Flashcards in Respiratory System Deck (110)
What is external respiration?
The process in the lungs by which oxygen is absorbed from the atmosphere into blood within the pulmonary capillaries and carbon dioxide is excreted.
What is internal respiration?
The exchange of gasses between blood in the systemic capillaries and the tissue fluid and cells
What is pulmonary ventilation?
The bulk movement of air in/out of lungs. The ventilatory pump comprises the rib cage with its associated muscles and the diaphragm
Describe the conducting part of the respiratory system and give examples:
A series of cavities and thick walled tubes which conduct air between the nose and the deepest recesses of the lungs and in doing so warm, humidify and clean it. The conducting airways are in the nasal cavities, larynx, trachea, bronchi and bronchioles i.e no gas exchange
Describe the respiratory part of the respiratory system and give examples:
Comprises tiny thin walled airways where gasses are exchanged between air and blood. The airways are respiratory bronchioles, alveolar ducts and sacs and alveoli. They have large surface areas for gas exchange
What is the upper respiratory tract?
Nasal cavity to larynx
What is the lower respiratory tract?
Trachea to alveoli
What are the 3 things that need to happen in the nasal cavity?
1. Air needs to be warmed to 37 degrees
3. Humidify the air by saturating with H2O
Where is the first place where the air is filtered in the nasal cavity?
In the nares (nostrils) by vibrissae
What is the function of the mucus membrane and what is it made up of in the nasal cavity?
To humidify and warm the air. It is made up of respiratory epithelia and a layer of mucus. There are ciliated cells and mucus cells (goblet cells) that are sticky to capture the dirt.
What does smoking do to the nasal cavity?
Paralyses the cilia so they need to constantly blow their nose or cough etc.
What is under the mucus membrane in the nasal cavity?
A rich blood supply for heat exchange and warming. There are also serous gland that secrete a watery secretion
What is on the lateral surface of the nasal cavity and what is their function?
There are 3 sloping shelves (conchae) which increase the surface area of the mucus membrane . They are made up of turbante bones for turbulance
Describe the sinuses:
They are air filled and open the cavity. They lighten the face and add resonance to the voice.
What is on the roof of the nasal cavity?
This is where the olfactory epithelium is found. Turbulance caused by sniffing carries the air up into the epithelium.
What are the 3 parts of the pharynx and do they carry food or air?
1. Nasopharynx - air
2. Oropharynx - air and food
3. Laryngopharynx - air and food
They each have an anterior opening
Describe the epiglottis:
Points up when it is open and down and posteriorly when its closed. Its made of elastic cartilage
As there is ______ branching, the diameter of tubes _______ and surface area _________
Increased, decreased, increased
Describe the structure of the trachea:
Supported by C shaped rings of cartilage. Free ends of the cartilage are connected by trachealis muscle (smooth), where contraction narrows the diameter of the trachea.
Describe the cell layers of the trachea and their functions:
Lined with ciliated epithelium (pseudostratified coloumnar) the cilia transports a mucus sheet upwards to the nasopharynx (muscocillary escalator) mucus comes up.
Where does the esophagus sit in relation to the trachea?
The esophagus sits immediately posterior to the trachea, lying in the small groove formed by the trachealis muscle
What is an asthma attack and what can you take to stop one?
Constriction of smooth muscle in bronchioles where there is no cartilage so the airways shut. Can take a bronchodilator e.g salbutonol, which relaxes the smooth muscle.
What are the sources of mucus in the bronchus?
Mucus glands and goblet cells
Name the cell layers in the bronchus:
Cilia - pseudostratified columnar epithelium and goblet cells - smooth muscle - mucus glands - catilage plates (moon shaped) - bronchus wall (leads to alveoli)
Name the cell layers of bronchioles:
Cilia - club cells (watery secretions to keep the airways hydrated) and ciliated simple columnar epithelium goes to cuboidal transition - smooth muscle (leads to alveoili)
What are alveolar sacs?
Bunch of alveolis together (grapes)
What are alveolar ducts?
Tubes made up of alveoli sacs
What are alveoli covered in?
Capillaries - pulmonary
What are the 3 types of cells found in alveoli and what are their functions?
1. Squamous pneumocytes - flat and skinny
2. Surfactant cell - secretes surfactant that helps to reduce surface tensions. Reduces work of breathing by keeping alveoli open
3. Alveolar macrophage - wandering cell - last defence mechanism