Docstoc
EXCLUSIVE OFFER FOR DOCSTOC USERS
Try the all-new QuickBooks Online for FREE.  No credit card required.

Slide 1 - Troy High School

Document Sample
Slide 1 - Troy High School Powered By Docstoc
					       Introductory Question #6
1)   Name the four stages of food processing. (see pg.
     853).
2)   From pg. 845, name the four types of feeders and the
     organism example shown.
3)   How are the alimentary canals different in an
     earthworm, grasshopper, a bird, and a cow (ruminant
     animal).
4)   Explain what peristalsis is and what causes it to occur.
5)   Name the cells that line the stomach which secrete
     HCl and pepsin. What are folds in the stomach called?
6)   What function do the villi serve in the lining of the
     intestines? Name the (3) segments of the small
     intestines and the (4) regions of the large intestines.
7)   How is an essential nutrient different from any other
     nutrient? (pg. 849) Give three examples of a fat-
     soluble and three examples of a water soluble vitamin.
Digestion & Nutrition
      Chapter 41
Overview: Food processing occurs in
             four stages



                                             Small
                                         molecules

                    Pieces
                    of food                          Nutrient
                                                     molecules
                              Chemical breakdown     enter body
              Mechanical      (enzymatic hydrolysis) cells        Undigested
              breakdown                                           material

 Food



1 INGESTION           2 DIGESTION                3 ABSORPTION     4   ELIMINATION


                                                                                    Figure 21.2
  Digestion occurs in specialized
           compartments

• Food is digested in compartments housing
  hydrolytic enzymes
• Most animals have a specialized digestive
  tract
• Relatively simple animals have a sac with a
  single opening
  – This is called a gastrovascular cavity
  – Example: hydra

                              Mouth

        Tentacle




                                                   Hydrolytic
                                        Flagella   enzymes

                                 Food
                                 particle

                                  Engulfment
             Food        Gastro- of food
             (Daphnia,   vascular particle
             a water     cavity
             flea)                Digestion in
                                  food vacuole
                                                                Figure 21.3A
• In most animals, the digestive compartment
  is an alimentary canal
  – This is a tube running from mouth to anus
  – This tube is divided into specialized regions that
    process food sequentially

                  Crop   Gizzard
          Esophagus                Intestine
          Pharynx


                                                     Anus

          Mouth

           EARTHWORM



                                                            Wall of intestine

                                          Interior of intestine
                                                                                Figure 21.3B
          Grinding




   Esophagus
                    Stomach
          Gizzard                    Anus




                                               Esophagus
                                                      Stomach
                         Intestine                              Gizzard
        Crop
                                                                          Intestine
  Mouth     Gastric pouches

GRASSHOPPER                                 Mouth

                                                Crop

                                                                             Anus


                                            BIRD
                              storage

                                                                                 Figure 21.3B (cont)
• Ruminants such as cows process cellulose
  in a four-chambered stomach
                         Re-absorption water
             Intestine        3 Omasum     1 Rumen   Fermentation/microorganisms

                                                       Esophagus




                Rumen
                            4 Abomasum           2 Reticulum
                                                      Size sorter/microorganisms
   Releases acids/digestive enzymes


                                                                   Figure 21.12B
• Humpback whales strain their food from
  seawater using large, brushlike plates called
  baleen
  – When they feed, they take in large amounts of
    seawater in which the fish and krill live
  – They must filter out the water in order to get a
    meal
• In a typical day, a humpback whale’s digestive
  system will process as much as 2 tons of fish and
  krill
  – They store the excess energy they harvest in the form of
    blubber
  – In about 4 months, a humpback whale eats, digests, and
    stores as fat enough food for an entire year
   Animals ingest their food in a
           variety of ways
• Animal diets are highly
  varied
  – Herbivores are plant-eaters
  – Carnivores are meat-eaters
  – Omnivores eat both plants
    and other animals




                                  Figure 21.1A
• Most animals ingest chunks of food




                               Figure 21.1E
– Some animals are
  suspension feeders,
  consuming particles
  from water



– Some are substrate
  feeders, living in or on
  their food source



                             Figure 21.1B, C
– Some are fluid
  feeders, sucking
  liquids




                     Figure 21.1D
     Adaptations of vertebrate
     digestive systems reflect diet
• Herbivores and omnivores generally have
  longer alimentary canals than carnivores
  – Plant matter is more difficult to digest than meat
  – Nutrients in vegetation are less concentrated
    than in meat
• Some mammals house cellulose-digesting
  microbes in the colon or cecum
  – The cecum is a pouch where the large and small
    intestines connect
  – Examples: horses and elephants
• Other mammals re-ingest their feces to
  recover nutrients
  – Examples: rabbits and some rodents
                                Small intestine



Small
intestine      Stomach

                                                   Large to
                                                   house
                Cecum
                                                   bacteria to
                                                   break down
                                                   plant
                                                   material
               Colon
               (large
               intestine)




   CARNIVORE                HERBIVORE             Figure 21.12A
                             Oral cavity
Mouth
Tongue                       Pharynx
Salivary
glands

                                     Esophagus
           Liver
                   Stomach




                                       Pyloric
                                       sphincter
                                                   Stomach
Gall-
bladder
                         Small
Pancreas                 intestine          Small
                                            intestine
                         Large
                         intestine


 Rectum

                        Anus                            Figure 21.4
Digestion begins in the oral cavity

• The teeth break up food
• Saliva moistens it
• Salivary enzymes begin the hydrolysis of
  starch
• The tongue pushes the chewed food into the
  pharynx
                      TEETH

                      Incisors


                      Canine

                      Premolars

                      Molars



                      “Wisdom”
                      tooth
Tongue




Salivary
glands



Opening of a
salivary gland duct


                        Figure 21.5
 The food and breathing passages
      both open into the pharynx
• The swallowing reflex moves food from the
  pharynx into the esophagus
  – At the same time, food is kept out of the trachea
                                    Bolus of food
Tongue
                                    Epiglottis                              Epiglottis
                                    up                                      down
Pharynx


Larynx
                                    Esophageal      Larynx                                Larynx
                                    sphincter       up                                    down
          Trachea                                                           Esophagus
          (windpipe)                Esophagus


             Sphincter contracted                       Sphincter relaxed                Sphincter contracted




                                                                                                   Figure 21.6
   The human digestive system
   consists of an alimentary canal
        and accessory glands
• When food is swallowed, it is moved through
  the alimentary canal by peristalsis
  – Peristalsis is rhythmic muscle contraction in the
    walls of the digestive tract
  – Ringlike sphincter muscles regulate the passage
    of food
 The esophagus squeezes food
       along to the stomach
• Peristalsis in the esophagus moves food
  boluses into the stomach

     Circular                        Relaxed
     muscle layer                    muscles
                                     Circular       Relaxed
                                     muscles        muscles
                                     contract,
                    Bolus of         constricting
                    food             passageway
                                     and pushing
                                     bolus down
                    Longitudinal
                    muscles
                    contract,
                    shortening
                    passageway
                    ahead of bolus

                    Stomach
     Longitudinal
     muscle layer

                                                              Figure 21.7
  The stomach stores food and
    breaks it down with acid and
              enzymes
• The stomach mixes food with gastric juice
  – The gastric juice contains pepsin, which begins
    the hydrolysis of protein
                   Interior surface   Pits
                   of stomach                           Gastric juice
                                                        (mucus, HCI,
Food particle                                           and pepsinogen)
                                                                           3
                                                    Epithelium
                   Gastric
                   juice                                  Pepsinogen           Pepsin (active
                                                                      2        enzyme)
                                                    Mucous
                                                    cells            HCI
Pyloric
sphincter
                      Gastric                                        1
         STOMACH                               Chief cells
                      gland




                                             Parietal cells



                                                                                 Figure 21.8
The small intestine is the major organ of
chemical digestion and nutrient absorption
DUODENUM:
• Alkaline pancreatic juice neutralizes stomach
  acids
  -Its enzymes digest polysaccharides,
  proteins, nucleic acids, and fats

• Bile emulsifies fat droplets for attack by
  pancreatic enzymes
  – It is made in the liver and stored in the gall
    bladder
                         Bile

      Liver




 Gall-                                       Stomach
 bladder

                  Bile          Acid chyme



Duodenum of                                  Pancreas
small intestine




                                             Figure 21.10A
• The lining of the small intestine is folded and
  covered with tiny, fingerlike villi
  – Villi increase the absorptive surface
• Nutrients pass through the epithelium of the
  villi and into the blood
  – The blood flows to the liver
  – The liver can store nutrients and convert them to
    other substances the body can use
• (1) the Duodenum: a section
  that receives secretions from
  the pancreas and liver; a
  receiving area for chemicals
  and partially digested food from
  the stomach;

• (2) the Jejunum: where most
  of the nutrients are absorbed
  into the blood and considered
  to be roughly 40% of the small
  gut in man

• (3) the Ileum: where the
  remaining nutrients are
  absorbed before moving into
  the large intestine; considered
  to be about 60% of the
  intestine in man
• Enzymes from the walls of the small
  intestine complete the digestion of many
  nutrients




                                             Table 21.10
                                       INTERIOR OF INTESTINE
                  Blood vessel
                  with blood      Nutrient
                  en route to     absorption
                  the liver
                                                                      Nutrient
                                                                      absorption
                                                               Microvilli


                         Epithelial
                         cells

                         Lumen
Muscle
layers
                         Blood
Circular folds           capillaries

Villi                    Lymph                                      EPITHELIAL
                         vessel                                       CELLS
                    Nutrient
                    absorption




INTESTINAL WALL                                VILLI


                                                                     Figure 21.10B
    Bacterial Infections can cause
                  Ulcers
• New evidence suggests that a spiral-shaped
  prokaryote causes gastric ulcers
  – Helicobacter pylori growth erodes protective
    mucus and damages the stomach lining
 Large Intestine Reclaims Water

• Undigested        Large
                    intestine
  material passes   (colon)


  to the large
  intestine, or
  colon                         End
                                of small                    Small
  – Water is                    intestine                   intestine

                                                       Rectum
    absorbed
                                                    Anus

  – Feces are                                   Nutrient
                                                flow
    produced                         Appendix

                    Cecum
                                                           Figure 21.11
   A healthful diet satisfies three
                  needs
• An animal’s diet provides
  – fuel for its activities
  – raw materials for making the body’s own
    molecules
  – essential nutrients that the body cannot make
   Chemical energy powers the
               body
• Once nutrients are inside cells, they can be
  oxidized by cellular metabolism to generate
  energy
  – This energy is in the form of ATP
• The energy a
  resting animal
  requires each day
  to stay alive is its
  basal metabolic rate
  (BMR)




                         Figure 21.14
• More energy
  is required for
  an active life

  – Excess
    energy is
    stored as
    glycogen or
    fat




                    Table 21.14
      Body Fat and Fad Diets

• The human body tends to store excess fat
  molecules instead of using them for fuel
• A balanced diet includes adequate amounts
  of all nutrients
• Fad diets are often ineffective and can be
  harmful




                                           Table 21.15
    A healthful diet includes 13
                vitamins
• Most of these vitamins function as
  coenzymes
  Essential minerals are required
       for many body functions
• Minerals are elements other than carbon,
  hydrogen, oxygen, and nitrogen
  – They play a variety of roles in the body
 Vegetarians must be sure to obtain
     all eight essential amino acids
• The eight essential amino acids that adults
  require must be obtained from food
  – They are easily
                                           ESSENTIAL
    obtained from                          AMINO ACIDS

    animal protein                         Methionine


  – They can also be                       Valine

                                           (Histidine)
    obtained from the                      Threonine

    proper combination                     Phenylalanine

    of plant foods                  Corn   Leucine

                                           Isoleucine
                                                           Beans and
                                           Tryptophan      other
                                                           legumes
                                           Lysine
                     Figure 21.16
Table 21.17 (Fat-soluble vitamins)
Table 21.17 (Water-soluble vitamins)
Table 21.18
Diet can influence cardiovascular
         disease and cancer
• Choice of diet may reduce the risk of
  cardiovascular disease and cancer
         BEHAVIORAL                             UNAVOIDABLE
        RISK FACTORS                            RISK FACTORS


          Fatty diet      High         High        Aging
                         blood        blood
                       cholesterol   pressure


          Lack of                               Family history
          exercise


                          CARDIOVASCULAR
                             DISEASE
          Smoking                                Being male



                                                                 Figure 21.20
Table 21.20
• A sound diet supplies
  – enough raw materials to make all the
    macromolecules we need
  – the proper amounts of prefabricated essential
    nutrients
  – enough kilocalories to satisfy our energy needs
       Getting Their Fill of Krill
• Animals obtain and
  process nutrients in a
  variety of ways
• Humpback whales eat
  small fishes and
  crustaceans called krill
  – This painting shows how
    the whales corral their
    food using “bubble nets”
Video #5-Digestion & Fluid Balance (Ch. 41)
1.   What organism is used by Dr. Carol Beuchat to illustrate
     how fluid is regulated and the role played by the urinary
     tract in maintaining homeostasis? (1st segment)
2.   How is a complete digestive system different from an
     incomplete one? What function does each segment
     (region) of the digestive system have?
3.   Name two enzymes mentioned by Dr. Sokolowski that play
     a role in the digestive system. How is the diet of a dog
     different from a cat? What are the nutritional needs for a
     cat and dog? What is the name of the café mentioned in
     the video?
4.   The final segment discusses the role the kidneys play in
     maintaining homeostasis. What kind of machine is the
     patient connected to?

5.    **Write the title for each segment and FIVE statements
     for each segment.
         Video#6:
Laparoscopic Cholecystectomy



    *Write 10 Statements from the
                video

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:4
posted:2/1/2013
language:English
pages:52