Respiratory, Circulatory, and Digestive Systems Overview

What are the main structures of the respiratory system?

Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli.

What is the pathway of air from the external environment to the alveoli?

Air enters through the nasal cavity or mouth, travels down the pharynx, passes through the larynx, moves into the trachea, branches into bronchi, then bronchioles, and finally reaches the alveoli.

How does the structure of the alveoli support efficient gas exchange?

Alveoli have a large surface area, thin walls, a moist lining, and a good blood supply, facilitating rapid gas exchange.

What are the main components of the circulatory system?

The heart, blood vessels (arteries, veins, capillaries), and blood.

What is the function of arteries?

To carry oxygenated blood away from the heart to the body.

What is the function of veins?

To carry deoxygenated blood back to the heart.

What is the function of capillaries?

To facilitate the exchange of oxygen, carbon dioxide, nutrients, and waste between blood and tissues.

What is mechanical digestion?

The physical breakdown of food into smaller pieces, examples include chewing, peristalsis, stomach churning, and bile emulsifying fats.

What is chemical digestion?

The process of breaking down food into simpler molecules by enzymes.

What role do enzymes play in digestion?

Enzymes break down carbohydrates, proteins, and fats into absorbable units.

How are the diaphragm and intercostal muscles involved in breathing?

The diaphragm contracts and moves downwards for inhalation, while intercostal muscles expand the rib cage; during exhalation, the diaphragm relaxes and the rib cage contracts.

How do diseases like asthma affect gas exchange?

Diseases like asthma can constrict airways, reducing airflow and efficiency of gas exchange.

What is the role of valves in veins?

Valves prevent the backflow of blood, ensuring it flows towards the heart.

What is the direction of blood flow through the heart?

Blood flows from the body into the right atrium, to the right ventricle, to the lungs, back to the left atrium, to the left ventricle, and out to the body.

What are the three key phases of the cardiac cycle?

Atrial contraction, ventricular contraction, and relaxation.

What is the difference between oxygenated and deoxygenated blood?

Oxygenated blood is rich in oxygen and found in the left side of the heart; deoxygenated blood is low in oxygen and found in the right side of the heart.

What are the four major components of blood?

Red blood cells (carry oxygen), white blood cells (immune response), platelets (blood clotting), and plasma (liquid transport medium).

What are antibodies and antigens in relation to blood types?

Antigens are substances on the surface of red blood cells that determine blood type; antibodies are proteins in plasma that attack foreign antigens.

What is the significance of blood transfusions?

Blood transfusions must match blood types to prevent immune reactions.

How does the lymphatic system assist in fluid balance?

The lymphatic system returns excess fluid from tissues back into the bloodstream.

What is the role of lymph nodes?

Lymph nodes filter lymph and help defend the body against infection.

How is the small intestine adapted for absorption?

The small intestine has villi and microvilli, providing a large surface area, thin walls, and a rich blood and lymph supply.

What causes diarrhoea and why can it be dangerous?

Diarrhoea is caused by infections or irritants that affect absorption; it can lead to dehydration and loss of electrolytes if prolonged.