Respiration

The ins and outs

Functions

1. To bring O2 into the body and transfer it to the blood stream

2. To remove CO2

Circulation and respiration work together to achieve these functions

Why Do We Need Oxygen? Oxygen acts as a fnal hydrogen acceptor in

cell respiration

Recall Cellular Respiration: C6H12O6 + 6O2 6CO2 + 6H2O + ATP

- ATP is the energy for the cell and therefore requires oxygen to be present for the energy to be released.

Respiratory Surface The surface through which gas exchange takes

place

Characteristics:1. Thin walled for diffusion2. Moist for dissolving gases3. In contact with a source of O24. In contact with a system that transports O2

Respiration

The process that involves:a) Inhaling and exhaling of airb) Exchange of gases between

cells and environmentc) Chemical reactions where O2

used to release energy from food

Inspiration Rib cage moves up

and out. Diaphragm and

intercostal musclescontract.

Diaphragm movesdown and flattens

Pressure in lungsdecreases and airrushes in.

Expiration Rib cage moves down

and in. Diaphragm and

intercostalmuscles relax.

Diaphragm moves up. Pressure in lungs

increases and air ispushed out.

Negative Feedback Cycle see curriculum online

Internal Respiration

The exchange of gases between the blood and the tissues.

Oxygen diffuses out of blood and into tissues.

Carbon Dioxide diffuses out of tissues and into blood.

External Respiration

Exchange of gases between the air and the alveoli in the lungs.

Carbon dioxide diffuses out of blood and into the lungs (alveoli)

Oxygen diffuses into the blood and out of the lungs (alveoli).

During external respiration, oxygen must travel through these structures (in the following order):1. Nostril2. Nasal cavity3. Pharynx4. Glottis5. Larynx (includes vocal cords)6. Trachea7. Bronchus (pl. bronchi)8. Bronchiole (pl. bronchioles)9. Alveolar ducts10. Alveolus (pl. alveoli)

From here, oxygen enters the body through the capillaries, this is the start of internal respiration

1. Nostril Air enters the nostril Nostril has hairs and

mucus Hairs trap large particles Mucus traps smaller

particles, bacteria, and moistens the air

2. Nasal Cavity/Nose Separated from the mouth by a

bony plate called the hard plate Turbinate bones:

Extend into the nasal cavity to increase the amount of surface area

Helps warm the air Functions:

Air warmed, moistened and cleaned

Lining of the nasal cavity contains many blood vessels that warms the air

Secretes mucus which moistens and traps dust and particles

Has cilia small hair like structures that trap particles

3. Pharynx Tube common to both

respiratory and digestive systems

Starts at the back of the nasal cavity and extends to the larynx (voice box)

Larynx Box like structure at opening of the respiratory pathway Formed by cartilage

Trachea Wind Pipe Tube that extends from the

larynx into the throat Divides into two smaller

tubes: Right bronchi Left bronchi

Made of smooth muscle that has c-shaped rings of cartilage embedded

Keeps the trachea from collapsing and ensures that it is always open

Trachea Diagram

Bronchi Supported by rings of cartilage Branch into smaller tubes The smallest tubes are the bronchioles Alveolar ducts:

At the end of the bronchioles that lead into the alveoli Alveoli (s. alveolus):

Air sacs where gas exchange takes place

Bronchi Diagram

Gas Exchange in Alveoli

Lungs Each bronchus with all of its bronchioles, alveolar ducts

and alveoli is a lung No muscle Elastic

Responds passively to the action of the ribs muscles and diaphragm

Right lung: Larger than the left lung Has three lobes: upper, middle, and lower

Left lung: Has two lobes: upper and lower

External Membranes of the Lungs There are two external membranes surrounding the lungs

Parietal pleura Pulmonary pleura

These two membranes have water sandwiched in between them

This fluid is called interpleural fluid Indirectly connects the lungs to the ribcage

Lung Diagram

External Membranes of the Lungs Diagram

Mechanics of Breathing Involuntary:

Proceeds without thought Voluntary:

Control can occur but eventually you would get tired Involuntary would take over

Diaphragm: Dome shaped muscle laying above the waistline Separates thoracic and abdominal cavities

Thoracic cavity: is the space in your chest above the diaphragm Abdominal cavity: is the space of your abdominal area

Intercostal muscles: Attach 12 ribs Have you ever eaten ribs before? Then you have been eating

intercostal muscles

Diaphragm Diagram

Intercostal Muscles Diagram

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