To deliver chemical signals called hormones to target cells/tissues around the body, using the blood circulatory system to do so
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What are the two main types of hormones?
1.Protein/peptide/amino acid derivative hormones with examples including adrenaline, insulin and glucagon. 2. Steroid hormones such as oestrogen and testosterone
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What is the difference between the way steroid and non-steroid hormones affect target cells/tissues?
Steroid hormones can diffuse directly through the phospholipid bilayer and alter cell activity but non-steroid hormones cannot
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What is the difference between endocrine and exocrine glands
Endocrine glands are ductless glands that secrete hormones directly into the blood whereas exocrine glands have ducts in which they secrete hormones into rather than directly into the bloodstream
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What will target cells/tissues for hormones posses?
Specific cell surface membrane receptors that are complimentary in shape to the hormone molecule for which they can bind to
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How do non-steroid hormones affect cell activity?
Bind to specific cell surface receptors, activates a G protein, activates an effector molecule (usually an enzyme), turns an inactive molecule into an active second messenger, triggers a cascade of enzyme controlled reactions
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What is the common effector molecule and second messenger molecule inside cells?
Adenylyl cyclase - converts ATP into cAMP (cyclic adenosine monophosphate)
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Describe the structure of the adrenal glands
Endocrine glands, above the kidneys on both sides, divided into the outer adrenal cortex and the adrenal medulla. Well supplied with capillaries to directly secrete hormones
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Which part of the adrenal glands produce steroid hormones and how do these hormones affect cell activity
Adrenal cortex. Pass through phospholipid bilayer, binds to specific receptor in cytoplasm, receptor-steroid hormone complex enters nucleus, binds to specific receptor on chromosomal material, stimulates mRNA production, code for protein production
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Name three examples of steroid hormones
1. Mineralocorticoids - control Na + K conc in blood, as a result control BP. 2. Glucocorticoids - control carbo, fats, prot metabolism in liver e.g. cortisol to raise C6H12O6. 3. Precursor molecules - converted to sex hormones to regulate sexual
10 of 24
Name some of the effects of adrenaline
Relaxation of smooth muscle in bronchioles, increasing heart rate and stroke v, vasoconstriction to increase BP, stimulate glycogen->glucose conversion, pupil dilation, increased mental awareness, inhibiting gut action, body hair stands up
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What is unique about pancreatic function
It has both endocrine and exocrine function. Endocrine - hormones secreted from the islets of Langerhans into blood, exocrine - pancreatic juices containing enzymes secreted into the pancreatic duct to go to the small intestine
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Briefly describe pancreatic exocrine function
Most pancreatic cells synthesis+secrete digestive enzymes. Arranged into groups (acini) around a tubule to join into the pancreatic duct. E.g. amylase, lipase and NaHCO3 to neutralise contents of digestive system
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Describe the arrangement of the endocrine parts of the pancreas
Group of cells called islets of Langerhans amongst the acini containing alpha and beta cells
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Outline the mechanism of insulin secretion
Glucose moves in, metabolised to ATP, increased ATP causes K+ channels close, alters PD to become more +ve, triggers Ca channels, Ca floods in, causes vesicles w/ insulin to move to+fuse with membrane, release insulin via exocytosis
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What is the name of blood glucose conc. being too high/ too low for too long?
Too high = hyperglycaemia, too low = hypoglycaemia
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What happens when blood glucose rises too high?
β cells, islets of Langerhans, secrete insulin, target cells hepatocytes/muscle cells etc., causes more glucose transporter protein vesicles to fuse to membrane to increase glucose uptake, glucose->glycogen/fats, more used in respiration
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What happens when blood glucose falls too low?
α cells, isles of Langerhans, causes glycogen->glucose (glycogenolysis), more fatty acids used in respiration amino acids/fats converted additional glucose by gluconeogenesis
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What is diabetes mellitus
A condition in which the body is no longer able to produce sufficient insulin to control its blood glucose conc.
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Describe type 1 diabetes
Juvenile onset, insulin-dependent, autoimmune cause destroys β cells, viral attack, genetic component, no longer able to synthesise sufficient insulin
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Describe type 2 diabetes
Non-insulin dependent diabetes, decreased insulin reponsiveness, usually later in life, obesity, lack of exercise, high sugar diet, asian/afro Caribbean, family history
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Describe type 1 diabetes treatment
Regular insulin injections and careful blood glucose monitoring, insulin pump therapy, islet cell transplant, complete pancreas transplant, stem cell potential from bone marrow
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Descirbe type 2 diabetes treatment
Lifestyle changes, lose weight, regular exercise, monitor diet, medication to reduce liver glucose release, severe cases insulin injections
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List some advantages of sourcing insulin from genetically modified E. coli bacteria
Exact human copy so faster acting+effective, less chance of developing insulin tolerance, less chance of rejection, lower risk infection, cheaper than animals, process adaptable to demand, fewer moral objections
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Other cards in this set
Card 2
Front
What are the two main types of hormones?
Back
1.Protein/peptide/amino acid derivative hormones with examples including adrenaline, insulin and glucagon. 2. Steroid hormones such as oestrogen and testosterone
Card 3
Front
What is the difference between the way steroid and non-steroid hormones affect target cells/tissues?
Back
Card 4
Front
What is the difference between endocrine and exocrine glands
Back
Card 5
Front
What will target cells/tissues for hormones posses?
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