Respiratory System Flashcards
What is respiratory system
It consist of a system of tubes that delivers air into lungs. Oxygen diffuse into the blood and carbon dioxide diffuses out. It is considered as a cardiopulmonary system
Collaborates with urinary system to regulate the body’s acid base balance
Primary function
Gas exchange
Communication
Olfaction- smell
Acid base balance
Blood pressure regulation
Blood and lymph flow
Blood filtration
Expulsion of abdominal contents
Principle organs
Nose
Pharynx
Larynx
Trachea
Bronchi
Lungs
Zones of respiratory system
Conducting zone - air flow
Respiratory zone- gas exchange
Some authorities use
Upper and lower respiratory tract
The nose
Warm, cleans and humidifies inhaled air
Detects odour
Resonating chambers that amplifies noise
The pharynx (throat
The regions
Nasopharynx
Oropharynx
Larynogopharyx
All contribute to speech, breathing and swallowing
The larynx voice box
Primary function is to keep food and drink out of the air
Addition role: phonation the production of sound
Walk are muscular for swallowing and voice control
Epiglottis
Stops food and drink form reaching airway
Trachea (windpipe )
Rings of hyaline cartilage prevents tube from collapsing
Lung
Right lung
Smaller
Three lobes- superior middle and inferior
Left lung taller and narrower because of the heart
Has a indentation- cardiac impression
Two lobes inferior and superior
Bronchial tree
Branching system of air tubes in each lung
Right- slightly wider and more ventricle then left
Secondary lobar branches 3R and 2L
To segmental tertiary bronchi R=10 and L=8
Brochioles
Lack cartilage
Terminal brochioles
Respiratory bronchioles
Considered the beginning of the respiratory zone since alveoli participate in gas exchange
Divide into alveoli ducts
Alveoli
150 million alveoli in each lung providing 70m2 of surface for gas exchange
Cells of alveolus
- squamous type 1 alveolar cells- allow for rapid gas diffusion
- great type 2 alveolar cells- prevent lung collapse and easier inflammation
- alveolar macrophages (dust cells)
Alveoli
Respiratory membrane consist of ;
- squamous alveolar cells
- endothe
Pleurae
Lines the thoracic wall and forms the surface of the lung
It creates the expansion of the lungs and therefore the drop in pressure when the diagram contracts
The pleural fluid function
1 reduce friction
Acts as a lubricant allowing lungs to expand and contract
2 create pressure gradient by expanding the lungs when we inhale
3 compartmentalisation separates
What is pulmonary ventilation
Breathing
Consist of a repetitive cycle: one cycle of inspiration (inhaling) and expiration ( exhaling)
What is respiratory cycle
One complete inspiration and expiration
- quiet respiration: while at rest effortlessly and automatic
- forced respiration: deep, rapid breathing such as during exercise
What do respiratory muscles do
Breathing muscles change lung volumes and create differences in pressure relative to the atmosphere
Diaphragm
Prime mover of respiration
Contraction flattens diaphragm enlarging thoracic cavity and pulling air into lungs
Relaxation allows diaphragm to bulge upwards again compressing the lungs and expelling air
Accounts for two thirds of airflow
Flattening=
- increases the superior to inferior dimension of the thoracic cage
- pushes sternum and ribs enlarging the anterior to posterior dimension
Internal intercostal respiratory muscle
Enable forced expiration by depressing the ribs
External intercostal respiratory muscle
Increase/ decrease the size of thorax
The enlargement of the thorax allow the lungs to expand and fill with air
Intercosta (internal and external intercostals)
Stiffens the thoracic cage during respiration
Prevents it from caving inward when diaphragm descends
Contribute to enlargement and contraction of thoracic cage
Add about one third of the air that ventilates the lungs
Scalenes respiratory muscles
Synergist to diaphragm
Quiet respiration hold ribs one and two stationary
Neural control of breathing
Breathing depends on repetitive stimuli of skeletal muscles from brain
- skeletal muscles cannot contract without nervous stimulation
- breathing requires a coordination action of multiple muscles
- ceases if nerve connections to thoracic muscles are servered
Respiratory centre controllled by two levels of the brain
Cerebral and conscious
Autonomic and unconscious (medulla oblongata and pons)