Campbell Biology Chapt 41 Part Ii

Front 1

Food process

Back 1

Ingestion

Digestion

Absorption

Elimination

Front 2

Strategies for ingestion

Back 2

Filter feeders: sift food particles from water (humpback whale), includes suspension feeders

Substrate feeders: animals that live on food source (worms, maggots)

Fluid feeders: suck fluids from host (mosquito)

Bulk feeders: eat relatively large pieces of food (humans, pythons)

Front 3

Digestion

Back 3

Process of breaking food down into molecules small enough to absorb

Mechanical and chemical

Front 4

Chemical digestion

Back 4

Splits food into small molecules that can pass through membranes through enzymatic hydrolysis (adding water to split binds)

Used to build larger molecules

Front 5

Mechanical digestion

Back 5

Chewing food to increase surface area of food

Front 6

Absorption

Back 6

Animals cells take up small molecules (amino acids, simple sugars) from digestive compartment

Front 7

Elimination

Back 7

Undigested material passes out of digestive compartment

Front 8

Intercellular digestion

Back 8

Particles of food are engulfed by phagocytosis and liquids by pinocytosis

Food vacuoles fuse with lysosomes with hydrolytic enzymes

These enzymes break food down

Front 9

Extracellular digestion

Back 9

Breakdown of food particles outside of cells

Occurs in compartments that are continuous with the outside of the animals body

Have a gastriovascular cavity (digest and distributes nutrients)

Front 10

Complete digestive track or alimentary canal

Back 10

Digestive tube with Mouth and anus (more complex body simple)

Deutoerosomes

Food moves in one direction, tube is organized into special regions to digest and absorb in an stepwise fashion

Front 11

Mammalian digestive system

Back 11

2 openings

Long tube-gastrointestinal tract

Accessory glands (liver, gallbladder, pancreas )

Special compartments: pharynx, esophagus, stomach, sm. Intestine, lrg intestine, rectum, anus

Nerves and hormones control digestive activities

Front 12

Oral cavity

Back 12

First stage of digestion: both mechanical and chemical

Teeth of various shapes increase surface area

Front 13

The mouth

Back 13

Lips: orbicularis Oris muscle

Cheeks: mass eater and buccinator muscles

Tongue: skeletal muscle, taste buds

Uvula: projection in back keeps from stuff going in nasal passage

Tonsils and adenoids: lymphoid tissue, immunocompetent tissue, 1st line of defense against ingested or inhaled pathogens

Front 14

Salivary glands

Back 14

Saline to lubricant food

1. Parotid: stensens ducts

2. Submandibular: Wharton’s ducts

3. Sublingual

Front 15

Saliva contains...

Back 15

Amylase: enzyme, hydrolysizes starch and glycogen into smaller molecules (maltose), also releases food particles stick in teeth

Mucus: viscous mix of water, salt, cells, and glycoproteins (protects mouth from abrasions, lubricates food for swallowing)

Buffers: neutralize acid to prevent tooth decay

Lysozyme: antibacterial agent, targets peptidogylcan cell wall in bacteria

Front 16

Process of swallowing

Back 16

Tongue: shapes food into bolus, moves food back to pharynx

Pharynx: throat, opens to esophagus and trachea

Esophagus: connects to stomach (muscle tube usually collapsed except during swallowing)

Trachea: leads to lung

Front 17

Peristalsis

Back 17

Rhythmic contraction of smooth muscle that moves food down esophagus

Front 18

Parts that help move food

Back 18

Soft palate: closes off the nesopharynx

Trachea moves upward, epiglottis does to downward position

Sphincter (ring like valve) muscle: closes esophagus from stomach (relaxing it allows food to move through)

Front 19

Extra swallowing image

Back 19

A

Front 20

4 layers of digestive tract

Back 20

1. Mucosa

2. Submucosa

3. Muscularis

4. Serosa

Front 21

Mucosa

Back 21

Simple columnar epithelial cells supported by connective tissue and smooth muscle

Lines lumen

Glandular epithelial cells produce enzymes

Goblet cells produce mucus

Front 22

Submucosa

Back 22

Loose connective tissue

Contains blood vessels

Peyers patches- lymph node nodules (helps protect from disease)

Front 23

Muscluaris

Back 23

2 layers of smooth muscle

-circular inner layer encircles tube

-longitudinal outer layer running perpendicular

Front 24

Serosa

Back 24

Squamous epithelium

Secretes serous fluid to moisten surface (prevents abrasions as organs slid against one another)

Front 25

Images

Back 25

A

Front 26

Esophagus

Back 26

Upper 1/3: striated muscle, voluntary control

Lower 2/3: smooth muscle layers of circular and longitudinal fiber arrangement (food is pushed through, peristalsis contractions, involuntary)

Front 27

Sphincter valves

Back 27

Regulates the movement of material btw compartments

Esophagus: gastroesophageal

Pyloric: gastric duodenal

Iieocecal

Internal and external of rectum

Front 28

Stomach digestion

Back 28

Receives food from thoracic cavity

Stomach is in abdominal cavity, stores food and begins digestion of proteins

Secretes gastric juice, mixes it with food by churning action of smooth muscles in stomach wall

This mixture is called chyme

Front 29

Stomach

Back 29

J-shaped organ with thick walls due to 3 layers of muscle (oblique, circular, longitudinal)

These muscles mechanically digest and stretch. Churning motion

Rugae- 4 according-like folds of mucosa

Controls movement of chyme into sm intestine

Front 30

Chemical digestion

Back 30

Two components of gastric juices: HCL and protease (pepsin)

HCL: Chyme has a pH of 2 (could dissolve a nail) allows for-kills bacteria, break down extracellular matrix and denatures proteins (exposing peptide bonds)

Protease: protein digesting enzyme called pepsin (adapted to acidic environments) attacks peptide bonds when exposed to make proteins smaller and further expose ingested tissue

Front 31

Pepsin

Back 31

Portease or protein digesting enzyme

Cleaves proteins into smaller amino acids at peptide bonds (phenylaline, tryptophan, tyrosine)

Front 32

Gastric pit of stomach

Back 32

3 types of cells: mucous, chief, parietal

Parietal and chief cells produce components of gastric juices

Front 33

Mucous cells

Back 33

Secrete mucus and protect cell lining from pepsin

Adds new layer of epithelial cells every 3 days to replace before lining is fully eroded (when this is ineffective, ulcers appears)

Acid tolerant bacteria, pylori, causes ulcers

Front 34

Chief cells

Back 34

Secrete inactive pepsinogen

HCL clips off small portion of molecule and exposes its active site, activating pepsin (forms in lumen of stomach, not in cells to protect them)

Positive feedback system: activated pepsin stimulates more pepsinogen molecules

Front 35

Parietal cells

Back 35

Secrete hydrogen and chloride ions separately into lumen of stomach (Use ATP pump for H ions, Cl-diffusion)

This prevents harm to cells

Front 36

Digestion

Back 36

Empties every 2-6 hours after a meal

Contracts and relaxes muscle to churn food every 20 seconds

Foods are not absorbed in stomach but alcohol and other liquids are

Front 37

Stomach dynamic

Back 37

Backflow of acid chyme: from stomach into lower esophagus (acid reflux) due to sphincter at top of stomach, irritates esophagus creating “heartburn”