Respiratory System: Slides 22-44 (Tissues/ Blood Supply/ Respiration) Flashcards
What are three key components of an Airway Wall.
Where are each found and what purpose do they have?
- Cartilage
- Found in larger airways
- Helps keep airways open
- Smooth muscle
- Found predominantly in smaller airways
- Controls diameter of airway (constrict/dilate)
- Reduce airflow (via constriction)
- Elastic Fibre
- Predominate smaller airways and respiratory portion of respiratory system
- Elastic recoil provides force for expiration
What part of the respiratory system (primarily) is affected in asthma?
Bronchioles
- Chronic inflammation that leads to thickening of the bronchial wall
What controls smooth muscle contraction in bronchioles?
Parasympathetic nervous system
In an asthma attack, what causes the sudden constriction of the bronchioles?
Parasympathetic nervous system stimulation as well as chemical messengers such as histamine involved in allergic reactions
Breakdown of the alveolar walls is called?
Emphysema
What are two detrimental effects of emphysema?
Breakdown of alveolar walls = Less surface area for gas exchange and loss of elastic fibres
- Reduced elastic recoil
- Reduced respiratory efficiency
What type of epithelium would you find in the nasal cavity, nasopharynx and large airways of the respiratory system?
- Pseudostratified epithelium
Describe the Respiratory epithelium of the nasal cavity, nasopharynx and large airways:
(include: 3 types of cells and their functions)
- Pseudostratified epithelium
- Has ciliated columnar epithelial cell
- Cilia sweeps layer of mucus up the airway to remove any accumulated foreign material
-
Goblet cells
- Secrete mucus. forming the mucus layer (which acts as a conveyer belt)
-
Basal Cells (gives appears of pseudostratified)
- Stem cells: Constantly renew epithelium
What kind of epithelium is found in the oropharynx?
Stratified squamous non-keratinized epithelium
As we go further into the branches of the lower respiratory tract what happens to the epithelium?
Gradually becomes simpler:
- simple columnar
- simple cuboidal
- simple squamous (VERY thin)
What cells make up the alveolar wall?
Type one alveolar cells (pneumocytes)
-very thin squamous epithelial cells
For what two reasons are type two alveolar cells important?
What is another name for them?
Surfactant cells
- Produce surfactant = fluid that breaks down surface tension in fluid (like soap = slippery)
- Stem cells = divide and renew themselves as well as type 1 pneumocytes
Between the alveoli is a thin wall of _______ with embedded _______
Between the alveoli is a thin wall of Connective tissue with embedded capillaries
How many plasma membranes does an oxygen molecule have to cross in order to pass from the air space (of alveoli) to a hemoglobin molecule in a red blood cell
- Type I pneumocyte
- Endothelial cell forming wall of capillary
- basal laminal
- endothelium of capillary
- membrane of RBC
How do Alveolar Macrophages assist in removing debris?
- Ingest debris in alveoli
- Enter airways
- Become trapped in mucus sheet
- Carried toward pharynx via capillary action
- Either expectorated (spit out) or swallowed
The pulmonary veins are interlobular. What does this mean?
They do not follow the airways, unlike the pulmonary arteries.
Travel their own path
Label:
- Smooth muscle
- Alveolar Sac
- Alveolar Duct
- Alveolus
- Capillaries
- Elastic Fibres
- Respiratory bronchiole
What increases volume of pleural cavity (leading to inhalation)?
Contraction of external intercostals and diaphragm
Exhalation during quiet breathing results from?
Relaxation of external intercostals and diaphragm decreases volume of pleural cavity causing exhalation (Quiet breathing)
What three muscles are involved in forced inhalation but not quiet inhalation?
What are they collectively known as?
Hint: think muscles that elevate the rib cage
- Scalenes
- Sternocleidomastoid
- Pectoralis minor
Accessory respiratory muscles
What 2 muscles would aid in forced exhalation?
- Abdominal wall muscles
- Internal intercostal muscles
Name the muscle(s) that contract to:
- Lift ribs superiorly and
- move sternum anteriorly
What event in respiration are they involved in?
External Intercostals
Quiet inhalation
What is the diaphragms role in quiet breathing?
Contraction flattens diaphragm
Increases vertical diameter of thoracic cavity
Relaxation of ______ and _____ leads to quiet exhalation
Relaxation of external intercostals and diaphragm leads to elastic recoil of lung tissue and quiet exhalation
What feature of alveoli aids in quiet exhalation?
Elastic recoil of lung tissue = pushes air out
What role do the following muscles have in forced inspiration?
- Sternocleidomastoid
- Scalenes
- Pectoralis minor
What role do the following muscles have in forced inspiration?
- Sternocleidomastoid - elevates sternum
- Scalenes - elevate ribs 1 and 2
- Pectoralis minor - elevates ribs 3-5
What role do the abdominal muscles have in forced expiration?
- move inferior ribs inferiorly
- compress viscera - move diaphragm superiorly
