Fetal Pig Systems Class Mammalia
1. Be able to trace these from start to finish from memory
2. read lab manual on vertebrate evolution
I. External Anatomy of the Pig
1. Sus scrofa
2. Segmented into: head, neck, trunk (thorax and abdomen), and tail
3. Lips
4. Nares the 2 openings of the nose
5. Eyelids upper and lower
6. Umbilical cord
7. Digitigraded means they walk on their digits (i.e., toes)
8. Urogenital opening
a. males directly posterior to the umbilical cord
b. females next to anus and covered by the genital papilla
9. Mammary papillae both sexes have and are developed beore sex determination
occurs. Much the same way human males have nipples. They are per-cursors
to the mammary glands, which form later on.
10. Oral Cavity teeth, tongue, hard & soft palate
11. Two holes next to each other for different systems
a. esophagus opening to digestive tract
b. glottis opening to the respiratory system
12. Epiglottis circular flap of skin that covers the glottis
Internal Anatomy
II. Skeletal System of the Pig
1. All vertebrates conform to similar design
2. Axial and appendicular skeletal systems
3. Articulations where two bones meet also known as a joint
4. Six different types of joints
a. Sutures these are only joints that are immovable (in skull)
b. Compression Joints
c. Gliding Joints
d. Hinge Joints
e. Pivot Joints
f. Ball-and-socket Joints
III. Muscular System of the Pig
1. Terminology
a. Origin and Insertion the bones to which the muscle is attatched
at each end
b. Type of Articulation between the muscle and the bone (e.g., tendons)
c. Action of Movement
1. flexion
2. extension
3. adduction towards the midline
4. abduction away from the midline
5. rotation
IV. Digestive System of the Pig
1. Mouth is first part of digestive system (DS)
2. Teeth mechanical breakdown of food
3. Salivary glands add enzymes to break down the food
a. Amylase the enzyme being produced
4. Thus digestion actually starts in the mouth
5. Esophagus
6. Smooth muscles ring the esophagus and the digestive system and involuntarily
control digestion
7. Stomach highly ridged with villi (both macro- and micro-)
8. Has glandular cells in this lining
a. one type produces the product called pepsin
b. another produces hydrochloric acid
9. Cardiac Sphincter valve between esophagus and stomach
10. Pyloric Sphincter valve between stomach and duodenum (i.e., small
intestines)
11. Small Intestines 3 divisions
a. Duodenum receives ductwork from both liver and pancreas
b. jejunum
c. ilium
12. Liver makes bile and detoxifies blood
13. Connected from duodenum by the bile duct is the Gall Bladder, located
just underneath the left liver lobe. Each liver lobe (there are 4) makes
bile and secretes it into the duct where it can be stored in the GB for
use during digestion
14. Gall Bladder stores the bile made in the liver
15. Bile acts to emulsify fats
16. Pancreas diffuse glandular structure embedded in the mesenteries
that support the stomach and intestines
17. Pancreas produces two end-products
a. enzymes used in digestion
b. hormones secreted into the circulatory system (specifically the
hepatic portal system)
18. Cecum blind pouch right at the connection between the small and
large intestines.
19. Cecum primarily a storage organ holds bacteria that further
help breakdown indigestible food. Humans reduced to vestigial appendix
20. Colon another name for the large intestines primarily responsible
for absorbing water from the food bolus traveling through the DS
21. Rectum
22. Anal sphincter muscle controls movement of feces out the anus
23. Mesenteries
V. Excretory System of the Pig
1. Homeostasis the regulating of internal processes (think of a balancing
act)
2. One important homeostatic process is the elimination of toxic metabolic
by-products
3. Two toxic by-products of metabolism
a. carbon dioxide eliminated by circulatory system (and eliminated
via resp. sys)
b. nitrogen eliminated by excretory system
4. Regulation of ion concentrations (sodium, potassium, etc) and water
concentrations are dually handles by excretory and circulatory system
5. Kidneys the main units of nitrogenous waste removal
6. These are against the dorsal wall of the abdominal cavity and are
intimately connected to the circulatory system via the renal art/veins
7. Kidney also function in excess water, salts, and other substances
8. Hilus connection between the art/veins and the kidney
9. Ureter runs posterior from kidneys
10. Bladder holds the urine and further concentrates it
11. Urethra urine leave via this duct from the bladder
12. Remember order :
a. kidney > ureter -> bladder > then the urethra
VI. Reproductive System of the Pig
1. Note here there is also a difference between the ductwork in a male
and female. Males- share structures with excretory system.
Females dont share.
Male
1. Scrotal sacs hold the testis
2. Internal testis
a. seminiferous tubules produce the sperm
b. epididymus - storage site after sperm produced
c. vas (ductus) deferens discharge tubule
d. urethra common ductwork the excretory and reproductive system
share
3. Semen mixture of sperm gametes and fluid suspension
4. Several Glands make the semen
a. Prostate Gland
b. Semianl Vessicles
c. Cowpers Gland (aka, Bulbourethra)
5. Penis
Female
1. Ovaries produces gametes
2. Ova (aka, eggs) erupt from ovary and captured by fallopian tube
(aka, oviduct)
3. Taken to the uterus
4. Branched horns uterus meets up together
5. Vagina each horn opens into the vagina
6. Vagina opens directly to outside environment
7. Internal fertilization in mammals
a. sperm is injected into vagina by male penis
b. sperm swims up the oviduct and meet with ovum
VII. Respiratory System of the Pig
1. Main functional units of the respiratory system are the;
a. lungs
b. heart
2. epiglottis
3. glottis
4. larynx
5. tracheae
6. bronchus primary and secondary
7. bronchioles
8. terminal bronchioles
9. respiratory bronchioles
10. alveoli highly vascularized and site of gas exchange
VIII. Circulatory System of the Pig
1. Heart main functional organ of the circulatory system
2. Heart covered in a thick membrane called a pericardial sac
3. Heart has 4 chambers
a. 2 atria
b. 2 ventricles
4. allows for double circulation to the lungs and the body with NO
mixing between the oxy and deoxy blood
5. Spleen functions in the storage and release of blood cells made
elsewhere
6. Aorta major artery in mammalian body
7. Aorta leaves the LV of the heart as the aortic arch then runs posteriorly
and dorsaly following the VC as the dorsal aorta
8. Veins one-way valves inside prevent back-flow of blood. Lower
blood pressure than arteries because the are after the cap beds
9. Pulmonary trunk (aka, pulmonary arch)
10. Divides into left / right pulmonary arteries to the lungs carrying
deoxy blood
11. From lungs via pulmonary veins back to the heart
Circulatory Blood Flow through heart
1. Anterior Systemic + Posterior Systemic
2. Anterior Vena Cava + Posterior VC
3. Right atrium
4. Right Ventricle
5. Pulmonary trunk
6. L/R pulmonary Arteries
7. Lungs
8. L/R pulmonary Veins
9. Left Atrium
10. Left Ventricles
11. Aortic Arch
12. Dorsal Aorta
13. Anterior Systemic + Posterior Systemic
14. Major veins of Anterior Vena Cava
1. Subclavian vein from thoracic and arms
2. Internal Jugular Vein from tracheae, larynx, neck and brain
3. External Jugular Vein from head and shoulders
15. Major Veins of the Posterior Vena Cava
1. Hepatic Vein from 4 lobes of liver and diaphragm
2. Renal Vein from kidneys, adrenals, gonads
3. Common Iliac Veins from abdominal wall. Tail, pelvis and legs
16. Hepatic Portal System embedded in the mesenteries
17. Portal System :
a. artery cap bed portal cap bed veins
IX. Nervous System
1. read and know basic structures