Respiratory System Flashcards
1
Q
Respiratory System
A
- provides route of O2 into the body and CO2 out of the body
- consists of air passages and lungs
- air passages connect lungs with air outside the body through openings at the nose and mouth
- blood carries O2 from lungs to cells
- blood returns CO2 from cells to lungs
2
Q
Anatomy of the respiratory system
A
- nasal cavity - nose
- pharynx
- larynx
- trachea
- two bronchi (1 bronchus in each lung)
- bronchioles
- alveoli
- lungs
3
Q
Nasal cavity
A
- main air route entry
- anterior nares (nostrils) separated into right and left by midline septum, part cartilage and part bone.
- posterior nares found at the back of the nasal cavity and form entry of the naso-pharynx
- lateral walls formed by maxillae of the skull
- nasal lining is ciliated columnar epithelium
4
Q
Function of nasal cavity
A
- warm, moisten and filter air
- protect underlying epithelium via mucous membrane
- smell - conveyed by olfactory nerves to brain
5
Q
Pharynx (throat)
A
- tube like structure 12-14cm long from base of skull to oesophagus
- posterior to nasal and oral cavities
- made of muscle and lined with mucous membrane
- soft palate acts as valve between nasal and oropharynx - closing nasopharynx during swallowing and oropharynx during respiration
6
Q
3 parts of pharynx
A
Nasopharynx:
- nasal portion of pharynx
- contain pharyngeal tonsils (adenoids) prominent in young children and shrink with age
Oropharynx:
- oral part of the pharynx
- contains palatine tonsils
Laryngopharynx:
- laryngeal part of pharynx
7
Q
Structure of pharynx
A
3 layers of tissue:
- mucous membrane lining
- fibrous tissue
- smooth muscle tissue
8
Q
Functions of pharynx?
A
- Passageway for air and food
- Warming & humidifying
- Taste
- Hearing- via auditory tube
- Protection- via lymphatic tissue (Pharyngeal & Laryngeal Tonsils)
- Helps with speech
9
Q
Larynx (voice box)
A
- lies at root of tongue and extends to trachea
- after puberty - grows larger in males (Adam’s apple) = deeper voice
- lined by ciliated mucous membrane
- triangle shape consisting largely of cartilage and muscle
- interior aspect houses vocal cords
10
Q
Function of larynx
A
- Sound
- Protection of respiratory tract - ensures food
passes into the oesophagus and not into the
respiratory passages via Epiglottis- closes over Larynx when eating - Passageway for air between pharynx & trachea
- Humidify, warming and filter air
11
Q
Trachea
A
- continuation of larynx
- runs vertically down thoracic cavity - divides into right and left bronchi
- 10-11cm in length
- lies in front of oesophagus
- Composed of a series of ‘C’ shaped cartilage - connected by fibrous tissue - keeps trachea constantly open
12
Q
Trachea layers
A
- outer layer - fibrous and elastic tissue encloses cartilage
- middle layer - cartilage and bands of smooth muscle
- inner. Layer - lined with ciliated columnar epithelium, containing goblet cells
13
Q
Function of trachea
A
- support - won’t collapse - due to cartilage
- regular beating of cilia - wafts mucus with particles up towards larynx
- cough reflex, abdominal and respiratory muscles contract to expel mucous/foreign material.
- warming, humidifying and filtering of air.
14
Q
Two bronchi
A
- formed when trachea divides (similar structure to trachea)
- right - 2.5cm long, wider and shorter, divides into 3, one to each lobe of the lung
- left - 5cm long, narrower, divides into 2 branches, one to each lobe
- structure and function = same as trachea
- bronchi subdivide into bronchioles - alveolar ducts - then finally alveoli (tiny air sacs)
15
Q
Bronchioles
A
- minute branch of bronchi
- cartilage diminishes and muscle takes over
Function: - warming and humidifying
- defence against microbes
