I. ORAL CAVITY AND PHARYNX
A. SALIVARY GLANDS – outgrowths of the oral epithelium
SALIVARY DUCTS – stalk of each outgrowth 1. PAROTID GLAND
ventrad and craniad of the base of the pinna
PAROTID DUCT
passes across the external surface of the masseter muscle
penetrates the upper lip
2. SUBMAXILLARY GLAND
roundish mass
angle of the jaw near the posterior margin of the masseter
SUBMAXILLARY DUCT
accompanied by the SUBLINGUAL DUCT in cats
pass internal to the digastric and mylohyoid muscle
situated external to the lining of the mouth cavity
runs forward nearly to the symphysis of the mandible and then penetrates the lining
3. SUBLINGUAL GLAND
elongated
surrounds the submaxillary duct 4. MOLAR GLAND
present in cats only
situated between the skin and the external surface of the mandible, in front of the masseter
5. INFRAORBITAL GLAND
lies in the floor of the orbit B. ORAL CAVITY
1. LIPS and CHEEKS
boundary of the oral cavity 2. VESTIBULE
lies between the teeth and lips 3. HARD PALATE
anterior portion of the roof of the oral cavity
supported by the premaxillary, maxillary and palatine bones
mucous thrown into roughened transverse ridges
4. SOFT PALATE
posterior portion of the roof of the oral cavity
lacks bony support OUTLINE
I. Oral cavity and pharynx A. Salivary glands B. Oral Cavity C. Pharynx
II. Hyoid apparatus, larynx, trachea, and esophagus A. Hyoid apparatus
B. Larynx C. Trachea D. Esophagus
III. Pleural and pericardial cavities A. Lungs
B. Heart C. Diaphragm IV. Peritoneal cavity
A. Liver B. Gallbladder C. Stomach D. Spleen E. Small Intestine F. Peyer’s Patches G. Pancreas H. Caecum
I. Large Intestine / Colon J. Rectum
K. Anus
L. Cavities, Ligaments And Mesenteries M. Ducts
5. NASOPALATINE DUCTS
pair of openings found at the anterior end of the hard palate, behind the incisor teeth
connect the mouth and nasal cavities by way of the INCISIVE FORAMINA of the maxillary bones
6. TONGUE
fleshy muscular organ
formed by the fusion of four components:
(a) primary tongue
(b) gland field/ tuberculum impar (c) a pair of lateral lingual swellings 7. FRENULUM
vertical fold
anterior margin of the attachment of the tongue to the floor of the oral cavity
in cats, a fold runs forward from the frenulum on each side within the teeth, and terminates anteriorly in a well-marked flattened papilla which bears the openings of the submaxillary and sublingual ducts
8. FILIFORM PAPILLAE
covers the anterior part of the tongue
hard and spine-like
pointed posteriorly
provided with microscopic taste buds 9. FUNGIFORM PAPILLAE
covers the remainder of the tongue
provided with microscopic taste buds 10. VALLATE PAPILLAE
four to six
arranged in V-shaped row
each consisting of a round elevation set into a pit
at its sides are some very large fungiform papillae
C. PHARYNX – lies posterior and dorsal to the soft palate
1. EPIGLOTTIS
leaf-shaped structure that conceals the pharynx’s free posterior margin
projects from the base of the tongue
guards the entrance into the respiratory tract
2. ISTHMUS OF FAUCES
opening formed by the free border of the palate
leads into the cavity of the pharynx 3. TONSILLAR FOSSA
pits shortly anterior to the free border of the soft palate on each side
contains the palatine tonsil
bounded in front and behind by low folds:
(a) anterior GLOSSOPALATINE ARCH (b) posterior PHARYNGOPALATINE
ARCH 4. PALATINE TONSIL
small mass of lymphoid tissue 5. NASOPHARYNX
revealed dorsal to the soft palate upon slitting along its median line
6. POSTERIOR NARES / CHOANAE
anterior end of the nasopharynx
internal ends of the nasal passages 7. AUDITORY/EUSTACHIAN TUBE
pair of oblique slits posterior to the choanae on the lateral wall of the nasopharynx
canals which connect the pharynx with the cavity of the middle ear
“Because of the formation of the palate and the consequent posterior migration of the posterior nares, the air no longer enters the oral cavity, but proceeds directly into the pharynx”
II. HYOID APPARATUS, LARYNX, TRACHEA, AND ESOPHAGUS
A. HYOID APPARATUS – mammals: derived from the second and third gill arches
– supports the base of the tongue
– serves for the origin and insertion of muscles 1. HYOID BODY
rabbit: stout bone
cat: narrow bar
2. HORNS / CORNUA
rabbit: short processes which are
connected by slender, tendinous muscles with the jugular process of the occipital bone
cat: long and slender ANTERIOR horn,
consist of a chain of four bony pieces, the last which articulates with the tympanic bulla; short POSTERIOR horn united to the larynx
B. LARYNX / VOICE BOX – chamber with cartilaginous wall
– constitutes the projection in the throat, ADAM’S APPLE
1. GLOTTIS
a large opening is situated on the top of the larynx
epiglottis projects from its ventral margin 2. THYROID CARTILAGE
a large shield-shaped cartilage
supports the ventral wall of the larynx
3. CRICOID CARTILAGE
posterior to the thyroid cartilage
forms a ring around the larynx 4. ARYTENOIDS
pair of projecting cartilages
supports the dorsal rim of the glottis between the glottis and the opening of the esophagus
5. TRUE VOCAL CORDS
extends from the arytenoids cartilages to the thyroid cartilages
nearly occlude the opening 6. FALSE VOCAL CORDS
cats: situated lateral to the true vocal cords and extending from the tips of the arytenoids to the base of the epiglottis C. TRACHEA / WINDPIPE – posterior to the larynx
– its walls are stiffened by cartilaginous rings, which are dorsally incomplete, leaving a soft strip in the dorsal wall of the trachea into which the esophagus fits
1. THYROID GLAND
flattened elongated body lying against the trachea and internal to the muscles
anterior end of each lobe is at a level with the cricoid cartilage
2. ISTHMUS
connects the caudal ends of the two lobes
crosses the ventral side of the trachea D. ESOPHAGUS – soft tube which proceeds
posteriorly dorsal to the larynx
III. PLEURAL AND PERICARDIAL CAVITIES MAMMALIAN TRUNK
Divisions:
anterior THORACIC region 3 coelomic cavities:
2 laterally located PLEURAL cavities
1 median PERICARDIAL cavity
posterior ABDOMINAL region
A. LUNGS - composed of innumerable minute air-cells, ALVEOLI
right lung > left lung
divided into 3 lobes:
smaller ANTERIOR
larger MIDDLE
MEDIAL lobe
- projects into a pocket formed by a special, dorsally directed fold of the mediastinal septum, CAVAL FOLD
LATERAL lobe 1. PLEURAL CAVITY/SAC
contains the soft spongy lung 2. MEDIASTINAL SEPTUM
partition which stretches from the heart to the ventral median line
consist of the two medial walls of the right and left pleural sacs in contact with each other
3. MEDIASTINUM
space between the two walls of the mediastinal septum (that separate at the level of the heart)
4. PLEURA
smooth moist membrane lining the pleural sac
Division:
(a) PARIETAL pleura
lines the inside of the pleural cavity
covers the anterior face of the diaphragm
forms the MEDIASTINAL SEPTUM together with the MEDIAL WALL of the other pleural sac
(b) VISCERAL pleura
passes over the surface of the lung to which it is indistinguishably fused
5. CAVAL FOLD
supports the POSTCAVAL VEIN which ascends from the liver to the heart and inclosed in the free dorsal margin of the fold
B. HEART – surrounded by 3 coelomic layers: visceral pericardium, parietal pericardium, and parietal pleura of the mediastinal septum
1. PARIETAL PERICARDIUM
pericardial sac
sac of thin tissue inclosing the heart, attached at its anterior end, where vessels enter and leave the heart
separated from the heart by the pericardial cavity
2. VICERAL PERICARDIUM
invested at the surface of the heart
inseparably adherent to the heart wall
continuous with the pericardial sac at the anterior end
3. PERICARDIAL CAVITY
narrow space between the pericardial sac and the heart
4. THYMUS
mass of gland issue extending forward in the median line ventral to the anterior part of the heart
larger in younger specimen
gland of the internal secretion
derived from the entodermal lining of gill pouches of the embryo
development of cells of the immune system, T-cells
5. RADIX / ROOT
narrow region that serves as the attachment of the lung
artery, vein, bronchus pass to the lung and veins from the lung
6. PULMONARY LIGAMENT
cat: a pleural fold to which the lung is attached (to the dorsal thoracic wall) 7. DORSAL AORTA
large vessel injected which arches away from the heart to the left and descend toward the diaphragm
C. DIAPHRAGM
muscular dome-shaped partition
forms the posterior wall of the pleural sac
separates the pleural from the peritoneal cavity
consist partly of the transverse septum and other coelomic membranes; then invaded by muscle buds from the adjacent cervical myotomes
plays an important role in respiratory movements
ORIGIN: ribs, sternum, vertebrae
INSERTION: central tendon
its center consist of connective tissue forming a circular tendon, CENTRAL TENDON
peculiar to mammals
penetrated by the ESOPHAGUS, AORTA, and POSTCAVAL VEIN
“When contracted, the diaphragm flattens, thus
lengthening the pleural cavities posteriorly and causing air to rush into the lungs.”
IV. PERITONEAL CAVITY – abdominal cavity
its anterior wall is formed by the DIAPHRAGM
lined by a membrane, PERITONEUM Division:
PARIETAL peritoneum
VISCERAL peritoneum / SEROSA
A. LIVER – grayish brown in preserved specimens
convex anterior and concave posterior surfaces
divided into RIGHT and LEFT lobes, each of which is subdivided into MEDIAN and LATERAL
left lateral > right lateral
right medial > left medial
cat: RIGHT LATERAL lobe is deeply cleft
into two lobules
situated between the stomach and the liver is a small CAUDATE lobe
secretes bile, stores and filters blood, and takes part in metabolic functions, for example, the conversion of sugars into glycogen.
B. GALLBLADDER – imbedded in the right median lobe
rabbit: on its dorsal surface
cat: cleft
storage and concentration of bile C. STOMACH
1. CARDIA
area of junction of the stomach and esophagus
2. CARDIAC END
region adjacent to the cardia 3. FUNDUS
saclike bulge to the left of the cardia 4. BODY
5. PYLORUS
area of junction of the stomach and small intestine
6. PYLORIC VALVE
thickened ridge inside the pylorus 7. PYLORIC END
constriction, beyond which the small intestine makes an abrupt bend
8. GREATER CURVATURE
larger, convex posterior surface of the stomach from the cardia to the pylorus 9. LESSER CURVATURE
shorter slightly concave anterior surface 10. RUGAE
marked ridges in the wall of the stomach D. SPLEEN – attached to the left border of the
stomach
helps to destroy old red blood cells, form lymphocytes, and store blood
E. SMALL INTESTINE
1. DUODENUM
supported by a part if the dorsal mesentery, the MESENTERY PROPER 2. JEJUNUM
3. ILEUM 4. VILLI
fingerlike projections of the mucous membrane
5. ILEOCOLIC VALVE
elevation projecting into the ileum F. PEYER’S PATCHES – aggregations of lymph
nodules present in the wall of the intestine
thickened oval light-colored spots along the colon
G. PANCREAS – definite, compact, pinkish gland
secretes juices into the small intestine
secretes hormones, glucagon, insulin and somatostatin into the blood stream
H. CAECUM – marks the junction of small and large intestine
vermiform appendix absent I. LARGE INTESTINE / COLON
passes forward as the ASCENDING COLON; then urns and extends across the peritoneal cavity from right to left as the TRANSVERSE COLON; then turns abruptly at the left and proceeds straight posteriorly as the DESCENDING COLON
extract water and form feces J. RECTUM
terminal portion of the descending colon K. ANUS
opening at the lower end of the alimentary canal through which feces are released L. CAVITIES, LIGAMENTS AND MESENTERIES
1. MESENTERIES / LIGAMENTS
– double-walled membranes formed by the peritoneum
(a) DORSAL mesentery
specifically, the MESENTERY
PROPER, supports the
duodenum
intact in mammals (b) VENTRAL mesentery
persist in the region of the liver and urinary bladder
2. MESOGASTER
passes over the stomach
forms the visceral peritoneum of the stomach
incloses the stomach between its walls 3. GREATER OMENTUM
owes its origin in part to the rotation of the stomach
its line of attachment to the greater curvature is original dorsal surface of the stomach, while the lesser curvature is the original ventral surface
4. GASTROHEPATODUODENAL LIGAMENT/ LESSER OMENTUM
passes from the lesser curvature of the stomach to the posterior surface of the liver
Division:
(a) GASTROHEPATIC LIGAMENT
from the lesser curvature to the liver
its portion which contains the caudate lobe forms a LESSER PERITONEAL SAC which continues anteriorly the cavity of the greater omentum
(b) HEPATODUODENAL LIGAMENT
from the liver to the duodenum
in which the common bile duct passes to the intestine
HEPATIC PORTAL VEIN
has a free border which forms the ventral rim of an opening or slit, FORAMEN EPIPLOICUM, which serves as the entrance into the cavity of the omentum
5. GASTROSPLENIC / GASTROLIENAL LIGAMENT
portion of the great omentum between the spleen and the stomach
6. GASTROCOLIC LIGAMENT
secondary fusion formed between the mesogaster ant the mesentery of the intestine
7. FALCIFORM LIGAMENT
extends from between the two median lobes of the liver to the median ventral line
thin sheet with concave posterior border 8. CORONARY LIGAMENT
stout ligament
attaches to the liver to the central tendon of the diaphragm
circular in form and its ring of
attachment to the liver bounds a small space on the anterior face of the liver which is free from serosa
9. MESODUODENUM
part of the dorsal mesentery
supports the duodenum 10. DUODENORENAL LIGAMENT
attaches the duodenum to the right kidney
M. DUCTS
1. COMMON BILE DUCT
bounds the duodenum to the liver
cystic duct + hepatic duct
2. BILE DUCT
runs in the hepatoduodenal ligament 3. CYSTIC DUCT
from the gall bladder 4. HEPATIC DUCT
from the lobes of the liver
5. PANCREATIC DUCT
(a) principal duct – joins the common bile duct at the point where the latter enters the duodenum
(b) secondary/accessory duct – enters the duodenum
6. AMPULLA OF VATER
slightly swollen chamber where bile and pancreatic ducts unite
