Human Physiology: The Respiratory System just the notes

These flashcards cover key concepts related to the respiratory system, highlighting definitions and processes crucial for understanding human physiology.

Oxygen transport

98.5% as oxyhemoglobin, 1.5% as dissolved gas in plasma.

Carbon dioxide transport

7% as dissolved gas in plasma, 23% bound to hemoglobin and proteins, 70% as bicarbonate ion.

External respiration

Gas exchange occurring in the lungs between air in alveoli and blood in capillaries.

Internal respiration

Gas exchange occurring between systemic capillaries and body tissue cells.

Pressure gradient

The driving force that facilitates the diffusion of gases during respiration.

Boyle’s Law

Describes the inverse relationship between volume and pressure of gases.

Diaphragm

Main muscle of inspiration that helps expand the thoracic cavity.

Elastic recoil

The tendency of lung tissue to spring back after being stretched during inhalation.

Labored breathing

Occurs when greater oxygen intake is needed, involving accessory muscles.

Dorsal respiratory group (DRG)

Neurons in the medulla that control the basic rhythm of breathing.

Ventral respiratory group (VRG)

Neurons that activate both inspiratory and expiratory muscles during forceful breathing.

Central chemoreceptors

Monitor CO₂ and pH levels in cerebrospinal fluid to regulate breathing.

Peripheral chemoreceptors

Detect changes in blood O₂ and CO₂ levels to signal adjustments in respiratory rate.

Hering-Breuer Reflex

Inhalation reflex preventing overstretching of the lungs.

Proprioceptors

Sensory receptors that monitor muscle activity and adjust breathing during exercise.

Irritant receptors

Stimuli that initiate sneezing or coughing reflexes for clearing irritants.

Dorsal respiratory group (DRG)

Neurons that activate the diaphragm and external intercostal muscles during their most active stage.

Ventral respiratory group (VRG)

Neurons that activate accessory muscles for forceful inhalation and exhalation.

Forceful inhalation

Occurs when the diaphragm and accessory muscles of inhalation (sternocleidomastoid, scalene, pectoralis minor) contract.

Forceful exhalation

Occurs when accessory muscles of exhalation (internal intercostal, external oblique, internal oblique, transverse abdominis, rectus abdominis) contract.

Accessory muscles of inhalation

Muscles that assist in inhalation during forceful breathing, including sternocleidomastoid, scalene, and pectoralis minor.

Accessory muscles of exhalation

Muscles that assist in exhalation during forceful breathing, including internal intercostal, external oblique, internal oblique, transverse abdominis, and rectus abdominis.

Normal Inhalation

Dorsal respiratory group (DRG) sends the signal (+) to Diaphragm (contract). External intercostal (contract) for 2 sec.

Normal Exhalation

Ventral respiratory group (VRG) stops the signal (-) to Diaphragm (relax). External intercostal (relax) for 3 sec.

Labored Inhalation

Dorsal respiratory group (DRG) sends the signal (+) to Diaphragm (contract), External intercostal (contract), Sternocleidomastoid (contract), Scalene muscles (contract), Pectoralis minor (contract) for more than 2 sec.

Labored Exhalation

Ventral respiratory group (VRG) stops the signal (+) to Diaphragm (relax), External intercostal (relax), Sternocleidomastoid (relax), Scalene muscles (relax), Pectoralis minor (relax) for more than 3 sec.