Organs of Respiration in the Cat

Organs of Respiration in the Cat

Examine these slide at low power first to find the field which best demonstrates the listed features. Label the indicated features, and briefly describe their functions.

Locate and examine the following organs of the respiratory tract in the cat. Review the function of each as you locate them.

Here is an image of fresh lungs deflated and then inflated to show the dramatic difference in volume.

(See Gilbert, Pictorial Anatomy of the Cat, pp 37-41)

Make three illustrations:
1) anterior view of entire respiratory system
2) view down into larynx
3) mid-sagittal section of head

1)  ANTERIOR VIEW OF WHOLE SYSTEM

 

Respiratory_Overview_P4210172_sm

Click to see a labeled view of the system.

thyrohyoid_memb_P4224027

Clear away muscles to see: (Here is a labeled anterior view of the larynx.)
thyrohyoid membrane (connects the larynx to the hyoid bone)
larynx
thyroid cartilage (largest of the laryngeal cartilages, forms the front of the larynx)
cricoid cartilage (ring shaped cartilage upon which the larynx sits)
trachea
tracheal rings
esophagus (behind trachea)

bronchus_P4224026

R & L pleural cavities (Here is a labeled view of the thoracic respiratory organs.)
anterior lobes of R & L lungs (termed superior lobes in human)
middle lobes of R & L lungs (termed middle in human, L lacking)
posterior lobes of R & L lungs (termed inferior lobes in human)
pericardium
root of the lungs
bronchi (behind heart, esp on R side)
pulmonary ligament, attached to:
diaphragm
phrenic nerve
heart lung preparation

heart_lung_prep_P1010064

In butchering, the heart and lung are removed from the thorax as a unit. These images show the heart nestled between the right and left lungs of a goat.

Here are images of the same preparation inflated (1), and inflated (2).

2)  VIEW DOWN INTO LARYNX


Make a transverse cut through the thyrohyoid membrane and esophagus well above the top of the larynx. Do not cut the epiglottis. Lift the larynx up out of the throat. Snip the esophagus to open it up to below the larynx.
Draw:
epiglottis
arytenoid cartilage
false vocal cords
vocal cords
glottis
esophagus

Here is a labeled view down into the larynx.

3)  MID-SAGITTAL SECTION THROUGH THE HEAD AND NECK: (p. 39 in Gilbert)

Students may make this cut in order to view the following set of features. First, taking care to be exactly mid-sagittal, make a clean cut with a sharp scalpel through successive soft tissues of the tongue (from below) and pharynx to bone (through the neck to the vertebral column), then use a sharp hacksaw to cut through skull and vertebra. Wash the cut surfaces to view the features more clearly. Note that one half will show the nasal septum, the other the conchae.

If you do not make this cut, view a cat which has been so prepared. Each student should locate the following features on this mid-sagittal section:


external nares (external nose openings)
nasal conchae
hard palate
soft palate
eustachian tube opening (near the sella turcica)
nasopharynx (“pharynx” in cat)
sphenoid sinus (directly above nasopharynx)
palatine tonsils (lateral rear wall of the mouth)
genioglossus muscle (main muscle of tongue)
fenulum (membrane ties tongue down)
Here is a labeled view of a midsagittal section of the head.

 

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