B4 Flashcards Preview

Science Biology > B4 > Flashcards

Flashcards in B4 Deck (25)
Loading flashcards...
1
Q

What is blood?

A

Blood is a liquid tissue consisting of:

  • Plasma
  • White blood cells
  • Red blood cells
  • Platelets
2
Q

What are the functions of the blood?

A
  • Plasma transports all your blood cells and dissolved substances (e.g. amino acids) around the body
  • Red Blood Cells contain haemoglobin that binds (sticks) to oxygen to transport it from the lungs to the tissues
  • White blood cells help to protect the body against infection
  • Platelets are cell fragments that start the clotting process at the wound
3
Q

What function do plasma help the blood with?

A

-Is a yellow liquid
-Plasma transports all your blood cells + dissolved substances around the body including:
Hormones
Nutrients, such as water, glucose, amino acids, minerals + vitamins
-Waste substances e.g. carbon dioxide + urea

4
Q

What function do Red blood Cells help the blood with?

A

-Red Blood Cells contain haemoglobin that binds (sticks) to oxygen from the air in your lungs to transport it from the lungs to the tissues

5
Q

What function do White blood cells help the blood with?

A

-White blood cells form part of the body’s defence system against harmful microorganisms
Some white blood cells form:
•Antibodies against microorganisms
•Antitoxins against poisons made by microorganisms
•Engulf and digest bacteria and viruses

6
Q

What function do Platelets help the blood with?

A
  • Platelets are cell fragments that start the clotting process at wound sites to form a scab
  • This protects the new skin as it grows + stops bacteria entering through the wound
7
Q

What makes blood red?

A

-The red blood cells

8
Q

What makes up the human circulatory system and what does it do?

A
  • The blood
  • Blood vessels
  • The heart

-It transports substances to and from the body cells

9
Q

How does blood flow around the body?

A
  • In the blood vessels

- Main types of blood vessels are arteries, veins and capillaries

10
Q

What are the functions and features of arteries?

A
  • They carry blood away from the heart (always oxygenated blood except from the pulmonary artery which goes to lungs)
  • Have thick muscular walls
  • Have small passageways for blood
  • Contain blood under high pressure
  • Small lumen
11
Q

What are the functions and features of veins?

A
  • Carries blood to the heart from the organs(always de-oxygenated blood except from the pulmonary vein which goes from lungs to heart)
  • Have thin walls
  • Contain blood under low pressure
  • Have valves to prevent blood flowing backwards
  • Large lumen
12
Q

What are the functions and features of capillaries?

A
  • Form a huge network of tiny vessels linking the arteries and the veins
  • Found in the muscles and lungs
  • Very thin walls
  • Very low blood pressure
  • Where gas exchange takes place. Oxygen passes through capillary wall and into tissues, Carbon dioxide passes from tissues into the blood
13
Q

Do humans beings have a double circulatory system?

A

Yes

14
Q

What are the four chambers of the heart?

A
  • Right Atrium
  • Left Atrium
  • Right Ventricle
  • Left Ventricle
15
Q

What path does the blood follow as it enters and leaves the heart?

A
  • Blood comes from the veins(pulmonary + vena cava) to the atriums
  • It travels through the tricuspid and the bicuspid valve to the left and right ventricles
  • Then the ventricles contract so the blood can exit through the arteries (pulmonary + aorta)
16
Q

What is the heart?

A

An organ that pumps blood around the body

17
Q

What is a stent and how can it solve the problem of coronary heart disease?

A
  • A stent is a metal mesh that is placed in the artery

- It can be used to keep narrowed or blocked arteries open anywhere in the body

18
Q

What do statins do?

A

-Reduced cholesterol levels in the blood, reducing the risk of coronary heart disease

19
Q

How can damaged heart valves be replaced?

A
  • Using biological valves taken from animals such as pigs or cattle or from human donors
  • Using mechanical valves made of materials such as titanium and polymers
20
Q

How is the resting heart rate controlled?

A

-By a group of cells in the right atrium that form a natural pacemaker

21
Q

How do artificial pacemakers work?

A
  • The electrical device sends strong, regular electrical signals to your heart that stimulate it to beat properly
  • Used to correct any irregularities in the heart rhythm
22
Q

What is a natural pacemaker?

A

A group of cells in the right atrium that control the heart rate

23
Q

When are artifical hearts used?

A
  • To keep patients alive while they wait for a transplant

- So their own diseased heart can rest and recover

24
Q

What does the phloem transport?

A

Food (sugar)

25
Q

What does the xylem transport?

A

Water