Regions of the pig- caudal pelvic pectoral cranial and umbilical
Anterior is front part of pig and posterior is back end
dorsal is back of pig
Diet- omnivores, plants and animals. eat roots fruits leaves grasses and flowers. Captivity they feed on corn and soybeans with a vitamin mixture added to the diet, wild eat other animals and what is listed above.
Girls have urogenital papilla and males do not.
Excretory system-
Kidneys-There are three different regions internally (outer cortex, middle medulla, and innermost renal pelvis). Blood enters kidneys viz renal artery, then forced through a maze of small tubules, which is the function unit of the kidney. There are small tubules that filter water, ions and wastes and other materials from the blood and form urine that is then passed through the collecting ducts to the base of the renal pyramids and into the renal pelvis. Urine collects in the renal pelvis which drains into the ureter.
Renal blood vessels-These are veins that carry filtered blood from the kidneys to the posterior vena cava. They carry unfiltered blood from the aorta to the kidneys. The arteries are obscured by the renal veins.
Ureters- Their urine is formed by kidneys. They contain the nitrogenous wastes ions, drugs and other material filtered from the blood by the kidneys. There are 2 ureters that are hollow tubes that exit the two kidneys. Urine passes through the ureters to reach the urinary bladder for storage.
Bladder- Urine is stored in urinary bladder until mammal eliminates fluid waste through urination. Then the urine exits the bladder to the outside through the urethra.
Digestive system-
Head-It starts with mouth, and then it can let pig eat as well as reduce the size of food so it can easily swallowed.
Abdomen- The stomach is responsible for breaking down the nutrients. Then the food moves down in stomach and then into the small intestine. The small intestine absorbs nutrients. Then it goes to large intestine, and then out the anus.
Circulatory system- This system controls the body temp. It provides channels for the immune system. It protects the body and participates in maintenance of body fluid for homeostasis.
Thoracic Cavity- The thymus is large. It develops the immune system, and then later decreases in size, and becomes fairly unimportant.
Heart and Lungs:
Reproductive system- The female pig(sow) can be pregnant once it is 8 months. It usually is fertile until 18 months, and males pigs (boars) are sexually mature at 8-10 months. During productive months sows enter into phase “heat” every 21 days when not pregnant. The sow gets pregnant, and the gestation period lasts 115 days.
Respiratory system- It removes carbon from the blood.
trachea- It is a large diameter tube located in throat and thoracic cavity. It has cartilaginous rings in walls to keep the airway open. Carries air directly into lungs.
Nervous system:
Cranial region- It has four major brain regions. It is a relay and processing center for info coming into brain via spinal cord and brain stem.
Cervical region-The brain and spinal cord comprise the central nervous system. Spinal cord serves as a relay of info between brain and body. It relays on neural info is critical, spinal cord processes neural info locally.
Lumbar region-It has many pairs of spinal nerves as there are vertebrae. There are large bundles of thousands of axons that project from the spinal cord to the body but not the head. Spinal nerves also contain thousands of axons that originate in the body and project to the spinal cord. Cranial nerves are similar of spinal nerves for the head. The neural info enter and or leaves brain viz these 12 pairs of cranial nerves, visual sensory info enters the brain via the optic nerve.
Crayfish
Geographic Location-They are found anywhere where there is freshwater that is not overpopulated. This includes streams, rivers, lakes, ponds, and sometimes water filled ditches.
Immune System- They have an innate immune system, and a rapid defense against diseases, but does not offer long lasting immunity to them.
Circulatory System- They have an open circulatory system, which pumps blood to the hemocoel while the blood circulates back to the circulatory system between cells.
They have no veins.
2 arteries leave heart.
The abdominal aorta is towards the posterior, and the anterior dorsal aorta is towards the anterior.
Blood flows from dorsal arteries to the capillaries, and then into tissue spaces known as sinuses which function as veins. The blood goes through the gills and returns to the pericardial sinus which surrounds the heart.
Digestion- 4 major organs(Pyloric stomach, Digestive Glands, Cardiac stomach, and intestine). The cardiac stomach contains a gastric mill which grinds the food using its two sets of chitinous teeth and a set of medial teeth. The food is then taken to the pyloric stomach where to the digestion is about finished. The digestive gland secretes digestive enzymes and aids in the absorption of the products of digestion. The intestine which is a long white cord that runs from the stomachs to the anus of the crayfish is the last process of digestion.
Food Capture-They eat just about anything(shrimp, fish, insects, worms, water plants, snails, plankton, dead plants and animals, live fish(rare). Due to how fast a crayfish is they are able to catch live fish if it is easy enough for them to do.
Gas Exchange-Also known as respiratory organ, which provides oxygen to the organism. The circulatory system then delivers this to the cells. Gills are the organs in which allow gas exchange to take place. Used to get the amount of oxygen needed for being in water. The oxygen goes in the hemolymph and carbon dioxide transfers out.
Thermoregulation- Ectothermic( They are cold blooded and their body temperature is regulated by their environment).
Homeostasis- Crayfish maintain homeostasis by shedding their exoskeleton as they grow. How big and fast they grow depends on many different components such as, water quality, temperature, and food availability.
Reproduction- Occurs in the late summer, early fall. Lays 200-400 dark colored eggs in a single hatch. Hatches anywhere from 10-20 weeks. Females secretes a sticky substance and attaches the eggs with this substance to her swimmerets. When carrying eggs female is in “berry-stage”. After hatching the young crayfish remain attached to the swimmerets for one to two weeks. Lifespan is 3-8 years.