Why do we breathe? Flashcards
What are the functions of the Respiratory System?
- Respiration
- Regulation of Blood PH
- Voice Production
- Smell (Olfaction)
- Protection
What is the function of Respiration?
- Ventilation= Movement of air in & out of lungs.
- External Respiration= Gas exchange between lungs & blood.
- Transport of respiratory gases.
- Internal Respiration= Gas exchange between blood & tissues.
What are the divisions of the Respiratory System?
-Structural Classification oUpper respiratory tract oLower respiratory tract -Functional Classification oConducting zone oRespiratory zone (in lungs)
What does the Nasal Cavity consist of?
NASAL CAVITY =From nostrils (nares) to choana. =Vestibule= Entry to nasal cavity. -Stratified squamous epithelium, sweat & sebaceous glands & hair follicles. =Hard Plate= Floor of nasal cavity. -Bone. =Septum= Separates nasal cavity into left & right parts. -Cartilage & bone. =Conchae= Bony “ridges” in nasal cavity. -Superior, middle & inferior concha -Superior, middle & inferior meatus =Epithelium of concha (& most of the nasal cavity) is pseudostratified ciliated columnar epithelium.
What are the functions of the Nasal Cavity?
-Passageway for air
-Cleans the air
-Humidifies and warms the air
=via warm blood flowing through nasal cavity.
=via moisture from mucous epithelium and excess tears which drain into nasal cavity.
-Olfaction (or smell)
-Sound of your voice
What are the 3 regions of the Pharynx?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Describe the Nasopharynx
- Posterior to nasal cavity
- Pseudostratified ciliated columnar epithelium.
- Houses openings of Eustachian tubes.
- Posterior surface of nasopharynx has the pharyngeal tonsils.
Describe the Oropharynx
- Posterior to oral cavity
- Stratified squamous epithelium
- Palatine tonsils and lingual tonsils
Describe the Laryngopharynx
- Lies posterior to epiglottis
- Stratified squamous epithelium
What are the 6 Paired and 3 Unpaired Cartilages that make up the Larynx?
6 paired -Arytenoid -Corniculate -Cuneiform 3 unpaired -Thyroid (Adam’s apple) -Cricoid -Epiglottis
What are the functions of the Larynx?
- Maintains an open passageway for air movement
- Directs food into the oesophagus away from respiratory tract
- Sound production via vocal folds
- Trap debris from entering lungs
Describe the Trachea (how many cartilage rings, type of lumen, whats between the cartilage rings)
- Descends from the larynx and sits anterior to oesophagus.
- Has 15-20 ‘C-shaped’ hyaline cartilage rings→support.
- Dense connective tissue and smooth muscle in between cartilage rings.
- Tracheal lumen lined with pseudostratified ciliated columnar epithelium with goblet cells (mucous producing).
When moving from the trachea to terminal bronchioles what changes happen?
-Increase in smooth muscle.
-Decrease in cartilage.
-Change in epithelium in lumen from pseudostratified ciliated columnar→
simple ciliated columnar→simple ciliated cuboidal.
On the Alveolus side what does it contain?
=Simple squamous epithelium -Type 1 pneumocyte -Gas exchange→simple diffusion -Type 2 pneumocytes -Cuboidal cell -Secretes a surfactant to reduce surface tension -Macrophages =Basement membrane
What do the lungs consist of?
-Cone shaped with a base and apex
-Left lung has 2 lobes + cardiac notch
-Right lung has 3 lobes
-Lobes separated by fissures
-Hilum on medial surface – entry point for blood and nervous supply,
lymphatic vessels and bronchi
-Hilum
-Bronchopulmonary segments
What are the factors that affect Gas Exchange through the Respiratory Membrane and Explain?
1.Thickness of the respiratory membrane
=Thicker membrane reduces the rate of movement of gas.
2.Surface area
=Lower surface area reduces volume of gas exchange taking place.
3.Diffusion coefficient
=Diffusion coefficient – how easily a gas can diffuse in and out of a liquid or tissue.
=A relative number.
4.Partial pressure - pressure exerted by each gas in a mixture of gases
=When the partial pressure (Pp) of a gas is greater on one side of the respiratory membrane compared to the other side, the gas moves from the side with the higher Pp to the side with the lower Pp.