Hormonal communication Flashcards
(104 cards)
1
Q
what does the endocrine system do?
A
regulates body activities in order to regulate homeostasis
2
Q
what are hormones?
A
proteins that are chemical messengers which travel by blood
3
Q
what are exocrine glands and give example?
A
glands that secrete substances into ducts e.g. salivary glands secrete saliva into your mouth
4
Q
what are endocrine glands?
A
a group of cells that excrete chemicals into the blood stream
5
Q
what are target cells?
A
cells that have receptors embedded in the plasma membrane that are a complementary shape to a specific hormone
- only these cells will respond to that hormone and undergo a response
6
Q
what soluble are steroid hormones?
A
lipid soluble
7
Q
where can steroid hormones pass through?
A
phospholipid plasma membrane
8
Q
what do steroid hormones bind to and where?
A
bind to steroid hormone receptors in the cytoplasm or nucleus forming a hormone receptor complex
9
Q
what does the hormone receptor complex act as?
A
a transcription factor, either facilitating or inhibiting the transcription of a specific gene
10
Q
are non-steroid hormones hydrophobic or hydrophyllic?
A
hydrophyllic
11
Q
where can non-steroid hormones not pass directly through?
A
cell surface membranes or target cells
12
Q
what does binding of non-steroid hormones trigger?
A
a cascade reaction mediated by chemicals called secondary messengers
13
Q
what hormones to the adrenal glands produce?
A
hormones that help regulate your metabolism, immune system, blood pressure, response to stress and other essential functions
14
Q
where is the adrenal cortex and what hormones does it produce?
A
found in the outer region of the adrenal gland and produces essential hormones such as cortisol and aldosterone
15
Q
where is the adrenal medulla and what hormones does it produce?
A
found in the inner region of the adrenal gland and produces non essential hormones such as adrenaline
16
Q
what type of signal is involved in the hormonal system?
A
chemical messengers
17
Q
what type of signal is involved in the nervous system?
A
nervous impulses
18
Q
what is the speed of the transmission in the hormonal system?
A
slow
19
Q
what is the speed of the transmission in the nervous system?
A
rapid
20
Q
where is the target for the hormonal system?
A
cells in specific organs
21
Q
where is the target of the nervous system?
A
specific parts of the body
22
Q
what is the response of the hormonal system?
A
slow, long lasting
23
Q
what is the response of the nervous system?
A
fast, short lived
24
Q
what is the effect of the hormonal system?
A
may be permanent and irreversible
25
what is the effect of the nervous system?
temporary and reversible
26
where are the adrenal glands located?
on top of each kidney
27
what are the adrenal glands made of and how big are they?
- made of 2 distinct parts surrounded by a capsule
- they are 3x5cm
28
what are the target organs of adrenaline?
- SA node in heart
- iris
- alimentary canal
- liver
29
what does each target organ for adrenaline have for the hormone and where?
each target organ will have the same complimentary receptors for adrenaline on the cell surface membrane
30
what does adrenaline attaching to the receptors in target organs trigger?
a different cascade of reactions in each cell type
31
what are the physiological responses of adrenaline?
- increased heart rate and stroke volume
- smooth muscle of bronchioles relax
- arterioles in skin constrict- reduces blood flow to some areas
- non-essential systems shut down so more blood can be diverted to muscles
- erects body hair
- dilates pupils
- blood glucose rises
32
how does the fight or flight response work?
in a potentially dangerous situation, the body automatically triggers a series of physical responses intended to help the animal survive by preparing the body to either run or fight for life
33
what is the threat detected by in the fight or flight response?
the autonomic nervous system
34
what happens when the fight or flight response is triggered?
- the hypothalamus signals the sympathetic nervous system and adrenal corticol system
- the adrenal medulla releases adrenaline and noradrenaline into the blood
- the pituitary gland releases a hormone that activates the adrenal cortex to release other hormones
35
what are mineralocorticoids used for?
helps control blood pressure by maintaining the balance between salt and water concentration in the blood and body fluids
36
what are mineralocorticoids and glucocorticoids?
groups of steroid hormones
37
what is an example of a mineralocorticoids?
aldosterone
38
what are glucocorticoids used for?
- to regulate metabolism by controlling how the body converts fats, proteins and carbohydrates to energy
- regulate blood pressure and cardiovascular function in response to stress
39
what is are some examples of glucocorticoids and what are their functions?
- cortisol- metabolism and blood pressure
- corticosterone- immune response: lowers inflammatory reactions
40
what are androgens used for?
- small amounts of male and female sex hormones are released- their is relatively small compared with the larger amounts of hormones
- released by ovaries
41
what are some examples of androgens?
- oestrogen
- testosterone
42
what is the other name for epinephrine?
adrenaline
43
what are the hormones released from the adrenal medulla?
adrenaline and noradrenaline
44
what does adrenaline do?
- increases the heart rate, sending blood quickly to the muscles and brain
- rapidly raises blood glucose concentration levels by converting glycogen to glucose in the liver
45
where is the adrenal cortex located?
the outer region of the adrenal gland
46
what does the adrenal cortex produce?
hormones that are vital for life such as cortisol and aldosterone
47
where is the adrenal medulla locted?
inner regions of the gland
48
what does the adrenal medulla produce?
non essential hormones such as adrenaline
49
what is the adrenal medulla controlled by?
the pituitary glands
50
when are hormones released from the adrenal medulla?
when the sympathetic nervous system is stimulated
51
see real flashcard for diagram of adrenal gland
52
which endocrine organ produces insulin?
pancreas
53
how do steroid hormones cause an effect on their target cells?
- lipid soluble
- passes through phospholipid bilayer
- binds to receptors in nucleus
- forming a hormone receptor complex
- acts as a transcription factor
54
what is the process of first and second messengers using adrenline?
1) adrenaline binds to membrane receptor (primary messenger targeting liver cell)
2) activation of G protein and then enzyme (adenylyl cyclase)
3) active enzyme (adenylyl cyclase) produces cyclic AMP (secondary messenger)
4) stimulates glycogen hydrolysis (glycogen to glucose)
55
how much of the pancreas is made up of acinar cells?
85%
56
what do acinar cells produce?
amylase, protease, lipase, NaHCO3
57
what are acini cells located anatomically?
next to the ducts which release products straight into the duodenum
58
what is the islet of langerhan?
clusters of tissue within the pancreas
59
what is within the islet of langerhan?
- alpha cells- form 30% of islet mass
- secrete glucagon (protein based hormone)
- beta cells (mostly) - form 60%
- secrete insulin (protein based)
60
how do you spot a duct?
- surrounded by pink strands
- has a layer of cuboidal epithelium
61
how do you spot the islet of langerhan?
- lightly stained
- large spherical clusters
- produce and secrete hormones
62
how do you spot a pancreatic acini?
- darker stained
- small, berry like clusters
63
are acini endocrine or exocrine and why?
exocrine- release digestive enzymes in digestion system
64
is the islet of Langerhans endocrine or exocrine?
endocine
65
what does amylase do?
breaks down starch
66
what does protease do?
break down proteins
67
what does lipase do?
breaks down lipids
68
what does sodium hydrogen carbonate do?
they are secreted to neutralise stomach acid
69
why do we maintain glucose levels?
- too much glucose and water potential of blood plasma falls
- too little glucose and water potential of blood plasma rises
70
what is glycogen?
a polymer containing sugar
71
how does insulin promote glucose uptake?
1) increases uptake of glucose into cells
2) rate of respiration increases
3) increases glycogenesis and inhibits glycogen break down
4) inhibits gluconeogenesis
5) more glucagon release
72
what is a hormone?
chemical messengers that travel through the blood plasma
73
what are the two types of hormones?
protein and lipids
74
what are some examples of endocrine glands?
- ovaries
- pancreas
- thyroid
- adrenal
75
what is cell signalling?
a process by which cells interact with the environment or other cells
76
what is the difference between primary and secondary messengers?
- primary- extracellular
- secondary- intracellular
77
what are two target organs of adrenaline?
- digestive system
- heart
78
where are the alpha and beta cells in the pancreas?
islet of langerhan
79
why do glucose levels have to be tightly controlled?
- brain only uses glucose and is highly sensitive
- can damage cells
80
how can you change levels of glucose in the body?
- diet- carbs are broken down in the digestive system to release glucose
- glycogenolysis
- gluconeogenesis
- glycogenesis
- exercise
- respiration
81
what is glycogenolysis?
stored glycogen in the liver is broken down to glucose and released into the blood stream
82
what is gluconeogenesis?
glucose is produced from other biological molecules e.g from glycerol and amino acids in the liver
83
what is glycogenesis?
when excess glucose is taken in through the diet is converted into glycogen
84
what is the mechanism of action with insulin?
- blood glucose levels increase
- beta cells detect this and release insulin
- all cells, except those in the brain, have insulin receptors
- insulin then increases the uptake of glucose by enabling movement of glucose receptors to the cell membrane
85
what is the mechanism of action with glucose?
- antagonistic to insulin
- inhibited by glucose
- glucagon mainly works on the liver and fat cells
- of blood glucose levels decrease:
- B cells stop producing insulin (a cells detect this)
- A cells release glucagon
86
what is the negative feedback loop for high glucose levels?
- high glucose levels
- B cells detect
- release insulin
- the effectors are all cells except those in the brain
- response is 'how does glucose produce insulin uptake'
87
what is the negative feedback loop for low glucose levels?
- low glucose levels
- a cells detect
- release glucagon
- mainly by the liver
- increases glycogon to glucose
- reduces glucose uptake into liver cells
- high levels of gluconeogenesis
88
what happens in type 1 diabetes?
the B cells in the islet of Langerhans do not produce insulin
89
where is it said type 1 diabetes arises from?
an autoimmune response where the bodys own immune response attacks the B cells
90
when does type 1 diabetes usually begin?
at childhood
91
what happens in type 2 diabetes?
the body cannot effectively use insulin and control their blood sugar levels
92
why does type 2 diabetes occur?
- the persons B cells do not produce enough insulin
- the persons body cells do not respond to it properly
- due to glycoprotein insulin receptors on the cell membrane not working properly
93
what is type 2 diabetes as a result of?
- excessive body weight
- physical inactivity
- excessive overheating of refined carbs
94
what is common with uncontrolled diabetes?
hyperglycaemia (raised blood sugar)
95
what are the symptoms of diabetes?
- high blood glucose concerntration
- glucose present in urine
- excessive need to urinate (polyuria)
- excessive thirst (polydipsia)
- constant hunger
- weight loss
- blurred vision
- tiredness
96
what is the treatment of type 1 diabetes?
- regular injections of insulin
- regular test glucose conc.
- the insulin administered increases amount of glucose absorbed by cells and causes glycogenesis (glucose to glycogen)
97
what are the treatments of type 2 diabetes?
- regulate carb intake
- lose weight if obese
- drugs to stimulate insulin production
98
what did medically produced insulin used to come from?
- cows
- pigs
99
where is medically produced insulin from now?
genetically modified bacteria
100
what are some advantages of medically produced insulin?
- less likely to produce an allergic reaction
- can be produced in higher quantities cheaper
- concerns over using animal products in humans
101
what potential do totipotent stem cells have in diabetes treatment?
potential to grow into any type of the bodys cell types
102
where would the stem cells used in diabetes be taken from?
embryos
103
what may these stem cells induce?
the formation of tumours as our ability to control growth and differentiation in stem cells is limited
104
