digestive system notes

Question 0

Mucosa

Answer 0

Location: Innermost
Tissue: Epithelium and some smooth muscle
Function: resists abrasion, lubrication, absorbs and secretes

Question 1

Four tunics or layers of the digestive tract

Answer 1

Mucosa
Submucosa
Muscularis
Serosa

Question 2

Submucosa

Answer 2

Location: after mucosa
Tissue: loose connective areolar
Function: contains nerves, absorbs, holds blood vessels

Question 3

Muscularis

Answer 3

Location: second outermost layer, between Muscularis and serosa
Tissue: smooth muscle, involuntary control
Function: contact, movement (move food through digestive tract)

Question 4

Serosa

Answer 4

Location: outermost
Tissue: epithelium and connective
Function: outer layer that holds it all together

Question 5

gastric rugae

Answer 5

Giant wrinkles/ folds that allow the stomach to expand when it is full

Question 6

epiglottis

Answer 6

Covers the larynx when swallowing to prevent food from entering the respiratory tract

Question 7

smooth muscle,

Answer 7

.

Question 8

microvilli,

Answer 8

Cytoplasmic extensions

Question 9

villi,

Answer 9

Tiny finger-like projections of mucosa
Increase surface area 600times
Within center is a capillary network and lymphatic vessel that transport the absorbed nutrients

Question 10

lacteals,

Answer 10

.

Question 11

hepatic artery

Answer 11

Brings oxygen rich blood to the liver, where liver cells process nutrients and detoxify harmful substances from the blood

Question 12

messentaries

Answer 12

Connective tissue sheet that holds the organs in place

Question 13

Functions of the digestive system

Answer 13

Take in food, break it down, and absorb digested molecules, which provides nutrients for the body
Also eliminates wastes

Question 14

Digestive tract

Answer 14

One way tube leading from the mouth to the anus, plus all the associated organs, which secrete fluids into the digestive tract to aid in digestion. Nutrients cross the wall of the digestive tract to enter the circulation

Question 15

The body wall of the abdominal cavity and abdominal organs are covered with

Answer 15

Serous membranes

Question 16

Peritoneum

Answer 16

Lines abdominal cavity

Question 17

Greater omentum

Answer 17

Mesentery that reaches from the greater curvature of the stomach to the transverse colon and posterior body wall
Long double fold of Mesentery that accumulates fat

Question 18

Oral cavity

Answer 18

Mouth (physical and chemical breakdown of food)

Question 19

Mastication

Answer 19

Chewing

Question 20

Salivary glands

Answer 20

1. Parotid -watery
2. Submandibular - watery
3. Sublingual - mucous

Question 21

Salivary glands respond by

Answer 21

Secreting substances that begin the chemical breakdown of food

Question 22

Saliva

Answer 22

Moisten, lubricate food, break down

Question 23

Salivary amylase

Answer 23

Enzyme, breaks down starch

Question 24

Lysozyme

Answer 24

Breaks down some bacteria, 1st line of defense, with food entering your body

Question 25

Pharynx

Answer 25

Throat

Question 26

Esophagus

Answer 26

Muscular tube lined with stratified squamous material, which helps protect against abrasion/damage Extends from pharynx to the stomach

Question 27

Cardiac sphincter

Answer 27

Keeps food moving one way from esophagus to stomach | Opening to the stomach

Question 28

Peristalic waves

Answer 28

Wave like muscle contractions Smooth muscle "Squeezes" the food down the throat

Question 29

Fundus

Answer 29

Superior portion of the stomach

Question 30

Body

Answer 30

Largest portion of the stomach

Question 31

Main function of the stomach

Answer 31

Storage and mixing

Question 32

Mucus

Answer 32

Lubricates and protects against acid and pepsin damage

Question 33

Hydrochloric acid

Answer 33

pH of 2.0 Activates pepsin Kills bacteria

Question 34

Pepsin

Answer 34

Enzyme Breaks down proteins Optimal pH is 2.0

Question 35

Chyme

Answer 35

Mixture of stomach secretions and food

Question 36

Heartburn

Answer 36

Backwash/ reflux of acidic chyme into esophagus

Question 37

The rate at which the stomach empties is a

Answer 37

Negative feedback loop

Question 38

Cecum

Answer 38

Proximal end of large intestine

Question 39

Colon

Answer 39

About 1.5-1.8 m long | Consists of ascending, transverse, descending, sigmoid

Question 40

Rectum

Answer 40

Relatively thick muscular tunic

Question 41

Anal canal

Answer 41

Last 2-3cm of digestive tract | External anal sphincter formed by skeletal muscle

Question 42

Takes 18-24 hours for

Answer 42

material to pass through large intestine

Question 43

Mass movements

Answer 43

Every 8-12 hours, strong contractions propel contents toward anus

Question 44

Feces are formed by

Answer 44

the removal of water and salts, secretion of mucus, and extensive action of microorganisms

Question 45

Microorganisms

Answer 45

make up about 30% of the dry weight of feces

Question 46

Liver

Answer 46

Weighs about 3 pounds | Divided into two major lobes and two smaller lobes

Question 47

Functions of the liver

Answer 47

1. Detoxification of harmful substances 2. Produce bile and bile salts- these break down fat droplets into smaller droplets and neutralize stomach acids; bile also contains waste products from blood and stores them 3. Nutrient storage- removes sugars and vitamins from blood and stores them 4. Nutrient conversion- some nutrients can be converted into others

Question 48

Pancreas

Answer 48

Secretes substances to neutralize chyme and break down lipids and proteins and carbohydrates Essential to the proper breakdown of food

Question 49

Small intestine

Answer 49

6 meters long Consists of duodenum, jejunum, ileum Absorption of nutrients

Question 50

Duodenum

Answer 50

25 cm long | Completes a 180 degree turn as it leaves the stomach

Question 51

The pancreas is located

Answer 51

Within the arc of the duodenum

Question 52

Common bile duct | Pancreatic duct

Answer 52

Join each other and lead into the duodenum

Question 53

There is a gradual decrease in

Answer 53

Diameter, number of folds, and number of villi as one progresses through the small intestine

Question 54

ileocecal valve

Answer 54

Found at the junction of the ileum and the cecum | Allows material to pass in one direction

Question 55

Lymphnodes

Answer 55

Found throughout the length of the digestive tract | Help protect the intestinal tract from infection

Question 56

Secretions of the small intestine

Answer 56

Mucus protects the duodenum from gastric secretions | Various enzymes digest starches, lipids, and simple sugars

Question 57

Jejunum

Answer 57

2.5 cm long

Question 58

Ileum

Answer 58

3.5 cm long