Chapter 41 Nutrition Flashcards
In animals diet provides
- Chemical energy
- organic building bocks (organic carbon and nitrogen)
- essential nutrients (must have, cannot make themselves)
What are the four classes of essential nutrients?
- essential amino acids
- essential fatty acid
- vitamins
- minerals
Can the body make essential nutrients?
No
Animals require how many amino acids?
20
Can synthesize About half from molecules in their diet
___________ amino acids must be obtained from food in preassembled form
“__________” proteins provide all amino acids
Ex: eggs, meat, cheese
Essential
Complete
Vitamins are __________molecules required in the diet in Small amounts
How many vitamins are essential for humans?
Organic
13,
two categories: fat-soluble and water-soluble
Minerals are simple __________ nutrients, usually required in small amounts
Inorganic
Deficiency of vitamin D that may lead to a condition of weakening and softening of the bones brought on by extreme calcium loss
Rickets
Malnourishment produced by severe protein deficiency
kwashiorkor disease
Long-term absence from the diet of one or more essential nutrients
Malnourishment
Results when a diet does not provide enough chemical energy
Undernutrition
Neural tube defect‘s were found to be the result in a deficiency in ___________ In pregnant mothers
Folic acid, vitamin B9
What are the main stages of food processing?
- ingestion is the act of eating
- digestion
- absorption
- elimination
What are the four main feeding mechanisms of animals?
- suspension feeders (many are aquatic line whales)
- substrate feeders (Live in or on their food source)
- fluid feeders
- bulk feeders (humans)
The process of breaking food down into molecules small enough to absorb
Digestion
- mechanical digestion
- Chemical digestion (enzymatic hydrolysis)*
The uptake of nutrients by body cells
Absorption
- type of digestion were food particles are engulfed by phagocytosis
- food vacuoles, containing food, fuse with lysosomes containing hydrolytic enzymes*
Intracellular digestion
The breakdown of food particles outside of cells
Occurs in compartments that are continuous with the outside of the animals body
Extracellular digestion
Animals with simple body plans have a __________ that functions in both digestion and distribution of nutrients
Gastrovascular cavity
A complete digestive track with two openings. Mouth and anus.
It can have specialized regions that carry out digestion and absorption in a stepwise fashion
Alimentary canal
- pushes food along
- rhythmic contraction of muscles in the wall of the canal
Peristalsis
Please regulate the movement of material between compartments
Sphincters (valves)
Initiates digestion of carbohydrates/polymers of glucose
Occurs in the oral cavity, found in saliva
Salivary amylase
Two components of saliva?
- salivary amylase
- Mucus (A viscous mixture of water, salt, cells, and glycoproteins)
The combination of saliva and food is called…
Bolus
Junction that opens to both the esophagus and the trachea
Pharynx (throat)
Swallowing is a reflex action where the soft palate closes of the ___________.
Trachea moves up causing the ____________ to cover the glottis.
Nasopharynx
Epiglottis
What covers the opening to the windpipe when swallowing?
Epiglottis
When does coughing occur?
When The epiglottis fails to close off the windpipe
What allows food to enter the stomach?
Esophageal sphincter
- a muscular tube that extends from the pharynx to the stomach
- usually collapsed except when swallowing when it receives the bolus
- peristalsis rhythmic contractions
Esophagus
What is the end product of the stomach?
Chyme
Gastric juice has a low pH of about two and kills bacteria and denatures proteins
What is gastric juice composed of?
- hydrochloric acid (HCL)
- pepsin
- protease
Protein digesting enzyme, that cleaves proteins into smaller peptides
Protease
Secrete hydrogen and chloride ions separately into the lumen (cavity) of the stomach
Parietal cells
-secrete inactive pepsinogen
Chief cells
What activates pepsinogen?
What is pepsinogen converted to?
Hydrochloric acid
Pepsin
- pepsin activates more pepsinogen*
- largest section of the elementary canal
- major organ of digestion and absorption
Small intestine
protein digestion starts In the….
Stomach
The first portion of the small intestine is where chyme from the stomach mixes with digestive juices
- pancreas
- liver
- gallbladder
- Small intestine
Duodenum
The pancreas has endocrine and ___________ functions
Exocrine
(Exocrine) pancreas produces…
Sodium bicarbonate:
Pancreatic amylase:
Trypsin and chymotrypsin:
-protease activated in the lumen of the stomach
Lipase:
nuclease:
Neutralize stomach acid
Digest starch
Protein digestion
Digest fat
Break down nucleic acids
- largest gland
- produces bile
- aids in digestion and absorption of fats in small intestine
- destroys nonfunctional red blood cells
- aids in detoxification
Liver
The epithelial lining of the ___________ produces several digestive enzymes
***most digestion occurs here
Duodenum
The ___________ and __________ mainly function in absorption of nutrients and water
Jejunum and ileum
____________ surface creates a brush border that greatly increases the rate of nutrient absorption
Microvilli
Villi contains:
-blood capillaries for nutrient absorption
•sugars and amino acids
•glycerol and fatty acids
The Hepatic portal vein carries nutrient-rich blood to the…
Liver
Epithelial cells absorb fatty acids and monoglycerides and recombine them into ____________
Triglycerides
small fat globule composed of protein and lipid (fat). are found in the blood and lymphatic fluid where they serve to transport fat from its port of entry in the intestine to the liver and to adipose (fat) tissue.
Chylomicrons
Chylomixrons
- what is the composition?
- how are they transported?
Fat surrounded phospholipids
Carried by lymph
- part of the large intestine
- connects where the small and large intestine meet
- aids in the fermentation of pant material Appendix-extension that plays a minor role in immunity
Cecum
- connected to the small intestine
- ascending colon, descending colon, sigmoid colon enters the rectum
Colon
- contains the cecum, colon, rectum, anal canal
- absorbs water, salt, and some vitamins
- stores indigestible materials until it can be eliminated
Large intestine
A major function of the _________ is the recovery of water that has entered the alimentary canal
Houses bacteria that live on unabsorbed organic material some produce vitamins
Colon
Many __________ have large, expandable stomachs
Carnivores
Why do you herbivores and omnivores generally have longer alimentary canal’s then carnivores?
More time and surface area for digestion/ absorption of plant matter because it is harder to digest
Many herbivores have ______________, where mutualistic organisms digest cellulose
The most elaborate adaptations for an herbivores diet have evolved in the animals called ___________
Fermentation chambers
Ruminants
In animals that break down additional nutrients in the large intestine will later feed on feces to retrieve these nutrients
Ex: rabbits
coprophagy
the ________ division of the nervous system and the endocrine system helps to regulate The digestive process
Enteric
When the stomach stretches, what is released?
What does it do?
Gastrin
Released in bloodstream, then activates receptors in the stomach to Stimulates gastric juices
In humans, energy is stored first in the ________ and __________ cells in the polymer glycogen
Excess energy is stored in __________ tissue, The most space efficient storage tissue
Liver and muscle
Adipose
When chyme enters the duodenum, it responds by releasing two hormones….
What do they do?
CCK and secretin
CCK-stimulates the release of digestive enzymes
Secretin-stimulates the pancreas to release bicarbonate
It’s chyme is rich in fats, high levels of ________ and _________ act on the stomach and inhibit peristalsis to slow digestion down
CCK, secretin
CCK stimulates the release of digestive enzymes from the __________ and the _________.
Gallbladder and pancreas
The _______ is the site for glucose homeostasis
Liver
A carbohydrate rich meal raises insulin levels, which triggers the synthesis of ________
Glycogen
Low blood sugar causes glucagon to stimulate the breakdown of _________ and release ________.
Glycogen, glucose
In the pancreas,
_______ cells secrete insulin
_______ cells secrete glucagon
Beta
Alpha
Insulin-dependent diabetes is known as type ____. This is an autoimmune disorder. Immune system destroys the beta cells.
Non-insulin-dependent diabetes is known as type _____. The target cells do not respond to insulin.
1
2
- -One of the signals that triggers the feeling of hunger
- secreted by the stomach wall
Ghrelin
2._____________ acts on the brain to suppress appetite
Insulin
- -produced by adipose tissue that also suppresses appetite
- if fat levels decrease, this also decreases so that appetite can increase
Leptin
- Secreted by small intestine after meals, acts as an appetite suppressant counteracts ghrelin.
PPY
