RESPIRATION SYSTEM

https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/lung_introduction/v/meet-the-lungs

https://www.youtube.com/watch?v=dZdYImQaOEk

Respiratory System in animals

Function:allows for the exchange of gases between the blood and the external air.

The Human Respiratory Tract

• The human respiratory system includes• the lungs and all structures that move air to and from

the lungs.

• The respiratory tract is lined with cilia to filter debris and dust.

• The air flowing through the respiratory system is also warmed to body temperature and saturated with water.

Lungs and External Exchanges of Gases

• The branching of the bronchioles and numerous alveoli of the lungs provide a large surface area for gas exchange.

• The alveoli are in close contact with blood vessels, forming the respiratory membrane which facilitates gas exchange.

Lungs and External Exchanges of Gases

• The branching of the bronchioles and numerous alveoli of the lungs provide a large surface area for gas exchange.

• The alveoli are in close contact with blood vessels, forming the respiratory membrane which facilitates gas exchange.

• Bronchioles lead to the alveoli, each of which is surrounded by an extensive capillary network.

Lungs and External Exchanges of Gases

Lungs and External Exchanges of Gases in Aquatic animals

• use gills to facilitate gas exchange.

• The gills have an extensive capillary network that directly exchanges gases with water flowing over the gills.

• Countercurrent flow vs Parallel flow

Respiration in Plant

Plants require O2 for respiration to occur (in mitochondria) and they also give out CO2

RESPIRATION

PHOTOSYSTESIS

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How do plants exchange gases with the environment?

O2 (for respiration)

CO2 (for photosynthesis)

CO2 (from respiration)

O2 (from photosynthesis)

Plants exchange gases by diffusion through leaves, stem and roots.

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How do plants exchange gases withthe environment?•Plants, unlike animals, have no specialised organs for gaseous exchange but they have stomata and lenticels for this purpose.

•There are 2 main reasons why plants can get along without respiratory organs :

1. Each plant part takes care of its own gas- exchange needs. There is very little transport of gases from one plant part to another.

2. Plants do not present great demands for gas exchange.

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How do plants exchange gases withthe environment? (cont.)

In leaf

Stoma: gases mainly diffusethrough it

Guard cells: control the opening and closing of stoma

A plant cuticle is a protecting film covering the epidermis of leaves, young shoots and other aerial plant organs without periderm

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Roots are not covered by a cuticle. Gas exchange takes place all over their surfaces.

In Roots

In StemPores in stems called lenticelslenticels allow gas exchange

Lenticels

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In StemLenticel: gases diffuse through it

on the woody stems

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Gas exchange in the daytime and in the dark

Oxygen

Carbon dioxide

Time of happening

uptake release

release uptake

both in the daytime and in the dark

takes place only when the light intensity is high enough

Respiration Photosynthesis

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Gas exchange in the daytime

In the daytime:

light intensity is high rate of photosynthesis >

rate of respiration

a net uptake of carbon dioxide & a net release of oxygen

net uptake of CO2

net release of O2

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Gas exchange in the dark

In the dark

light intensity is very low photosynthesis stops and

only respiration occurs

a net uptake of oxygen and a net release of carbon dioxide from respiration

uptake of O2

net release of CO2