week 11 (digestive system -digestion, eliminative, absorptive & distributive processes; utilization processes: liver & cell metabolism)

Question 1

digestion

Answer 1

l: digestive system
f: complex process of turning the food you eat into nutrient

Question 2

absorption

Answer 2

l: happens mostly in small inestine
f: absorp nutrients and vitmins in food

Question 3

metabolism

Answer 3

l: mostly liver
f: keeps the body at homeostatis

Question 4

mechincal digestion

Answer 4

purely physical process that does not change the chemical nature of the food. Instead, it makes the food smaller to increase both surface area and mobility.

Question 5

chemical digestion

Answer 5

Chemical digestion involves the secretions of enzymes throughout your digestive tract. These enzymes break the chemical bonds that hold food particles together.

Question 6

mastication

Answer 6

definition: chewing
area(s): mouth
how it process facilitates digestion: mechinal digestion
muscle tissue: in the jaw and mouth region
branch of motor nervous system: voluntary

Question 7

degulitition

Answer 7

definition: swallowing
area(s): throat/buccal cavity
how it process facilitates digestion: allows food to go to eposgus
muscle tissue: touge
branch of motor nervous system: voluntary

Question 8

propulsion

Answer 8

definition: pushing/forcing food towards an area
area(s): buccal cavity, stomach, small intestine, large, rectum
how it process facilitates digestion: allows food to continue to move throughout the tract
muscle tissue: tonuge, smooth muscle tissue
branch of motor nervous system: voluntary/involuntary

Question 9

perisalisis

Answer 9

definition: wave like contractions
area(s): eposgus and stomach
how it process facilitates digestion: moves food and further digests it
muscle tissue: smooth muscle tissue
branch of motor nervous system:involuntary

Question 10

segmantation

Answer 10

definition: separates chyme and then pushes it back together
area(s): intestines
how it process facilitates digestion: always chyme to be chemical digested and absported
muscle tissue: smooth muscle
branch of motor nervous system: involuntary

Question 11

defactation

Answer 11

definition: pooping
area(s): rectum/anus
how it process facilitates digestion: release of feces
muscle tissue: smooth mucle
branch of motor nervous system: involuntary/ vountary

Question 12

vomiting

Answer 12

Vomiting is the body’s way of protecting you from threats. When it detects a harmful substance or something irritating, your body actually thinks you’re being poisoned. The body’s natural reaction is to rid the body of that threat, causing it to expel the contents of the stomach.

Question 13

diaharring

Answer 13

the contents in your digestive system move so quickly through the digestive system that the intestines don’t have enough time to absorb the fluids, or when the digestive system produces extra fluid. The result is stools that contain excess fluids, making them loose and watery.

Question 14

consitputation

Answer 14

waste or stool moves too slowly through the digestive tract or cannot be eliminated effectively from the rectum, which may cause the stool to become hard and dry.

Question 15

digestive enzymes

Answer 15

Amylase

• made in the pancreas and salivary glands
• startch to maltose

Maltase

• maltose to glucose
• made in small intestine

Lactase

• lactose to glucose/galactose
• made in small intestine

Lipase

• lipids (fats/oils) to fatty acids/glycerol
• made in pancreas

Proteases

• protien to amino acids
• made in pancreas/stomach

Question 16

what must ____ be reduced to to be digested

Answer 16

a. carbohydrates (polysaccharides) - glucose

b. fats (lipids) - fatty acids

c. proteins (polypeptides) - amino acids

Question 17

chyme

Answer 17

the pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.

Question 18

hydrolysis

Answer 18

Hydrolysis is any chemical reaction in which a molecule of water breaks one or more chemical bonds

Question 19

chemical digestion of the stomach

Answer 19

a. Hydrochloric acid

Hydrochloric acid helps your body to break down, digest, and absorb nutrients such as protein. actives pepsinogen

b. Pepsinogen (inactive pepsin)

a substance which is secreted by the stomach wall and converted into the enzyme pepsin by gastric acid.

c. Mucus

Gastric mucus is a gel-mucous barrier secreted by epithelial cells and glandular cells in the stomach wall. It acts as part of a barrier that protects the stomach wall from the acid and digestive enzymes within the stomach lumen.

d. Gastric lipase

an acidic lipase secreted by the gastric chief cells in the fundic mucosa in the stomach

Question 20

pancreatic juices

Answer 20

a. Trypsin (inactive to not digest pancreas)

-digest proteins into peptides

b. Chymotrypsin

-digest proteins into peptides

c. Carboxypeptidase (inactive to not digest pancreas)

-digest proteins into peptides

d. Pancreatic lipase

-the principal triglyceride–digesting enzyme in adults

e. Pancreatic amylase

-starch-digesting enzyme

Question 21

enterokinase

Answer 21

a protease of the intestinal brush border that specifically cleaves the acidic propeptide from trypsinogen to yield active trypsin

Question 22

how do bicarbonates in pancratic juices help with digestion

Answer 22

in neutralising the low pH of the chyme coming from the stomach

Question 23

role of bile in lipid molecules

Answer 23

lipid carriers and are able to solubilize many lipids by forming micelles - aggregates of lipids such as fatty acids, cholesterol and monoglycerides

Question 24

small intestine enzymes

Answer 24

protease

• protien to amino acids
• made in pancreas/stomach

maltase

• maltose to glucose
• made in small intestine

lactase

• lactose to glucose/galactose
• made in small intestine

sucrase

-sucrose to fructose/glucose

-made in small intestine

Question 25

mechincal digestion in large intestine

Answer 25

a. haustral churning

haustra remains relaxed and become distended while they fill up. - when distension reaches maximum fill, walls contract and squeeze contents into next haustra.

b. peristalsis

wave like contractions to move food

c. mass peristalsis

strong peristaltic wave that begins in transverse colon and drives contents of the colon into the rectum

Question 26

body flora in large intestine

Answer 26

plays important roles in angiogenesis and maintenance of mucosal barrier integrity

Question 27

endocrine hormones which aid in digestion

Answer 27

a. Gastrin

• stimulation of acid secretion from gastric parietal cells
• stimulation of mucosal growth in the acid-secreting part of the stomach
• produced by ‘G’ cells in the lining of the stomach and upper small intestine

b. Cholecystokinin (CCK)

• stimulates the gallbladder to contract and release stored bile into the intestine
• made on duodenum

c. Secretin

• hormone released into the bloodstream by the duodenum (especially in response to acidity) to stimulate secretion by the liver and pancreas.
• made in small intestine

Question 28

enteric nervous system

Answer 28

The enteric nervous system consists of the neurons and neuroglia cells found within the wall of the digestive tract. More specifically, it consists of two interconnecting ganglionated plexuses: one located between the circular and longitudinal smooth muscle layers; and one located within the submucosa.

The neural ‘circuitry’ of this system includes sensory, motor and interneurons. This means it can make complex reflex responses even when all connections to external neural ‘circuitry’ are severed.

Normally, the enteric nervous system governs the basic activity of the digestive system including peristaltic contractions of the outer muscle layers, movement of the muscularis mucosa, and secretions of the mucosa and submucosa glands.

Although visceral smooth muscle contracts spontaneously, the coordination required for peristalsis, segmentation, mixing, etc. depends on the enteric nervous system

Question 29

relationship between enteric and automatic nervous system

Answer 29

The autonomic nervous system alters the activity of the enteric nervous system, as well as having direct contact with other digestive wall tissues.

The parasympathetic axons terminate at the enteric plexuses and at smooth muscle and glandular epithelial tissue directly. Impulses on the parasympathetic neurons cause an increase in smooth muscle motility and an increase in glandular secretions.

The axons of the sympathetic motor axons terminate at the enteric plexuses and on the smooth muscle tissue (both in the wall of the digestive tract and the wall of the blood vessels).

The release of norepinephrine from the axon terminals slows muscle motility in the gut wall and reduces glandular secretions.

Question 30

neurtal reflexes

Answer 30

Many neurons of the ENS are components of GI (gastrointestinal) reflex pathways that regulate GI secretion and motility in response to stimuli present in the lumen of the GI tract.

The initial components of a typical GI reflex pathway are sensory receptors (such as chemoreceptors and stretch receptors) that are associated with the sensory neurons of the ENS. The axons of these sensory neurons can synapse with other neurons located in the ENS, CNS, or ANS, informing these regions about the nature of the contents and the degree of distension (stretching) of the GI tract.

The neurons of the ENS, CNS, or ANS subsequently activate or inhibit GI glands and smooth muscle, altering GI secretion and motility

Question 31

digestive gland secretions

Answer 31

a. Saliva

i. average in 24 hrs

ii.

b. Gastric juices

i. average in 24 hrs

ii.

c. Pancreatic juices

i. average in 24 hrs

ii.

d. Bile

i. average in 24 hrs

ii.

e. Intestinal juices

i. average in 24 hrs

ii.

Question 32

metabolism

Answer 32

is the chemical reactions in the body’s cells that change food into energy

Question 33

catabolism

Answer 33

the sequences of enzyme-catalyzed reactions by which relatively large molecules in living cells are broken down, or degraded

Question 34

anabolism

Answer 34

Anabolism requires energy to grow and build

he synthesis of complex molecules in living organisms from simpler ones together with the storage of energy

Question 35

nutrient

Answer 35

six principle classes

1. proteins - building blocks
2. carbs - fuel your body
3. fats- supports vitamin and mineral absorption, blood clotting, building cells, and muscle movement
4. vitamins- warding off disease
5. minerals- help support the body
6. water - hydrate

Question 36

protein anabolism

Answer 36

a. nutrient type used in the process

Amino acids

b. key events of protein synthesis

amino acid synthesis

transcription

translation

post translational modifications

protein folding

c. four hormones that stimulate protein synthesis

Insulin, GH and IGF-I

d. four examples of jobs proteins do within all cells

helps repair and build your body’s tissues, allows metabolic reactions to take place and coordinates bodily functions. In addition to providing your body with a structural framework, proteins also maintain proper pH and fluid balance.

e. examples of protein(s) produced by the following cell types in order to do their job:

red blood cell Hemoglobin

skeletal muscle cell actin and myosin

fibroblast fibrin, fibronectin, and collagen

liver cells Major plasma proteins

Question 37

protein catabolism

Answer 37

a. role of proteases

digesting long protein chains into shorter fragments by splitting the peptide bonds that link amino acid residues

b. product(s) produced

amino acids

c. conditions (e.g. hormone) that could trigger protein catabolism

glucagon, glucocorticoids and adrenaline

Question 38

cellular respiration in relation to catabolism

Answer 38

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

catabolism is breaking bonds which is seen here

Question 39

cellular respiration and throixyn

Answer 39

has a profound effect on cellular respiration. Abnormally high levels of this hormone accelerate respiration in conjunction with a general increase in metabolism while pathologically low amounts cause low levels of respiration with a general slowing of metabolic activity

Question 40

lipid anabolism

Answer 40

a. description of lipogenesis

Lipogenesis is defined as the synthesis of fatty acids from nonlipid precursors

b. example of hormones which stimulate lipogenesis

high carbohydrate diet

Question 41

lipid catabolism

Answer 41

a. description of lipolysis

metabolic process through which triacylglycerols (TAGs) break down via hydrolysis into their constituent molecules: glycerol and free fatty acids

b. example of hormones which stimulate lipolysis

noradrenaline (epinephrine), noradrenaline (norepinephrine), glucagon, growth hormone and cortisol