The Respiratory System - Flashcards (30 QA)

30 practice flashcards covering key concepts from the respiratory system lecture notes.

What is respiration?

The exchange of respiratory gases (O2 and CO2) between an organism and its environment to meet energy requirements.

What are the primary and secondary functions of the respiratory system?

Primary: bring O2 into the body and CO2 out; Secondary: phonation, temperature regulation, acid-base balance, sense of smell; works with the cardiovascular system.

What is external respiration?

Exchange of O2 and CO2 between inhaled air and pulmonary capillaries.

What is internal respiration?

Exchange of O2 and CO2 between blood in systemic capillaries and body cells.

Which structures comprise the upper respiratory tract?

Nose (external nares and nasal cavity), pharynx, and larynx.

What is the function of the larynx?

Protects the lower airways, facilitates respiration, and enables phonation (voice production).

What are the four layers of the tracheal wall?

Mucosa, submucosa, hyaline cartilage rings, and adventitia.

What is the role of the epiglottis?

Covers the laryngeal inlet during swallowing to prevent food from entering lower airways.

What is the diaphragm's role in breathing?

Contracts to increase thoracic volume during inspiration, lowering pressure to draw air in; relaxes during expiration.

What characterizes avian respiration?

Nine air sacs; unidirectional airflow; lungs hold air; no diaphragm; air flow regulated by sternum and ribs; unidirectional flow enables efficient gas exchange.

Describe the sequence of air flow in a bird’s breathing cycle.

Inhalation to posterior air sacs; exhalation to lungs; second inhalation to anterior air sacs; second exhalation from anterior air sacs through the trachea.

Why is unidirectional airflow advantageous in birds?

It provides a continuous supply of fresh, oxygen-rich air through the lungs for efficient gas exchange.

What are the amphibian respiration modes discussed?

Cutaneous respiration (through skin), buccal respiration (mouth cavity), and pulmonary respiration (lungs used as needed).

What is cutaneous respiration?

Gas exchange through moist, highly vascularized skin.

How does buccal respiration work in frogs?

The floor of the mouth moves to draw air in and out; nostrils open; glottis closed during buccal respiration; predominate resting breathing.

Do frogs have ribs or a diaphragm?

No; frogs lack ribs and a diaphragm; ventilation is via buccal pumping.

What is notable about snakes' lungs?

Right lung is fully formed; left lung is vestigial; head-end portion handles gas exchange; tail-end acts as an air sac; aquatic snakes may use the left lung for buoyancy.

How are dog and cat lungs lobed?

Left lung has cranial and caudal lobes with a shared cranial lobar bronchus; Right lung has cranial, middle, caudal, and accessory lobes.

What composes the alveolar membrane?

Alveolar lining fluid with surfactant, epithelial layer and basement membranes, thin interstitial space, capillary basement membrane, and capillary endothelial membrane (0.2–0.6 μm thick).

What are the three major alveolar cell types?

Alveolar macrophage, Type I pneumocytes, Type II pneumocytes.

What is the role of Type II pneumocytes?

Produce pulmonary surfactant to lower surface tension and can differentiate to replace damaged Type I cells.

What is the role of alveolar macrophages?

Phagocytic cells that move within the alveolar lumens and connective tissue to clear debris.

What is the trachea's cartilage structure?

C-shaped rings of hyaline cartilage with gaps filled by the trachealis muscle; lined by ciliated pseudostratified epithelium with goblet cells.

What distinguishes bronchi from bronchioles?

Bronchi have cartilage rings; bronchioles lack cartilaginous support and are smaller; bronchi primarily conduct air, bronchioles conduct air and gas exchange.

Describe the bronchial branching pattern.

Primary bronchi from the trachea; secondary bronchi in the lungs; tertiary bronchi near the bottom; diameters decrease from primary to tertiary.

What is the flow of air from trachea to alveoli?

Trachea → primary bronchi → secondary bronchi → tertiary bronchi → bronchioles → alveolar ducts → alveoli.

How are fish gills structured for gas exchange?

Gill arches with filaments and lamellae; lamellae contain capillaries; large surface area facilitates diffusion; water flows over gills.

What is counter-current exchange in fish gills?

Blood in gill capillaries flows opposite to the water flow in lamellae, maximizing the diffusion gradient for O2 uptake.

What is the main advantage and limitation of the fish gill system?

Advantage: unidirectional flow and counter-current diffusion enable efficient O2 uptake with less water movement; Limitation: gills require water and cannot function in air.

What is respiratory-locomotor coupling in horses?

One breath per stride during movement; nasal breathing accounts for a large portion of airway resistance during exercise; breathing and stride are linked.