Bio 2 3Rd Exam Review Chapter 48

Front 1

what kind of heterotrophs are out there?

Back 1

herbivore - plant materials
carnivore - other animals
omnivore - both plant and
animals

Front 2

digestive systems (vertebrates)

Back 2

one way tube with a separate mouth and anus and accessory organs

Front 3

how does a digestive system (vertebrates) function?

Back 3

functions to ingest and digest food, absorb nutrients, and eliminate indigestibles

Front 4

whats included in the GI tract?

Back 4

-mouth
-esophagus
-stomach
-small intestine
-large intestines
-rectum
-anus

Front 5

mouth

Back 5

-with 32 teeth (adults),
canines and incisors to cut food, molars and premolars to grind food
-3 pairs of salivary gland
-epiglottis prevents food from entering the trachea when swallowing
-pharynx last area both air and food pass through

Front 6

what does choking involove?

Back 6

choking involves food entering trachea instead of esophagus

Front 7

mechanical digestion

Back 7

can include cutting and grinding of food with teeth and churning and mixing of food thru peristalsis and with in stomach

Front 8

process of swallowing

Back 8

-elevation of the palate to seal off the nasal cavity
-folding of the epiglottis over the trachea
-pressure against the pharynx to initiate swallowing
-the swallowing center stimulates successive waves of contraction

Front 9

esophagus

Back 9

-muscular tube that passes bolus (moistened mass of chewed food swallowed) to stomach
-food moves through rythmic contractions (peristalsis) of the two layers of smooth muscle
-sphincter muscles at entrance of stomach must relax before food can enter stomach
-acid reflux results from incomplete closure of sphincter allowing acid to move onto the esophagus

Front 10

what are the layers of the alimentary canal, moving from inside to outside?
*from deep to superficial**

Back 10

1)mucosa
2)submucosa (contain plexuses- nerves that regulate activites of GI tract)
3)muscularis
4)serous

Front 11

what are layers of the muscularis?

Back 11

-there are two layers of smooth muscle oriented in differnt directions
-one is circular and one is longitudinal
-these orientations promote perstalsis (movement of material thru tract) and segmentation (mechanical mixing of material)

Front 12

where does digestio begin?

Back 12

-salivary amylase begins digestion of starch in the mouth
-pepsin begins digestion of protien in the stomach
-lipids begin digestion in the small intestine (duodenum)

Front 13

where is most digestion completed?

Back 13

most digestion of all orgainc molecules is completed in the duodenum (1st 25cm) of the small intestine and the small intestine also is the primary site of nutrient absorption in the mammalian digestive system.

Front 14

what is acid reflux?

Back 14

when gastric fluid is able to move past Gastroesophageal spincter (muscle that encircles tubes and acts as a circular valve to control flow) and affect the esophagus (tube used only to transport bolus)
**referred to as heart burn**

Front 15

what remedies heart burn or acid reflux?

Back 15

over the counter remedies like Tums or Rolaids lower the acidity of stomach fliud

Front 16

Peristalsis

Back 16

rythmic contraction in the digestive tract from the pharynx to the anus that mixes and moves the bolus (mouth to stomach) and chyme (stomach to small intestines) thru tract.

Front 17

what are the gastric glands within the stomach?

Back 17

-mucus secreting gland: mucus (protects stomach walls from low pH)
-parietal cells: secrete HCl (produces low pH which helps to denature protiens, activates pepsinogen into pepsin which then begins to hydrolyze protien and kills microorganisms) and intrinsic factor (facilitates vitamin B12 absorpption necessary for RBC production which leads to lack of pericious anemia)
-chief cells: produce pepsinogen, precursor (activates by lowering pH) to pepsin which begin digestion of protien

Front 18

what color are the gastric secretions?

Back 18

green

Front 19

consider the subsequential processes occuring in the stomach

Back 19

1.the arrival of food into the stomach triggers gastric juice secretion
2. secretion of HCl lowers pH, activating pepsinogen into pepsin
3. the acidic chyme moves through the pyloric sphincter to the small intestine
the increasing acidity of the stomach is primarily directes towards the start of protein digestion.

Front 20

what is and what is not absorbed through the stomach wall?

Back 20

Nutrients are NOT absorbed through the stomach wall
Water, Alcohol, Asprin ARE absorbed through the stomach wall

Front 21

gizzard

Back 21

ares where food is ground in some animals such as birds

Front 22

crop

Back 22

where birds store food in a modified portion of the lower esophagus

Front 23

what are the roles of the liver?

Back 23

-first organ to recieve the products of digestion
-produces bile
-removes excess glucose and produces glycogen for storage
-stores vitamins
-destroys old and damaged red blood cells
-removes alcohol, toxins, pesticides, and carcinogens from blood

Front 24

why is the liver the first organ to recieve products from digestion?

Back 24

because the hepatic portal system connects the liver to the small intestines

Front 25

what doe sthe hepatic portal vein do?

Back 25

carries blood with ingested materials to the liver which screens blood and then if continues on through the hepatic vein

Front 26

What is bile?

Back 26

hepatocyte cells in dilute form, move through the gallbladder where it is stored and concentrated, released into the duodenum where the bile salts act as emulsifier/digester of lipids

Front 27

what happens after the bile emulsifies and lipases hydrolyze fats into triglycerides?

Back 27

the triglycerides are combined with protiens in the small intestine to make them into water soluble particles called chylomicrons which are absorbed into lymphatic capillaries.

Front 28

what simulates the secretions of pepsinogen and HCL from the gastric gland?

Back 28

parietal cells

Front 29

what is the role of secretin?

Back 29

secretin stimulates the release of pancreatic fliud, which contains digestive enzymes and buffers

Front 30

rumen

Back 30

1st stomach of ruminants which serves as a fermentation chamber in which bacteria and protoza degrade cellulose
-**this allows cows to survive in a diet consisting almost entirely of cellulose**

Front 31

what is cecum?

Back 31

-area in horse, rodent, and lagomorphs where microorganisms digest cellulose

Front 32

what is coprophagy?

Back 32

a process in which animals, such as rodents, rabbits, and hares consume their feces to assure complete digestion

Front 33

how are digested fats absorbed?

Back 33

through lacteals (capillaries) which are part of the lymphatic system and located in villi of the small intestines

Front 34

how much is small intestine absorption?

Back 34

8.5 liter out of total 9 liter of material passing through

Front 35

what does a pancreas do ?

Back 35

secretes in an exocrine function:
-lipase
-trypsin
-chymotrypsin
-DNase
-RNase
-bicarbonate (nuetralizes acidic chyme) through the pancreatic duct

Front 36

as an exocrine gland, the pancrease secretes ?

Back 36

its product through the pancreatic duct onto the free surface of the small intestine.

Front 37

as an endocrine gland the pancreas secretes?

Back 37

its hormone (insulin- which triggers glucose uptake by cells and glucagen which trigger conversion of glycogen into glucose) directly into the blood stream.

Front 38

what are digestive secretions primarily regulates by?

Back 38

by nerve and hormonal signals

Front 39

the majority of nutrient absorption is?

Back 39

chyme (thick soupy acidic liquid) enters the small intestine (primarilyin first portion: duodenum)
the pancreas then releases enzymes and bicarbonate to complete digestion and accomplish majority of absorption
**undigested food is transported to the large intestines**

Front 40

where does most nutritent absorption occur?

Back 40

in the duodenum (the first portion of the small intestine)

Front 41

why does the most nutrient absorption occur in the duodenum?

Back 41

the surface area of the duodenum (small intestine) is greatly increased thru the structures of circular folds, villi, and microvilli.

Front 42

what is the surface area of the small intestine in human?

Back 42

300 square meters

Front 43

lactose intolerance

Back 43

the inability to digest milk sugars leading to gastrointestinal pain when dairy products are consumed

Front 44

what are the epithelial wall of the small intestines like?

Back 44

covered with fingerlike protrusions (villi) which are in tuen covered in micro-villi

Front 45

gluconeogenesis

Back 45

process in which amino acids and lactic acid are converted to glucose

Front 46

what is the large intestine structure like?

Back 46

contains 3 segments with no villi

Front 47

what is the purpose of the large intestine?

Back 47

-4% absorption
-storage of undigested chyme as it is convertes to feces
-vitamin K production (via bacteria and absorption
-reabsorption of salts (active transport and water (thru osmosis) from chyme.

Front 48

what is an advantage to active transport of salts?

Back 48

water can be reabsorbed thru osmosis

Front 49

Diarrhea is a symptom of what?

Back 49

decreased water reabsorption

Front 50

what are the required macronutrients?

Back 50

-fats
-carbohydrates
-protiens

Front 51

what is the quickest energy source?

Back 51

simple sugar, such as glucose

Front 52

by controlling your weight you may prevent yourself from what?

Back 52

obesity

Front 53

what can obesity lead to ?

Back 53

can lead to typeII diabetes and cardiovascular disease

Front 54

what does LDL stand for?

Back 54

low density lipoprotiens

Front 55

is LDL bad for you? and why?

Back 55

yes considered bad for your health because it transports cholesterol

Front 56

what are vitamins

Back 56

organic compounds obtained thru diet that are required for metabolic reaction
**often form coenzymes and antioxidants**

Front 57

how are vitamins and essential amino acids similar?

Back 57

they can only be synthesized and must be ingested

Front 58

what are minerals used for?

Back 58

trace amounts of metallic ions that are required as cofactors in reactions

Front 59

Birds store food in a modified portion of the lower esophagus called the
A. crop.
B. epiglottis.
C. gizzard.
D. alimentary canal.
E. pharynx.

Back 59

A. crop.

Front 60

Which of the following is the primary site of nutrient absorption in the mammalian digestive system?
A. pharynx
B. stomach
C. small intestine
D. large intestine
E. pancreas

Back 60

C. small intestine

Front 61

Digestion of which major nutrient type begins in the stomach?
A. carbohydrates
B. lipids
C. nucleic acids
D. proteins
E. vitamins

Back 61

D. proteins

Front 62

The diarrhea that is a symptom of diseases like cholera is due to problems in the function of which digestive organ?
A. stomach
B. small intestine
C. large intestine
D. appendix
E. gall bladder

Back 62

C. large intestine

Front 63

Cows are able to survive on a diet consisting almost entirely of cellulose because
A. cows are autotrophic.
B. the cow, like the rabbit, ingests its feces.
C. cows can manufacture all 20 amino acids out of sugars in the liver.
D. unlike humans, the saliva the cow produces has enzymes capable of digesting cellulose.
E. cows have cellulose-digesting, symbiotic microorganisms in their rumens.

Back 63

E. cows have cellulose-digesting, symbiotic microorganisms in their rumens.