The Respiratory System - Veterinary Comparative Anatomy

These flashcards cover key concepts from the lecture on the respiratory system in veterinary comparative anatomy, focusing on the anatomy and functions of the larynx, trachea, lungs, and air sacs across different species.

What is the structure of the lower respiratory tract?

A short, bilaterally symmetrical, tube-shaped musculocartilagenous organ consisting of several cartilages.

What are the functions of the larynx?

Protection, vocalization, and swallowing (epiglottis).

What is the innervation of the larynx?

Cranial laryngeal nerves (mucous membrane of larynx) and caudal laryngeal nerves (laryngeal muscles except cricothyroideus).

How does the epiglottis vary among different species?

Sharp-pointed in carnivores and horses, rounded in ruminants and pigs.

Which cartilages form the larynx?

Cricoid, thyroid, epiglottis, and arytenoids.

What structures are found in the laryngeal cavity?

Lateral laryngeal ventricle in dogs and horses, median laryngeal recess in pigs and horses.

What connects the trachea to the lungs?

The primary bronchi.

What defines the trachea's structure?

Consists of a series of C-shaped hyaline cartilages connected by ligaments.

How does the trachea compare among different species?

It varies in length and the number of cartilaginous plates—ox and sheep have 48-60 plates.

What is the significance of the tracheal bronchus?

It supplies the cranial lobe of the right lung.

What is the main function of the syrinx?

Vocalization, located at the tracheal bifurcation.

What distinguishes avian lungs from mammalian lungs?

Bird lungs are small, unlobed, and do not have pleural cavities or alveoli.

What are air sacs in birds?

Blind, thin-walled extensions of the bronchial system that aid in respiration.

How many air sacs do most birds have?

Typically 9 air sacs, with only the clavicular one being unpaired.

What is the function of air sacs in birds?

They act as bellows during respiration for continuous airflow.

What are the two types of parabronchi in avian lungs?

Paleopulmo and neopulmo.

What muscles control the vocal folds?

Lateral cricoarytenoid muscle and cricothyroid muscle.

How do bird air capillaries function?

They allow for a continuous flow of gas exchange, not terminating like mammalian alveoli.

What major blood flow arrangement do avian lungs have?

Crosscurrent arrangement for efficient gas exchange.

What is the primary bronchus?

The first branch from the trachea leading to the lungs.

What does the cricoid cartilage resemble?

A signet ring shape.

What separates the openings of the primary bronchi?

Pessulus, a short vertical bar in the syrinx.

Which species has a more complex syringeal apparatus?

Passeriformes (songbirds) with more pairs of syringeal muscles.

What role does the sternotrachealis muscle play?

It helps pull the trachea toward the syrinx to facilitate vocalization.

What unique feature do avian air sacs provide to the body?

Lightness and lowering of the center of gravity for improved flight stability.

How does the weight of horse lungs compare to cattle lungs?

Horse lungs weigh approximately 12-13 lb (6 kg); cattle lungs weigh about 7.5 lb (3.5 kg).

What is a notable anatomical feature of the trachea of long-necked bird species?

It is often longer than the neck.

What connects the air sacs in birds to the bronchi?

The cranial and caudal groups of air sacs are connected to the ventral and primary bronchi respectively.

What is the main difference between air sacs and lungs in birds?

Air sacs are not involved in gas exchange but help to facilitate airflow through the lungs.

What are the names of the lobes in the lungs of pigs?

Left cranial lobe, left caudal lobe, right cranial lobe, middle lobe, and right caudal lobe.

Which lobe is often associated with the tracheal bronchus?

Right cranial lobe.

Where are the pulmonary lymph nodes located?

Around the bronchial tree of the lungs.

What kind of cartilage is found in the trachea of different species?

Hyaline cartilage, C-shaped in form.

What anatomical feature helps birds to cool down during flight?

Air sacs, which facilitate the evaporation of heat.

What happens when food particles obstruct the larynx?

Reflex muscular action closes the entrance to the larynx.

How many lobes does the horse lung have?

2 lobes with varying anatomy compared to the cow.

What distinguishes the right lung from the left lung in mammals?

The right lung typically has more lobes than the left lung.

Why are the Bifurcation and carina important?

They mark where the trachea splits into the primary bronchi.

How many secondary bronchi does a chicken approximately have?

40 to 50 secondary bronchi.

What is the significance of the epiglottic cartilage?

It prevents food from entering the larynx during swallowing.

What do the vocal ligaments do?

They vibrate to produce sound.

Where does the trachea extend from and to?

From the cricoid cartilage of the larynx to its bifurcation.