Physiology Flashcards
Nerve: major output of the PNS
Vagus n./CN X – feeds thorax and upper abdomen (75% of nerve fibers)
Describe the nerve structure of the SNS
Nerves pass from SC into paravertebral chain ganglions and on to post-ganglionic nerves that reach the viscera
Reenter via gray rami
Spinal Level: pre-ganglionic cardiac and pulmonary sympathetic fiber origin
T1-5
List the NTs for the PNS and SNS
PNS: Acetylcholine/Cholinergic (post-ganglionic)
SNS: Norepinephrine/Adrenergic (post-ganglionic)
List the function of the cholinergic and adrenergic NTs
Cholinergic = calming/relaxing
Adrenergic = gear up the system
List the subtypes of cholinergic NTs
- Muscarinic (post-synaptic and effector)
- Nicotinic (pre/post-synaptic in ANS)
List the subtypes of Adrenergic NTs
Alpha 1 = vascular smooth mm; vasocon (PNS)
Alpha 2 = decrease SNS discharge (PNS)
Beta 1 = atria, SA node, ventricles (SNS)
Beta 2 = bronchial smooth mm; bronchodil (SNS)
Term: breathing
pulmonary ventilation
Describe how air move in/out with inspiration/expiration
Inspiration: diaphragm contracts and is pulled down, the increased volume of the lung decreases the pressure in the lungs and air flows from the high pressure (environment) to the low pressure (lungs)
Expiration: diaphragm recoils and moves up, the decreased volume of the lungs increaes the pressure in the lungs and air flows from the high pressure (lungs) to the low pressure (environment)
Term: difference between the amount of oxygen in the arterial and venous systems
A-V O2 difference
Term: where gas exchange does not occur
Anatomic dead space
Term: volume of air normally exhaled/inhaled per breath
Tidal Volume (VT)
Term: Additional volume take in (beyond tidal volume)
Inspiratory reserve volume (IRV)
Term: Additional volume let out (beyond tidal volume)
Expiratory reserve volume (ERV)
Term: Volume of air that remains in the lungs after a forceful expiratory effort
Residual volume (RV)
Describe what would occur if you had not RV
You lungs would collapse
Describe what happens to RV in conditions like chronic bronchitis and emphysema
Air trapping increases RV
Term: Maximum amount of air that can be inhaled after a normal tidal exhalation; VT + IRV
Inspiratory capacity (IC)
Term: amount of air remaining in the lungs at the end of a normal tidal exhalation; ERV + RV
Functional residual capacity (FRC)
Describe what FRC represents
The point at which the forces tending to collapse the lungs are balanced against the forces tending to expand the chest wall
Term: maximum amount of air that can be exhaled following a maximum inhalation, IRV + ERV
Vitcal capacity (VC)
Term: product of tidal volume and respiratory rate
Minute ventilation VE
Term: amount of air blown out over time
Forced expiratory volume (FEV)
Term: amount of air blown out in the 1st second
FEV1
Term: maximum volume of air exhaled from a full inhalation (exhaling as forcefully as you can)
Forced vital capacity (FVC)
List FEV, FVC, and FEV/FVC ratios
- normal
- obstructive disease
- restrictive disease
- FEV = 4.0; FVC = 5.0; 80%
- FEV = 1.3; FVC = 3.1; 42%
- FEV = 2.8; FVC = 3.1; 90%
Explain why the FEV/FVC ratio is high for restrictive disease and low for obstructive disease
High: b/c you have a hard time getting air in; but they can get air out
Low: b/c you can’t get all the air out
List the normal values
- pH
- HCO3
- PCO2
- 7.4
- 22-26 mEq/L (high = basic)
- 35-45 mmHg (high = acidic)
Describe the carbonic acid-bicarbonate buffering system
The body can compensate for altered pH through 2 systems
- lungs: blow off/hold CO2 (short term)
- kidneys: absorb/regenerate bicarb (long term)
Describe control of ventilation
2 main regulatory centers: medullary inspiration and expiration center establish rate and depth of breathing
The cortex can override these centers for active expiration
Receptor location: detect CO2 or O2 levels in the blood
Brain, carotid bodies, aortic bodies
** result in inc/dec rate of breathing
Receptor location: detect increased fluid in lung tissue
Alveoli
** result: rapid, shallow breathing
Receptor location: detect physical activity
Joints/mm
** Result in inc breathing rate
Type of receptor: sensitive to changes in PO2, PCO2, H+
Peripheral chemoreceptors
Type of receptor: sensitive to acute stretch of alveoli, act as a safety mechanism to decrease duration of inspiration
lung receptors
Type of receptor: sense movement in skeletal mm
mechanical receptors
REVIEW METABOLIC/RESPIRATORY ACIDOSIS/ALKYLOSIS CHART
YOU’LL DO IT
Term: an abnormally low concentration of oxygen in the blood
hypoxemia
Term: deficiency in the amount of oxygen reaching the tissues
hypoxia
