THE CIRCULATORY SYSTEM

Question 1

also known as the cardiovascular system, is responsible for transporting blood throughout the body.

Answer 1

THE HUMAN CIRCULATORY SYSTEM

Question 2

KEY COMPONENTS OF HUMAN CIRCULATORY SYSTEM: has three main parts:

Answer 2

the heart
blood vessels
blood.

Question 3

is a muscular organ that pumps blood throughout the body.

Answer 3

HEART

Question 4

These are tubes or channels that carry blood throughout our body.

Answer 4

BLOOD VESSELS

Question 5

3 types of blood vessels

Answer 5

Arteries
Veins
Capillaries

Question 6

Carry oxygen-rich blood away from the heart to the body’s organs and tissues.

Answer 6

ARTERIES

Question 7

Carry oxygen-poor blood back to the heart.

Answer 7

VEINS

Question 8

Tiny blood vessels that connect arteries and veins.

Answer 8

CAPILLARIES

Question 9

4 components of blood

Answer 9

Red blood cells
White blood cells
Plasma
Platelets

Question 10

• nutrients and wastes.

Answer 10

Red Blood Cells

Question 11

• fight diseases and protect the body from infection.

Answer 11

White Blood Cells

Question 12

• where the other components float in.

Answer 12

Plasma

Question 13

• gather at the site of injury and help the clotting process.

Answer 13

Platelets

Question 14

Found in vertebrates, including humans, this system involves blood flowing exclusively within a network of interconnected vessels.

Answer 14

Closed Circulatory System:

Question 15

Found in invertebrates like insects
and mollusks, this system involves blood, called hemolymph, flowing freely through body cavities.

Answer 15

Open Circulatory System

Question 16

are more efficient for larger, more active animals, as they can maintain higher blood pressure and deliver oxygen and nutrients more quickly.

Answer 16

Closed circulatory systems

Question 17

are suitable for smaller, less active animals with lower metabolic demands.

Answer 17

Open circulatory systems

Question 18

The circulatory system, powered by the heart, is essential for maintaining life. The closed circulatory system found in vertebrates is highly efficient, allowing for rapid transport of oxygen, nutrients, and waste products throughout the body. In contrast, the open circulatory system in invertebrates is less efficient, but it is sufficient for smaller organisms with lower metabolic demands.

Question 19

Blood Circulation: Step by Step

 Deoxygenated blood returns to the right atrium via: Superior vena cava (from upper body) and Inferior vena cava (from lower body).

 Blood flows through the tricuspid valve into the right ventricle.

 Upon contraction, blood is pumped through the pulmonary arteries to the lungs.

 In the lungs, blood becomes oxygenated at the alveoli.

 Oxygenated blood returns to the left atrium via the pulmonary veins.

 Blood flows through the mitral valve into the left ventricle.

 The left ventricle pumps oxygenated blood into the aorta (largest artery).

 Blood travels through smaller vessels: Arteries → Arterioles →
Capillaries.

 In capillary beds, blood delivers: Oxygen, Nutrients, and Immune factors.

 Waste and carbon dioxide are collected from tissues.

 Blood flows into venules, then larger veins.

 Veins merge into: Superior vena cava and Inferior vena cava.

 Blood returns to the right atrium, completing the cycle.

Question 20

Blood Circulation Summary
➡️ Right Atrium ➡️ Right Ventricle ➡️ Lungs ➡️ Left Atrium ➡️ Left Ventricle ➡️ Body ➡️ Back to Right Atrium

Question 21

The Heart

The heart is asymmetrical, with the left side being larger than the right side, correlating with the different sizes of the pulmonary circulation and systemic circulation. In humans, the heart is about the size of a clenched fist.

Question 22

Pulmonary Circulation

Happening to the right side of our heart and pump bloods to the lungs.

 Right Atrium - recieve the deoxygenated blood from the entire
body and send it to right ventricle.

 Right Ventricle - responsible for pumping deoxygenated blood to the lungs, where it picks up oxygen.

Question 23

Systemic Circulation

the pathway through which oxygenated blood is pumped from the left side of the heart to the rest of the body.

 Left Atrium - receives oxygen-rich blood from the lungs and pumps it into the left ventricle for distribution to the body.

 Left Ventricle - receives oxygen-rich blood fromthe left atrium and pumps it intothe aorta for circulationthroughout the body.

 Superior vena cava - drains blood from the head and from the veins that come from the arms.

 Inferior vena cava - drains blood from the veins that come from the lower organs and the legs.

 Tricuspid valve - to control the flow of blood between the heart’s right atrium and right ventricle. It ensures blood flows in the correct direction, preventing backflow.

 Bicuspid valve - also known as the mitral valve, is to control blood flow between the left atrium and the left ventricle of the heart.

 Pulmonary valve - its primary function is to allow deoxygenated blood to leave the heart for oxygenation in the lungs and prevent backflow of blood from the pulmonary artery into the right ventricle.

 Aortic valve - The aortic semilunar valve, also known as the aortic valve, is a crucial component of the heart that regulates blood flow from the left ventricle to the aorta. Its primary function is to ensure unidirectional blood flow, preventing backflow from the aorta into the left ventricle during the heart’s relaxation phase (diastole).

 Aorta - the aorta is the major artery of the body, taking oxygenated blood to the organs and muscles of the body.

 Aortic arch - the aortic arch is a specific curved section of the aorta that helps distribute blood to the head and upper extremities.