midterm 1 Flashcards
1
Q
Where does 1/3 of the hepatic blood supply come from?
A
Hepatic artery proper
2
Q
Where does 2/3 of the hepatic blood supply come from?
A
Venous blood from hepatic portal vein
- All blood leaving absorptive surfaces of digestive tract flows through hepatic portal vein
- Liver cells extract nutrients or toxins from blood before it joins systematic circulation via hepatic veins
3
Q
What is the gallbladder?
A
Stores and concentrates bile prior to excretion into small intestine
4
Q
What is the cystic duct?
A
extends from gallbladder and joins common hepatic duct to form common bile duct
5
Q
What stimulates bile release?
A
CCK
6
Q
What are the 3 parts of the small intestine?
A
Duodenum, Jejunum, Ileum
7
Q
What are the functions of the duodenum? (2)
A
- Receive chyme from the stomach
- Neutralize acids before they damage absorptive surfaces of small intestine
8
Q
What are the functions of the jejunum?
A
Chemical digestion and nutrient absorption
9
Q
What breaks down material on the microvilli in the small intestine?
A
Brush border
10
Q
What are the functions of the large intestine? (4)
A
- Absorption or reabsorption of nutrients
- Compaction of intestinal contents into feces
- Absorption of important vitamins produced by bacteria
- Storage of fecal material prior to defecation
11
Q
What is absorbed or reabsorbed in the large intestine? (5)
A
Water, Nutrient, Bile salts, Organic wastes, Vitamins and toxins created by microbiome
12
Q
What are the parts of the large intestine? (3)
A
cecum, Colon, Rectum
13
Q
Where does material go after the ileum?
A
cecum
14
Q
What are haustra?
A
pouches in wall of colon that allow for expansion and elongation of colon
15
Q
What creates haustra?
A
teniae coli
16
Q
What are the 4 regions of the colon?
A
Ascending, transverse, descending, sigmoid
17
Q
Does the large intestine have villi?
A
no
18
Q
What does the microbiome refer to?
A
Bacteria, fungi and viruses that live in and on the human body
19
Q
What vitamins are produced by bacteria in colon? (3)
A
Vitamin K, Biotin, Vitamin B5
20
Q
What is vitamin K used for?
A
synthesizing clotting factors in liver
21
Q
What is biotin used for?
A
glucose metabolism
22
Q
What is vitamin B5 used for?
A
Manufacturing steroid hormones and neurotransmitters
23
Q
Which of the vitamins produced in the colon is fat soluble?
A
K
24
Q
Define energy
A
ability to perform work
25
What are the forms of work in the body? (4)
Chemical - storing CHO by forming glycogen for later use
Electrical - maintenance of distribution of ions across cell membranes
Mechanical - force production by skeletal muscle
Transportation - circulation of blood throughout body to deliver oxygen, nutrients and other compounds to tissues
26
What are the 2 states of energy?
Potential and Kinestic
27
What is an endogenous reaction?
process of reactions that store energy
- re-phosphorylating ATP
28
What are exogenous reactions?
reactions that release enegry
29
What is used to store and release energy in cells?
ATP
30
How is ATP broken down to create enegry?
enzymes (ATPases) break down ATP to create ADP and P
31
How is ATP re-phosphorylayted? (3)
ATP-CP, creatine phosphate
Glycolysis
Oxidative phosphorylation, aerobic meabolism, cellular respiration
32
What are the steps in oxidative phosphorylation? (4)
Glycolisis, conversion to Acetyl CoA, Citric Acid Cycle, Electron Transport Chain
33
What is a calorie?
heat required to raise temperature of 1 gram of water by 1 degree C
34
What is direct calorimetry? (bomb calorimetry?)
Measures energy directly
- food samples are borned in closed system surrounded by bath of water
- heat is released when food is burned
- because thermal energy of food is directly measured process is called direct calorimetry
35
How any Cal is in 1 gram of CHO?
4
36
How any Cal is in 1 gram of protein?
4
37
How any Cal is in 1 gram of fats?
9
38
How any Cal is in 1 gram of alchohol?
7
39
What is direct calorimetry in humans?
Same principle as with food
- Measures temperature change by measuring heat associated with energy expenditure
40
Pros and cons for direct calorimetry in humans
Pros - very precise measurements made
Cons
- slow response times
- confided spaces needed
- equipment can generate heat
41
What is indirect calorimetry?
Relies on relationship between oxygen consumption (VO2) and carbon dioxide production (VCO2)
42
How many Calories are burned with every litre of O2 used?
5
43
Pros and cons to open circuit calorimetry?
Pros
- fats and accurate
- can be portable
Cons
- expensive
- require significant training
- some activities are incompatible with system
44
What is double labelled water? (DLW)
used safe stable isotopes of oxygen and hydrogen (both components of water) to determine energy expenditure over 1-3 weeks
45
pros and cons to DLW
pros - high validity and reliability
cons - very expensive to collect and analyze samples
46
What are triaxial accelerometers?
sense body movements in all 3 planes
47
pros and cons to triaxial accelerometers
pros
- relatively inexpensive
- can be used in many activities with little impact on normal movements
cons
- less accurate
- susceptible to manipulation from erroneous movemtns
48
What does it mean to be in energy balance?
energy in = energy out
49
Why is food intake typically underestimated?
portion size errors
50
How is energy intake measured?
analyzing daily food and beverage consumption
51
What is total energy expenditure? (TEE)
resting metabolism + thermic effect of food + physical activity
52
What is Basal metabolic rate? (BMR)
measure of amount of energy necessary to keep body alive at complete rest
- measure under defined laboratory conditions
- primarily used for research
53
What is resting metabolic rate? (RMR)
accounts for additional biological functions that occur at rest (digestion or thermoregulation
- used for practical purposes
54
What is RMR also known as?
resting energy expenditure (REE)
55
How much higher is RMR than BMR?
10%
56
What influences on RMR are not under voluntary control? (6)
sex, gender, age, genetics, body size, thyroid hormones
57
What influences on RMR are under some voluntary control? (2)
Starvation, amount of fat free tissue
58
What influences on RMR are under complete voluntary control? (4)
exercise, environmental temperature, high altitude, caffiene
59
Why is the Cunningham equation more accurate for athletes?
takes fat free mass into account
60
What is the thermic effect of food? (TEF)
energy required for digestion and absorption of food
- ~10% of total caloric intake of day
61
What increases TEF?
proteins more than CHO, fats have little effect
62
What can have a substantial impact on TEE?
physical activity
63
What are monosaccharides?
simple sugars, form building blocks of complex CHO
64
What are the monosaccharides? (3)
Glucose, Fructose, Galactose
65
What are disaccharides?
simple CHOs made of 2 monosaccharide molecules
66
What are the 3 disaccharides and what are they made of?
Sucrose - glucose + fructose
Lactose - glucose + galactose
Maltose - glucose + glucose
67
What are polysacchrides?
chains of glucose molecules
68
What is the storage form of glucose for plants?
Starch
69
What is the difference between amylopectin and amylose?
Amylopectin - branched chain, contains thousands of glucose units
Amylose - linear chain containing hundreds of glucose units
70
What are good sources of starch?
Gains legumes, tibers
71
What is fiber?
Indigestible, structural molecule for plants (cellulose)
72
What is functional fibre?
Added to foods to make texture more solid
73
Where does CHO digestion begin?
mouth
74
What does salivary amylase digest CHO into?
monosaccarides, disaccharides, shorter polysaccharides (oligosaccharides)
75
Where does CHO digestion resume?
Duodenum (brush border)
76
What does lactase do?
digests lactose into glucose and galactose
77
What does maltase do?
digests maltose into 2 glucose units
78
What does sucrase do?
Digests sucrose into glucose and fructose
79
What is facilitated co-transport?
2 step process in intestinal epithelial cells to absorb glucose and galactose?
80
What are the steps in facilitated co-transport
1. SGLT allows sodium to diffuse into cell brining glucose or galactose with it
2. NA/K ATPase pumps sodium out of cell to maintain concentration gradient
81
What do hepatocytes do?
capture galactose and fructose and convert the into glucose
82
What are blood glucose levels maintained by?
Pancreas
\
83
What does finer do in GI tract?
helps move chyme through via peristalsis
- source of vitamin K, B5 and biotin
84
What are the numbers for the glycemic index?
Low - less than 55
Medium - 56-69
High - 70+
85
What is the glycemic index?
measurement of how much and how quickly food raises blood glucose levels
86
What are the primary functions of CHO in body? (5)
- Energy produciton
- energy storage
- building macromolecules
- sparing protein
- lipid metabolism
87
What does GLUT-1 transport?
universal
88
What does GLUT-2 transport?
glucose in liver and intestines
89
What does GLUT-3 transport?
found in neurons
90
What does GLUT-4 transport?
dependant on insulin and found in fat, skeletal and cardiac muscle
91
What does GLUT-5 transport?
only in brush border, primarily fructose
92
What is primary role of CHO?
supply energy to all cells
93
How many ATP molecules come from oxidative phosphorylation?
32-34
94
How much glycogen is stored in body?
~3000kcal in skeletal muscle
~1000kcal in liver
95
What can low CHO intake lead to?
gluconeogensis (breakdown of amino acids into glucose)
