Mass transports (organs and that)

Define cells

The basic building blocks of all living organisms

Define tissue

A group of cells with a similar function and structure

Define organ

A group of tissues working together to perform a specific function

Define organ system

A group of organs workng together to perform a function

Name each structure

Describe inspiration

• Intercostal muscles contract

• Ribs move upwards and outwards

• Diaphram flattens

• Volume of the chest increases

• Pressure inside the chest decreases

• Air is drawn into the lungs

Describe expiration

• Intercostal muscles relax

• Ribs move downwards and in

• Diaphram moves upwards

• Volume of chest decreases

• Pressure inside the chest increases

• Air is forced outside of the lungs

How are alveoli adapted for gas exchange?

• Thin walls → shorter diffusion path

• The air in and out allow for ventilation → creates a steep concentration gradient for CO2 and O2

• Good blood supply → maintains concentration gradient for CO2 and O2

• Large surface area → spherical and there are lots of them

• Moist lining → allows gases to dissolve ad diffuse into the blood supply

What is the function of an artery?

Arteries carry oxygenated blood AWAY from the heart

How do the structures of arteries relate to their function?

• Thick muscular wall

  ↳ Withstand and maintain high pressure

• Narrow lumen

  ↳ Maintains high pressure needed to transport blood efficiently

• Elastic fibres

  ↳ Allow the artery to stretch and recoil as the heart beats, helping it maintain a continuous blood flow

What do veins do?

Carry deoxygenated blood from the body to the heart

How does the structure of veins relate to its' function?

• Thiner walls

  ↳ Blood pressure is lower in veins

• Large lumen

  ↳ Wide lumen reduces friction since the pressure is much lower

• Valves

  ↳ Prevent the backflow of blood

What do the capillaries do?

Exchanges oxygen and nutrients and carry away waste products (like CO2) between blood and tissues

How does the structure of capillaries relate to their function?

• One cell thick walls

  ↳ Short diffusion distance

• Small diameter

  ↳ Allows the capillaries to fit between cells and tissues

• Permeable walls

  ↳ Allows substances to diffuse easily

What are the 4 main components of blood?

• Plasma

• White blood cells

• Red blood cells

• Platelets

What is the function of plasma?

• Suspends blood cells and platelets → straw coloured

• Transports substances

  ↳ oxygen, removes waste products such as carbon dioxide

What is the function of red blood cells?

To carry oxygen from the lungs to every cell in the rest of the body

What is the function of white blood cells?

To fight infection by pathogens and stop disease

What do platelets do?

Clots the blood

How do red blood cells carry oxygen to cells?

The oxygen moves in by diffusion into the red blood cells in the lungs.

They also have haemoglobin inside tem which binds with the oxygen so that it can be carried for respiration.

How are red blood cells adapted for their function?

• Biconcave shape → larger surface area for rapid diffusion of oxygen

• Contains haemoglobin → binds to oxygen to be used in respiration

• No nucleus → contains more haemoglobin to carry more oxygen

• Small → pass through capilaries

What are the 2 types of white blood cells?

• Phagocytes

• Lymphocytes

What is the function of phagocytes?

They engulf pathogens through phagocytosis to destroy them

What is the function of lymphocytes?

They produce antibodies that stick pathogens together

How is heart rate controlled?

By a group of cells in the right atrium which act as pacemakers