Endocrine system Flashcards
(102 cards)
1
Q
The endocrine system consists of
A
many organs and endocrine glands that secrete hormones
2
Q
Hormones control/ coordinates body processes that
A
require multiple organs to interact for a combined effect
3
Q
Hormones have a longer…… and a slower…..
A
longer effect period and slower response
4
Q
Hormones are
A
chemical messengers that are secreted in small quantities and transported in the blood
5
Q
Homeostasis
A
Internal conditions are kept near constant by control systems
6
Q
Sensory cells are responsible for
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detecting information about the conditions in the body and in the surroundings
7
Q
Physiological factors that are controlled
The conditions inside the body that should be maintained so that cells are able to function
A
Core body temperature- metabolic wastes- Blood pH- blood glucose concentration- water potential of the blood - concentration of respiratory gases in the blood core body
8
Q
…… influence how the cells work
A
features of the surrounding tissue fluid
9
Q
The features of the surrounding tissue fluid that influence how a cell works……,……. and……
A
Temperature/ water potential / glucose concentration
10
Q
How come the glucose concentration of the surrounding tissue fluid effect how a cell works
A
- low glucose levels would mean the cell will lack energy since respiration will not happen
-High glucose levels will have an osmotic effect in which metabolic rate is affected
11
Q
How come the temperature of the surrounding tissue fluid affect how a cell works
A
- high temperature will increase the metabolic rate, but going over this might cause the proteins to denature
- low temperate means a low metabolic rate
12
Q
How come water potential of surrounding tissue fluid affect how a cell works
A
- too much water leaving the cell by osmosis bc of a low water potential in the tissue will lead the cell to shrink which will slow or stop metabolic reactions
- too much water entering the cell by osmosis bc of high water potential in the tissue fluid will cause the cell to burst or undergoing lysis which might stop metabolic reactions
13
Q
(positive feedback) Changes in the environment causes the change to….. ex.
A
amplify. depolarisation of neurones This is an example of positive feedback. The more sodium ions there are, the more voltage changes, sp the more ion channels open, so the more sodium ions diffuse in.
14
Q
Positive feedback mechanisms are NOT….. They are useful for …..
A
Homeostatic control. activating processes
15
Q
While positive feedback ……. negative feedback …..
A
activates processes. ensure normalcy can be restored quickly
16
Q
Negative feedback mechanisms are part of
A
the homeostatic control system
17
Q
Normal glucose level in the blood
A
90mg per 100cm3 of blood
18
Q
Blood glucose concentration is controlled by….. in the…..
A
islets Langerhans in the pancreas
19
Q
The two cell types that take part in the regulation of glucose in the islets Langerhans
A
Beta cells and alpha cells
20
Q
compare the beta and alpha cells of the islets of Langerhans
A
Alpha cells are larger and secretes glucagon increase the glucose concentration . Beta cells smaller secret insulin decreases the glucose concentration
21
Q
glucagon….. glucose concentration
A
increases
22
Q
Alpha and beta cells act as an…. and ….. for the effectors
A
receptors and the hormonal control of the effectors
23
Q
Alpha and beta are the receptors and the hormonal control of the effectors…….
A
liver, muscle and adipose fat
24
Q
Alpha and beta cells play both the…. and ….. roles
A
receptors and main control or coordinator
25
Glucagon and insulin work.....
antagonistically
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When glucose is absorbed into the blood from the small intestine
The blood passes by the pancreas where the increased glucose concentration is detected. Alpha cells stop secreting glucagon while beta cells increase the secretion of insulin into the blood. insulin is transported to the effectors liver, muscle and adipose fat. Insulin binds to the receptors on the effectors and triggers the absorption of glucose into the effectors. Beta cells stop secreting insulin when the set point is reached
27
Other than the absorption of glucose into the effectors what does the insulin trigger?
- an enzyme is stimulated causing the glucose to phosphorylate
-two enzymes are stimulated allowing glucose to be added to glycogen
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Glycogenesis is
The process of converting glucose to glycogen
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Insulin is made up from
51 amino acids
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( low glucose level) the blood passes through the....
the blood passes through the pancreas where the low blood glucose level is detected. Alpha cells secretes glucagon while beta cells stops the secretion of insulin. While the secretion of insulin decreases the absorption of glucose into the live, muscle and adipose fat become less. The glucagon binds to its receptors on the liver and initiate a reaction cascade, ending with the break down of glycogen into glucose (glycogenolysis). The enzyme breaking down the glycogen acts on multiple endings allowing the glucose levels to increase quickly. Glucagon also stimulates enzymes responsible for making glucose from amino acids and glycerol by a process known as gluconeogenesis
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Glucagon uses a process called
second messenger model
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Complementary glucagon receptors are only found in the
liver
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glucagon uses a process called
second messenger model
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The conversion of glycogen to glucose
glycogenolysis
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The conversion of non-carbohydrates to glucose
gluconeogenesis
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The enzyme glycogen phosphorylase (glycogenolysis) increases the glucose levels quickly by
Acting of multiple endings of the glycogen
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The enzyme in glycogenoylsis
glycogen phosphorylase
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Adrenaline acts in the same way as....but
glucagon. but only allows glycogenolysis
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Adrenaline is secreted from..... during......
Adrenaline glands above the kidney. stress and excitement
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Adrenaline receptors are found in the
liver and muscle
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The inability to control glucose levels is either due...... or......
The lack of the production of insulin or the responsiveness
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Type one diabetes
(insulin dependent) patients with type one diabetes are unable to produce insulin. It begins in childhood, and it might be due to an autoimmune responsive where the immune system attacks the islets of Langerhans or the lack of the gene coding for insulin. The development of this type happens too fast. The symptoms include high blood glucose concentration- glucose in urine- need to urinate excessively- genital itching- weight loss- blurred vision- tiredness- increased thirst and hunger
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patients with type one diabetes are
unable to produce insulin
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Type one diabetes might be due to
an autoimmune responsive or the lack of genes for insulin
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Type two diabetes
(insulin independent) Is due to the receptors that are complementary to insulin losing responsiveness or due to an inadequate supply of insulin from the pancreas. Usually present in patients over the age of 40, but age has decreased over the years due to poor diet and obesity. the development is slower than type 1. it has the same symptoms as type 1
46
After a meal for a normal person vs a diabetic one?
The blood glucose concentration increases. The beta cells in the pancreas islets of Langerhans secrete insulin as a response. Insulin binds to insulin receptors in the liver, muscles, and adipose fat, and stimulates the absorption of the glucose into the effectors. In addition, it stimulate an enzyme for the phosphorylation of glucose and two enzymes for adding glucose to glycogen. As a result, glucose level will decrease in the blood moving to the kidneys. At the kidneys some glucose will be absorbed according to the kidney glucose reabsorption threshold. However, the glucose concentration will decrease slowly due to the use of the cells of the glucose, so more glucose will be travelling to the kidneys. The glucose will exceed the kidney glucose reabsorption threshold. Hence, More glucose will be passed in the urine. This is combined with extra water and salt that will increase in thirst and hunger
47
Why do diabetic patients struggle with constant hunger and thirst?
it is be glucose blood concentration will exceed the kidney glucose reabsorption threshold. As result more glucose is passed in the urine, and this will cause salt and extra water to be passed too.
48
The lack of insulin will result in less insulin absorbed into the liver. Therefore
This shortage causes metabolism of fats and proteins into glucose as alternative source but that means keto-acids will build up in the blood meaning its pH starts to decrease. Hence, tiredness
49
What happens if the liver can not absorb glucose/ the body lacks glucose
The shortage will cause the body to metabolism of fats and proteins into glucose. As a result, accumulations of Keto-acids will lower the blood pH and causes fatigue and tiredness
50
How to manage type one diabetes?
type one diabetes patients receive regular intravenous insulin injections. The insulin is made in large amounts by a genetically engineered cells for the insulin pens to be available. They inject themselves two to four times a day, and the dose of insulin matches the amount of glucose intake. The biosensors are devices that allow the correct dose of insulin to be given by measuring the blood glucose concentration. They have a pad saturated with glucose oxidase which is responsible for catalysing the reaction to make gluconolactone. testing a small simple of glucose leads to the generation of an electrical current. The hight the glucose concentration the higher the electrical current.
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type 1 patients can live a normal life through
A combination of managing carbohydrate intake, insulin injections and careful exercising
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The same management for type 1 with addition of (type 2)
Drugs to either stimulates more insulin production or to slow down the rate of absorption of glucose from the small intestine
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explain how are dip stick tests are used for glucose concentration in urine samples
Glucose oxidase catalyses the conversion of glucose to gluconolactone. Peroxide catalyses the reaction of hydrogen peroxide. A color will be seen. The higher the glucose concentration the darker the color.
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what is the internal environment?
it is the surroundings of cells making up an organism it
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homeostasis
maintaining a constant internal environment maintaining
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The function of endocrine system
to coordinate the body's organs so that they work together
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The endocrine system is based on
the production of chemical messengers called hormones
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Hormones are produced by..... in very...... and transported in.....
endocrine glands- very small quantities- in the blood endocrine
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Hormones control body processes that
that requires several organs to interact for a combined effect
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The function of hormones
hormones control the body processes that require several organs to interact for. combined effect
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hormones act for a ....... period than nerve impulses
longer
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What affect the blood glucose levels ?
eating causes blood glucose levels to rise- vigorous exercise causes blood glucose levels to fall. when are asked about regulation you talk about insulin and glucagon
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Blood glucose levels are monitored and controlled by the
Pancreas
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depending on the blood glucose levels the pancreas......
produces and releases different hormones
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Insulin is released when
Blood glucose concentration is high
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When insulin is released, the liver
stores excess glucose as glycogen
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when the blood glucose levels are low, the pancreas releases
glucagon
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When the pancreas secretes glucagon, the liver
converts the stored glycogen into glucose
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The release of insulin causes
The liver to store glucose in the form of glycogen (glycogenesis)
The increase of the metabolic rate by activating the enzyme responsible for glucose phosphorylation
stimulation of protein synthesis in some cells
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The release of glucagon causes
the conversion of glycogen to glucose in the liver (glucogenolysis)
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Glycogen is stored in the....
the liver and the muscles
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Why not just leave the excess glucose in the blood
The blood will become too concentrated that might cause crenation in red blood cells
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How come low blood sugar is dangerous?
It will make the red blood cells burst (lysis)
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Hormones production is controlled by
negative feedback
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Negative feedback is
the reduction of level of a subtense bc of a process that the substance carries out
76
positive feedback
is an increase in the level of a substance because of a process it carries out
77
Example of positive feedback
increasing osetrogen concentration increases LH output
78
The breakdown of glycogen to glucose is called
Glycogenolysis
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The formation of glycogen from glucose
Glycogenesis
80
Gluconeogenesis
is a metabolic pathway that results the generation of glucose. It is a process that leads to the generation of glucose from variety of sources such as pyruvate, lactate, glycerol and certain amino acids
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is a metabolic pathway that results the generation of glucose. It is a process that leads to the generation of glucose from variety of sources such as pyruvate, lactate, glycerol and certain amino acids
Gluconeogenesis
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Blood enters the liver in
Hepatic portal vein: digested food from the gut
Hepatic artery: oxygen and nutrients from the aorta
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Blood leaves the liver through
Hepatic vein- deoxygenated blood to the lungs for re-oxygenation.
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The liver receives a
dual vascular supply dual
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Portal venous blood from the.... and ..... and arterial blood from the..... mix together in..... before leaving through....
intestine and spleen- aorta- sinosoids- hepatic central vein then the hepatic vein
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The liver is organised into.....
Lobules
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Lobules take the shape of.....
polygonal prisms
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In cross section each lobule is....
Hexagonal
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Within each lobule
there's hepatocytes within the hepatic cords separated by sinusoids. within the cords bile canaliculi provides passage through the intercellular channels to the nearest branch to the bile duct
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within the hepatic cords
bile canaliculi provides passageway through intercellular channels to the nearest bile duct branch
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Sinusoid is lined with
endothelial with kupffer cells
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Kupffer cells
phagocytic macrophages that engulf the bacteria entering the sinusoids and digest it . They also remove the unwanted debris from the blood.
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Glucose is not suitable for storage bc.....
It is a small soluble molecule that will lead to osmotic attraction of water and tissue swelling
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Glycogen is suitable for storage
Large insoluble molecule so it will not have an effect on the osmotic pressure
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... of glycogen is stored in the liver and .... of glycogen is stored in the muscles
25%-75%
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The liver makes about... of bile per day
1 dm3
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The major component of bile is
bile salts
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Bile salts are made from
cholesterol
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The function of bile salts
is to emulsify fats
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If the cholesterol is present in excess in bile.....
will form harmful gallstones
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Bile contains a greenish yellow product from old erythrocytes
bilirubin
102
The components f Bile
Bile salts, cholesterol, bilirubin
