The document discusses digestion and nutrition. It covers the major modes of nutrition like photoautotrophs, chemoautotrophs, photoheterotrophs, and chemoheterotrophs. It also discusses the different dietary categories like herbivores, carnivores, and omnivores. The four main stages of food processing are ingestion, digestion, absorption, and elimination. The human digestive system and its parts like the mouth, esophagus, stomach, small intestine, and large intestine are described. Key concepts around regulation of digestion, nutritional requirements, appetite regulating hormones, protein and vitamin needs are summarized as well.
The excretory products of the sponges- ammonia and other nitrogen containing substances.
Excretion occurs through both the oscula and the surface of the sponge.
It tells about the phylum porifera, ceolenerata, pltyhelminthes.......................................................................................................................!!!!!!!!!!!!!!!!!!!!!!!!!!
Medical Physiology of the GIT:
Mucosa, principles of GIT function, afferent sensory innervation, GI reflexes, motility throughout the GI system, control of stomach emptying, coordination of motility, GI secretions, Gastric events following ingestion of a meal......
The extent to which a species can adapt to an anthropogenically influenced environment is dependent on the evolutionary history of the species, the antipredatory adaptations of the population under study, the individual experiences, tolerances and learning capacities of animals, and their sensory limitations.
The excretory products of the sponges- ammonia and other nitrogen containing substances.
Excretion occurs through both the oscula and the surface of the sponge.
It tells about the phylum porifera, ceolenerata, pltyhelminthes.......................................................................................................................!!!!!!!!!!!!!!!!!!!!!!!!!!
Medical Physiology of the GIT:
Mucosa, principles of GIT function, afferent sensory innervation, GI reflexes, motility throughout the GI system, control of stomach emptying, coordination of motility, GI secretions, Gastric events following ingestion of a meal......
The extent to which a species can adapt to an anthropogenically influenced environment is dependent on the evolutionary history of the species, the antipredatory adaptations of the population under study, the individual experiences, tolerances and learning capacities of animals, and their sensory limitations.
Maternal Bisphenol A Programs Offspring Metabolic SyndromeDES Daughter
by the Collaborative on Health and the Environment
On this call Drs. Ross and Desai presented evidence that prenatal exposure to EDCs, specifically the plastic component Bisphenol A, can increase the relative risk of adult obesity and metabolic syndrome. They also discussed the significance of these findings for neonatal and childhood care, and the need for strategies for the prevention and therapy of obesity to address programming effects of the early life environment.
Sources: http://www.healthandenvironment.org/partnership_calls/15308
Thousands suffer from the gastrointestinal syndrome called leaky gut syndrome, but the underlying cause is still a mystery.
The method by which the condition occurs has been described. A gap in the mucosal lining in the gut which leads to contents like partially digested food, bacteria and fungi finding a way into the blood stream.
BIS2C. Biodiversity and the Tree of Life. 2014. L11. Symbioses and the Human ...Jonathan Eisen
BIS2C. Biodiversity and the Tree of Life.
At UC Davis Spring 2014.
Lecture 11.
Symbioses and the Human MIcrobiome
Slides for Lectures by Jonathan Eisen
Many people who try an Ancestral Diet don’t get adequate relief for their digestive complaints. A key reason why may be the presence of SIBO. This presentation will discuss symptoms, causes, pathophysiology, diagnosis and treatment of SIBO. A simple breath test can diagnose SIBO and treatments include diet, antibiotics, herbal antibiotics, elemental diet, and probiotics. Central in all treatment of SIBO is a low- carbohydrate, grain-free diet (Specific Carbohydrate Diet, Gut and Psychology Diet, modified Low Fodmaps Diet). Discussion will include why an ancestral diet can benefit digestion and how the SIBO diets differ from standard Paleo/Primal diets.
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder).In this system, the process of digestion has many stages, the first of which starts in the mouth. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body.
Chewing, in which food is mixed with saliva begins the process of digestion. This produces a bolus which can be swallowed down the esophagus and into the stomach. Here it is mixed with gastric juice until it passes into the duodenum, where it is mixed with a number of enzymes produced by the pancreas. Saliva also contains a catalytic enzyme called amylase which starts to act on food in the mouth. Another digestive enzyme called lingual lipase is secreted by some of the lingual papillae on the tongue and also from serous glands in the main salivary glands. Digestion is helped by the mastication of food by the teeth and also by the muscular actions of peristalsis and segmentation contractions. Gastric juice in the stomach is essential for the continuation of digestion as is the production of mucus in the stomach.
Peristalsis is the rhythmic contraction of muscles that begins in the esophagus and continues along the wall of the stomach and the rest of the gastrointestinal tract. This initially results in the production of chyme which when fully broken down in the small intestine is absorbed as chyle into the lymphatic system. Most of the digestion of food takes place in the small intestine. Water and some minerals are reabsorbed back into the blood in the colon of the large intestine. The waste products of digestion (faeces) are defecated from the anus via the rectum.
Lecture 4 digestion and nutrition 2nd sem 2008-2009
1. Lecture 4. Digestion and Nutrition
Major Nutritional Modes
Mode of Nutrition Energy Carbon Source Examples
Source
Autotrophs
Photoautotrophs Light CO2 Photosynthetic prokaryotes,
including cyanobacteria; plants;
certain protists
Chemoautotrophs Inorganic CO2 Certain prokaryotes (i.e.
chemicals Sulfolobus)
Heterotrophs
Photoheterotroph Light Organic Certain prokaryotes
compounds
Chemoheterotrophs Organic Organic Many prokaryotes and protists;
compounds compounds fungi; animals; parasitic plants
15. •
chewing mouthparts
adapted for seizing
and crushing food
•
mandibles are strong,
toothed plates whose
edges can bite or tear
•
maxillae hold the
food and pass it
toward the mouth
16. •
birds lack teeth
•
bills are often
provided with
serrated edges
•
In some, the upper
bill is hooked for
seizing and tearing
prey
17. Four types of teeth found in mammals:
•
incisors, for biting, cutting, and stripping
•
canines, for seizing, piercing, and tearing
•
premolars, for grinding and crushing
•
molars, for grinding and crushing
18. •
an elephant’s tusk is a
modified upper incisor
•
used for defense,
attack, and rooting
•
a male wild boar has
modified canines that
are used as weapons
19.
20. Types of Digestive System
•
Incomplete – there is only one opening; no anus
Paramecium Hydra
21. Types of Digestive System
•
Complete – there is a mouth opening and an anus
22. Four Main Stages of Food Processing
•
Ingestion – the act of eating
•
Digestion – breaking food down into molecules
small enough for the body to absorb
•
Absorption – small molecules are taken in
by the animal’s cells
•
Elimination – undigested material passes out of
the digestive compartment
23. •
digestion is entirely intracellular in
protozoa and sponges
24. •
radiates, turbellarian flatworms,
and ribbon worms (nemerteans)
practice both intracellular and
extracellular digestion
•
in extracellular digestion, certain
cells lining the lumen of alimentary
canals form digestive secretions;
other cells function in absorption
•
for arthropods and vertebrates
digestion is almost entirely
extracellular
25. Gut movement
•
alternate constriction of
rings of smooth muscle of
the intestine
•
constantly divide and
squeeze contents back
and forth
•
for mixing of food
•
waves of contraction of
circular muscle behind
the gut and relaxation in
front of bolus
•
sweeps food down the
gut
31. •
trypsin, chymotrypsin, and carboxypeptidase
are secreted in inactive form by the pancreas
–
the intestinal enzyme,
enteropeptidase, converts
inactive trypsinogen into
active trypsin
–
active trypsin then
activates the other two
32. Human Small Intestine
•
Made up of three regions:
1. duodenum
- Nearest to the stomach; 26 cm in length
- With Bruner’s glands
-
produce mucus-rich alkaline secretion with
bicarbonates to
-
protect the duodenum from the acidic content
of chyme;
-
provide alkaline condition for the intestinal
enzymes to be active; and
-
lubricate the intestinal walls
33. Human Small Intestine
•
Made up of three regions:
2. jejunum
- Next to duodenum; 2.5 m in length
3. ileum
- Last segment of the small intestine; 3.5 m in length
- Contains Peyer’s patches
-
Organized lymphoid tissues
-
Protects the intestinal lumen from pathogenic
bacteria
34.
35. •
Food is called chyle once it is in the small intestine
36. Human Large Intestine
•
the colon recovers water that has entered the alimentary canal
as the solvent to various digestive juices
•
the large intestine harbors a rich flora of mostly harmless
bacteria
•
the terminal portion of the colon is called the rectum, where
feces are stored until they can be eliminated
41. •
the length of the vertebrate digestive system is
also correlated with diet
42. •
ruminants (deer, cattle, and sheep) have the
most elaborate adaptations for a herbivorous
diet
43. Nutritional Requirements
•
A nutritionally adequate diet satisfies three
needs:
–
fuel (chemical energy) for all the cellular work of the
body
–
organic raw materials animals use in biosynthesis
(carbon skeletons to make many of their own
molecules)
–
essential nutrients
44. –
If the diet of a person or other animal is chronically
deficient in calories, undernourishment results
–
an animal whose diet is missing one or more
essential nutrients is said to be malnourished
–
marasmus, general undernourishment from a diet
low in both calories and protein
–
kwashiorkor, protein malnourishment from a diet
adequate in calories but deficient in protein
–
overnourishment or obesity results from excessive
food intake
45. •
in mammals, a hormone called leptin,
produced by adipose cells, is a key player in a
complex feedback mechanism regulating fat
storage and use
46. Appetite-regulating hormones
•
ghrelin (stomach wall)
–
triggers feelings of hunger as mealtimes approach
•
leptin (adipose tissue)
–
suppresses appetite
•
PYY or peptide-tyrosine-tyrosine (small intestine)
–
after meals
–
appetite suppressant; counters ghrelin
•
insulin (pancreas)
–
a rise in blood sugar level after a meal
47. •
animals require 20 amino acids to make proteins
•
essential amino acids must be obtained from
food in prefabricated form
–
eight amino acids are essential in the adult human
(phenylalanine, lysine, isoleucine, leucine, valine,
methionine, tryptophan, and threonine) with
histidine and arginine essential for normal growth of
children
48. •
protein deficiency from a vegetarian diet can
be avoided by eating a combination of plant
foods that complement each other to supply all
essential amino acids
49. •
vitamins are organic molecules required in the
diet in small quantities
•
13 vitamins essential to humans have been
identified
•
water-soluble vitamins generally function as
co-enzymes
52. •
Minerals are simple inorganic nutrients, usually
required in small amounts
–
humans and other vertebrates require large
quantities of calcium and phosphorus for the
construction and maintenance of bone
–
iron is a component of the cytochromes and of
hemoglobin
–
while sodium, potassium, and chloride have a
major influence on the osmotic balance between
cells and the interstitial fluids, excess consumption
of salt (sodium chloride) is harmful