Session 10 - Respiratory system Flashcards
Main functions of the respiratory system?
• Provides for gas exchange—intake of O2 and elimination of CO2 • Helps adjust the pH of body fluids • Contains receptors for sense of smell • Filters inspired air • Produces vocal sounds (phonation) • Excretes small amounts of water and heat
The three basic steps of respiration
• Ventilation (breathing) • External (pulmonary) respiration = exchanges of gases of the lungs with the blood • Internal (tissue) respiration = exchanges of gases from the blood to the cells
What does The upper respiratory system: consist of
• Nose • Nasal cavity • Pharynx (throat), and associated structures
What does The lower respiratory system consist of?
• Larynx (voice box) • Trachea (windpipe) • Bronchi (airways) • Lungs
What is the conducting zone consist of?
Function?
consists of a series of interconnecting cavities and tubes both outside and within the lungs.
•the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles
oFunction: to filter, warm, and moisten air and conduct it into the lungs.
What does the respiratory zone consist of?
Function?
consists of tubes and tissues within the lungs
•the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
oFunction: the main sites of gas exchange between air and blood.
Nasal cavity duct openings?
Duct from the paranasal sinuses (which drain mucus) open in the nasal cavity and the nasolacrimal ducts (which drain tears - that’s why your nose runs when you cry) open in nasal cavity.
What type of Epithelium lines the nasal cavity?
Also known as Airway epithelium
Ciliated pseudostratified columnar epithelium with goblet cells which produce a moving mass of mucus.
Functions of the nasal structure
o Ciliated pseudostratified columnar with goblet cells:
Lines the nasal cavity
Warms air due to high vascularity
Mucous moistens air and traps dust
Cilia move mucous towards pharynx
o Olfactory epithelium: Detecting olfactory stimuli ( sense of smell)
o Paranasal sinuses: Modifying speech vibrations as they pass through the large, hollow resonating chambers. - gives us the ability to chnge pitch and tone. That’s why when you are sick your voice changes as the paranasal sinuses are full/blocked etc
• Resonance refers to prolonging, amplifying, or modifying a sound by vibration.
Functions and regions of rhe pharynx
o Functions:
Passageway for food and air
Resonating chamber for speech production
Tonsils (lymphatic tissue) in the walls protects entryway into body
o Distinct regions: nasopharynx, oropharynx and laryngopharynx
The larynx connects the…
and it’s function
laryngopharynx with the trachea
Function: voice production
What is the trachea ?
and what are the layers of thr tracheal wall?
The windpipe
Anterior to the oesophagus
Explain the bronichial tree? and the structural changes as the branching becomes more extensive
Consists of bronchi - they start large and end up small
The bronchial tree begins at the trachea and ends at the terminal bronchioles
* refer to picture for order
Structural changes:
as the branching becomes more extensive -
oThe mucous membrane: (epithelial layer)
•Gradually changes from pseudostratified ciliated to cuboidal non-ciliated
oRings of cartilage:
•Gradually replaced by rings of smooth muscle and then connective tissue
What divides the Primary Bronchi into left and right
the trachea divides into a right primary bronchus and a left primary bronchus - supply each lung
oCarina: An internal ridge formed by a posterior and inferior projection of the last tracheal cartilage, at the point where the trachea divides into right and left primary bronchi
What does the Secondary bronchi supply?
What does the tertiary bronchi supply?
o Secondary bronchi: Supply each lobe of the lungs (3 right + 2 left)
o Tertiary bronchi: Supply each bronchopulmonary segment (10 in each lung)
• The teritary divide into bronchioles which in turn branch repeatedly and divide into smaller tubes called terminal bronchioles
What role does the sympathetic nervous system and parasympathetic nervous system
oSympathetic nervous system: stimulates adrenal glands to release epinephrine that relaxes bronchiolar smooth muscle.
• dilates airways and improves lung ventilation
o Parasympathetic nervous system: cause contraction of bronchiolar smooth muscle
• constricts of distal bronchiole
what is the Pleural membrane and pleural cavity ?
oPleural membrane: A double-layered serous membrane that enclose and protect each lung
- Visceral pleura covers lungs
- Parietal pleura lines thoracic cavity
oPleural cavity: A potential space between the visceral and parietal pleurae
- Contains a pleural fluid secreted by the membranes.
- Reduces friction between the membranes, allowing them to slide easily over one another during breathing (inflation and deflation)
Location of the lungs and what are they enclosed and protected by?
Location: in the thoracic cavity; extend from the diaphragm to just slightly superior to the clavicles and lie against the ribs anteriorly and posteriorly.
oEnclosed and protected by the pleural membrane.
How many lobes does the right and left lung have?
The right lung: three lobes separated by two fissures-Oblique and horizontal fissure
•The left lung: two lobes separated by one fissure-Oblique fissure
medial (mediastinal) surface of the lungs
oBlood vessels and airways enter lungs at hilus
oForms root of lungs
oCovered with pleura (parietal becomes visceral)
What’s the order of the Microscopic airways following on down the bronchial tree?
What are the lobules?
Terminal bronchioles
respiratory bronchioles
alveolar ducts
alveolar sacs
alveoli
oLobules: Small compartments of bronchopulmonary segment
- Wrapped in elastic connective tissue (function: stretch and recoil when breathing)
- Each contains an arteriole, a venule, and a branch from a terminal bronchiole
How many cell types are there of the alveoli sacs
3 - 4 types
Type 1 alveolar cells
Type 2 alveolar cells (septal cells)
Alveolar dust cells
Fibroblasts
Type I alveolar cells:
- Form a continuous lining of the alveolar wall. (form the sac)
- Site for gas exchange.
- Are the most prevalent alveolar cells
** Single layer of cells where gas passes through them into the pulmonary capillaries or from the capillaries into the alveoli
Type II alveolar cells (septal cells):
- Found between type I alveolar cells
- Secrete alveolar fluid containing surfactant (detergent)
–Surfactant lowers the surface tension of alveolar fluid, preventing the collapse of alveoli with each expiration - very important
Alveolar dust cells
Wandering macrophages that remove debris
Fibroblasts:
•Produce reticular and elastic fibers
Blood supply to the lungs
Pulmonary arteries:
Carry deoxygenated blood from the right heart to the lungs for oxygenation
Blood supply to the lungs
Bronchial arteries:
branch from the aorta and deliver oxygenated blood to the lungs primarily perfusing the muscular walls of the bronchi and bronchioles
perfuse: supply (an organ or tissue) with a fluid by circulating it through blood vessels or other natural channels.
Answers on tutorial print out
Label microscopic anatomy of a lobule of the lung
Answers on tutorial print out
