Respiratory and circulatory system

The trachea branches into two narrower airways called ____________

Answer explanation

The trachea branches into two narrower airways called bronchi. These bronchi lead to the lungs, allowing air to flow in and out during respiration.

Capillaries surround the ________________ , where gas exchange occurs.

Answer explanation

Capillaries surround the alveoli, which are tiny air sacs in the lungs. This is where gas exchange occurs, allowing oxygen to enter the blood and carbon dioxide to be removed.

Which body system helps the respiratory system bring oxygen into the body?

• circulatory

• digestive

• excretory

• muscular

Answer explanation

The muscular system aids the respiratory system by facilitating breathing. Muscles like the diaphragm contract to allow air to enter the lungs, thus helping to bring oxygen into the body.

The narrow blood vessels where gas exchange occurs are

________________

Answer explanation

The narrow blood vessels where gas exchange occurs are called capillaries. They facilitate the exchange of oxygen and carbon dioxide between blood and tissues.

A blockage of blood vessels in the brain can cause

• a heart attack

• a stroke

• heart failure

• hypertension

Answer explanation

A blockage of blood vessels in the brain restricts blood flow, leading to a stroke. This condition can cause brain damage and loss of function, unlike a heart attack, heart failure, or hypertension, which affect the heart.

Which part of the blood carries dissolved molecules such as glucose and salt?

• plasma

• platelets

• red blood cells

• white blood cells

Answer explanation

The plasma is the liquid component of blood that carries dissolved substances like glucose and salts, making it essential for transporting nutrients and waste products throughout the body.

The large muscle that contracts and relaxes to move gases into and out of the lungs is the ___________

Answer explanation

The diaphragm is the primary muscle responsible for breathing. It contracts to draw air into the lungs and relaxes to push air out, making it essential for gas exchange.

A respiratory infection in which the bronchi swell is ______________

Answer explanation

A respiratory infection characterized by the swelling of the bronchi is known as bronchitis. This condition leads to symptoms like coughing and difficulty breathing, making 'bronchitis' the correct answer.

The smallest blood vessels are ____________

Answer explanation

The smallest blood vessels are capillaries. They connect arteries and veins, allowing for the exchange of oxygen, carbon dioxide, and nutrients at the cellular level.

Small, irregularly shaped pieces of cells in blood are

Answer explanation

Small, irregularly shaped pieces of cells in blood are known as platelets. They play a crucial role in blood clotting and are essential for wound healing.