lab 2 - comparative anatomy - external anatomy and digestive system

nictitating membrane

unique trait only to pigs, it is an extra membrane underneath the eyelid that acts as an additional layer of protection and helps lubricate the eye

mammary papillae

in males, it is an vestigial organ, in females, it is used for breastfeeding

genital papilla

flap in female pigs that covers genitalia, where vagina and urethra are in 1 common area

scrotal swelling

how to determine sex of male pig

digestive system organ order

1. oral cavity

2. pharynx

3. esophagus

4. stomach

5. small intestine

6. large intestine

7. rectum

8. anus

oral cavity

breaks down food mechanically (with teeth) and chemically (with enzymes, such as amylase)

pharynx

opening in back of the mouth where digestive system and respiratory system meet

esophagus

tube that sits behind trachea, taking food and liquids to the stomach

stomach

where the food is chemically digested and where initial protein digestion begins. secretes HCl and pepsin that helps chemical digestion.

small intestines

where most digestion and absorption of nutrients occur, breaking down proteins, carbs, and fats.

doudenum

first part of the small intestine that receives chyme and mixes with digestive enzymes coming from the pancreas, liver, and gallbladder

jejunum

second part of the small intestines that does most of the nutrient absorption

illium

last part of the small intestine where more nutrients are absorbed

large intestines

where chyme enters and the colon recovers lost water from waste as it leads to the rectum; more water absorbed = drier stool = constipation; less water absorbed = wetter stool = diarrhea

rectum

where stool is held before leaving the body

anus

where stool is released

masseter muscle

overlies the lower jaw

salivary glands

(parotid and mandibular) secretes saliva

saliva

mode up of amylase, mucous, and water

amylase

digestive enzymes for chemical breakdowns of food

mucous

lubricates food which helps swallowing

tongue

taste and movement of food

teeth

mechanical digestion, helps grind down food

hard palate

part of mechanical digestion; functions as a ‘washboard’, located on top of the mouth

soft palette

blocks food and other substances from entering nasal passages when swallowing and is important for speech

epiglottis

covers the trachea (windpipe) when swallowing, making sure food goes down esophagus

esophageal (cardiac) sphincter

prevents the acidic contents of the stomach from moving into the esophagus

pyloric sphincter

opens and closes to control the passage of partially digested food and stomach juices into the duodenum

rugae

folds in stomach wall to allow stomach expansion

caecum

pouch with anaerobic bacteria for extra digestion of cellulose (reduced or absent in carnivores/ominivores_

liver

produces bile; produces glycogen for storage; detoxification

gallbladder

stores bile for fat breakdown

pancreas

produces digestive enzymes (trypsin), sodium bicarbonate and hormones (insulin and glucagon (which regulates metabolism)

spleen

not digestive; acts as a filter for blood as part of the immune system.

bile

produced by liver, stored in gallbladder, essential for breaking down fats and absorbing fat soluble vitamins