BMS1058 - Pulmonary System Flashcards
What is the difference between Pulmonary, External and Internal respiration?
Pulmonary: Exchange of air between the atmosphere and the pulmonary
alveoli of the lungs
External: Exchange of gases between
pulmonary alveoli and blood in
pulmonary capillaries
Internal: Exchange of gases between blood in systemic capillaries and cells of tissue
What are the components for the upper and lower respiratory system?
These structures are known collectively as the conducting zone.
Other than gas exchange, what are the functions of the respiratory system?
Regulation of blood pH
Receptors for smell, filters inspired air, vocal sounds, excreting water and heat
Describe the external and internal nose.
EXTERNAL NOSE:
- protects inner nose
- warm, moisten and filter incoming air
- olfactory receptors
- modify speech vibrations
INTERNAL NOSE:
- nasal cavity
- large inferior respiratory region
- smaller superior olfactory region
Describe the respiratory epithelium
Ciliated columnal epithelium
+
Goblet cells
Describe the Pharynx
- Skeletal muscle lined with
mucous membrane - Passageway for air and
food - Resonating chamber for
speech - Tonsils
What are the 4 layers of the Trachea?
- Respiratory mucosa – ciliated epithelial cells
- Submucosa – areolar connective tissue (seromucous glands and ducts)
- Hyaline cartilage: 16-20 C-shaped horizontal rings
- Aventitia – areolar connective tissue
Trachea divides into right and left bronchus.
Describe the Clara cells. Where are they found?
Found in the Bronchioles.
- Non-ciliated secretory cells.
- Protect against harmful effects of
inhaled toxins and carcinogens. - Develop into epithelial cells.
- Produce surfactant.
Each lunch is divided into _____, wheach each has many ______.
What do they contain?
lobes
lobules
Contains lymphatic vessels, arteriole, venule and branch from terminal bronchiole.
Alveoli contain 2 types of epithelial cells. Describe them.
TYPE 1:
- simple squamous epithelial cells
- most abundance
- main site of gas exchange
TYPE 2:
- also called Septal cells
- rounded epithelial cells
- found in between Type 1 cells
- microvili
- secrete pulmonary alveolar fluid
What other cells are found in the alveoli?
Macrophages - phagocytes that remove fine dust and debris
Fibroblasts - cells that produce connective tissues (e.g. elastic fibres)
What are the 4 layers of the respiratory membrane?
- Alveolar wall (Type I and II
pneumocytes and macrophages) - Epithelial basement membrane
- Capillary basement membrane
- Capillary endothelium
What occurs in inhalation? When excerising/forced breathing, what else is involved?
Active process (muscle contraction involved)
Pulmonary alveoli pressure < atmospheric pressure. Increase the eize of lungs.
Diaphragm contracts.
External intercostals contract and elevate ribs.
Increase verticle diameter of thoratic cavity.
[When excercising/forced breathing, accessory muscles involved.]
What are the accessory muscles used in inhalation?
Sternocleidomastoid muscles - elevate sternum
Scalene muscles - elecate first two ribs
Pectoralis minor muscles - elevate ribs 3-5
What occurs in passive exhalation?
Lung air pressure > atmosphere air pressure
Elastic recoil of chest wall and lungs
Diaphragm adn external intercostals relax.
Diameter of thoracic cavity reduces.
Alveolar pressure increases - air flows out of lungs.
What occurs in forceful exhalation?
Abdominal and internal intercostal muscles contract.
- Contraction of abdominal moves ribs downwards and forces diaphragm up.
- Contraction of internal intercostals pulls ribs inferiorly
Increases pressure in abdominal region and thorax.
What are the factors affecting pulmonary ventilation?
Surface tension of alveolar fluid
Lung compliance (effort required to stretch the lungs and chest wall, high=expands easily)
Airway resistance
What are the 2 main mechanisms that control respiration?
Central Pattern (autonomic)
- Inspiratory and expiratory muscles.
- controlled by medulla neurons
- fine tuned by pons
Voluntary
- origin in Cerebral cortex
- additional influences
The respiratory centre is located across the Medulla and Pons. How does the Medulla and Pons control respiration?
Medulla
- co-ordinates quiet and forced breathing
- controls frequency of ventilation
Pons
- controls volume and depth of ventilation
Respiratory centre:
- Pontine respiratory group in the pons
- Medulla respiratory centres in medulla oblongata
What does the Medullary respiratory centre consist of?
Dorsal Respiratory Group (DRG):
- controls diaphragm and external intercostal muscles
- inspiration and experiation in quiet breathing
Ventral Respiratory Group (VRG):
- Controls accessory inspiratory and
expiratory muscles
- Inspiration and expiration during
forced breathing
How does the Dorsal Respiratory Group (DRG) control quiet breathing?
The Postine Respiratory Group transmits nerve impulses to the medulla ___. This modifies the basic rhythm of breathing generated by ___. Exercising, speaking or sleeping.
DRG
VRG
Cortical influences ________ alter our breathing pattern. They are a ________ mechanism.
Increased CO2 and H+ stimulates the ___ neurons and breathing _______.
Voluntarily
Protective
DRG
resumes
What do chemoreceptros monitor in the lungs? What about the difference between central and Peripheral chemoreceptors?
CO2, O2 and H+
Central chemoreceptors - measure cerebral spinal fluid - CO2 and H+
Peripheral chemoreceptors - measure blood CO2, O2 and H+
