Untitled Flashcards Set

Diaphragm

Prime mover of respiration; contraction flattens diaphragm, enlarging thoracic cavity, pulling air into lungs.

External Intercostals

Muscles that stiffen thoracic cage, prevent inward collapse during inspiration, contributing about 1/3 of air inhaled.

Scalenes

Muscles that fix or elevate ribs 1 and 2, assisting in inspiration.

Erector spinae, pectoralis major and minor, serratus anterior that increase thoracic volume during forced inhalation.

Accessory Muscles in Forced Respiration

Abdominal Muscles in Forced Expiration

Increase abdominal pressure by pushing viscera against diaphragm, aiding in forced expiration.

Brainstem Centers for Breathing

Ventral respiratory group generates rhythm, dorsal respiratory group modifies rate and depth, pontine respiratory group adapts breathing to activities.

Boyle's Law

At constant temperature, gas pressure is inversely proportional to volume; increase in lung volume causes air to flow in.

Inhalation Process

Thoracic cavity expands, lung volume increases, intrapulmonary pressure drops below atmospheric pressure, allowing air to flow in.

Exhalation Process

Thoracic cavity contracts, lung volume decreases, intrapulmonary pressure rises above atmospheric pressure, causing air to flow out.

Bronchodilation Causes

Sympathetic stimulation and epinephrine increase bronchiole diameter, reducing resistance and increasing airflow.

Bronchoconstriction Causes

Parasympathetic nerves, histamine, cold air, irritants decrease bronchiole diameter, increasing resistance and reducing airflow.

Pulmonary Compliance

Ease of lung expansion, influenced by elasticity of lung tissue and surface tension in alveoli.

Surface Tension in Alveoli

Surfactant reduces surface tension, prevents collapse, and maintains airflow in alveoli.

Anatomical Dead Space

Air in the conducting zone that doesn't participate in gas exchange, approximately 150 mL.

Alveolar Ventilation Rate (AVR) Calculation

AVR = (Tidal volume - Dead space) × Respiratory rate.

Tidal Volume (TV)

Volume of air inhaled and exhaled in one breathing cycle, approximately 500 mL.

Inspiratory Reserve Volume (IRV)

Additional air inhaled with maximum effort, approximately 3,000 mL.

Expiratory Reserve Volume (ERV)

Additional air exhaled with maximum effort, approximately 1,200 mL.

Residual Volume (RV)

Air remaining in lungs after maximum expiration, approximately 1,300 mL.

Vital Capacity (VC) Calculation

Max air exhaled after max inhalation: VC = TV + IRV + ERV, approximately 4,700 mL.

Inspiratory Capacity (IC) Calculation

Max air inhaled after tidal expiration: IC = TV + IRV, approximately 3,500 mL.

Functional Residual Capacity (FRC) Calculation

Air remaining in lungs after tidal expiration: FRC = RV + ERV, approximately 2,500 mL.

Total Lung Capacity (TLC) Calculation

Max air lungs can hold: TLC = RV + VC, approximately 6,000 mL.

primary bronchus (1°)

feeds air to 1 lung

secondary bronchus (2°)

feeds air to 1 lung lobe

tertiary bronchus (3°)

feeds air to 1 lung segment

cardiac notch

why is there only 2 lobes on the left lung

c-shaped rings

is the primary bronchi supported by cartilage plates or hyaline cartilage c-shaped rings

cartilage plates

is the secondary bronchi supported by cartilage plates or hyaline cartilage c-shaped rings

cartilage plates

is the tertiary bronchi supported by cartilage plates or hyaline cartilage c-shaped rings

bronchopulmonary segment

functionally independent unit of the lung tissue that allows for parts of the lung to be removed and still maintain ability to function

true

true or false smaller space is better for gas diffusion

conduction zone

movement of air

respiratory zone

the exchange of gas

squamous alveolar cells (stationary), great alveolar cells (stationary), alveolar macrophages (wandering)

name the cells of the alveolus and which are stationary and wandering

respiratory cycle

one complete inspiration and expiration

yes

does an increased surface area = increased gas exchange

spirometer

what measures the force of exhale

partial pressure

concentration of gas not liquids

Hb + H^+ = releasing O2

chloride shift during the systemic gas exchange

Hb - H^+ = bind O2

CO2 unloading during alveolar gas exchange

7.35 - 7.45

arterial blood level of pH

40 mm Hg

arterial blood level of PCO2

95 mm Hg

arterial blood level of PO2

pH

the most potent stimulus for breathing

acidosis

blood pH lower than 7.35

alkalosis

blood pH higher than 7.45

hypocapnia

PCO2 less than 37 mm Hg

most common cause of alkalosis

hypercapnia

PCO2 greater than 43 mm Hg

most common cause of acidosis

ischemic hypoxia

inadequate circulation of blood

anemia hypoxia

due to anemia resulting from inability of blood to carry enough oxygen

histotoxic hypoxia

metabolic poisons such as cyanide prevent tissues from using oxygen

cyanosis

blueness of skin (sign of hypoxia)

small cell carcinoma

most dangerous lung cancer