The respiratory system

The respiratory system

• Provides oxygen for the body and allows carbon dioxide to leave the body

• Works closely with the circulatory system

• Also closely intertwined with the digestive system

types of respiratory system

1. direct gas exchange

   1. small organisms such as protists using their cell surface

2. gills

   1. fish

3. skins

   1. amphibians

4. tracheal system

   1. insects

5. lungs

nasal cavity

• Point of entry for oxygen into the body

• Other functions include smelling and protecting your airways from airborne debris

oral cavity

• Oxygen can also enter your body through your mouth

• Parts of the digestive system shares the same tract as the respiratory system

pharnyx

• A.k.a. throat

• Connects your oral cavity and nasal cavity

• Moves air to the larynx

• Moves food to the esophagus

larnyx

• A.k.a. Voice box

• Prevents food from getting into the respiratory system

• Epiglottis helps cover the opening of the larynx

• Creates sound to help with oral communication

epiglottis

• Flap of cartilage located by the larynx that can open or close the respiratory tract

• Open when you are breathing

• Closed when you are eating or drinking

• You cannot breathe and eat/drink at the same time! (otherwise, you will choke)

trachea

• A.k.a. Windpipe

• Brings air to the lungs

• Made up of rings of cartilage connected by ligaments and muscles

• Branches off into two bronchi

Bronchi/Bronchioles

• Bronchi (sing. bronchus) are the larger branches

• Bronchioles are the smaller branches

• Both work to transport oxygen to the alveoli throughout the lungs

Lungs

• Two lungs in humans

• Contain sites for gas exchange and protect the structures within

• Made up of connective tissue

Alveoli

• Small air sacs at the end of bronchioles with lots of capillaries

• Gas exchange occurs here (O₂ gets absorbed by the bloodstream and CO₂ gets expelled)

Diaphragm

• A layer of muscle located beneath the lungs

• Controls breathing along with other muscles found around the rib cage

Breathing

• Breathing in (inhalation): external intercostal muscles and diaphragm contract (i.e. moves down), enlarging the space for lungs to expand

• Breathing out (exhalation): external intercostal muscles and diaphragm relax (i.e. moves up), shrinking the space for lungs to contract

Problems with the respiratory system

• tuberculosis

  • infectious disease

• coronavirus

• covid-19