Week 1 - Respiratory system structure Flashcards
What are the 5 functions of the respiratory system?
- Extensive as exchange SA between air and circulating blood
- Moves air to and from exchange surfaces from outside environment
- Protects respiratory surfaces from outside environment
- Produces sounds
- Participates in olfactory sense
What are the two zones of the respiratory system?
Conducting Zone
Respiratory Zone
Describe the Zones in the respiratory system (mentoion branching and alveoli)
23 times branched passageways
Irregular dichotomus pattern
Each airway gives rise to two daughter airways
Air reaches alveoli surrounded by capilliaries
Alveoli appear as buds in the bronchiole wall from branch 17
from branch 20 whole airway is alveoli.
Describe the Respiratory Mucosa
Lines conducting portion of respiratory system.
In the upper respiratory system it contains mucous glands
In the conducting portion of the lower respiratory system it contains smooth muscle.
Describe the nasal cavity
Air enters respiratory system
Nasal hairs in nasal vestibule perform first particle filtration
Air flow through the three nasal meatuses
Describe the palates
Hard Palate: forms floor of nasal cavity and oral cavity
Soft Palate: Extends posterior to hard palate
Divides superior nasopharynx from lower pharynx.
Describe the Pharynx
A chamber shared by digestive and respiratory system.
Extends from internal nares to entrances to larynx and esophagus.
Three Divisions: Nasopharynx
Oropharynx
Larynopharynx
What is the larynx
A cartilaginous structure that surrounds the glottis.
What is the glottis
Responsible for sound production by opening and closing
Describe the bronchi separation
Right and left primary bronchi separated by internal ridge (carina)
What is the bronchial tree?
Formed by the primary bronchi and their branches
Primary bronchus have branches to form secondary bronchi (lobar bronchi), one goes to each lobe.
Extrapulmonary bronchi - left and right bronchi branch outside the lungs.
Intrapulmonary - branchges inside the lungs.
Describe Secondary bronchi
Branch to form tertiary bronchi, also called segmental bronchi which supply air to a single bronchopulmonary segment
There are 10 BPS in right lung and 8 or 9 in left.
What is the bronchial structure
Each tertiary bronchus branches into multiple bronchioles, which branch into terminal bronchioles.
Describe the bronchiole structure
No cartilage, dominated by smooth muscle.
Autonomic control regulates smooth muscle allowing stretch and recoil of bronchioles controlling airflow and providing resistance in lungs.
Describe alveoli structure
Air filled pockets within the lungs
where all gas exchange takes place
What is external respiration
Includes processes exchanging O2 and CO2 with the environment.
. Pulmonary ventilation
. Gas diffusion
. Storage and transport of O2 and CO2
. The exchange of dissolved gases
What is internal respiration
Called cellular respiration, involves uptake of O2 and CO2 within individual cells.
What is pulmonary ventilation?
The physical movement of air in and out of 4respiratory tract
Provides alveolar ventilation - the physical movement of air in and out of alveoli.
What is Boyles Law
P = 1/V
What is the compliance of the lung?
An indicator of expandability
Low compliance requires greater force, higher requires less
How does breathing Occur? (brain)
Initiated by RCC in Medula oblongata. Activation causes a contraction in the diaphragm and intercostals.
What happens during inspiration?
Diaphragm down, rotates ribs to horizontal plane. External intercostals move ribs upand out which increases thoracic cavity.
What happens during expiration?
Passive event, muscles relax.
Describe surface tension in the alveoli
Thin film of fluid lines alveoli and surface tension of film is an important factor. Attractive forces between adjacent molecules of liquid stronger than those between liquid and gas. Contributes to passive recoil force and stabilizes alveoli
What are the muscles involves in respiration?
Inspiration: Sternocleidomastoid
Scalenes
Ext and int intercostals
Diaphragm
Expiration: Int Intercostals
Ext and int abdominal obliques
Transverse and rectus abdominis
Quiet Breathing Vs Forced Breathing
Quiet - Involves active inhilation, diaphragmatic breathing or deep breathing. Costal breathing or shallow breathing
Forced - Hypernea, involves active inhalation and exhalation. Assisted by accessory muscles, maximum levels occur in exhaustion.
Ventilation Equations
Minute ventilation = Bpm x TV
Alveoli Ventilation = Bpm x (TV - DV)
What is inspiratory reserve volume?
The volume of air that can be inspired at the end of tidal ispiration.
What is tidal volume?
The volume of gas inspired or expired during an unforced respiratory cycle
What is the functional residual capacity?
The amount of gas remaining in the lungs after a normal quiet tidal expiration
What is the insipratory capacity?
The max amount of gas that can be inspired
What is expiratory reserve volume?
The volume of gas that can be expired at the end of a total expiration
What is Vital Capacity?
The max amount of gas that can be expired after a max inspiration.
What is the residual volume
The volume of gas left in the lungs after a maximal expiration.
What is the total lung capacity?
The total amount of gas in the lungs at the end of a maximal inspiration.
What are other important respiratory calculations?
FEV1 - forced exp volume in 1 sec
FVC forced vital capacity
Forced expiratory ratio = FEV/FVC
What is the composition of air?
760mmHg
Nitrogen (N2) ~ 78.6%
Oxygen (O2) ~ 20.9%
Water Vapour (H2O) ~ 0.5%
Carbon Dioxide (CO2) ~ 0.04%
