lesson 7 - function of circulation

Question 1

What is the circulatory system?

Answer 1

A vascular system that controls the movement of fluid by muscle movements following a specific pattern

Question 2

Main functions of the circulatory system?

Answer 2

1.It transports gases (from the respiratory system), nutrient molecules, waste
materials (ex. urea from the digestive system), and hormones from the endocrine system

2. It regulates internal temperature
3. Protects against blood loss, pathogens, and toxic substances

Question 3

Three components of the circulatory system

Answer 3

1. Heart: moves fluid
2. Blood vessels: conduct fluid from one area to another (e.g. veins and arteries)
3. Blood: specialized fluid

Question 4

2 Types of Circulation

Answer 4

1. Open circulatory system: the route taken BY the blood, WITHIN the heart (ex: insect)
2. Closed circulatory system: the route taken by the blood FROM the heart TO the lungs, and BACK (ex. earthworm)

Question 5

Functions of blood

Answer 5

1. Transports oxygen, water, nutrients, and other chemicals to your cells
2. Removes waste products from the tissues and delivers them to the areas where they can be removed from your body
3. Helps to regulate body temperature, fight infection, and heal wounds

Question 6

What is vasodilation?

Answer 6

An increase in blood flow by widening or dilating the vessels. It helps the body to lose heat more rapidly

Question 7

What is vasoconstriction?

Answer 7

A decrease in the flow of blood by narrowing or constricting the blood vessels near the surface of the skin. It reduces the amount of heat that is dissipated from the skin, and helps the body to conserve heat.

Question 8

What is in our blood?

Answer 8

1. Plasma (Water + dissolved gases + proteins + sugars + vitamins + minterals + waste products)
2. Solid parts (RBC, white blood cells, platelets)

Question 9

What is plasma made up of?

Answer 9

92% water, 7% blood proteins, 1% organic/inorganic ions (ex. sodium, potassium, chloride, bicarbonate)

Question 10

The major blood proteins

Answer 10

Fibrinogens, globulins, and albumins

Question 11

What do fibrinogens do?

Answer 11

Fibrinogens assist in clotting bloodW

Question 12

What do globulins do?

Answer 12

Globulins are types of antibodies

Question 13

What do albumins do?

Answer 13

Albumin helps balance osmotic pressure and carry hormones

Question 14

What is the composition of blood?

Answer 14

55% Plasma, 4% White blood cells & platelets, 41% RBC’s

Question 15

Functions of RBC/Erythrocytes

Answer 15

Transports oxygen to cells, transports carbon dioxide away from cells, and has iron in the hemoglobin protein which binds to oxygen (They do NOT contain nuclei)

Question 16

Functions of white blood cells/leukocytes

Answer 16

They engulf and destroy pathogens and produce antibodies (They contain nuclei)

Question 17

How do platelets work, and how is fibrin formed?

Answer 17

Platelets are formed from fragments of bone marrow cells.

When blood vessels rupture, chemicals get released and attract platelets. The platelets then rupture and break open and releases chemicals which mix with the chemicals from the plasma, creating an enzyme called thromboplastin. Thromboplastin reacts with thrombin in the presence of calcium, and thrombin will then react with fibrinogen (plasma protein) which results in the production of an insoluble protein called fibrin.

Fibrin forms into a mesh that traps RBC’s and platelets and forms a blood clot.

Question 18

Three major types of vessels

Answer 18

Arteries, veins, capillaries

Question 19

Arteries have highly elastic walls. What does the elasticity do?

Answer 19

The elasticity allows arteries to expand and snap back during the contraction and relaxation of ventricles. The expansion and contraction keeps the blood flowing in the right direction

Question 20

Tell me about veins (hint: walls, elastic, valves)

Answer 20

They have thinner walls in comparison to the arteries, though aren’t as elastic and can’t contract to move blood back to the heart like arteries do.

Veins have one-way valves that prevent blood from flowing backwards; this is especially important in the legs because they make sure the blood flows upwards to your heart, against the downward pull of gravity

Question 21

What are capillaries?

Answer 21

The smallest blood vessels which are spread throughout the body in a fine network. They are a single layer of cells and the average diameter of a capillary (8μm) is JUST large enough for the largest blood cells to pass through in a single file

Question 22

Where does blood flow from?

Answer 22

The heart –> large arteries –> smaller arteries –> aterioles –> capillaries –> venules –> smaller veins –> larger veins –> back to heart

Question 23

Three types of circulation

Answer 23

Cardiac, pulmonary, systemic

Question 24

Explain cardiac circulation

Answer 24

Cardiac circulation – the route taken by the blood within the heart

Question 25

Explain pulmonary circulation

Answer 25

Pulmonary circulation – the route taken by the blood from the heart to the lungs and back

Question 26

Explain systemic circulation

Answer 26

Systemic circulation – the route from the heart to the rest of the body and back

Question 27

Valves in the heart

Answer 27

Atrioventricular and semilunar valves

Question 28

Atrioventricular valves

Answer 28

Right atrium 🡪 tricuspid valve 🡪 right ventricle

Left atrium 🡪 bicuspid/mitral valve 🡪 left ventricle

Question 29

Semilunar valves

Answer 29

Between ventricle and large arteries (the pulmonary & aortic valve)

Question 30

Right atrium receives __ blood from superior/inferior vena cava

Answer 30

deoxygenated

Question 31

Superior vena cava takes blood from __, __, and __

Inferior vena cava takes blood from __ __ __

Answer 31

1. head, chest, and arms
2. all other parts

Question 32

Right ventricle pumps blood to __ __ that feed into the lungs

Answer 32

pulmonary arteries

Question 33

Pulmonary arteries are the ONLY arteries that..

Answer 33

contain deoxygenated blood

Question 34

Pulmonary veins bring ___ blood to the left atrium

Answer 34

oxygenated

Question 35

Left ventricle pumps blood into the largest vessel: the __, which brings blood to the rest of the body

Answer 35

aorta