Human Digestive and Circulatory Systems Quiz

A biological soap produced by the liver that breaks down fats by increasing the surface area of fat droplets.

The first part of the small intestine where digestive enzymes from the pancreas are released.

A digestive organ that produces enzymes for digestion, including amylase, protease, and lipase.

The main site of nutrient absorption in the digestive system.

A hormone released by the pancreas after a meal, causing cells to take up glucose for energy.

The first part of the small intestine where chemical digestion continues, enzymes and bile are added, and nutrients are absorbed into the bloodstream.

A pouch-like organ that stores and concentrates bile produced by the liver.

The process by which the body breaks down food into smaller molecules that can be absorbed and used.

The large tube that connects the mouth to the stomach, where food is chewed and mixed with saliva.

The last part of the digestive system, where water is absorbed from undigested food, before waste is eliminated.

The cardiac cycle is the continuous sequence of relaxation and contraction of the heart that pumps blood throughout the body.

The sinoatrial node (SA) is a specialized group of cells located in the right atrium that acts as the heart's natural pacemaker, initiating and regulating the heart's rhythm.

The atrioventricular node (AV) is a group of cells located between the atria and ventricles, where electrical signals from the SA node are briefly delayed before being transmitted to the ventricles.

The pulmonary circuit is a low-pressure circulatory system that carries deoxygenated blood from the heart to the lungs and returns oxygenated blood back to the heart.

The systemic circuit is a high-pressure circulatory system that carries oxygenated blood from the heart to the rest of the body and brings deoxygenated blood back to the heart.

The largest artery in the body, carrying oxygenated blood from the left ventricle to the rest of the body.

A large vein that carries deoxygenated blood from the lower body to the right atrium.

The valve that controls blood flow between the right atrium and right ventricle.

The muscular wall that separates the right and left sides of the heart.

The valve that controls blood flow from the right ventricle to the pulmonary trunk.

The phase of the cardiac cycle when the heart muscle relaxes and fills with blood.

The phase of the cardiac cycle when the heart muscle contracts and pumps blood out.

The higher number in a blood pressure reading, representing the pressure in the arteries when the heart beats.

The lower number in a blood pressure reading, representing the pressure in the arteries when the heart is at rest.

The sound made when the mitral and tricuspid valves close, marking the start of systole.

Mostly water, but also contains proteins and other dissolved substances. It makes up about 40% of blood mass.

Blood clotting is their primary function. They clump together at the site of a wound, plugging the hole to stop the bleeding.

They carry oxygen to the body cells. They contain hemoglobin, which binds to oxygen molecules. This is crucial for oxygen transport throughout the body.

They defend the body from infections by engulfing and destroying pathogens. They line blood vessels and work harder when the body is challenged by pathogens. They make up less than 1% of blood mass.

They are blood vessels that move blood away from the heart. They have thick, muscular walls because they need to transport blood under high pressure.

They are blood vessels that move blood towards the heart. They have thinner walls than arteries and contain valves to support blood flow.

They are the smallest functional unit of the circulatory system. They connect the arterial and venous systems. They are very thin.

They prevent blood from flowing backward. They are important for maintaining blood flow through the veins.

Tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged. They are the smallest functional units of the respiratory system, clustered in groups and surrounded by capillaries. Their thin walls allow for efficient gas exchange with the surrounding capillaries.

Muscles between the ribs that help expand and contract the chest cavity for breathing.

A sheet of muscle used in the process of inhalation/exertion.

The main branches of the trachea, leading to each lung.

The primary organ for gas exchange.

The trachea is a tube that carries air from the nose and mouth to the lungs. It's like a highway for air.

Inhalation is the process of breathing in air. During inhalation, the diaphragm contracts (moves down) and the intercostal muscles contract (move up and out), increasing the volume of the chest cavity and pulling air into the lungs.

Exhalation is the process of breathing out air. During exhalation, the diaphragm relaxes (moves up) and the intercostal muscles relax (move down and in), decreasing the volume of the chest cavity and pushing air out of the lungs.

The process of gas exchange between alveoli in the lungs and the blood. Oxygen from the inhaled air moves into the blood, whereas carbon dioxide waste from the blood moves into the alveoli to be exhaled.

The process of gas exchange between the blood and the body's cells. Oxygen from the blood is delivered to the cells, while carbon dioxide waste is taken from cells into the blood.

The volume of air inspired or expired in a normal, quiet breath.

The amount of air that can be forcefully inspired after a normal inspiration

The amount of air that can be forcefully expired after a normal exhalation.