The Respiratory System Flashcards
What are the functions of the Resp. system?
Gas Exchange - O2 and CO2 exchange communication- vocalization Olfaction- smell Acid-base balance - release CO2 BP regulation - help make angiotensin ll Blood and Lymph flow - pressure gradients Blood Filtration - filter small clots Expulsion and abdominal contents - breath holding
Organs of the resp. system?
Nose Pharynx Larynx Bronchi Lungs- Bronchi, bronchioles, alveoli
Conducting Zone VS RESP Zone:
CONDUCTING ZONE: serves for air flow
RESP ZONE: consist of alveoli & other gas exchange regions.
What is the flow of air from the nose to the trachea?
nose -> pharynx (back of throat) -> larynx (voice box) -> trachea.
What is pulmonary ventilation?
the rhythmic movement of air into/out of the lungs. (a.k.a. breathing)
External Respiration
the gas exchange between the alveoli and the blood
Transport of respiratory gases occurs between?
between the lungs and the cells of the body.
What is Internal Respiration
the gas exchange between the blood surrounding
the cells of the body.
What muscles are used in inhalation?
Diaphragm and external intercostals
FORCED exhalation requires what muscles?
internal intercostals and rectus abdominis
What is tidal volume?
volume of one breath inhaled/exhaled. Approximately 500 ml
Inspiratory reserve volume (IRV)
amount of air that can be forcefully inhaled after normal tidal volume inhalation (3000ml)
External reserve volume (ERV)
amount of air that can be forcefully exhaled after the normal tidal volume exhalation. (1200 ml)
Residual Volume (RV)
the amount of remaining in the lungs after maximum exhalation (1300ml)
Vital Capacity (VC)
Maximum amount of air that can be exhaled after a maximal inspiration (4700ml) decrease with age.
what are the three regions of the Pharynx?
nasopharynx, oropharynx, laryngeal pharynx.
The structure of the trachea
4 inches long
located just under larynx anterior to esophagus
moist, smooth tissue called mucosa
Adventitia- outside layer of trachea
Mucociliary Escalator:
the mechanism of debris removal. The mucus traps inhaled particles and the upward beating of the ciliary move it upward.
Anatomy of lungs and bronchial tree
2 lungs:
Right side- 3 lobes 2 fissures (horizontal, oblique)
Left side - 2 lobes 1 fissure (oblique), has cardiac impression
both have apex, base, costal surface (pressed against ribcage), mediastinal surface (face towards the heart)
Hilum - split where lungs have bronchial tubes.
What is the airflow from the trachea to brachial tree?
trachea -> Primary (main) Bronchi -> SEcondary (lober) bronchi -> tertiary (segmental) bronchi -> Bronchioles -> Terminal Bronchioles -> Resp. Bronchioles -> Alveolar Ducts
Bronchial Tree Anatomy
main bronchi- enter lungs
lober bronchi - enter lobes
segmental bronchi - enter segments
10 on right; 8 on left
Pulmonary and Bronchial Circulation
Pulmonary: system of blood vessels that form a closed circuit between the heart and lungs.
Bronchiales: supplies fully oxygenated arterial blood to the lungs themselves.
3 Types Alveoli:
150 millions in each lung.
- Squamos - thin simpler; for gases
- Great - round, repair epithelium produce SULFACTANT (breaks hydrogen bonds)
- Alveolar macrophages - wander around phagocytosis, keep alveoli free of debris 100 million die a day.
Resp Membrane:
thin barrier between alveolar air and blood.
Consists of:
- alveolar cells
- endothelial cells of blood capillary
- very thin film of moisture inside the alveolus
Thickening in membrane:
- diffusion slows down
- not enough O2; too much CO2
- caused by extra fluid
- causes pneumonia
What are the pleura membranes?
Visceral - serous membrane covering lungs
Parietal - adheres to mediastinum, inner surface of rib cage
Pleural Cavity- potential space between pleura contains pleural fluid.
What are the functions of the pleura?
reduce friction, create pressure gradient, compartmentalization
The muscles of respiration and their roles:
Synergists - external intercostals
Forced inhalation- erector spinae, sternocleidomastoid, pectoralis major/minor, serratus anterior
Forced expiration- rectus abdominis and internal intercostals.
What is Valsala Maneuver?
deep breath, holding it and then contracting the abdominal muscles.
Brainstem and the breathing control points.
MEDULLA- sets rhythm
uses VRG and DRG
PONS -modifies/influence the VRG and DRG
-adapts breathing to special circumstances.
Control Chemoreceptors - MEDULLA
responds to pH found in cerebral spinal fluid; not sensitive to O2. MOST IMPORTANT AT 75%
Peripheral CHemoreceptors - Carotid & aortic bodies
Responds to O2 & the pH of blood. 25%
Stretche receptors
inflation reflex: prevent OVER inflation
Irritant Receptors
Responds to smoke, dust, pollen, cold, excess mucus
Cortical Influences (cerbral cortex)
voluntary control over breathing (bypass brainstem)
What is hypercapnia?
High CO2
What are pressure gradients?
air moves from HIgh to LOW.
760mm Hg
anything higher than this is POSITIVE PRESSURE; anything below is NEGATIVE PRESSURE.
What is Boyl’s Law?
if lung volume if higher, pressure is lower (air moves into lungs)
if lung volume is lower, pressure is higher (air moves out of lungs)
Pleura membranes in ventilation
Membranes stick together by cohesion of water.
This allows for inspiration (inhaling).
If there is too much water lung will collapse
How is resistance to airflow caused?
increasing resistance decreases airflow.
1. Bronchiole Diameter
BRONCHODILATION - epinephrine and sympathetic stimulation increase airflow.
BROCHCONSTRICTION - histamine, cold air, parasympathetic system. Suffocation can occur from anaphylactic shock.
2. Pulmonary Compliance- ease with which the lungs or thoracic wall can expand
ANATOMICAL DEAD SPACE
Conducting zone
can be altered by sympathetic (increase dead space but allows greater flow) and parasympathetic (decrease dead space but slower flow)
physiological dead space
Sum of anatomic dead space and any pathological alveolar dead space.
RESP EQUATION
OC2 + H2O = H2CO3 = H* + HCO3
As CO2 unloads moving left pH becomes more alkaline causing hyperventilation.
AS O2 moves right causing pH to be acidic thus causing hypoventilation.
To exhale pressure must be higher.
Composition of air
78.6 Nitrogen, 20.9 O2, 0.04 CO2
PARTIAL PRESSURE
the separate contribution of each gas in a mixture
What Partial Pressure Gas in Exchange
Gases diffuse down their own gradients until the partial pressure of each gas in the air is equal to it’s partial pressure in water.
GAS ALWAYS FLOWS TO WHERE PARTIAL PESSURE IS HIGHER
What factors change the rate of gas exchange.
pressure gradient
resp. membrane surface
resp. membrane thickness- thickness 0.5 um
ventilation-perfusion coupling- the ability to match air flow and blood flow to each other.
VENTILATION PERFUSION COUPLING IN LUNGS
blood vessels change diameter. Poorly ventilated -> constrict well ventilated -> dilate bronchi change diameter well perfused -> bronchodilation poorly perfused ->bronchoconstriction
Most of the CO2 you exhale comes from?
bicarbonate ions transported in RBC
