Lab 6 (begin Exam 2) Flashcards
Tongue
Manipulates food during chewing and initiates swallowing
Stratified squamous epithelium, skeletal muscle, nervous
Oral Cavity
The mouth
Where food enters the digestive tract
Strat squam epithelium, skeletal muscle, nervous
Pharynx
First area food passes through in posterior oral cavity
Common passageway for food, fluid, and air
2 layers muscle, stratified squamous epithelium in mucosa
Esophagus
Food passageway that conducts food to the stomach with peristaltic motion
Skeletal muscle superiorly and smooth closer to stomach
Stomach
Mechanically and chemically digest food
Muscle and simple columnar epithelium
Large intestine
Consolidate and propel the unusable fecal matter toward the anus and eliminate it from the body. It also a habitat for bacteria to produce vitamins b and k and reclaims water from undigested food
Smooth muscle, simple columnar epith.
Anus
Where feces are excreted
Smooth muscle, epith.
Salivary glands
Empty secretions into digestive cavity, secretions contain enzymes that aid in digestion
Stratified epithelium
Liver
Processes the blood, breaks down, balances, and creates nutrients and metabolizes drugs into forms that are easier to use
Connective tissue proteins (collagen, proteoglycans, glycoproteins)
Gallbladder
Stores and concentrates bile from the liver
Mucosa, smooth muscle, peri muscular layer, serosa
Pancreas
Secretes pancreatic juice to help break down food, control blood sugar, and tell stomach when to empty
Exocrine tissue, islets of Langerhans (endocrine cells)
Teeth
(mastication) chew and mash food
Enamel, dentin, cementum and pulp
Taeniae Coli
Move fecal matter through the large intestine
Long bands of smooth muscle
4 types of teeth
Incisors, Canines, Premolars, Molars
Incisors
Chisel and shear food
Age of appearance: 6-8 months and 7 years
Canines
Tearing
Age of appearance: 16-20 months and 11 years
Pre molars
Grinding
Age of appearance: 11 yrs
Molars
Fine grinding
Age of appearance: 6-7 years
Mucosa
Secretion of mucus, digestive enzymes, and hormones. Absorption of end products into blood, protection against disease
Epithelium, areolar connective, muscularis mucosae (thin smooth muscle)
Inner most layer
4 tissue types of small intestine
Mucosa, submucosa, muscularis externa, Serosa
Submucosa
Blood vessels absorb and transport nutrients, elastic helps maintain shape of organ
Areolar and dense irregular CT
BV, lymph vessels, nerve fibers
Muscularis Externa
Segmentation and peristalsis of digested food along the tract are regulated
Inner and outer layer of Smooth muscle (circular and longitudinal)
Serosa
Reduces friction as the digestive system organs slide across one another
Areolar connective tissue and simple squamous epith.
Duodenum length
20-25cm
Jejunum length
2.5 meters
Ileum length
3 meters
How is SI vs. LI function related to differences in Histology
The main function of the small intestine is to absorb nutrients so there is a maximum amount of surface area to do so. There are villi and microvilli in the small intestine. The large intestine removes excess water from the fecal matter and does not require the same amount of surface are so it has crypts but no villi. It is lined with simple columnar cells
Physio Ex
Read and review PhEx pgs 119-130
Chemical digestion
Amylase
optimal pH 7
Around the pH of the mouth because amylase is secreted by salivary glands to digest starch to maltose
Only digests starch, NOT cellulose
Smallest substrate starch can be broken down into
Glucose monosaccharide
Pepsin
Secreted by Chief cells in the stomach to digest peptides into amino acids
Optimal pH ~2 (stomach acidity)
Lipase
Mostly present in small intestine
Digestion of fats (triglycerides) with the help of bile salts
Splits tri into 2 fatty acids
gastric and lingual lipase active in stomach in addition to pancreatic lipase of small intestine
Fat digestion makes things more acidic (lower pH)
Optimal pH of lipase is ~8
Bile salts
Emulsify lipids
Separate the big lipid clumps and increase SA of lipids available to lipase
