Upper respiratory system:
- nose, nasal cavity, paranasal sinuses, and pharynx.
- Pipes that warm, filter and humidify the air.
- nasal cavity : Pseudostratified ciliated columnar epithelium
Lower respiratory system
- larynx, trachea, bronchi, bronchioles, and alveoli.
- Pipes that continue the warming, filter, humidify and end in alveoli
elastic cartilage flap that covers the glottis when food goes by,preventing food from entering the trachea
opening to the larynx
upper portion of the trachea containing the vocal cords
- Pseudostratified ciliated columnar epithelium mucus and cilia trap and move dust up to throat, protect alveoli.
- mucus – is from goblet cells and mucus cells.
- C-shaped cartilage prevents collapse of the trachea
alveoli what kind of cell?
- Simple Squamous epithelium
- Alveoli – surrounded by capillaries that are wrapped in elastic fibers.
2 layer serous membrane that covers the lung, visceral pleura and parietal pleura
Sympathetic nervous system on the respiratory system
Dilates bronchiolar smooth muscle, Beta 2 receptors, epinephrine.
Parasympathetic nervous system on respiratory System
Constricts bronchiolar smooth muscle, muscarinic cholinergic receptors, acetylcholine
constricts bronchiolar smooth muscle, histamine release by mast cells.
- Simple squamous epithelium
- alveolar macrophages – dust and mircorganism patrol
- oily secretion, lipids and proteins, reduces the moist surface tension of sac
- prevents the alveolar sac from collapsing.
Capillaries are what cell
Simple squamous epithelium
- Always ACTIVE
- Movement of air into alveoli due to decreased pressure and increased volume available.Alveoli expand due to elastic fibers wrapped around the sac.
- Maximum inspiration- Pectoralis minor, sternocliedomastoid m also contract
- can be passive or active
- Movement of air out of lungs due to increased pressure and decreased volume available.Alveoli relax and have elastic recoil due to elastic fibers
- Expiration – diaphragm and external intercostals relax, passive changes.
- Forceful expiration- internal intercostals and rectus abdominis m. contract, active changes
- expandability of the lungs depends on:
- elastic fibers around alveoli,
- respiratory muscles and ribs.
- elastic connective tissue fibers around the alveoli (rubber bands)
- surfactant – breaks surface tension of water, prevents collapse of alveoli
- visceral pleura – negative pressure keeps lung inflated.
air enters the thoracic cavity, increases pressure between the visceral andparietal pleura and collapses the lung.
Fibrosis of the lung
- chronic inflammation causing decreased elastic recoil.
- Normal alveoli are destroyed, scar tissue and non-elastic pockets remain intthe lung tissue. This is called emphysema.
amount of air moved in one respiratory cycle. Average person = 500 cc
Quiet V Deep Breathing
Quiet Breathing – active inspiration, passive expiration Deep Breathing – active inspiration, active expiration
Respiratory Minute Volume
volume of air moved per minute.
amount of air that reaches the alveoli minus the anatomical dead space air.
Inspiratory Reserve Volume
IRV, additional inspiration volume above tidal volume
Expiratory Reserve Volume
ERV, additional expiration volume expelled after the tidal volume
IRV + VT + ERV , the maximum air that you can inhale and exhale in one cycle.
Forced Expiratory Volumes
- a healthy person can forcefully expel 80% of the air in their lungs in 1 sec. And
- within 2 sec, they can expel over 90%.
- In 3 sec. 98% or more is expelled.
What is the primary driver of respirations?
What is functioning for rate of breathing?
Medulla – Dorsal Respiratory Group – always functioning for rate of breathing
What changes depth/rate of breathing?
Pons – Pneumotaxic Center – changes depth and modifies rate of breathing.
- 1. Carotid bodies – glossopharyngeal nerve, CO2, O2 and pH
- 2. Aortic bodies – vagus nerve, CO2, O2 and pHpCO2 – small increases quickly trigger deeper and faster breathing. hypercapniapO2 – requires large decreases, to 40 mm Hg, to cause increases in breathing. hypoxia
- 3. Stretch receptors – monitor the expansion of the lungs, protective reflexes.
inflation reflex, prevents overstretch of the lungs
- allergen hypersensitivity reaction, IgE and Mast Cells = histamine release in bronchioles
- Expiratory Wheezing
- chronic condition, variety of causes including smoking, coal mining etc
- Decreases surface area and elastic fibers, increases diffusion barrier for gases
- patients have both obstruction of the airways anddecreased diffusible alveolar surface area.
- Expiratory wheeze due to bronchiolar constriction AND alveolar crackles due to lung tissue inflammation.
Long/Short acting Brochiodilators
- Albuterol – short acting, ‘rescue inhaler to stop bronchiole spasms. Beta-agonist (Symp. NS)
- Salmeterol- long acting, used for maintenance to bronchiole spasms Beta-agonist.
reduces mucus & dilates bronchioles.
long acting tablet, broncho-dilator esp. night asthma.