Exam 3 Review Flashcards
1
Q
digestive process that involves taking food into the digestive tract
A
ingestion
2
Q
digestive process that involves moving food through the alimentary canal; includes swallow and peristalsis
A
propulsion
3
Q
involuntary major means of propulsion; involves alternating waves of contraction and relaxation of muscles in the organ walls
A
peristalsis
4
Q
digestive process that involves increasing the surface area of ingested food, physically preparing it for digestion by enzymes; includes chewing, mixing food with saliva by the tongue, churning food in the stomach and segmentation
A
mechanical breakdown
5
Q
a type of mixing wave that mixes food with digestive juices, makes absorption more efficient by repeatedly moving different parts of the food mass against the intestinal wall
A
segmentation
6
Q
digestive process that involves a series of steps in which enzymes secreted into the lumen of the alimentary canal break down complex food molecules to their chemical building blocks
A
digestion
7
Q
main function: where the swallowing process is initiated; food is ingested then chewed and mixed with enzyme containing saliva that begins the process of digestion
A
the mouth
8
Q
main function: passes food from the mouth to the stomach, propulsion that starts with deglutition (swallowing)
A
esophagus
9
Q
main function: temporary food storage tank that start the chemical breakdown of proteins
A
atomach
10
Q
main function: production of bile
A
liver
11
Q
main function: supplies most enzymes needed to digest chyme, as well as bicarbonate to neutralize stomach acid
A
pancreas
12
Q
main function: storage of bile
A
gallbladder
13
Q
main function: major organ of digestion and absorption
A
small intestine
14
Q
main function: absorbs most of the water remaining in indigestible parts of food, temporarily stores indigestible food, eliminates indigestible food and absorbs metabolites created by bacteria
A
large intestine
15
Q
What type of macromolecules does the organ digest?
1. mouth
2. stomach
3. liver
4. pancreas
5. gallbladder
6. small intestine
7. large intestine
A
- carbohydrates (starch)
- proteins
- lipids
- proteins, carbs, lipids and nucleic acids
- lipids
- carbs, proteins and nucleic acids
- some carbs
16
Q
major roles: mouth
A
ingestion, propulsion. mechanical breakdown and digestion
17
Q
major roles: eophagus
A
propulsion via peristalsis
18
Q
major roles: stomach
A
propulsion, protein digestion, mechanical breakdown, absorption
19
Q
major roles: liver
A
produces bile that breaks down lipids
20
Q
major roles: pancreas
A
produces pancreatic juice and secretes insulin & glucagon by pancreatic islet cells
21
Q
major roles: small intestine
A
propulsion via peristalsis, mechanical breakdown via segmentation, digestion and absorption
22
Q
major roles: large intestine
A
absorption, propulsion and excretion
23
Q
main subdivisions of the small intestine
A
- Duodenum
- Jejunum
- Ileum
24
Q
first section of the small intestine, connected to the stomach, curves around the head of the pancreas
A
duodenum
25
middle portion of the small intestine, major site for nutrient absorption
jejunum
26
final section of the small intestine, joins large intestine at ileocecal valve
ileum
27
most common motion of the small intestine after a meal
segmentation
28
most common motion of small intestine between meals
peristalsis
29
main subdivisions of the large intestine
1. cecum
2.appendix
3.colon
4. rectum
5. anal canal
30
first part of the large intestine
cecum
31
mass of lymphoid tissue in the large intestine
appendix
32
types of colons
ascending, descending, transverse and sigmoid
33
last segment of the large intestine that opens body exterior at anus; has 2 sphincters
anal canal
34
innervation of the GI tract
enteric nervous system (gut brain) with over 100 million neurons
35
enteric neurons make up the bulk of?
2 intrinsic nerve plexuses that provide nerve supply to the walls of tract and control motility
1. submucosal nerve plexus
2. myenteric nerve plexus
36
how are intrinsic and extrinsic controls of the GI tract mediated
intrinsic (short reflexes) via the enteric nervous system and extrinsic (long reflexes) via CNS
37
parasympathetic input to the GI tract
enhances the digestive process
38
sympathetic input to the GI tract
inhibits digestion
39
adjacent segments of the alimentary canal organs alternately contract and relax; food is moved distally
peristalsis
40
nonadjacent segments of the alimentary canal organs contract and relax; food is moved forward and backward
segmentation
41
which organ creates/ secretes: salivary amylase
salivary glands in the mouth
42
which organ creates/ secretes: amylase
pancreas
43
which organ creates/ secretes: proteases
the pancreas (trypsinogen and chymotrypsinogen) and the stomach (pepsinogen)
44
which organ creates/ secretes: lipases
created in the pancreas and secreted by chief cells in the stomach
45
which organ creates/ secretes: bile
created in the liver and stored in the gallbladder
46
which organ creates/ secretes: pepsin
stomach; secretory cells in the gastric glands
47
which organ creates/ secretes: bicarbonate
pancreas, stomach and duodenum
48
what is the purpose of salivary amylase?
begins the breakdown of starch, mastication and hydrolysis
49
what is the purpose of amylase?
breaks down starch or glycogen that made it past salivary amylase
50
what is the purpose of trypsin and chymotrypsin?
cleaves the protein into smaller peptides
51
what is the purpose of carboxypeptidases?
cleaves protein into single amino acid monomers
52
what is the purpose of lipases?
breaks down lipids into monoglyceride s plus two free fatty acids
53
what is the purpose of bile?
breaks down fat
54
what is the purpose of pepsin?
digest proteins
55
what is the purpose of bicarbonate?
neutralizes stomach acid entering the duodenum, creates a favorable pH for enzymes
56
which are secreted in their active or inactive form?
1. salivary amylase
2. amylase
3. proteases
4. lipases
5. bile
6. pepsin
7. bicarbonate
1. active
2.active
3.inactive
4. active
5. active
6. inactive
7. active
57
which digestive system secretion or enzymes are secreted in their inactive form?
proteases and pepsin
58
how are proteases secreted?
inactive to prevent the pancreas from digesting itself; activated in the duodenum by the enzyme enteropeptidase which first activates trypsinogen into trypsin and the trypsin activates carboxypeptidase and chymotrypsin
59
how is pepsin secreted?
inactive; pepsinogen is activated in the acidic pH range found in the stomach caused by the secretion of HCl via parietal cells of the gastric glands and is inactivated in the high pH of the duodenum
60
what is the name of the venous portion of the splanchnic circulation
hepatic portal circulation
61
what is the purpose of the hepatic portal circulation
drains nutrient rich blood from digestive organs and delivers blood to liver for processing before blood is returned to the right atrium
62
unique structural modifications of the stomach
1. rugae
2.modified muscularis externa
3. modified mucosa layer
4. mucosal barrier
63
what is the purpose of the structural modifications of the stomach?
1. rugae- allows the stomach to expand after eating
2.modified muscularis externa- smooth muscle layers that allow the stomach to churn, mix and move chyme as well as pummel it which increases physical breakdown and pushes it into small intestine
3. modified mucosa layer- gastric pits and glands to produce gastric juice
4. mucosal barrier- protects the stomach from harsh digestive conditions
64
structural modifications of the small intestine?
1. circular folds
2.villi
3.microvilli
65
what is the purpose of the structural modifications of the small intestine?
1. circular folds allow for more nutrient absorption by slowing chyme through lumen
2. villi contain capillary bed and lacteal for absorption
3. microvilli create a brush border that contains enzymes used for final carb and protein digestion
66
what is the most important substance secreted in the stomach
intrinsic factor via parietal cells
67
what is the purpose of intrinsic factor
needed for B12 absorption which is needed for RBC's to mature
68
what does lack of intrinsic factor cause
pernicious anemia
69
what happens to carbs after they are digested
glucose, fructose and galactose are absorbed into the intestinal capillaries and carried to the liver via the hepatic portal vein
70
fate of carbs after absorption
galactose and fructose are converted to glucose in the liver to be used for ATP production, stored as glycogen or if excess, converted to fat
71
what happens to proteins after they are digested
broken down into amino acids and absorbed into the intestinal capillaries and carried to the liver via the hepatic portal vein
72
fate of proteins after absorption
amino acids are used by cells for protein synthesis or can be converted to glucose/ fat
73
what happens to lipids after they are digested
broken down into monoglycerides and formed into micelles for absorption by enterocytes-reassembled into triglycerides- packaged into chylomicrons- enter lacteals- transported via the lymph system to the thoracic duct then to the bloodstream at the subclavian vein
74
metabolic functions carried out by bacterial flora in the large intestine
fermentation and vitamin synthesis
75
fermentation
ferments indigestible carbs and mucin; form short chain fatty acids that are absorbed by the large intestine and can be dispersed to body cells as fuel sources, releases irritating acids and gases
76
vitamin synthesis
synthesize B complex and some vitamin K needed by liver to produce clotting factors
77
all of the biochemical reactions inside a cell involving nutrients
metabolism
78
synthesis of large molecules from small ones
anabolism
79
hydrolysis of complex structures to simpler ones
catabolism
80
what is cellular respiration and what is its goal
catabolic breakdown of food fuels to form ATP in cells; goal is to trap chemical energy via ATP
81
pathways of cellular respiration
1. glycolysis
2. citric acid cycle
3. oxidative phosphorylation
82
where do the pathways of cellular respiration occur in the cell
1. glycolysis= cytosol
2. citric acid cycle- mitochondrial matrix
3.oxidative phosphorylation= inner mitochondrial membrane
83
oxygen requirements for each pathway in cell respiration
1. anaerobic
2. indirectly uses oxygen
3. directly uses oxygen
84
carbohydrate reactions
glycolysis, glycogenesis, glycogenolysis and glucogenesis
85
conversion of glucose to pyruvic acid
glycolysis
86
polymerizes glucose to form glycogen
glycogenesis
87
hydrolyzes glycogen to glucose monomers
glycogenolysis
88
forms glucose from noncarbohyrate precursors
glucogenesis
89
amino acid reactions
transamination, oxidative deamination and keto acid modification
90
transfers an amino acid from an amino acid to alpha-ketoglutaric acid to generate glutamic acid
transamination
91
removes an amine group as ammonia from glutamic acid to produce alpha-ketoglutaric acid
oxidative deamination
92
lipid reactions
beta oxidation, lipolysis and lipogenesis
93
converts fatty acids to acetyl-coA
beta oxidation
94
breaks down lipids to fatty acids and glycerol
lipolysis
95
forms lipids from acteyl-coA and glyceraldehyde 3-phosphate
lipogenesis
96
what is the importance of vitamins
most function as coenzymes; work with an enzyme to accomplish body functions
97
preferred energy source for:
1. brain
2.skeletal muscle
3. cardiac muscle
4.liver
5.adipose tissue
6. kidneys
7. most other tissue
1. glucose
2.glucose during activity and fatty acids at rest
3. fatty acids (main), lactate, glucose, and ketones as needed
4. fatty acids (main), amino acids and glucose
5.glucose and fatty acids
6. fatty acids (main) glucose
7.fatty acids and glucose
98
which can or cannot be stored in the body?
1.carbohydrates
2.lipids
3.proteins
1. stored as glycogen in the liver and skeletal muscle
2. stored as triglycerides in adipose tissue
3. not stored
99
energy yields when each undergoes catabolism?
1.carbohydrates
2.lipids
3.proteins
highest; lipids= 9 kcal/g
carbs and proteins= 4 kcal/g
100
structural material made from lipids
phospholipids= cell membrane, myelin sheath
cholesterol= cell membrane, steroid hormone synthesis and bile salts
101
which metabolic process dominates in each state?
1.absorptive
2.postabsroptive
1. anabolism- stores nutrients
2. catabolism
102
main hormone associated with each state?
1.absorptive
2.postabsroptive
1. Insulin
2. Glucagon
103
in postabsorptive state some organs shift the fuel they use for metabolism, why?
to preserve blood glucose for organs that depend on it like the brain and red blood cells
104
homeostatic balance where the rate of protein synthesis equals the rate of breakdown and loss
nitrogen balance
105
what are the two nitrogen imbalances?
1. positive nitrogen balance: synthesis exceeds breakdown; normal in children, regency and tissue repair
2. negative nitrogen balance: breakdown exceeds synthesis; stress, burns, infections, injury, poor dietary proteins and starvation
106
heat promoting mechanisms
1. constriction of cutaneous blood vessels
2.shivering
3.increase in metabolic rate
4.ehanced release of thyroxine
5.behavioral modifications
107
heat loss mechanisms
1. dilation of cutaneous blood vessels
2. sweating
108
three supportive tissue layers surrounding the kidneys
renal fascia, perirenal fat capsule, fibrous capsule
109
purpose of the renal fascia
anchors the kidneys and adrenal glands to surrounding structures
110
purpose of the perirenal fat capsule
fatty cushion, protects kidneys from trauma
111
purpose of the fibrous capsule
prevents infection in surrounding tissue from spreading to the kidneys
112
modifications seen on cells of PCT
1. epithelial cells with many mitochondria- provides energy for active transport and reabsorption
2. apical surfaces bear dense microvilli that form a brush border- enhance reabsorption
3. leaky tight junctions- facilitate paracellular transport of ions and water
4.transport proteins/channels
113
3 processes in the kidneys that form filtrate/urine
1.glomerular filtration
2. tubular reabsorption
3. tubular secretion
114
what does glomerular filtration do
produces cell and protein free filtrate
115
what does tubular reabsorption do
selectively returns 99% of substances from filtrate to blood in renal tubules and collecting ducts
116
what does tubular secretion do
selectively moves substances from blood to filtrate in renal tubules and collecting ducts
117
pressures that impact filtration through the membrane
-net filtration pressure
-outward pressure: hydrostatic pressure in glomerular capillaries
-inward pressure: hydrostatic pressure in capsular space and colloid osmotic pressure in capillaries
118
hydrostatic pressure in glomerular capillaries
glomerular blood pressure; chief force pushing water and solutes out of blood
119
forces that promote filtrate formation
outward pressure
120
forces that inhibit filtrate formation
inward pressure
121
filtrates pressure in capsule
hydrostatic pressure in capsule space
122
volume of filtrate formed per minute by both kidneys
glomerular filtration rate
123
normal glomerular filtration rate
120-125 ml/min
124
renin
an enzyme released by the kidney that raises blood pressure by initiating RAAS
125
what does renin do
plays a crucial role in regulating blood pressure, fluid balance and sodium balance by activating RAAS
126
parts of the nephron under hormonal regulation
distal convoluted tubule and collecting duct
127
four hormones that regulate reabsorption and secretion
ADH, aldosterone, ANP and PTH
128
