Exam 2 Flashcards
(139 cards)
Ventilation
process of moving air into and out of the airways and lungs in order to exchange oxygen and carbon dioxide
Respiratory System Anatomy
- pulmonary apparatus
- chest wall
- muscles
Pulmonary Apparatus
O2 inhaled into lungs and then carried to all cells in the body; CO2 is carried from body to lungs and exhaled
- consists of
- trachea*
- bronchi*
- bronchioles*
- alveoli
- lungs - bronchial tree
Bronchial Tree: Trachea
- 10-16 cm long
- 2-2.5 cm diameter
- inside lined with cilia (filtering system to clean air entering lungs)
- splits into two branches, primary bronchi
Bronchial Tree: Bronchi
- Primary bronchi (one in each lung)
- Secondary Bronchi
- Tertiary Bronchi
Keep subdividing until divide into bronchioles (no cartilage, just smooth muscle); branch into terminal bronchioles (respiratory bronchioles)
Alveoli
- Respiratory bronchioles open into alveolar ducts
- each duct leads to an alveolus
- tiny air-filled sac- approx. 480 million in adult lung
- filled with surfactant
- exchange of O2 and CO2 takes place here
Lungs
-porous and elastic (size and shape changes)
-asymmetrical, right lung larger than left
(R=three lobes, L=2 lobes)
-pink in infants
-gray-black color in adults
Chest Wall
- Houses the pulmonary apparatus
- consists of
- rib cage*
- abdominal wall
- abdominal contents
- diaphragm* - thoracic cavity
Rib Cage
- 12 ribs on either side
- attached to sternum, cartilage
Abdominal Wall
Forms the boundaries of the abdominal cavity
Abdominal Contents
includes all organs within the abdominal cavity
- stomach
- intestines
- lower esophagus
- colon
- appendix
- liver
- kidney
- pancreas
- spleen
Diaphragm
- forms the roof of the abdominal cavity and the floor of the rib cage
- large dome-shaped muscle stretching from one side of the rib cage to the other
- shaped like a inverted-bowl when relaxed, flattens when contracted (lowers rib cage)
- important for breathing AND for speech
Muscles of Respiration
- External intercostal muscles
- Internal intercostal muscles
External Intercostals
11 muscle pairs that run between the ribs. fibers run downward and forward. functions to pull up and elevate rib cage
Internal Intercostals
11 muscle pairs located underneath the external intercostals. fibers run downward and backwards (at a right angle to that of external ICs). function to pull down and lower rib cage
Accessory Muscles of Respiration
extra muscles (neck, thorax and abdominal) that may be recruited during respiration
Pleural Linkage
Pleural linkage is an external force needed for respiration
It is created by the linkage between the lungs and the thorax:
-each lung is covered by a membrane (visceral pleura)
-inner surface of thorax is lined with a membrane (parietal pleura)
-between the two membranes is a small space (pleural space)
-the difference between the pressure inside the lungs (alveolar pressure) and pressure in pleural space(intrapleural pressure) is called transpulmonary pressure
-intrapleural pressure is negative, transpulmonary pressure is positive, and alvolar pressure changes from slightly positive to slightly negative as a person breathes
Moving Air Into and Out of the Lungs
- air moves in and out of the lungs by increasing and decreasing air pressure in the lungs
- known as inhalation (inspiration) and exhalation (expiration)
Inhalation
when palV is negative, air is forced to enter lungs (moves from high to low pressure)
- to decrease Palv, volume of lungs and thoracic cavity must be englarged
- done by contracting diaphragm (increases vertical dimension of thorax) and external intercostal muscles (pull rib cage upwards)
- lunge expand–> Palv below Patmos–> air from atmosphere flows into respiratory system via mouth or nose
- done by contracting diaphragm (increases vertical dimension of thorax) and external intercostal muscles (pull rib cage upwards)
Exhalation
When Palv is positive, air moves out of lungs.
To increase Palv, volume of lungs must decrease
-done by relaxing diaphragm (decreases vertical dimension of thorax) and internal intercostal (return rib cage to original position)
-Lungs decrease–> Palv rises above Patmos –> air (containing CO2) from body atmosphere flows out of the lungs and respiratory system via mouth or nose
Rate of Breathing
- measured in breath per minute (BPM)
- Born with a very high rate of breathing 40-70 BPM
- decrease as a child matures into an adult: 12-18 BPM
- due to anatomical and physiological changes (increase in alveoli number and size)
- also due to maturation of the nervous system
Lung Volumes and Capacity
- lung volume refers to the volume of air inside the pulmonary apparatus
- movements involved in respiration can cause a change in lung volume by moving air into or out of the pulmonary apparatus
- 4 lung volumes and 4 lung capacities
Resting Expiratory Level (REL)
- state of equilibrium in the respiratory system–air does not go in or out
- occurs when palv=patmos
- occurs at the end of every breath in and every breath out (brief instant)
- lung volumes and capacities are measured in relation to REL, and expressed in liters or milliliters
Lung Volumes
- Tidal Volume (TV)
- Inspiratory reserve volume (IRV)
- Expiratory Reserve volume (ERV)
- Residual volume