very low
Oxygen Content	Oxygen-rich (except pulmonary artery)	Mixed (depending on location)	Oxygen-poor (except pulmonary vein)

Additional Types of Blood Vessels

Type	Description
Lymphatic Vessels	Part of the lymphatic system responsible for transporting lymph (a fluid containing white blood cells).
Sinusoids	Specialized capillaries with larger pores found in organs like the liver, spleen and bone marrow.

Sources:

India.com

PRACTICE QUESTION

Q.Consider the following statements regarding blood vessels:

Arteries carry oxygenated blood while veins carry deoxygenated blood without exception.
Capillaries are the only blood vessels where exchange of gases and nutrients occurs.
The walls of veins are thinner than those of arteries but have valves to ensure unidirectional blood flow.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 and 3 only

(d) 1, 2 and 3

Answer: (b)

Explanation:

Statement 1 is incorrect: While arteries usually carry oxygenated blood and veins deoxygenated blood, pulmonary arteries and veins are exceptions. Pulmonary arteries carry deoxygenated blood and pulmonary veins carry oxygenated blood.

Statement 2 is correct: Capillaries have thin walls that allow for the exchange of gases, nutrients and waste products between blood and tissues.

Statement 3 is correct: Veins have thinner walls and valves to prevent the backflow of blood especially in low-pressure systems.