hormonal communication

• Hormonal endocrine system uses... what sort of impulses?

  chemical impulses
• how are the hormones in the endocrine system transmitted

  in blood
• what is the response to endocrine system like

  slow and widespread, long lasting effects
• example of a non steroid hormone

  adrenaline, insulin
• How do non-steroid hormones work?

  cannot pass through cell membrane. They bind to a cell-surface receptor which triggers a reaction within the cell mediated by secondary messengers
• example of a steroid hormone

  oestrogen
• how do steroid hormones work

  they cross the phospholipid bilayer, bind to specific receptor proteins in the cytoplasm/nucleus ; the receptor-hormone complex acts as a transcription factor (turning genes on and off)
• Structure of adrenal glands

  -found on top of the kidneys

  -consist of an outer adrenal cortex (vital for life hormones) and an inner adrenal medulla (non essential hormones)
• hormones produced by adrenal cortex

  aldosterone, androgens, cortisol, cortiscosterone
• hormones produced by adrenal cortex function: cortisol

  regulates metabolism and blood pressure
• hormones produced by adrenal cortex function: cortiscosterone

  regular immune response
• hormones produced by adrenal cortex function: aldosterone

  regulates blood pressure
• hormones produced by adrenal cortex function: Androgens

  male and female sex organs
• What does adrenaline and noradrenaline do?

  ad: fight or flight response - increase heart rate and blood sugar conc

  norad: widens pupils, and passages in lungs, narrows blood vessels in nonessential organs
• Where are the Islets of Langerhans located? and what to they contain

  pancreas, alpha and beta cells
• What do alpha cells produce?

  glucagon
• what do beta cells produce

  insulin
• studying the histology of endo and exocrine tissue what does it look like?

  lighter part is endocrine, darker is exocrine
• What is glycogenesis?

  glucose to glycogen by insulin
• What is glycogenolysis?

  glycogen to glucose by glucagon
• What is gluconeogenesis?

  The formation of glucose by non carbs
• response to rise in blood sugar

  B calls detect rise

  insulin releases

  insulin binds w receptors on body cells

  blood sugar lowers

  B cells strop producing insulin
• what does insulin binding with receptors on body cells cause

  - Glucose transport protein channels to open

  - an increase number of carrier molecules in membrane so more glucose in cells

  - increase in glycogenesis

  - inhibits release of glucagon
• how is insulin secreted

  - glucose conc increases, glucose enters via glucose transporter

  - metabolism increases so more ATP from respiration

  - ATP binds to ATP sensitive potassium channels so they close

  - now less negative inside cell

  - causes Ca2+ channels to open so Ca2+ enters

  - causes vesicles to release insulin
• if there is a lowering blood sugar levels, what is the response?

  Alpha cells release glucagon

  binds to receptors and liver cells causing:

  - gluconeogenesis

  - an increase in glycogenolysis
• What is negative feedback

  A response to a change in the body that counteracts or opposes the initial change.
• what is the difference between diabetes mellitus and diabetes insipidus

  - malicious is when the body can't control blood (glucose can't produce insulin)

  - insipidus when kidneys cannot balance fluid in body (don't produce insulin or glycoproteins are not responsive to insulin)
• The difference between type one and type two diabetes mellitus

  Type one develops quickly at childhood, type to develop slowly with older people

  both can be treated with insulin,diet and exercise. Type two can be treated with drugs
• how can we produce insulin via genetically modified bacteria

  Cut out the insulin gene with restriction enzyme

  cut open plasmid with a restriction enzyme

  lipase joins together by sticky ends

  modify plasmid is taken up by bacteria

  bacteria grows and insulin extracted
• advantages of producing insulin by genetically modified bacteria

  Can make high quantities easily

  less likely to cause a reaction

  less ethical issues that come with stem cells
• what is a coordinated response (fight or flight)

  involves autonomic nervous system and endocrine system
• what is the fight or flight response

  Hypothalamus activates adrenal cortical system by releasing CRF

  this triggers pituitary gland to release ACTH

  stimulates adrenal cortex to release 30 hormones in the bloodstream
• what is the second messenger model in terms of adrenaline

  Adrenaline (first messenger) binds to receptors on liver ceell

  enzyme (adenylyl cyclase) on inside of membrane is activated

  converts ATP to cyclic AMP (cAMP- the second messenger)

  glycogenolysis enzymes are activated
• what are carotid arteries

  arteries that supy the brain in the neck
• what is the difference between chemo receptors and baro receptors

  chemo detects chem, baro detects pressure.

  both found in a aorta, and carotid arteries

  chemo found in medualla, baro found in vena cava
• what's the difference in how the Medela oblongata an SAN are connected, for increasing and decreasing heart rate

  If heart rate is being increased the medulla oblongata links to the SAN via accelerator nerve

  if the heart rate is decreased the medulla oblonga links to the SAN via the vagus nerve
• how is the heart rate sped up or slowed down via responses (controlled with chemo and carotid artifices)

  - Increasing muscular activity and respiration so more CO2 in blood so pH is lower

  - chemo receptors in carotid arteries detect changes and increase frequency of impulses sent to medulla oblongata (MO)

  - center of MO increases frequency of impulses to SAN via accelerator nerve

  - SAN note increases heart rate by increasing frequency of impulses

  - increase blood flow removeS CO2 faster

  - so CO2 levels return to normal
• What gland is also known as a ductless gland

  endocrine
• what is the neurotransmitter released by sympathetic neurons with similar effects to adrenaline

  noradrenaline
• how do hormonal and nervous systems control the heart rate

  - adrenaline from hormonal system increases heart rate

  - vagus nerve decreases heart rate

  - accelerator nerve increases heart rate

  - baroreceptors detect pressure changes

  - chemoreceptors detect pH level changes