lecture 17 Flashcards
What are the major functions of the respiratory system?
Gas exchange (Oxygen in, Carbon dioxide out), Regulation of blood pH, Voice production (phonation), Olfaction (sense of smell), Protection from pathogens and debris
What processes are associated with the respiratory system?
Ventilation (Movement of air into and out of the lungs), External respiration (Gas exchange between alveoli and blood), Gas transport (Movement of gases through the bloodstream), Internal respiration (Gas exchange between blood and body tissues)
What is the difference between the conducting and respiratory portions of the respiratory tract?
Conducting zone: Transports air (nose, pharynx, larynx, trachea, bronchi, bronchioles). Respiratory zone: Site of gas exchange (respiratory bronchioles, alveolar ducts, alveoli)
What are the anatomical divisions of the upper and lower respiratory tract?
Upper tract: Nose, nasal cavity, pharynx. Lower tract: Larynx, trachea, bronchi, lungs
List the respiratory structures that air passes through during inspiration and expiration.
Nasal cavity -> Pharynx -> Larynx -> Trachea -> Primary bronchi -> Secondary bronchi -> Tertiary bronchi -> Smaller bronchi -> Bronchioles -> Terminal bronchioles -> Respiratory bronchioles -> Alveolar ducts -> Alveolar sacs -> Alveoli
What are the major functions of the nasal cavity and pharynx?
Functions: air filtration, air humidification and warming, olfaction, resonance for speech, protection
What is the epithelial lining of the nasal cavity and pharynx?
Epithelial lining of nasal cavity: Ciliated pseudostratified columnar epithelium. Epithelial lining of pharynx: Ciliated pseudostratified columnar epithelium and non-keratinized stratified squamous epithelium
What are the anatomical features of the nasal cavity?
Nasal cavity: external nares (nostrils), nasal septum, nasal conchae, meatuses, olfactory region, hard and soft palate. Pharynx: nasopharynx, oropharynx, laryngopharynx.
What are the major functions of the larynx?
Functions: Air passageway, prevents food from entering airway, sound (voice) production
What are the anatomical features of the larynx?
Has a cartilaginous framework, made of paired and unpaired cartilage. Has vocal folds which help form the vocal cords that produce sounds.
- the hyoid, then the thyroid cartilage, then the cricoid cartilage
How do the vocal folds and larynx function in phonation?
The larynx houses the vocal folds which vibrate air from the lungs, creating sound that is shaped in the vocal tract to form speech.
- they vibrate and close to form the sounds
What is the primary function of the trachea?
The trachea serves as a passageway for air to travel to and from the lungs, also playing a role in warming, humidifying, and filtering air.
What are the gross anatomical features of the trachea?
The trachea (windpipe) is a cartilaginous tube that extends from the larynx to the bronchi, located anterior to the esophagus and comprised of 16-20 C-shaped cartilage rings.
- it facilitates air passage to and from the lungs
it is also inferior to the cricoid cartilage of the larynx
What is the significance of the C-shaped hyaline cartilage rings in the trachea?
The open part of C faces the esophagus, permitting expansion of the esophagus.
What are the features of the bronchial tree?
The bronchial tree is a branching system of airways that conducts air from the trachea into the lungs, leading to gas exchange in the alveoli.
What is the difference between the right and left primary bronchi?
Main primary: The right and left primary bronchi branch off from the trachea at the carina (T4-T5 vertebral level).
Right primary bronchus: Wider, shorter, and more vertical than the left. More prone to foreign object aspiration.
- Left primary bronchus: Narrower, longer, and more horizontal due to the position of the heart.
What are the lobar bronchi and their function?
Each primary bronchus branches into lobar bronchi, which supply individual lobes of the lungs: Structure remains similar to the primary bronchi but becomes slightly smaller in diameter.
Right lung: 3 lobar bronchi (superior, middle, inferior).
Left lung: 2 lobar bronchi (superior, inferior).
What are segmental bronchi?
each lobar bronchus divides into segmental (tertiary) bronchi, supplying specific bronchopulmonary segments (independent functional units of the lung). These segments are functionally and structurally independent, allowing for surgical removal of diseased segments without affecting the rest of the lung.
Right lung: 10 segmental bronchi.
Left lung: 8-10 segmental bronchi.
What are bronchioles?
Bronchioles have a diameter of less than 1 mm, no cartilage, only smooth muscle, and are lined with ciliated simple columnar or cuboidal epithelium.
What is the function of the respiratory bronchioles?
Respiratory bronchioles are the first structures of the respiratory zone where gas exchange occurs.
What are alveolar ducts and sacs?
Alveolar ducts are thin-walled passageways lined by alveoli, leading into clusters of multiple alveoli (alveolar sacs).
What are alveoli?
Alveoli are tiny air sacs where the primary site of gas exchange occurs, lined with simple squamous epithelium.
- Structure: Lined with simple squamous epithelium for easy gas diffusion. Surrounded by capillaries for oxygen and carbon dioxide exchange. Contain type I pneumocytes (gas exchange) and type II pneumocytes (produce surfactant to prevent alveolar collapse).
What is the respiratory membrane?
The respiratory membrane is a thin barrier in the lungs that facilitates gas exchange by allowing oxygen to move from the alveoli into the blood and carbon dioxide to move from the blood into the alveoli.
What histological changes occur along the bronchial tree?
The epithelium transitions from ciliated pseudostratified columnar to simple cuboidal, cartilage and submucosal glands decrease, and club cells become more prominent.
