Digestion & Nutrition

Breakdown (mechanical, chemical, thermal) of food into forms that can be used by the cell.

Carbohydrates, proteins, lipids, nucleic acids.

2 Monosaccharides linked together.

Sucrose = glucose + fructose
Maltose = glucose + glucose
Lactose = Glucose+Galactose

Nuclease, Lipase, Proteinase, Amylase

An enzyme that digests nucleic acids.

An enzyme that digests lipids.

An enzyme that digests proteins.

An enzyme that digests carbohydrates.

Alimentary Canal

1. Hormonal (Stimulation of gland, hormone secreted into blood, affects target cells.)

2.Humoral (Glucose, insulin, absorption)

1

Intrinsic - wholly contained in the the system.

Extrinsic - nerve comes from outside to contact nerves within the system.

Parasympathetic - stimulates

Sympathetic - Inhibits

Lacteals

4 (2 chemical control, 1 neural control, 1 local mechanical)

Stretching

Lines the abdomen and folds over onto itself into the Visceral peritoneum which covers the organs. All blood vessels and nerves are in the peritoneum.

Visceral Peritoneum

AKA the Falciform ligament. Not actually a ligament. Binds the liver to the anterior abdominal wall.

Sheets of fat

Drapes the stomach, large intestine and small intestine

Connects the liver to the stomach.

Holds the small intestine to the posterior abdominal wall.

Mucosa, Submucosa, Muscularis, Serosa

Innermost layer of Alimentary Canal.

Muscous membrane

Columnar Epithelium have microvilli for absorption

Stratified squamous epithelium in mouth and anus where there is no absorption.

Goblet cells for lubrication and protection.

Lamina Propria - loose connective tissue with lymph nodules; highest concentration towards anus.

Muscularis Muscosae - thin strips of muscle in mucosa that throw mucosa into folds and increase surface area.

Epithelium, Lamina Propria, Muscularis Mucosae

Absorption, Protection, Digestion, Propulsion

Loose connective tissue, blood capillaries, LACTEALS, innermost nerve plexus (SUBMUCOSAL PLEXUS). They affect muscles and glands. Control shape of mucosae and secretions. Functions in absorption.

Inner Circular muscle layer, Outer Longitudinal muscle layer

Myenteric plexus: Controls movement in the alimentary canal.

Serosa

Subserous Plexus - Meissner's plexus

Continuous tube that moves food, prevents backflow, slows speed. Starts in mouth. Digestion ends at the point at which a particular food is broken down into food usable by the body. Different foods leave digestion tract at different places. Function is to process food and break down into usable form.

Process food and break down into usable form.

Peristalsis (wave like movement)

Peristalsis (wave like movement) and Mixing (occurs in stomach)

Sympathetic nerves inhibit digestion.

Parasympathetic nerves enhance digestion.

Mechanical

Cheeks and tongue provide the entry, mastication & movement of food. Lips determine temperature and texture of food.

Hard Palate, Soft Palate, Teeth, Salivary Glands

Surface against which tongue can force food during chewing

Closes Nasopharynx during swallowing; contains the Uvula

"Punching bag"; responsible for snoring

32 Permanent; 20 non-permanent

Secrete saliva

Amylase and Mucus

enzyme to digest carbohydrates

Moistens food, taste, binds food into BOLUS

Parotid - largest; below the ear, secretes AMYLASE

Submandibular - floor of mouth inside jaw; secretes MUCUS

Sublingual - smallest; under tongue, secretes MUCUS

The tongue pushes against hard palate to force bolus back.

The soft palate closes the nasopharyx and the larynx is raised.

Muscles at the top of the esophagus relax.

Muscles contract & there is peristaltic movement.

1. Receive food from the esophagus

2. Mix with gastric juice

3. Initiate protein digestion

4. Move food into small intestine.

1 liter

Protease

Pyloric Sphincter (Pylorus)

Functions as a valve to keep food in the stomach while its being mixed, to let food into the small intestine & prevent food from re-entering the stomach from small intestine.

Mucus

Digestive Enzymes (pepsin & gastric lipase)

HCL

Intrinsic Factor (Vitamin B Absorption)

Gastrin (hormone to increase gastric activity)

Sympathetic impulses (inhibit gastric activity)

Cephalic Phase (brain)- Associations with senses trigger salivation; controlled by parasympathetic impulses

Gastric Phase (Stomach)- food in stomach triggers release of gastrin which stimulates gastric activity

Intestinal Phase (SI)- food in small intestine triggers intestinal gastrin to stimulate intestinal activity

water
glucose
salts
alcohol
some lipid soluble drugs

1. Squeeze stomach with diaphragm and abs

2. Raise soft palate to close trachea

3. Close glottis

4. open Mouth

Open wounds in mucus membranes

Gastric (in upper stomach caused by irritation)

Duodenal (in lower stomach in regions exposed to PEPSIN. Stress related)

Acinar

secretory

connects secretory cells to duodenum

Pancreatic amylase (digests starch and glycogen)

Pancreatic Lipase (Digests Triglycerides)

Trypsin (Proteinase)

Chymotrypsin (Proteinase)

Carboxypeptidase (Proteinase)

Nuclease (break down nucleic acids)

proteinase activated prior to duodenum

1. Nerve impulses

2. hormones - SECRETIN (released by duodenal membrane in response to chyme)

1.Deamination of amino acids
2.Protein Synthesis
3.Blood sugar concentration regulation
4.Fatty acid oxidation
5.Fat synthesis
6.Storage of:
a. glycogen
b. Vitamins A, D, B12
c. Iron
7.Detoxification
8.Blood filter
9.Secretion - bile

2 lobes, the right lobe is larger. HEPATIC LOBULES - functional units of liver made of hepatic cells.

Bile salts (aid enzyme action on fats by emulsification)

Bile pigments (bilirubin & biliverdin which come from breaking down blood)

Stores, concentrates, & releases bile

overconcentration of bile salts

in response to the hormone CHOLECYSTOKIN (cck) released in response to fat in the small intestine

1. Hepatitis (from a virus, toxins, drugs, alcohol)
a)Type A - Infectious; spread by materials contaminated with feces containing virus
b)Type B - Serum contaminated body fluids
c)Chronic hepatitis - hepatitis symptoms for more than 6 months; results in liver damage

2. Jaundice
a)OBSTRUCTIVE - obstruction of bile salts
b)Hepatocellular - liver dysfunction affecting bile production
c)hemolytic - excessive destruction of rbcs

9-10

18-20

1. Duodenum - 1/5 of SI; pyloric sphincter to jejunum receives secretions from pancreas and liver.

2. Jejunum - proximal 2/5 of SI

3. Ileum - Distal 2/5 of SI to large intestine.

4. Mesentery - supporting tissue containing nerves, blood vessels, lymphatic vessels which supply the SI

1. Intestinal Villi - projections of the mucous membrane which increase surface area/increase absorption

2. Lumen - cavity

3. Lacteal - Lymphatic Capillary

4. Microvilli - Smaller extentions of the intestinal villi

5. Intestional glands - secrete mucus to maintain movement through SI

1. peptidase - breaks down proteins

2. sucrase - breaks down disaccharides

3. maltase - breaks down disaccharides

4. lactase - breaks down disaccharides

5. enterokinase - activates TRYPSINOGEN

6. intestinal lipase - breaks down fats

7. mucus - maintain movement through SI; alkaline to neutralize ph in gastric juice

1. Neural - parasympathetic impulses stimulate

2. Chemical - presence of acid in SI will stimulate secretion of alkaline mucus

3. Mechanical - distention stimulates stretch receptors

1. Carbohydrates - begin in mouth and end in SI

2. Proteins - begin in stomach and end in SI

3. Fats - begin in SI and end in SI

by peristalsis

Peristalsis

Mixing-cuts chyme into small segments

Diarrhea - over distension or irritation of the SI resulting in PERISTALTIC RUSH

Ileocecal valve - prevents backflow between SI and Cecum

Beginning of the Large intestine

part of the large intestine

Cecum, Colon, Rectum, Anal canal, Anus

Ascending, Transverse, Descending, Sigmoid

between the sigmoid colon and anal canal

folds in the mucous membrane containing a branch of the rectal vein

Inflammation of the anal columns

Distal opening of the alimentary canal

1. lacks villi<br />2. tubular glands produce mucus<br />3. bacteria - colon bacilli can digest some substances that enzymes do not<br /> a)cellulose - energy<br /> b)vitamin synthesis - K, B12, thiamine, riboflavin<br /> c)Gas formation

1. Slower than SI, more surface area
2. peristalsis - Mass movements - large section of colon contricts as a unit, triggers defacation reflex

1. Undigestable material
2. Water - 75%
3. Electrolytes
4. Mucus
5. Bacteria

Chemical changes & the utilization of nutrients by the body.

Carbohydrates, proteins, lipids, vitamins, water, and minerals obtained in the diet.

Nutrients required which cannot be synthesized in adequate amounts.

Mouth, Esophagus, Stomach (Pylorus), Pancreas, Liver, Gallbladder, Small Intestine (Duodenum, Jejunum, Ileum), Large Intestine (Colon, Rectum, Anal Canal, Anus)

Mucosa (innermost; mucus membranes, epithelium for absorption; functions are Absorption, Protection, Digestion, Propulsion)
Submucosa (contains lacteals and submucosal plexus; functions in absorption)
Muscularis (contains myenteric plexus; inner circular muscle layer, outer longitudinal muscle layer)
Serosa (outer layer covered by peritoneal membrane; contains subserous plexus - meissners plexus)

Primarily: Oblique Muscle layer
Secondarily: Rugae for friction

Mucus, Digestive Enzymes (Pepsin, gastric lipase), HCL, Intrinsic factor (Vitamin B absorption)

Cephalic, Gastric, Intestinal

Water, glucose, salts, alcohol, some lipid soluble drugs

Gastric (Upper stomach, caused by irritation), Duodenal (Lower stomach, caused by stress - too much pepsin in regions and not enough food to digest)

Pancreatic amylase, Pancreatic lipase, Trypin, Chymotrypsin, Carboxypeptidase, Nuclease

Deanimation of amino acids, protein synthesis, blood sugar concentration regulation, fatty acid oxidation, fat synthesis, storage of (glucose, vit A D B12, iron), detoxification, blood filter, Bile secretion.

Obstructive (obstruction of bile ducts), Hepatocellular (liver dysfunction affecting bile productino), Hemolytic (excessive destruction of rbcs)

Pylorus - Pyloric Sphincter - Duodenum, Jejunum, Ileum, Mesentery (Supporting)

Vomiting, Diarhhea. Over distention or irritation of stomach or small intestine, respectively.

Undigestible material, Water (75%), Electrolytes, Mucus, Bacteria

Ribose, Deoxyribose

Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Trytophan, Valine, Arginine, Histidine

Heat needed to raise the temperature of 1 gram of water by 1 degree C (centigrade)

BMR is the Basal Metabolic Rate. Defined as the Rate of energy expended by a body at rest, following an overnight fast, under non-stressful conditions.

Age, Sex, Size, Body Temperature, Metabolic Rate

grains
vegetables
fruit
oils
milk (dairy)
meat & beans

Aerobic Respiration

38 ATP (2 Anaerobic + 36 Aerobic)

Glycolysis is the breaking down of glucose.

4 ATP, 2 NET ATP

Krebs,

Pyruvic acid

Maintaining the BMR

Calcium, Sodium, Potassium

4.1 kcal

4.1 kcal

9.6 kcal

Contain all 8 amino acids (adequate amounts). Meat, eggs, milk

Do not contains all 8 amino acids (inadequate amounts). Ex. Corn (lacks lysine and tryptophan)

Associations with SENSES trigger salivation; parasympathetic impulses stimulate gastric activity

Food in stomach triggers gastrin release, stimulates gastic activity

Food in small intestine triggers intestinal gastrin to stimulate intestinal activity

Enhance digestion

Inhibit Digestion

In the floor of the mouth inside jaw, secretes mucus

Smallest salivary gland

Under the tongue

Secretes mucus

Chyme

PTH

B

Villi (Intestinal villi)

stomach

Amylase, carbohydrate

Small Intestine, Small Intestine

Intestinal Lipase

A, D, B12?

Water (75%)

Parotid

Gallbladder

Enterokinase

Peristalsis

Carbohydrates, Proteins, Lipids, Vitamins, Water, and Minerals

Carbohydrates

Secondary

Organic compounds used as a energy source

Starches
Glycogen
Disaccharides
Monosaccharides
Cellulose

Glucose - Energy
Disaccharides - Stored until needed
Polysaccharides - Stored until needed
Excess glucose - Converted to glycogen and fat and stored

Glucose - Energy
Ribose - RNA Synthesis
Deoxirobose - DNA Synthesis
Gluconeogenesis - Synthesis of glucose from amino acids due to lack of glucose, glycogen and fat

approx. 50-60% of total body energy is obtained from carbohydrates

Triglycerides

Plant - corn, palm, peanut
Animal - meat, eggs, lard, milk
Cholesterol - in animal sources

Triglycerides ----> fatty acids + glycerol
Controlled by liver & stored in adipose tissue
Linoleic acid - essential lipid needed for phospholid membranes

Linoleic acid

need lipids in order to obtain lipid soluble vitamins

Enzymes

Meats, cheese, nuts
Metabolism (proteins are broken down into amino acids)
Essential amino acids that cannot be synthesized

Complete Proteins

Partially Complete proteins

Structural material
Enzyme formation
Energy as a last resort

Calorie (kcal)
Calorie

Bomb calorimeter

1 kcal/kg body weight/hour or approximately 1 kcal/meter of body surface/hour

More energy taken in than put out, will gain weight

More energy put out than taken in - will lose weight

Lack of nutrition or misuse of nutrients

Undernutrition
Overnutrition
Primary Malnutrition (inadequate diet)
Secondary Malnutrition (metabolic dysfunction)

Cytoplasm

mitochondria

Cofactors & Coenzymes

3 Steps: Glycolysis, Kreb's Cycle, Electron transport.

Glycolysis breaks down to form pyruvic acid. 2 net ATP produced. Pyruvic acid is used in the Krebs cycle. Krebs cycle produces 2 ATP, Hydrogen ions, CO2. Hydrogen is moved to the electron transport chain and generate electron potential and the bulk of ATP (36).

2 + 2 + 26 = 38 ATP

3 Steps: Glycolysis, Kreb's Cycle, Electron transport.

Glycolysis breaks down to form pyruvic acid. 2 net ATP produced. Pyruvic acid is used in the Krebs cycle. Krebs cycle produces 2 ATP, Hydrogen ions, CO2. Hydrogen is moved to the electron transport chain and generate electron potential and the bulk of ATP (36).

2 + 2 + 26 = 38 ATP