Camtasias Flashcards
1
Q
What are the three major pathways that PTH uses to increase plasma [Ca2+]?
A
Bone
Kidney
Intestine
2
Q
What is the major hormone that regulates plasma calcium concentration ( [Ca2+] )?
A
Parathyroid Hormone (PTH)
3
Q
What are the cells called that are sensitive to plasma [Ca2+]?
A
Follicular Cells
4
Q
T/F: When plasma [Ca2+] levels drop, PTH causes no bone formation to occur.
A
False! Initially, PTH interacts with the osteoblasts to cause bone formation. Cytokines are then released, stimulating osteoclasts –> net bone resorption.
5
Q
The reabsorption of these two elements are affected by PTH in the kidneys.
A
Calcium and Phosphate
6
Q
When the plasma [Ca2+] is lowered, phosphate reabsorption in the kidney is (increased/decreased).
A
Decreased
7
Q
What is found in the urine when plasma [Ca2+] is lowered?
A
Phosphorus
8
Q
Where is the origin of the enzyme that actives Vitamin D in our food?
A
The kidney
9
Q
What is activated Vitamin D called?
A
1,25 - dihydroxycholecalciferol
10
Q
1,25 - dihydroxycholecalciferol has an influence on the epithelial cells located here.
A
The intestines
11
Q
The intestinal epithelial cells increase the production of this.
A
Calbindin
12
Q
What is the role of calbindin?
A
It increases gastrointestinal absorption of calcium
13
Q
The major precursor of the major hormones created by the adrenal.
A
Cholesterol
14
Q
The rate-limiting step in the formation of adrenal hormones is ______.
A
the activation of cholesterol desmolase by ACTH
15
Q
In the case of the the glucocorticoids and the androgens, only one enzyme needs to be activated. It is this:
A
cholesterol desmolase
16
Q
Cells that lack 21-beta-hydroxylase can only make this.
A
Androgens
17
Q
What is an example of a mineralocorticoid made in the adrenal glands?
A
Aldosterone
18
Q
What is an example of a glucocorticoid that is made in the adrenal glands?
A
Cortisol
19
Q
Cells that lack 17-hydroxypregnenolone will only be forming this:
A
Mineralocorticoids
20
Q
Cells lacking the 12,20 lyase shunt production to these two steroid groups.
A
mineralocorticoids and gluccocorticoids
21
Q
Are fats water soluble?
A
NO WAY JOSE! Lipid soluble baby!
22
Q
Since fats are not water soluble, they are broken down into smaller fats by the process of?
A
EMULSIFICATION
23
Q
The digestion of fats is done exclusively by what enzyme?
A
Pancreatic Lipase
24
Q
Emulsification of fat is done by which two products: ___ AND ____
A
Pancreatic lipase and Bile acid
25
Who releases Pepsinogen?
Parietal cells
26
What happens to the monoglycerides and triglycerides right after they get into the epithelial cells?
They are reassembled into CHYLOMICRON
27
What are the components of a chylomicron?
Fat soluble vitamins
Cholesterol
TG
28
How does the chylomicron leave the cell? And where do they go?
They are EXOCYTOSED and most go into the LYMPHATICS (some can go to the LIVER via portal vein)
29
The proteins that enter the stomach are mechanically broken down by ____ and by what acid?
mechanically broken down by stomach contractions and HCL
30
The first enzyme of protein digestion is
Pepsinogen
31
Who releases Pepsinogen?
Parietal cells
32
T/F: Since FSH and LH are both released by the anterior pituitary, their feedback regulation is the same.
FALSE
33
T/F: Both FSH and LH are produced by the same cells.
TRUE
34
Where is GnRH released?
Hypothalamus
35
LH stimulates the release of ___ from the ____ cells in the testes.
testosterone; Leydig
36
How does testosterone get from the Leydig Cells to the Sertoli Cells?
It diffuses across the blood-testes barrier.
37
What do the sertoli cells do if they are in a testosterone-rich environment?
Stimulate spermatogenesis.
38
How do the sertoli cells keep testosterone around them?
They secrete an antigen-binding protein that keeps the testosterone local
39
T/F: Leydig cells provide the nutrients for the development of sperm.
False. The sertoli cells do this
40
What do the Sertoli cells secrete in order to provide negative feedback to stop the release of FSH?
Inhibin
41
What two hormones does the anterior pituitary gland secrete?
LH and FSH
42
What triggers reduction in the release of LH?
Testosterone in the systemic circulation feeds back to both the hypothalamus (reducing release of both LH and FSH) and the anterior pituitary (reducing LH release).
43
Once the peptides (of various lengths) make their way to the duodenum, what is released from the pancreas?
A bunch of enzymes in the ZYMOGEN form Chymotrypsinogen Trypsinogen Procarboxypeptidase
44
In order for the ZYMOGENS released by the pancreas to be turned into their active form, they need to interact with enzymes from\_\_\_\_\_?
The brush border
45
The brush border enzyme converts Trypsinogen (from pancreas) --\>
TRYPSIN
46
T/F: The activation of Trypsin signals for activation of the other pancreatic zymogens?
TRUE!!!
47
What does trypsin do?
It breakdown the peptide chains into individual amino acids or into di/tri-peptides
48
How does individual amino acids get into epithelial cell?
CO-TRANSPORTER
49
Who is the co-transporter that helps amino acids cross the brush border of the epithelial cell?
SODIUM
50
How do amino acids enter the interstitium?
Facilitated transporter
51
Once an amino acid is in the interstitial, what are its two routes?
1) Portal Vein (to liver)
2) Lymphatics (to thoracic duct and thence to venous system)
52
Di and Tri-peptides are moved into the epithelial cell by:
H+/(Peptide) CO-transporter
53
How many sites of enzyme release for the breakdown of protein?
2 sites!
Stomach -- pepsin
Pancreas -- trypsin
54
How many sites on enzyme release are there for the digestion of fats?
ONE! at the level of the pancreas (pancreatic lipase)
55
T/F: Enteric nervous system is essentially an intrinsic nervous system of the GI tract
TRUE
56
What are the two collections of nerves in the enteric nervous system?
MYENTERIC plexi and SUBMUCOSAL plexi
57
Does the myenteric and submucosal plexus communicate with each other?
Yes!
58
Low insulin causes acetyl CoA to become _____ in the liver
ketones
59
What are the two MAJOR muscle layers associated with the Enteric Nervous System?
Longitudinal and Circular
60
Enteric Nervous System: The small mucosal layer is associated with?
the depth of rugae of the absorptive surface
61
What plexus sits in between the longitudinal and circular muscle layers of the Enteric Nervous System?
MYENTERIC
62
Enteric Nervous System: What is the importance of the major muscle layers (longitudinal and circular)?
They are both involved in movement of structures through the lumen
63
Enteric Nervous System: The parasympathetic innervation is in what fiber form PREganglionic or POSTganglionic?
PRE
64
Since the parasympathetic is in the form of preganglionic fibers, what neurotransmitter is released? and onto what receptors?
Ach onto Nicotinic receptors
65
Enteric Nervous System: The sympathetic innervation is in what fiber form PREganglionic or POSTganglionic?
mainly POST
66
Since the sympathetic is in the form of postganglionic fibers, what neurotransmitter is released? and onto what receptors?
NE on adrenergic receptors (A1, A2, B1, B2)
67
T/F: The sensory neurons of the gut epithelium help balance out the level of activity done by both the sympathetic and parasympathetic by relaying messages to the myenteric + submucosal plexus as well as brain?
True
68
What are the two end-products of amino acid metabolism in liver cells?
The amine group is removed and it is metabolized into alpha-ketoacids. This becomes:
1) Further metabolized into H2O + CO2 + Energy or
2) a building block for the production of triglycerides.
69
What loop is formed by sensory neuron afferents that are sent all the way to the brain to control the outputs of parasympathetic and sympathetic?
LONG loop
70
These are the three major energy sources in the blood that are transported into cells in the presence of insulin.
Glucose, amino acids, and triglycerides.
71
In the muscle cells, insulin stimulates the exocytosis and proliferation of these two transporters:
GLUT-4 and Amino acid/Sodium (AA/Na+) cotransporters
72
The presence of insulin leads to a (greater/lower) amount of glucose entering the cell.
Greater
73
In the presence of insulin, glucose is stored as _____ in the muscle cells, and amino acids are stored as \_\_\_\_\_.
glycogen; protein
74
What is/are the transporter(s) upregulated by the presence of insulin in the adipocytes?
GLUT-4 (this is the ONLY receptor affected in the adipocytes)
75
Uptake of glucose in the adipocytes stimulates \_\_\_\_\_\_\_.
Fatty acids
76
Fatty acids + alpha-glycerol-phosphate = \_\_\_\_\_\_\_\_\_\_
Triglycerides
77
These are the major form of energy in the adipocytes
triglycerides
78
What is the major transporter for glucose in the liver cells?
GLUT-2
79
T/F: GLUT-2 transporters are always present in the liver cells.
TRUE
80
In liver cells, insulin creates the environment for synthesis of ______ from \_\_\_\_\_
glycogen; glucose
81
With high insulin, Glucose in the liver cells is converted into acetyl CoA, then \_\_\_\_\_\_, which are re-synthesized into \_\_\_\_\_\_\_
amino acids; triglycerides
82
Since triglycerides don't stay in the liver cells, how do they leave?
They are attached to VLDLs and transported to adipocytes for storage
83
With a lack of insulin, what happens in the muscle cells?
Glycogen is broken down into glucose and proteins broken down into amino acids. The glucose is broken down further into pyruvate and lactic acid before being released into the blood stream.
84
A lack of insulin causes what to happen to triglycerides in the adipocytes?
They are broken down into amino acids and glycerol, and they are released into the blood as energy.
85
Low insulin causes acetyl CoA to become _____ in the liver
ketones
86
Absorption of glucose, amino acids, and triglycerides is initially here.
GI epithelium
87
Along with alpha-glycerol phosphate and fatty acids, in the liver glucose can be converted to these.
triglycerides
88
Triglycerides are transported to adipocytes by
VLDL
89
With the help of this enzyme, triglycerides get into the adipocytes.
lipoprotein lipase
90
Lipoprotein lipase is secreted by these
Endothelial cells of adipocytes
91
What does lipoprotein lipase do?
Breaks down triglycerides into fatty acids and monoglycerides
92
T/F: Monoglycerides are stored in the adipocytes along with fatty acids.
False. Monoglycerides don't go into the adipocytes, but instead recirculate back to the liver to help form triglycerides.
93
Since triglycerides are not soluble in plasma, how do they get into adipose tissue?
They are exocytosed from the GI endothelial cells and transported to the adipose cells in the form of chylomicrons in the plasma
94
How do amino acids get into the liver and muscle cells?
Via an amino acid/sodium co-transporter
95
What are the two end-products of amino acid metabolism in liver cells?
The amine group is removed and it is metabolized into alpha-ketoacids. This becomes:
1) Further metabolized into H2O + CO2 + Energy or
2) a building block for the production of triglycerides.
96
The main goal in the post-absorptive state
to maintain blood glucose levels by mobilizing energy stores
97
In the liver, glycogen is broken down into
glucose
98
In the muscle, glycogen is metabolized into these before being transferred to the liver to be used in gluconeogenesis
pyruvate and lactate
99
This is a process to create glucose, unique to the liver and kidneys.
Gluconeogenesis
100
In the adipocytes, triglycerides are broken down into ________ to create energy when blood glucose drops.
glycerol and fatty acids.
101
Fatty acids can break down into this, the "fail-safe" back-up energy source for the nervous system in times of low blood glucose.
Ketones
102
Amino acids are metabolized into these, used in gluconeogenesis
alpha-ketoacids
