respiratory system

Question 1

functions of the respiratory system

Answer 1

• gas exchange (O2, CO2 between air, blood)
• speech and other vocalization
• olfaction (smell)
• helps controls pH of body
• aids in regulation of blood pressure by assisting angiotensin II production
• helps create pressure gradients for flow of lymph and venous blood
• expulsion of abdominal contents (holding breath while contracting abdominal muscles) during urination, defecation, and childbirth

Question 2

correct order of structures through with air flows into the respiratory tract

Answer 2

• air first enters the upper respiratory tract from the nose –> pharynx –> larynx
• then enters the lower respiratory tract from the trachea –> bronchi –> lungs (tubes then lead to the alveoli – diffuse)

Question 3

upper and lower respiratory tracts

Answer 3

• upper respiratory tract: consists of the respiratory organs of the head and neck, extending from the nose through the larynx
• lower respiratory tract: consists of the respiratory organs of the thorax, including the trachea, bronchi, and lungs

Question 4

boundary between the upper and lower respiratory tracts

Answer 4

larynx forms the entrance of the lower respiratory tract with the help of the epiglottis to prevent food or liquid from entering

Question 5

central chemoreceptors

Answer 5

• brainstem neurons that monitor pH and CO2 and O2 concentrations in the blood and CSF
• located near the surface of the medulla oblongata
• examples: aortic and carotoid bodies

Question 6

peripheral chemoreceptors

Answer 6

neurons in wall of aorta and carotid arteries that respond to pH, O2, and CO2 content of blood

Question 7

higher brain centers that influence respiration

Answer 7

the limbic system, hypothalamus and cerebral cortex influence the respiratory centers

Question 8

rhythm of unconscious breathing

Answer 8

set by nuclei in the medulla and pons

Question 9

medulla

Answer 9

2 respiratory nuclei in the medulla:
- ventral respiraory group: consists of neurons that set the basic cycle of inspiration and expiration
- dorsal respiratory group: receives input from the pontine respiratory group, chemoreceptors, and stretch receptors in the lungs. It modifies output from the ventral respiratory group to adjust breathing rhythm

Question 10

pons

Answer 10

contain the pontine respiratory group that modifies breathing rate to adapt to sleep, exercise, vocalization, and emotional responses

Question 11

roles of the diaphragm in breathing and its position in relation to the lung

Answer 11

function:
- prime mover of pulmonary ventilation
- contraction pulls it down and enlarges thoracic cavity for inspiration
- relaxes for expiration
- stimulated by phrenic nerve to relax

position:
- located inferior to the thoracic cavity

Question 12

epiglottis

position and function

Answer 12

• flap guarding the glottis, which is the superior opening to the larynx
• helps keep food out of the airway

Question 13

asthma

Answer 13

results from allergic reactions that stimulate intense bronchoconstriction and airway inflammation

obstructive disorders narrow the airways and interfear with airflow

Question 14

COPD: chronic obstructive pulmonary disease

Answer 14

includes chronic bronchitis, emphysema, and asthma

• chronic bronchitis and emphysema are usually caused by smoking cigarettes
• chronic bronchitis is associated with repeated respiratory infections where the airway is congested with sputum
• emphysema leads to the breakdown of alveolar walls and a loss of surface area for gas exchange

obstructive disorders narrow the airways and interfear with airflow

Question 15

effect of sympathetic and parasympathetic innervation to the lungs

Answer 15

• parasympathetic: (state of relaxation) keeps bronchioles partially constricted
• sympathetic: (state of exercise) dilates the bronchioles and increases airflow