2 - APP - Unit 5.1 - Respiratory System Flashcards
Respiratory system & Cardiovascular system
Use oxygen for metabolic reactions that release energy from nutrient molecules & produce ATP.
These reactions release carbon dioxide. Excessive amount of carbon dioxide is toxic to cells, so excess must be eliminated quickly and efficiently.
Systems for oxygen supply + eliminate carbon dioxide:
- Respiratory system
> provides gas exchange, intake oxygen & eliminate of carbon dioxide
> Contains receptors for sense of smell, filters inspired air, produces sounds & helps eliminate wasters.
- Cardiovascular system
> transports gases in the blood between lungs & body cells
Respiratory system - Upper respiratory tract
Composed of
- Nose or nostrils
- Nasal cavity
- Mouth
- Throat (pharynx)
- Voice box (larynx)
Respiratory system - Upper respiratory tract - Mucous membrane
Lining respiratory system
Secretes mucus
Mucus traps smaller particles like pollen or smoke.
Respiratory system - Upper respiratory tract - Cilia
Hair like structures lining the mucous membrane and moving the particles trapped in the mucus out of the nose
Respiratory system - Upper respiratory tract - Inhaled air…
… is moistened, warmed & cleansed by the tissue that lines the nasal cavity.
Respiratory system - Lower respiratory tract
Composed of
- Windpipe (=trachea)
- Bronchi (in the lungs)
- Bronchioles (in the lungs)
- Alveoli (in the lungs)
Respiratory system - Lower respiratory tract - Lungs
Deep in the lungs, each bronchus divides into secondary and tertiary bronchi, branching to smaller airways (=bronchioles), ending in air sacs (=alveoli)
Alveoli are bunched into clusters (= alveolar sacs)
Gas exchange occurs on surface of each alveolus by a capillaries network carrying blood coming through veins from other pars of the body.
Exchange of Gases - Respiration
Exchange of gases between atmosphere, blood & cells.
3 basic steps:
- External respiration - exchange between external environment & blood that takes place in the lungs
- Internal respiration - Gaseous exchange between blood and cells of the body
- Cellular respiration (=oxidation) - Occurs within cells mitochondria
Exchange of Gases - Respiration process
- Air inhaled through nostrils (=nares)
- Passes through nasal cavity to be warmed, moistened & filtered
- Filtered by nasal turbinates (=conchae)
- Passes through pharynx, larynx & into trachea
Exchange of Gases - Pharynx
At the bottom of pharynx, pathway divides in two tubes:
- Esophagus - for food, leading to stomach
- Trachea - for air, leading to bronchial tree
Exchange of Gases - Epiglottis
Small flap of tissue covering the top of the trachea when we swallow, keeping food and liquid from going into the lungs
Exchange of Gases - Trachea division
Trachea divides in:
- Right primary bronchi
- Left primary bronchi
Subdividing into smaller lobar bronchi, branching into segmental bronchi, branching into smaller & smaller branches of bronchial tree.
Exchange of Gases - Lungs
Right lung has three lobes
Left lung has two lobes
Air moves through smallest air tubes in the lungs (= bronchioles) terminating in clusters of air sacs (=alveoli)
Mechanism of Breathing - External respiration
= ventilation or breathing
Involves act of inhaling & exhaling air
Results in an exchange of gases between blood and air sacs
Normal quiet breathing:
- 500ml of air moves into respiratory passageways with each inspiration.
- Same volume out with each expiration
Mechanism of Breathing - External respiration - Tidal volume
Volume of air inspired (or expired)
Mechanism of Breathing - External respiration - Inspiratory reserve volume
Additional air inhaled by taking a very deep breath (average of 3100ml above the 500ml of tidal volume)
Mechanism of Breathing - External respiration - Expiratory reserve volume
Additional air exhaled by exhaling forcibly (1200ml of air above the 500ml of tidal volume)
Mechanism of Breathing - External respiration - Vital capacity
Sum of :
- Inspiratory reserve volume
- Tidal volume
- Expiratory reserve volume
Mechanism of Breathing - Inhalation mechanism
Intercostal muscles contract, raising ribs & expanding thoracic capacity
At the same time: diaphragm contracts & is pulled down, causing lungs to draw in air
Mechanism of Breathing - Exhalation mechanism
Intercostals & diaphragm relaxe, returning to their neutral positions & pushing air out of the lungs
Forced exhalation involves:
- contraction of internal intercostal muscles, collapsing the rib cage
- contraction of the abdominal muscles, forcing abdominal viscera against diaphragm, further reducing area of thoracic cavity
Mechanism of Breathing - Max oxygen intake & carbon dioxide expulsion…
… is accomplished during deep breathing, involving exaggerated movements of ribs and diaphragm.
Mechanism of Breathing - Eupnea
Normal quiet breathing
Involves shallow, deep (or both combined).
Mechanism of Breathing - Costal breathing
Shallow (chest) breathing
Upward & outward movement of the chest as a result of contraction of the external intercostals
Mechanism of Breathing - Diaphragmatic breathing
Deep (abdominal) breathing
Outward movement of abdomen as a result of the contraction and descent of the diaphragm
During deep, labored inspiration, accessory muscles of inspiration participate.
Includes: sternocleidomastoid, scalenes & pectoralis minor
Depending on adult lung capacity, natural breathing rate: 14 to 20 times a minute
Modified Respiratory Movements - Coughing
Long-drawn & deep inspiration followed by complete closure of the rima glottidis, resulting in a strong expiration suddenly pushing the rima glottidis open & sends a blast of air through the upper respiratory passages.
Modified Respiratory Movements - Sneezing
Spasmodic contraction of muscles of expiration that forcefully expels air through the nose and mouth
Stimulus may be an irritation of the nasal mucosa