The respiratory system- lecture 1 Flashcards
What is the function of the R system?
Gas exchange: • O2 passes from air to blood • CO2 passes from blood to air Also involved in: Speech- exhaling- larynx changing shape Smell- top of nasal cavity- specialized epithelium mucosa that catch particles in the air- cranial nerve that says to brain these are particles we’ve sensed and brain classifies them
Functional divisions of the Respiratory System
- Conducting Portion
- Transports air from external environment to alveoli sacs
- Conditions air (warms, moistens, filters)- needed as specialised structures are delicate- thus gaseous exchange can occur
- Respiratory Portion
- Thin, moist, delicate membrane
- Site of gaseous exchange- between alveoli sacs and BV
Where does the conducting portion start and finish?
Nasal Cavity to Terminal Bronchi
Nasal cavity has 3 undulations called conchae- what are they called?
Superior, middle and inferior.
Where does the nasopharynx extend from and to?
The nasopharynx extends from the base of the skull to the upper surface of the soft palate.
Where does the oropharynx extend from and to?
The oropharynx lies behind the oral cavity and extends from the uvula to the level of the hyoid bone.
Where does the laryngopharynx extend from and to?
The laryngopharynx is the lower part and lies inferior to the epiglottis. It extends to a point where the path divides into the digestive (oesophagus) and respiratory (larynx) systems. It then continues with the oesophagus.
How many paranasal sinuses are there and what do they do?
4 Paranasal sinuses
- Warm
- Moisten
- Filter
What are the 4 paranasal sinuses
Have frontal sinuses above eyes.
Ethmoid air cells- by bridge of nose.
Sphenoid sinus is posterior.
Maxillary sinus is either side of the main part of the nose to nostrils.
What do conchae do?
Conchae create turbulent air flow- as structure sucks in air and allows entry to paranasal sinuses.
What do sinuses do?
Sinuses filters pathogens.
What does the nasolacrimal duct do?
Nasolacrimal duct- excess tears emptied in there (in the nose)
How is the thoracic cavity divided?
Pulmonary cavities- where we have lungs
Mediastinum- contains heart, oesophagus, vessels etc.
How are the lungs split up?
Right lung has oblique and horizontal fissure (as has an extra lobe)- 3 lobes- has superior inferior and middle
L lung one oblique fissure splitting into 2 lobes due to having the heart on that side- has superior and inferior
What is the appearance of the either side of the lungs?
R- Short, broad and larger
L- Tall and narrow
Lung- Medial surface
Opening for bronchi
Opening for BV to a form the heart
Pulmonary vessels different from other vessels- arteries contain oxygenated blood normally- at lungs – pulmonary circulatory system isn’t true- arteries always away from heart
Conducting Portion- how are the lungs split up?
Trachea split into right and left bronchi.
Where it splits is called the carina.
Primary bronchi can then split into secondary bronchi.
Secondary bronchi split further.
Main bronchus splits into lobular and segmental branches.
Segment has its own air supply- can take out segment if damaged- as lung segmented can take out a section of it
Conducting portion – trachea to primary bronchi to lobar bronchi to segmental bronchi to terminal bronchi
Respiratory Portion- what is it?
Branching of terminal bronchioles to respiratory bronchioles and alveolar sacs.
The alveolar sacs are surrounded by capillary beds that:
- Receive deoxygenated blood via pulmonary arteries
- Send oxygenated blood via pulmonary veins = Site of Gaseous Exchange
What are the pulmonary vessels and what do they do?
Arteries – Carry blood away from the heart – Carry deoxygenated blood
Veins – Carry blood to the heart – Carry oxygenated blood
Both follow branching pattern of bronchi – to lungs, to lobes, to segments
Pulmonary arteries away from the heart.
Functional v Anatomical divisions
Functional system division: Conducting and Respiratory
Anatomical divisions:
Upper Respiratory Tract and Lower Respiratory Tract
Where does the URT start and finish?
URT = Nasal cavity to Pharynx to Larynx
also includes the sinuses