16 Flashcards
Function of URT and LRT
Bring air in optimum condition to the respiratory membrane.
What does the larynx do
P revents entry of food to LRT and contains the vocal cords.
Function of bronchial tree
The bronchial tree carries air to
alveoli, with changes to the epithelium, smooth muscle and cartilage reflecting function.
Where does gas exchange occur
Gas exchange occurs at the respiratory membrane in the alveo
Our Body cavities are lined with..
Serous membrane
Structure of serous membranes
- double layer of secretory tissue (epithelial cells) with fluid between layers
- visceral layer on the organ
- parietal layer on body wall
Examples of serious membranes within cavities
Thoracic cavity:
- pericardium
- pleura
Abdominopelvic cavity:
- peritoneum
Body cavities of the trunk
What does the thoracic cavity contain?
• Mediastinum
• Heart, vessels, pericardium
• Pleural cavities
• Lungs
What is the anterior boundary of the thoracic cavity
Sternum
What is the posterior boundary of the thoracic cavity
Thoracic vertebrae
What is the lateral boundary of the thoracic cavity
Ribs
What is the superior boundary of the thoracic cavity
Base of neck
What is the inferior boundary of the thoracic cavity
Diaphragm
Plural cavities - why are lungs seperate
So if one stops functioning, you have another
Where dies parietal pleura attach
Thoracic wall
- helps lift and contract lungs during breathing
Pressure is inversely propertiaonal to..
Volume
What is ventilation driven by?
Changes in thoracic cavity
Volume in expiration and inspiration
What is Boyes law
P = 1/V
Pressure inversely proportional
Volume
Pressure measured by
Collisions
• smallerspace=more collisions = increased pressure
• biggerspace=less collisions = decreased pressure
Pressure measured by collisions
• smallerspace=more collisions = increased pressure
• biggerspace=less collisions = decreased pressure
Air will move to ______ pressure space
Lower
To make air move when we breath we need to establish a
Pressure gradient
What is the pressure between breathes ?
pressure inside cavity = pressure outside. No gradient
Increased volume = ________ pressure = air flows ____
Decreased
In
Decreased volume = _____ pressure = air flows____
Increased
Out
Boyes law diagram - volume and pressure
Driving force for normal breathing
Pressure gradient
What connects sternum to ribs?
Costal cartilage (hyaline)
- synovial joints
- cartilaginous joints
The joints between the ribs
Sternacostal
- synovial
- except 1st = cartilaginous
Costochondral
- cartilaginous
Interchandra
- synovial
(Between cartilage
What kind of joint is sternocostal
- synovial
- except 1st = cartilaginous
What kind of joint in costochondral
- cartilaginous
What kind of joint is interchondral
- synovial
Why is first stenocostal cartilagnous
Add stability to base of neck
What forms the posterior section of thoricaic cavity
Articulation between thoracic vertebrae and ribs
- synovial joints
What kind of joint is Articulation between thoracic vertebrae and ribs
Synovial
Where to the ribs attach to the posterior
Vertebra
- constrotransverse: between rib and transverse process of vertebrae
- constovertebral: between rib and body of vertebrae
Which of the thoracic joints are not synovial joints
Costochondral and first sternocostal joint
Joints allow movement, muscle creates them
Yes
What do respiratory muscles do?
Move the rib cage to allow us to breathe
Primary muscles of respiration..
- diaphragm
- intercostals
Accessory muscle of respiration are…
Only activated when needed
What kind fo muscle is diaphragm
Skeletal
Structure of diaphragm in relaxation and contraction
- sheet of skeletal muscle
- some-shaped when relaxed
- flattens when contracted
What does contraction of the diaphragm do?
Contraction expands thoracic cavity, compresses abdominopelvic cavity
What does diaphragm seperate
Thorax from abdomens
Primary muscle of respiration
Diaphram
Three openings in the diaphragm
Relaxed vs flattened diaphragm
How do intercostal muscles attach between neighbouring ribs
Diaganallly
Function of external intercostals
- lefts rib cage and expands cavity
- inspiration is quiet and forced
Internal intercostals function
- depress rib cage and decrease cavity
- expiration - forced only
What are the accessory muscles ?
Several muscles that attach to the thoracic cage
Functions of accessory muscles
• Some accessory muscles increase cavity volume for forced inspiration
• Other accessory muscles decrease cavity volume for forced expiration
Muscles of respiration during normal ‘quiet’ inspiration
- Diaphragm contracts = flattens
• External intercostals contract = lifts ribs
Muscles of respiration during normal ‘forced’ inspiration
• Diaphragm contracts = flattens
• External intercostals contract = lifts ribs
Plus accessory muscles contract to further expand thoracic cavity
Muscles of respiration during normal ‘quiet’ expiration
• Passive process
• Diaphragm relaxes=dome shaped
• External intercostals relax= ribs no longer lifted
Muscles of respiration during normal ‘forced’ exspiration
• Passive process
• Diaphragm relaxes=dome shaped
• External intercostals relax= ribs no longer lifted
• Internal intercostals contract= depress ribs
• Accessory muscles contract to further decrease cavity volume
How do the lungs expand as the cavity does?
• Lung tissue is elastic and always trying to recoil
• The pleura make the lungs ‘stick’ to the thoracic wall
• Lungs expand during inspiration
• Lungs contract during expiration
Pleura contribution on thoricaic movement
• Visceral pleura on lungs
• Parietal pleura on thoracic wall
• Pleural fluid in between
– Slippery surface for frictionless movement against other structures – Fluid bond causes lungs to ‘stick’ to thoracic wall
• Therefore, thoracic wall movement results in lung movement
– Increase volume of thorax increase volume of lung decrease pressure in lung air flows in
What does recoil of lungs mean
Expand and go back to original shape
Lungs sticking to thoracic wall and moving shit will be in exam or prog test
Yes
Forced inhilation and forces exhalation
Big breath in:
- diaphragm, external intercostals and accessory muscles contract to increase thoracic cavity volume as much as possible
Big breath out:
- internal intercostals and accessory muscles contract (and diaphragm relaxes) decrease thoracic cavity volume as much as possible, to force air out
Key atomically features of thoracic cavity
- bones, joints and muscle form the thoricaic wall
- inside the cavity is the mediastinum, plus lungs within a double layer of pleuara
Relationship between presssure and volume
Boyes law: pressure in inversely proportional to volume
How do anatomical features change thoracic volume?
Insipiration: diagrpham and external intercostals contract. Accessory muscles contract for forced breathing
Expiration: Diaphragm relaxes. Internal intercostals and accessory muscles contract for forced breathing
How does our anatomy facilitate breathing ?
- muscles move bones at joints to increase volume/ decrease pressure for inspiration and to decrease / increase pressure for expiration
- pleural fluid adheres the lungs to the thoricaic wall to ensure lungs expand and recoil as the cavity volume changes
