Scientific Name: Sus scrofa
Order: "artiodactyla" (even-toed mammals)
gestation period - 4 months
fetal pigs in lab are between 80-100 days old with well developed organ systems
External Anatomy of the Fetal Pig
Eyelid, Pinna, External Nares, Vibrissae, Digits, Mammary Papilla, Umbilical Cord, Genital Papilla, Urogenital Opening, Scrotum, and Anus.
External openings of the nose used for breathing and sense of smell. Pigs have well-developed sense of smell and use smell as their primary sensory modality when foraging.
5 to 6 pairs of these strucures presents in both sexes, but develop into the mammary glands in only females.
Contains 2 umbillical arteries and 1 unbillical vein. Serves as a connection between fetus and fetal placenta. Vessels within cord are responsible for nutrient, gas, ans waste exchange between fetus and mother.
Glands of the Head and Neck - Fetal Pig
Parotid gland, mandibular gland, sublingual gland, thymus gland, and thyroid gland.
Small salivary gland. Has oval shape. Lies partially ventral to parotid gland and between the the parotid and angle of the jaw. Also called the "submaxillary gland".
Salivary gland is narrow and flat. Lies beneath skin, medial to lower jaw, and alongside tongue.
Large, elongated endocrine gland. Lies beneath skin on each side of, and over, trachea. Also extends down into thoracic cavity - lies on dorsal surface of heart. Hormones from thymus gland stimulate early development of immune system.
Small endocrine gland-darkly colored, has oval shape. Lies between 2 lobes of thymus gland, posterior to larynx and ventral to trachea. Remove 2 sternohyoid muscles to find.
Anatomy of the Mouth - Fetal Pig
Hard palate, soft palate, tongue, papillae of the tongue, pharynx, epiglottis and glottis.
Lies on floor of mouth, between lower jaws. Location of taste buds and aids in food manipulation.
Papillae of the Tongue
Small projections on tongue. Particularily large on anterior margins and base of tongue. Aid in manipulation of food.
Flap of skin which covers the glottis. Serves to separate esophagus from trachea and prevent food or liquid from entering trachea.
Tube commonly called the "windpipe". Extends from larynx in throat to lungs. Lined with cartilage rings which function to keep trachea open.
Commonly called "voice box". Connects to glottis anteriorly and trachea posteiorly. Contains vocal cords which can be viewed by making longitudnal mid-dorsal incision, and opening the cartilage.
Part of lung. Commonly known as "lung root" and is only part of lung attached to the body. Pulmonary vein, artery, and primary bronchi enter lung here.
Skeletal muscle located between lungs and liver. Primary muscle responsible for breathing.
Anatomy of Digestive System - Fetal Pig
Esophagus, stomach, lesser omentum, greater omentum, pyloric sphincter muscle, gall bladder, common bile duct, liver, spleen, pancreas, duodenum, small intestine, mesentery, cecum, large intestine, colon, and rectum.
Sheet of connective tissue which attaches to and anchors inside convex curve of stomach.
Sheet of connective tissue which attaches to and anchors outside concave curve of stomach.
Pyloric Spincter Muscle
"Doughnut-like" smooth muscle, found at posterior end of stomach. Separates stomach from the duodenum.
Organ is long, flat, finger-like projection to right of stomach. Functions to store blood. Dark red to purplish in color.
Has right and left lobe. Produces digestive enzymes. Right lobe of pancreas is beside pyloric sphincter, at base of stomach.
Veins of Fetal Pigs
Cranial vena cava, brachiocephalic veins, internal jugular vein, external jugular veins, cephalic veins, subclavian veins, axillary veins, subscapular veins, caudal vena cava, hepatic portal vein, umbillical vein, renal veins, common iliac veins, internal iliac veins, external iliac veins, femoral veins, and deep femoral veins.
Carry blood from the cephalic, subclavian, and jugular veins to the cranial vena cava.
Internal Jugular Vein
1st set of vessels to emerge from cranial vena cava, medially. Carry blood from head to brachioencephalic veins. Located on either side of trachea.
External Jugular Veins
2nd set of vessels to emerge from cranial vena cava, medially. Carry blood from head to brachioencephalic veins.
3rd vessels to emerge from cranial vena cava, medially. Carry blood from forelimb to brachioencephalic veins.
4th set of vessels to emerge from cranial vena cava, medially. Carry blood from the subscapular veins and axillary veins to brachioencephalic veins.
Carry blood from region of armpit and join with axillary vein to form subclavian vein.
Hepatic Portal Vein
Large vein (may be yellow). Located between stomach and liver. Carries blood from stomach, spleen, pancreas, and intestines to liver.
Arteries of Fetal Pig
Aortic Arch, Brachiocephalic Trunk, Left Subclavian Artery, Carotid Trunk, Common Carotid Arteries, External Carotid Artery, Internal Carotid Arteries, Right Subclavian Artery, Axillary Arteries, Brachial Artery, Aorta, Celiac Trunk, Cranial Mesenteric Artery, Renal Arteries, Caudal Mesenteric Artery, Umbillical Arteries, External Iliac Arteries, Internal Iliac Arteries, Femoral Arteries, Deep Femoral Ateries.
Artery that leaves left ventricle and gives rise to the brachiocephalic trunk, left subclavian artery, and aorta.
1st large artery arising from aortic arch. Carries oxygenated blood to neck, head, and right forelimb.
1st vessel to arise from right brachiocephalic trunk, medially. Carries blood anteriorly towards neck and head.
External Carotid Artery
Arteries are medial branches of common carotid arteries. Carry blood to area around masseter muscle and chin.
Right Subclavian Artery
2nd arteries to arise from right brachioencephalic trunk. Supplies blood to cervical vertebrae and right forelimb.
Continuation of subclavian arteries. Carry blood to armpit, shoulder, and forelimb.
Large vessel lying on mid-dorsal wall, length of abdominal cavity. Carries blood to entire posterior portion of body.
1st artery to branch off aorta, posterior to diaphragm. Carries blood to stomach, pancreas, and spleen.
Cranial Mesenteric Artery
2nd artery to branch off aorta, posterior to diaphragm. Carries blood to most of small intestine.
Caudal Mesenteric Artery
Branches off ventral surface of aorta before it splits into umbillical arteries. Carries blood to large interstine and colon.
Terminal end of aorta splits into these 2 arteries. Enter umbillical cord and carry blood to placenta.
External Iliac Arteries
Branch off aorta immediately anterior to umbillical arteries. Carry blood to thighs and hind limbs.
Internal Iliac Arteries
Branch dorsally off aorta, immediately to umbilical arteries. Carry blood to pelvic region.
1 of 2 branches of external iliac arteries. Carry blood to thigh and lower hind limb.
Large, kidney-bean-shaped organs located on posterior dorsal wall of abdominal cavity. Lie beneath layer of connective tissue on either side of dorsal aorta. Produce urine.
Tube transports urine to outside when bladder is emptied. Short in females, just ventral to anus. Longer in males ends at urogenital opening. Also functions to conduct semen in males.
Male Reproductive System - Fetal Pig
Scrotum, Testes, Epididymis, Ductus Deferens (vas deferens), Inguinal Canal, Seimnal Vesicles, Prostate Gland, and Penis.
Small, bean-shaped male reporductive organs contained in scrotum. Produce sperm and testosterone.
These are located superficially on posterior margin of testes. Long and coiled tubule which coils to use very little space. Functions in sperm storage and maturation.
Ductus Deferens (vas deferens)
Ducts which connect epididymis to urethra. Turn over the uterters to join urethra just anterior to where ureters enter the bladder. Function is to transfer sperm from epididymis to urethra during ejaculation.
Passageways through abdominal wall in groin of males through which ductus deferens and blood vessels pass to testes.
Small glands located near junction of ductus deferens and urethra. Produce some of seminal fluid.
Small gland which surrounds junction of ductus deferens and urethra. Produces some seminal fluid. To find, dissect between seminal vessicles.
Pair of glands near base of penis in pelvic canal on either side of urethra. Produce some of the seminal fluid. Also called "Cowper's glands".
Male copulatory organ located ventrally on exterior abdomincal wall, just posterior or umbillical cord.
Female Reproductive System - Fetal Pig
Ovaries, Uterine Tubes (Fallopian Tubes), Uterine Horns, Uterine Body, Vagina, and Genital Papilla.
Female reproductive organs. Small, bean-shaped located in dorsal abdominal wall, just posterior to kidneys. Produce eggs and hormones like estrogen and progesterone.
Uterine Tubes (Fallopian Tubes)
Small ducts found between ovaries and uterine horns. Passageways through which eggs reach uterus. Fertilization occurs in uterine tubes.
Wider tubes located at end of uterine tubes and connected to uterine body. Embryos develop within these tubes.
Mosts posterior tube of female reproductive tract. Is female copulatory organ and receives male penis during copulation.