Title: HUMAN ANATOMY
1HUMAN ANATOMY PHYSIOLOGY
2Human Digestive System
3Warm-Up - journal
- Write down in correct sequence all the organs (at
least 5) through which their food passes as it
travels along the digestive tract. - Then try to list any glands or organs that are
found along the digestive tract, but through
which food does not pass.
4(No Transcript)
5 Following the Digestive Trail
Accessory Organs
Tongue Epiglottis Pharynx (throat) Salivary glands
- Mouth
- Esophagus
- Stomach
- Small Intestine
- Large Intestine
Accessory Organs
Pancreas Liver Gall Bladder
6The Need for Digestion
- Major Functions
- 1. Ingestion - taking in food
- 2. Digestion-ability to process food in the body
into a form that can be absorbed and used or
excreted. - 3. Absorption -pulling nutrients out of the food,
occurs in the small intestine - 4. Defecation or Excretion -removal of undigested
food
7Overview Food processing occurs in four stages
Smallmolecules
Piecesof food
Nutrientmoleculesenter body cells
Chemical breakdown(enzymatic hydrolysis)
Mechanicalbreakdown
Undigestedmaterial
Food
1
3
4
2
INGESTION
DIGESTION
ELIMINATION
ABSORPTION
Figure 21.2
8A. Purpose
- Provides energy to stay alive
- Process of breaking food particles down into
molecules small enough to be absorbed by cells - To help build cells, tissues and organs
- ATP energy for synthesis
B. Why?
mitochondria
9C. Types
- 1. MECHANICAL (Physical)
- takes place in the mouth, your teeth chew the
food, and the stomach (churning) - 2. CHEMICAL
- using chemicals to digest/ break down food, this
takes place in your mouth and stomach where acid
and enzymes mix with the food.
10Review Nutrition
- Food broken down to usable nutrients and absorbed
into the bloodstream. - They are used by the body for metabolism,
building and repair - Nutrients include carbohydrates, proteins,
lipids, vitamins, minerals and water. - Carbohydrates
- Broken down into monosaccharides
- Bodys main source of energy.
- Proteins
- Broken down to amino acids
- Supply the raw materials for growth and repair.
- Lipids
- Broken down to 3 fatty acids and glycerol
- They are used to make steroid hormones, cell
membranes - Store energy
11Nutrient End product (building blocks) Transport
Carbohydrate Simple sugars (glucose fructose) Diffusion (w/out energy high to low)
Proteins Amino Acids Diffusion
Lipids (Fats) 3 Fatty Acids 1 glycerol Diffusion Active transport (with energy, low to high)
Draw/label this
IN Nutrients O2
To the cells
Artery
OUT CO2
12D. Gastro Intestinal Tract
- How is the digestive system similar to a vacuole
in a one celled organism? - One celled organism - Digestion is intracellular
(vacuoles release digestive enzymes) - Humans- digestion is Extracellular
- (outside the cells then absorbed into the
bloodstream)
Refer to RB pg 13 table 1-1
13 Following the Trail
- Mouth
- Esophagus
- Stomach
- Small Intestine
- Large Intestine
Accessory Organs
Pancreas Liver Gall Bladder
14Mouth
Following the Trail 1
- Functions
- The process begins in the mouth.
- Chewing initiates mechanical breakdown of food
and is followed by secretion of saliva, which
moistens and lubricates food for swallowing. - Saliva also contains amylases (enzymes), which
start the chemical breakdown of carbohydrates.
All thatin spit!
15Esophagus
Following the Trail 2
- The swallowing reflex begins in the pharynx and
initiates rhythmic waves of smooth muscle
contractions called peristalsis. - Brings food from mouth to stomach
- Food is now called a BOLUS
- Epiglottis
- Flap of tissue at back of throat that prevents
food from entering the wind-pipe - Peristalsis
- Wave-like contractions that move bolus to stomach
- Peristaltic contractions transport food to the
stomach and allow a person to swallow even if
he/she are upside down. - Click Here for animation
16Stomach
Following the Trail 3
But the stomach is made out of protein! What
stops the stomach from digesting itself?
mucus secreted by stomach cells protects stomach
lining
- Functions
- Continued mechanical digestion of Carbohydrates
(churns) - First PROTEIN digestion uses pepsin (enzyme)
- Bolus turned to CHYME
- disinfect food
- hydrochloric acid pH 2
- kills bacteria
- food storage- can stretch to fit 2L food
17Small intestine
Following the Trail 4
Small intestine has 3 parts
- Functions
- The small intestine completes digestion of food
materials by absorbing nutrients into the blood
stream - S.I. lined with tiny folds or fingerlike
projections, called villi, which, in turn, are
covered by microvilli which increase surface area - The villi contain capillaries and lymphatic
vessels for the absorption of nutrients - Nutrients move into blood stream by what process
(Think H to L!)? DIFFUSION!!!!!!!!! - Chemical digestion only
- Continued digestion of Carbohydrates
- Continued digestion of Proteins
- First FAT digestion
18Absorption in Small Intestines
Following the Trail 4 cont.
- Absorption through villi microvilli
- increases surface area for absorption
Cross-Section of small intestine
Microvilli
Villi
SMALL INTESTINES6 meters long,but can
stretchto cover a tennis court
19 Following the Trail 4 cont.
- As food enters the small intestine secretions
from the liver, gall bladder and pancreas are
added .
20Pancreas
Following the Trail 4 cont.
- Produces digestive enzymes
- Buffers
- neutralizes acid from stomach
pancreas
smallintestine
21Balancing Blood Sugar levels
Homeostasis
insulin
body cells takeup sugar from blood
liver storessugar
reducesappetite
blood sugar level
liver releasessugar
triggershunger
Feedback
glucagon
22Liver Gall Bladder
Following the Trail 4 cont.
- Produces bile
- breaks up fats
- gallbladder only stores bile
- (thats why you can have your gall bladder
removed)
FYI - bile contains colors from old red blood
cells collected in liver iron in RBC rusts
makes feces brown
23Large intestines (colon)
Following the Trail 5
- Function
- The large intestine does not contain villi and it
plays no role in digestion - Removes WATER from undigested chyme
- Lined with bacteria (E. coli)
- Only water and vitamin K are absorbed from the
large intestine - Undigested or unabsorbed food is eliminated
through the rectum and then anus.
24Rectum
- Last section of large intestines
- eliminate feces
- whats left over?
- undigested materials
- mainly cellulose from plants called roughage or
fiber - keeps everything moving cleans out intestines
- masses of bacteria
- Final stop for undigested materialthe anus!
So dont forget to wash your hands!
25Where does each nutrient get broken down?
26Carb- Digestion Protein Digestion Nucleic Acid Digestion Fat Digestion
Mouth, Throat, Esophagus Polysacch. Into Disacch.
Stomach Polypepties into smaller proteins DNA, RNA into nucleotides Fat into glycerol, fatty acids and glycerides
Small Intestine Disacch. Into Monosacch. Small proteins into amino acids Nucleotides into nitrogen base, sugar and phospate
27What enzymes break down each nutrient?
Carb Digestion Protein Digestion Nucleic Acid Digestion Fat Digestion
Salivary amylase (amylose is starch, a polysacch) Peptidases (amino acids are connected by peptide bonds) Nucleotidases (nucleotides are building block of DNA and RNA) Bile salts and Lipase (fats are made of lipids)
28E. Digestive Homeostasis Disorders
Body Invaders Digestive Problems Video
Discovery Health
- 1. Stomach
- 1) Mucus that prevents stomach from digesting
itself - a) Peptic ulcer occurs when layer of mucus fails
(open sores) - b) Gastric juices reach wall of stomach and begin
to break down (painful) - 2) Treatment
- Before Antacid would reduce amount of acid in
stomach but would return - Recently Ulcer is an infection by acid resistant
bacteria Helicobacter pylori - Treatment antibiotics
29- 2. Appendix
- No function may have once been used to digest
plants (vestigal organ) - Appendicitis inflammation of the appendix
caused by E. Coli bacteria
303. Large Intestine
- Constipation- too much water reabsorbed from the
feces - Diarrhea-too little water reabsorbed from the of
feces prolonged diarrhea can cause dehydration
of body tissues.
314. Colon Cancer
- One of the most common types of cancers in North
America - Colon section before the rectum on lg.
Intestine - Cause
- Diet low in fiber causes feces to move too slow
through colon - Hereditary predisposition
325. Gallstones
- small hard stones made of cholesterol that
collect in the gallbladder. - Due to a high saturated fat diet
- hereditary
33mouth ?break up food ?digest starch ?kill
germs ?moisten food
stomach ?kills germs ?break up food ?digest
proteins ?store food
liver ?produces bile - stored in gall
bladder ?break up fats
small intestines ?breakdown food - proteins -
starch - fats ?absorb nutrients
pancreas ?produces enzymes to digest proteins
carbs