Digestion

Question 1

What kind of muscles surround blood vessels, and what characterizes them

Answer 1

Smooth:unstriated, slow acting, autonomic control

Question 2

When muscles contract, the Z lines

Answer 2

Move towards the center of sarcomere

Question 3

Do the actin and myosin filaments change length as muscle contracts?

Answer 3

no, they just slide past each other

Question 4

Particulate feeders- methods of feeding

Answer 4

1) Suspension feeders- sessile animals that filter suspended particulates
2)deposit feeders-consume substrate and extract whatever nutrients they can
3) filter feeders, actively acquire and filter smaller organisms( from water)

Question 5

Predators and scavengers-methods of feedings

Answer 5

animals that eat other animals (one on one interactions)

Question 6

Herbivores

Answer 6

gut microbes are required to digest cellulose
adaptations for crushing plant material
Large amounts needed to meet energy demands

Question 7

omnivore

Answer 7

unspecialised feeders, adapted for consuming a range of food types, including plant and animal

Question 8

fluid feeders

Answer 8

liquid diet

Question 9

Invertebrate digestion

Answer 9

sponges digest theri food intracellulary
-the alimentary canal of most eumetazoans allows for extracellular digestion
-cnidarians and flatworms have a cavity with single opening (bind digestive)
-specialization occurs went here is one way transport of food form mouth to anus. ex) annelids

Question 10

Vertebrates

Answer 10

-tubular gastrointestinal tract plus accessory digestive organs

Question 11

Ways of getting energy from food

Answer 11

1)Physical fragmentation-chewing grinding, increased exposure to enzymes
2)chemical digestion-break down carbohydrates, lipids, and proteins into smaller units
3) absorption and waste excretion

Question 12

Mouth and teeth

Answer 12

-) devices for feeding and limited digestion
-patterns of dentition reflect diets in mammals
-human saliva contains the enzyme amylase, which initiates the breakdown of starch

Question 13

human saliva

Answer 13

-human saliva contains the enzyme amylase, which initiates the breakdown of starch

Question 14

Esophagus

Answer 14

1)The esophagus transfers food to the digestive region
-rhythmic waves of contraction(peristalsis) move food to the stomach
Birds and many invertebrates have a crop for storing food.
-The gizzard of birds and gastric mill of crustaceans assist in grinding food.

Question 15

Stomach

Answer 15

-Collapsible muscular bag
-mucus, HCL, and pepsinogen are secreted.
HCL kills most bacteria. mucus protects the lining of the stomach
HCL causes (inactive) pepsinogen to transform into (active) pepsin, a protease. some protein digested.
Goes to small intestine

Question 16

Small intestine

Answer 16

Food enters the small intestine(duodenum, jejunum, and ileum) from the stomach
duodenum, and receives pancreatic juice (first part of the small intestine)
-neutralize gastric acids
-enzymes critical for digestion,(eg.proteases,lipases,amylases)
Bile is produced by the liver, stored in the gallbladder, and transported to the duodenum (produces bile pigments, and bile salts)
The internal surface area of S.I. is increased by coiling and by villi and microvilli(on top of villi)

Question 17

Bile

Answer 17

Bile is produced by the liver, stored in the gallbladder, and transported to the duodenum
Produces bile pigments; worn-out blood cells
Bile salts: help emulsify fat

Question 18

What increases the internal surface area of S.I?

Answer 18

Coiling and by villi and microvilli

Question 19

Large intestine

Answer 19

Small intestine to Large,
Large intestine(colon) begins at the point where the appendix and cecum meet small intestine.
-Colon is shoter than the S.I and lacks villi
-no digestion occurs in the colon
-consolidation of waste via water absorption, absorption of products of bacterial metabolism.
-colon empties in to dectum: fecex excreted

Question 20

Variation of stomach variation of carnivores vs herbivores

Answer 20

Carnivores have a more convoluted stomach
-eat large items infrequently; need for expansion
Herbivores have larger stomach-plants are difficult to guess and are low in nutritional value. must consume large quantities

Question 21

Herbivore digestive system

Answer 21

Cellulose can only be digested with the aid of microorganisms(that produce cellulase)
Mammals ave three places to ferment cellulose
1)foregut:stomach
2)hindgut:cecum bigger than stomach
3)hindgut: colon eg) elephanr

Question 22

Foregut fermentation-reuminants

Answer 22

The rumen is a larger chamber housing bacteria, fermented food is regurgitated, re-chewed, and then swallowed again. eg) cows

Question 23

Hindgut fermentation(cecum)

Answer 23

-many non-ruminant herbivores (eg, horses, rodents, rabbits) have a large cecum that contains bacteria needed to break down cellulose
-Long intestines increase the opportunity for absorption
-rodents and lagomorphs also engage in coprophagy(eat their own poop to digest again)

Question 24

Hindgut fermentation(colon)

Answer 24

No cecum

Question 25

Predator digestive systems

Answer 25

shorter digestive tract; cecum small or absent