Question

name tyson lively class 2
lesson 4: what is blood?
read the article “what is blood?” on pages 163-164 in student book

1. what does the blood carry to the parts of the body?
2. what are the 3 main parts the blood is made of? fill in the diagram below.

percentages of the volume of this sample of blood
about 55%
about 1%
about 44%
this part is about 92%
7% of it is
1% is and
and

1. why is the shape of the red blood cells helpful?
2. what is the function (job) of the red blood cells?
3. what is the function (job) of white blood cells?

1. what is the function (job) of platelets?
2. how do platelets form a blood clot?

-16. label the microscopic image
show which part is
blood cells,
sma, and
e blood cells.

Explanation:

To answer these questions, we refer to basic biology knowledge about blood:

1. Blood carries oxygen, nutrients, hormones, and removes waste (like carbon dioxide) to/from body parts.
2. The 3 main parts of blood are:

• Plasma (liquid part, ~55% of blood volume): ~92% water, 7% proteins, 1% nutrients, hormones, electrolytes, etc.
• White blood cells (WBCs) and platelets (together ~1% of volume): WBCs fight infection, platelets help clotting.
• Red blood cells (RBCs, ~44% of volume): carry oxygen.

1. Red blood cells are biconcave discs, which increases surface area for efficient oxygen/carbon dioxide exchange and allows them to squeeze through narrow capillaries.
2. Red blood cells (RBCs) transport oxygen from the lungs to body tissues and carry carbon dioxide back to the lungs.
3. White blood cells (WBCs) defend the body against infections (bacteria, viruses, etc.) and foreign invaders, and help in immune responses.
4. Platelets (thrombocytes) help in blood clotting (hemostasis) to stop bleeding when a blood vessel is damaged.
5. When a blood vessel is injured, platelets stick to the damaged area, activate, and clump together (aggregate) to form a plug. They also release chemicals that trigger the coagulation cascade, leading to fibrin formation that reinforces the plug into a clot.

Answer:

s (for each question):

1. Oxygen, nutrients, hormones, and removes waste (e.g., carbon dioxide).
2. Plasma (55%), White blood cells + Platelets (1%), Red blood cells (44%).

• Plasma: ~92% water, 7% proteins, 1% nutrients/hormones/electrolytes.

1. Biconcave shape increases surface area for gas exchange and flexibility to pass through capillaries.
2. Transport oxygen (and carbon dioxide) between lungs and tissues.
3. Defend against infections/foreign invaders (immune response).
4. Help blood clotting (stop bleeding after vessel injury).
5. Stick to injury, aggregate, release clotting factors to form a fibrin - reinforced clot.