Respiratory System Flashcards
What does the respiratory system do?
The respiratory system filters the incoming air and transports it to the lungs for gas exchange
What are the organs of the respiratory system in order of incoming air?
- Nose
- Nasal Cavity
- Sinuses
- Pharynx
- Larynx
- Trachea
- Bronchial tree
- Lungs
How do amphibians undergo gas exchange?
Amphibians may have lungs, but they are usually small and not very effective
- They mainly rely on gas diffusion across body surfaces such as skin to carry out gas exchange.
NB: Favorite DAT question
What organisms rely on lungs for gas exchange?
The organisms that rely on lungs for gas exchange are:
- Most reptiles,
- Birds,
- All Mammals.
They use a negative pressure system called inspiration that draws air into the lungs.
What is the nasal cavity?
The nasal cavity is two chambers, medially divided into a left and right portion by the nasal septum.
- Consists of ciliated epithelial cells and hair that filter out dust and particles from the air.
- Contains olfactory receptors that detect smell
- Contains a mucous membrane that is rich in blood vessels.
- Air that passes over it is quickly warmed
- Also acts to trap dust and small particulates from the air. The cilia moves the mucous entrapped particles toward the pharynx, which is the back of the throat. The mucus is then swallowed and all the dust and potentially harmful microorganisms are then subjected to gastric juices.
Explain how the nasal cavity helps prevent respiratory infection.
Small breathable microorganisms are trapped by the mucous, cilia, and hair of the nasal cavity. The cilia move the mucous to the pharynx (back of the throat). The mucous is then swallowed and the microorganisms then have to contend with the powerful acids in the stomach.
What are the sinuses?
The sinuses are air filled spaces within the facial bones
- their main function is to create mucus that flows into the nasal cavity to help fight infection.
- They also help lighten the skull and improve our voice.
- If the sinuses are blocked due to an infection, the fluid movement is impeded and the increased pressure can cause headaches.
What is the Pharynx?
The Pharynx is the intersection of food and air.
- The first part is called the nasopharynx
- Air passes through the nasal cavity to here and then through the glottis to the larynx
What is the glottis?
The glottis is a hole that connects the pharynx with the larynx.
- A flap of tissue called the epiglottis covers the glottis while swallowing to prevent food from entering the larynx.
What is the larynx?
The larynx (voice box) is composed of hyaline cartilage and muscles bound together by elastic tissue.
- It sits on top of the trachea.
- It’s connected to the Pharynx via the Glottis.
- Vocal Cords are found here. The contracting or relaxing of these cords will determine the vocal sounds.
- Laryngitis: If the mucous membrane of your larynx becomes inflamed due to overuse or infection, the vocal cords can’t vibrate as freely and your voice sounds hoarse, and you have laryngitis.
What is laryngitis?
Laryngitis is when your larynx’s mucus membrane become inflamed from overuse or infection
- Your voice becomes hoarse because the vocal cords aren’t able to vibrate as freely.
What is the Trachea?
The Trachea is the tube that connects the larynx to the two bronchi.
- Made of Cartilage to prevent collapse
- Contains cilia bearing cells and goblet cells that make mucus
- branches into two bronchi that carry air into the left and right lungs.
What are goblet cells?
These are cells in the trachea that create mucus
What is Hyaline cartilage?
Hyaline cartilage is the most abundant cartilage found at the ends of long bones, larynx, trachea, bronchi, and in the ventral ends of the ribs.
What are bronchi?
Bronchi are branches from the trachea that bring air into the left and right lungs.
- branch into smaller passages called the bronchioles.
- The bronchi and larger bronchioles both have ciliated linings and cartilage.
- Smaller bronchioles less than 5 mm have neither glands or cartilage, but do have goblet cells for making mucus..
- Clara cells containing short microvilli are noted in the small bronchioles. These are sometimes referred to as club cells.
- The smallest bronchioles terminate into the alveolar sacs.
What are Clara cells?
Clara cells are dome shaped cells that contain short microvilli in the smaller bronchioles.
- They are also known as club cells.
- They help detoxify the lungs from harmful substances
- Toxins are degraded via P-450 enzymes.
- Also produce a surfactant like material which aids in reducing the surface tension of the bronchioles.
What is Asthma?
Bronchioles constrict reducing the diameter of the air passages. A person has a difficult time breathing and produces a wheezing sound as air is passed through the constricted passages. Drugs such as epinephrine cause the smooth muscles to relax and breathing is improved.
What are alveolar sacs?
The smallest bronchioles terminate into alveolar sacs that have bulges called alveoli.
- Hundreds of millions of alveoli represent the chambers where gas exchange occurs.
- Alveoli are highly vascular and very thin walled.
- Alveoli are responsible for the spongy structure of the lungs.
- Contain dust cells which act as macrophages to help prevent infection
- Contain surfactants to prevent the sacs from sticking together with hydrogen bonds.
