Transport in Humans

Flashcards covering key concepts about transport systems, circulatory functions, blood components, and immunity in humans.

What is the primary role of a transport system in large multicellular organisms?

To transport materials such as nutrients and oxygen to cells and remove waste products.

List some substances that need to be transported in the human body.

Oxygen, digested food, hormones, and nitrogenous waste products like urea.

How do unicellular organisms like amoebas exchange materials?

Through diffusion, as their cells are in close proximity to the surrounding environment.

What happens to diffusion rates in large multicellular organisms?

Diffusion alone is often insufficient for transporting materials to deep cells.

What mechanism allows water to move into cells?

Osmosis, which moves water from higher to lower osmotic potential.

What are the three main parts of the human circulatory system?

Blood, blood vessels, and the heart.

Where is the heart located in the human body?

Behind the sternum and between the two lungs.

What type of muscle is the heart made from?

Cardiac muscle.

What surrounds the heart and what is its function?

The pericardium, which contains pericardial fluid for lubrication.

What do the coronary arteries supply?

They supply glucose and oxygen to the cardiac muscles.

What are the upper chambers of the heart called?

Atria (singular: atrium).

What are the lower chambers of the heart called?

Ventricles.

What type of valves prevent blood backflow into atria during ventricular contraction?

Atrioventricular valves.

What is the major function of arteries?

To transport blood away from the heart at high pressure.

What type of blood do veins carry?

Deoxygenated blood, except for pulmonary veins.

What type of blood do arteries carry?

Oxygenated blood, except for pulmonary arteries.

What is the structure related to the function of arteries?

Thick elastic walls that withstand high pressures.

What mechanism aids blood flow in veins?

Contractions of skeletal muscles and valves preventing backflow.

What are capillaries and their significance?

Microscopic thin-walled blood vessels that connect arteries and veins, allowing material exchange.

What do red blood cells contain that allows them to transport oxygen?

Hemoglobin.

Define the process of phagocytosis.

The engulfing and digesting of foreign particles by phagocytes.

What is the lifespan of red blood cells?

About 120 days.

What is the function of white blood cells?

To protect the body against infection.

What are platelets primarily responsible for?

Blood clotting.

What happens during the cardiac cycle?

It consists of contraction (systole) and relaxation (diastole) of the cardiac muscles.

What causes hypertension?

Long-term high blood pressure which may result from various risk factors.

What is double circulation?

A system where the blood passes through the heart twice in one complete circuit.

How does oxygenation occur in the lungs?

Deoxygenated blood is pumped to the lungs for gas exchange.

What is the significance of valves in the heart?

They prevent backflow of blood during heart contractions.

Name two types of valve actions during heart contractions.

Atrioventricular valves prevent backflow and semilunar valves open to allow blood flow from the ventricles.

What does innate immunity refer to?

Natural immunity present from birth, acting as the first line of defense.

What are T and B lymphocytes responsible for in adaptive immunity?

Recognizing specific antigens and generating an immune response.

Define specificity in immunity.

The ability of the immune response to target specific pathogens.

What is the role of antibodies?

To bind to antigens, neutralizing or marking them for destruction.

What causes blood groups to clump?

Incompatible mixes of donor and recipient blood lead to agglutination.

Why is blood group O known as the universal donor?

It lacks A and B antigens, allowing it to be accepted by all blood groups.

How does the body respond to physical injury?

Through the inflammatory response, initiated by histamine release.

What are the two lines of defense in the nonspecific immune response?

Physical/chemical barriers and the phagocytic action.

What is the primary function of the respiratory system in relation to blood?

To facilitate gas exchange, providing oxygen to and removing carbon dioxide from blood.

How do mast cells contribute to inflammation?

By releasing histamine that increases blood flow to the injury site.

What happens after the primary immune response?

Memory lymphocytes remain, allowing for a faster secondary reaction upon re-exposure.

What is a blood clot primarily made of?

Fibrin threads that trap blood cells and platelets.

How are blood cells produced in humans?

In the bone marrow, where they originate and mature.

What is the relationship between blood pressure and vessel structure?

Arteries have thicker, more elastic walls due to higher pressure, while veins are thinner.

What role do phagocytes play in the immune system?

They engulf and digest pathogens to protect the body.

What is the normal range for human blood pressure?

120-140 mmHg systolic and 80-90 mmHg diastolic.

What can trigger the adaptive immune response?

Failure of the innate immune system to eliminate a pathogen.