Respiratory System

Function of respiratory SYstem

• Provides oxygen needed by the body
• Removes carbon dioxide produced as body uses energy
• Works in closely with the Circulatory System

Parts of respiratory system

• Nasal cavity
• Mouth
• Trachea
• Ciliated epithelial cells
• Bronchi
• Lung
• Alveoli
• Bronchioles

Structural features

• Some epithelial cells lining trachea and bronchi produce mucus
• Many epithelial cells have cilia (hairlike projections) to help move mucus and filter out foreign material
• Trachea supported by rings of cartilage to keep it open and allow air to flow
• Cartilage is a type of connective tissue, specialized cells in a matrix of strong but flexible fibres

Gas Exchange: Alveoli

• Alveoli: tiny air sacs at end of each bronchi branch
• Surrounded by a netwreok of capillaries
• Oxgeyn and carbon dioxide diffuse through thin walls

Gas Exchange: Diffusion

• Circulatorty system provides good blood supply to lungs
• Oxygen difuses from air in alceoli to blood in capillaries
• Carbon dioxide diffuses from blood in capillaries

Breathing

• Diaphragm - large sheet of muscle under lungs

To inhale (take air into lungs):

• Muscles expand rib cage and diaphragm contracts
• Volume of lungs increases
• Air rushes into lungs

To exhale (push air out of lungs):

• Muscles contract rib cage

Control of breathing

• Control over breathing is involuntary (automatic)
• Can override involuntary system temporarily
• Involuntary system takes over again after short period of time
• Controlled by part of brain that detects level of carbon dioxide
• When CO2 rises, breathing rate increases, heart beats faster
• This decreases concentration of CO2, and increases available oxygen

Diseases: Tuberculosis

Diseases: Cancer

Diseases: SARS

The circulatory system is responsible for the transportation of blood, nutrients, and oxygen throughout the body. It consists of the heart, blood vessels, and blood. The heart pumps blood through the arteries, which carry oxygenated blood away from the heart to the body's tissues. The veins then carry deoxygenated blood back to the heart, where it is pumped to the lungs to be oxygenated again. The blood also carries waste products, such as carbon dioxide, which are removed by the lungs and kidneys. The circulatory system is essential for maintaining homeostasis and ensuring that all cells in the body receive the necessary nutrients and oxygen to function properly.