Week 8
Post-Lecture Activity
RESPIRATORY SYSTEM
by GEORGETTE E. ZALDIVAR
Briefly explain the main cause or mechanism of increase in respiratory rate or depth and/or respiratory difficulties in the following cases: (one to two sentences only).
1. Initiation of exercise
Primarily due to neural alterations, the dorsal respiratory group (DRG) of the medullary respiratory center in the medulla receives excitatory impulses at the initiation of exercise, which causes respiration to rise suddenly. The changes include stimulation of the limbic system; sensory impulses from the muscles, tendons, and joints; and motor impulses from the primary motor cortex.
2. Moderate exercise
The increase in respiratory rate during moderate exercise is brought on by chemical and physical alterations in the bloodstream, including a slight drop in PO2 because of an increase in O2 consumption; an increase in PCO2 because of an increase in CO2 produced by contracting muscle fibers; and an increase in temperature because more heat released upon the increased use of O2.
3. Asthma attack
The hallmarks of asthma include chronic airway inflammation, hypersensitivity to stimuli, and airway obstruction. These symptoms may be attributed to a variety of factors, including edema of the airway mucosa, increased mucus secretion, injury to the airway epithelium, and smooth muscle spasms in the walls of smaller bronchi and bronchioles.
4. Abrupt ascent into high altitudes
The neurological system, which is controlled by impulses from the respiratory centers, regulates breathing. The peripheral chemoreceptors sense when there is a lack of oxygen due to an abrupt ascent into high altitudes and, in turn, cause hyperventilation.
5. Pneumonia
When particular microbes invade the lungs of vulnerable individuals, they release harmful chemicals that trigger immunological reactions and inflammation with detrimental side effects. The toxins and immunological response damage alveoli and bronchial mucous membranes; edema and inflammation cause the alveoli to swell with fluid, impairing ventilation and gas exchange.
6. Paralysis of phrenic nerve
Paralysis on the phrenic nerve will sequentially cause paralysis in the diaphragm, resulting in diminished breathing capacity, the inability to control voluntary breathing, and weakening of the diaphragm. Due to the lungs' diminished ability to adequately take in and expel outside air, they also struggle to maintain sufficient gas exchange.
7. Severe tuberculosis with resulting lung scar tissue
The occurrence of tuberculosis may leave behind resulting lung tissue, or fibrosis, which causes the body to have trouble transporting oxygen from the lungs into the bloodstream because of the thicker lung tissue. Moreover, the inflammation also reduces airflow in the lungs, resulting in breathing difficulties and increased rapid breathing to regulate the oxygen flow.
8. Severe anemia
Hyperventilation and a rapid heartbeat are signs of rather severe anemia or hemoglobin deficiency. These symptoms are brought on by the body's ongoing efforts to return oxygen levels to normal.
9. Advanced COPD (chronic obstructive pulmonary disease)
Advanced COPD, or chronic obstructive pulmonary disease, tends to result in alterations in oxygen and carbon dioxide levels in the blood or lungs; hence, in cases of low blood oxygen levels, the body may respond with rapid breathing to obtain the lacking oxygen. When the respiratory rate exceeds 25 bpm, it is thought to be COPD exacerbation signs; because the typical range of respiratory rate in people is 12–20 bpm.
10. Advanced pregnancy
Fluctuations in hormone levels of pregnant women cause vicissitudes in pulmonary function during advanced pregnancy. The continually expanding uterus limits lung expansion, which results in even faster breathing.
REFERENCES:
An Overview of Tachypnea in COPD. (2020). Verywell Health. https://www.verywellhealth.com/tachypnea-function-and-treatment-914914
Diaphragmatic Weakness & Paralysis. (n.d.). Columbia Surgery. Retrieved November 3, 2022, from https://columbiasurgery.org/conditions-and-treatments/diaphragmatic-weakness-paralysis
Lee, R. C. (2014). Respiration in man at high altitudes. https://open.bu.edu/handle/2144/7499
Tortora, G. J., & Derrickson, B. H. (2013). Principles of Anatomy and Physiology, 14th Edition (14th ed.). Wiley.