Respiratory System 1 Flashcards
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 (tissue) respiration?
The exchange of gases between blood in systemic capillaries and the tissue fluid and cells which surround them
What is cellular respiration?
The process within individual cells through which they gain energy by breaking down molecules such as glucose. It occurs in mitochondria, consumes oxygen and generates carbon dioxide
What is pulmonary ventilation?
Breathing describes the bulk movement of air into and out of the lungs. The ventilatory pump comprises the rib cage with its associated muscles and the diaphragm
What are the two functional parts of the respiratory system?
The conducting and respiratory parts
What is the conducting part of the respiratory system?
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.
What does the conducting airways involve?
Nasal cavities, pharynx, larynx, trachea , bronchi, bronchioles
Does gas exchange occur in the conducting part of the respiratory system?
No
What comprises the respiratory part of the system?
The tiny thin-walled airways where gases are exchanged between air and blood
What’s involved in the respiratory part of the system?
Respiratory bronchioles, alveolar ducts and sacs, alveoli themselves
Can gas exchange occur in the respiratory part?
Yes
What’s the upper respiratory tract?
Nasal cavity to pharynx
What’s the lower respiratory tract?
Larynx to alveoli
What does air need to be?
Warm (37 degrees)
Filtered
Humidified (increased H2O, saturated)
What is the nasal cavity covered in?
Respiratory epithelium
What does the respiratory epithelium include/do?
Ciliates epithelium and goblet cells, the later OH which secrete seromucous which is sticky and wet
What does the conchae do?
Increases surface area and air mixing, has a superior/medial/inferior aspect, is olfactory, and has a rich capillary network underneath the epithelium that warms the air
What does the sinus do?
Creates resonance and tone to voice
Describe the nasal cavity?
A tall narrow chamber lined with mucous membrane- the wet membrane humidifies and warms the air
What is the medial surface of the nasal cavity like?
Flat
What’s in the lateral surface of the nasal cavity?
Three sloping shelves (conchae) which Increase the surface area of the mucous membrane
What opens into the cavity and what does it do?
The air filled paranasal sinus, which lightens the face and adds resonance to the voice
What does the roof of the cavity carry?
The olfactory epithelium
What happens in the olfactory epithelium?
Turbulence caused by sniffing carries air up into the epithelium, and axons of olfactory receptor cells lead towards the brain through perforations in the overlying bone, the cribriform plate
In regards to the muscociliary escalator, how does smoking affect it?
It affects cilia movement by slowing it down and paralysing them, it also increases risk of infection (eg smokers cough) and increases mucous secretion
What is the epiglottis made from?
Elastic cartilage
What is the pharynx?
A vertical passage with three parts; each having an anterior opening
What closes the nasopharynx?
Soft palate
Is the pharynx only an airway?
No, it’s also a foodway and is primarily part of the gastrointestinal system- choking occurs if food goes down the trachea
Parts of the conducting zone in generation order?
Trachea Main stem bronchi Lobar bronchi Segmental bronchi Bronchioles Terminal bronchioles
Parts of the respiratory zone, in generation order?
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
What happens every time an airway tube divides?
It gets smaller in diameter
Describe the windpipe?
A tube about 12 long and as thick as your thumb
What is the windpipe supported by?
Incompleted c-shaped rings of cartilage
How are the free ends of the supporting cartilage connected?
By trachealis muscle (smooth)
What narrows the diameter of the trachea and does it have any functional significance?
Contraction- significance is debatable
What lines the trachea?
Ciliated epithelium (pseudostratified columnar), and the cilia transport a mucous sheet upwards to the nasopharnyx (mucociliary escalator)
What is posterior to the trachea, lying in the shallow groove formed by the trachealis muscle?
Oesophagus
