Karteikarten
Hormonal Communication
Karten in diesem Stapel (53)
- 1What is an endocrine gland?A group of cells which are specialised to secrete hormones into the blood
- 2What is the pineal gland?It is found in the brain and produces melatonin which affects reproductive development and daily cycles
- 3What is the thymus gland?It produces thymosin which promotes production and maturation of white blood cells
- 4What is an exocrine gland?Cells that secrete hormones through ducts into organs or the surface of the body
- 5What is a steroid hormone?Lipid soluble hormones that pass through the lipid component of the cell membrane and bind to steroid hormone receptors to form a hormone-receptor complex. This acts as a transcription factor which facilitates or inhibits the transcription of a gene.
- 6What is a non-steroid hormone?Hydrophillic hormones that bind to specific receptors on the cell surface membrane of the target cell. This triggers a cascade reaction mediated by second messenger chemicals.
- 7Compare the advantages and disadvantages of neuronal and hormonal communicationNeuronal communication is faster and more specific, whereas hormones are not broken down as quickly as neurotransmitters so they have a longer lasting and more widespread affect.
- 8Describe the structure and function of adrenal glandsThey are made up of two main parts:
- Adrenal cortex: the outer region of the gland, produces hormones vital to life eg. cortisol and aldosterone
- Adrenal medulla: the inner region of the gland, produces non-essential hormones such as adrenaline - 9What are the three main hormones produced by the adrenal cortex? What different organs control the production of these hormones?Glucocorticoids - hypothalamus, mineralocorticoids - signals triggered by the kidneys, androgens
- 10What is cortisol?A glucocorticoid that helps regulate metabolism by controlling how the body converts fats, proteins and carbohydrates to energy. They also regulate blood pressure and cardiovascular function.
- 11What is corticosterone?A glucocorticoid that works with cortisol to regulate immune response and supress inflammatory reactions.
- 12What is aldosterone?A mineralocorticoid that helps control blood pressure by maintaining the balance between salt and water concentrations.
- 13What are androgens?Male and female sex hormones
- 14What are the hormones secreted by the adrenal medulla?Adrenaline and noadrenaline
- 15What is adrenaline?A hormone that increases heart rate and blood glucose concentrations
- 16What is noadrenaline?Hormone that works with adrenaline in response to stress, producing effects such as increased heart rate, widening of pupils, widening of air passages and narrowing blood vessels in no essential organs
- 17What are the two main functions of the pancreas?As an exocrine gland - produces enzymes and releases them via a duct into the duodenum
As an endocrine gland - produces hormones and releases them into the blood - 18What tissue makes up most of the pancreas?Exocrine glandular tissue
- 19What is the exocrine glandular tissue in the pancreas responsible for?Producing digestive enzymes and an alkaline fluid called pancreatic juice. These are secreted into ducts which eventually lead to the pancreatic duct. From here they are released into the duodenum, the top part of the small intestine.
- 20What are the three enzymes that the pancreas exocrine tissue secretes?Amylases, proteases and lipases
- 21What is the pancreas' role as an endocrine gland?Producing insulin and glucagon
- 22What are islets of Langerhans?specialised cells within the pancreas responsible for producing insulin and glucagon and secreting them directly into the bloodstream
- 23What are pancreatic acini?Cells that make up the exocrine tissue of the pancreas - produce and secrete digestive enzymes
- 24What are the two types of cell within the islets of langerhan?Alpha and beta cells
- 25How do you distinguish between islets of Langerhans and pancreatic acini under the microscope?Islets of Langerhans are lighter in colour, large spherical clusters
Pancreatic acini are darker and in small clusters - 26What is the difference between alpha and beta cells?Alpha produce glucagon, beta produce insulin
- 27Which cells are larger and more abundant in islets of Langerhans?Alpha cells
- 28What is the normal blood glucose concentration?90mgcm^-3
- 29What is glycogenolysis?When glycogen is broken down into glucose
- 30What is gluconeogenesis?Production of glucose from non-carbohydrate sources
- 31What is glycogenesis?production of glycogen from glucose
- 32What cells do not have insulin receptors on their cell surface?Red blood cells
- 33What are the five in which insulin lowers blood concentration?1) Increases rate of absorption of glucose by cells - in particular skeletal muscle cells
2) Increases the respiratory rate of cells
3) Increasing rate of glycogenesis
4) Increasing rate of glucose to fat conversion
4) Inhibiting the release of glucagon from alpha cells - 34How is blood glucose concentration increased?Eating carbohydrate rich foods, glycogenolysis, gluconeogenesis
- 35How is blood glucose decreased?Respiration, glycogenesis
- 36What are the only cells in the body that do have glucagon receptors?Liver cells and fat cells
- 37How does glucagon raise blood glucose concentration?Glycogenolysis, reducing amount of glucose absorbed by liver cells, increasing gluconeogenesis
- 38Describe the mechanism of how insulin is released from beta cells?1) At normal blood glucose concentration, potassium ion channels are open and a potential of -70mV is maintained across the membrane of the cell.
2) When blood glucose concentration increases, glucose enters the cell via glucose transporters
3) The glucose is metabolised inside the mitochondria, producing ATP
4) The ATP binds to ATP-sensitive potassium channels and causes them to close
5) Potassium ions no longer diffuse out of the cell causing the potential difference to reduce to -30mV and depolarisation occurs
6) Voltage-gated calcium ion channels open
7) Calcium ions enter the cell and cause secretory vesicles to release insulin by exocytosis - 39What is hyperglycaemia?Raised blood sugar
- 40What are the symptoms of diabetes?High blood glucose concentration, glucose present in urine, excessive need to urinate (polyuria), excessive thirst (polydipsia), constant hunger, weight loss, blurred vision, tiredness
- 41What is type 1 diabetes?When you are unable to produce insulin - autoimmune response where body attacks beta cells
- 42What is type 2 diabetes?When beta cells do not produce enough insulin or body cells do not respond properly to insulin
- 43How is type 1 diabetes treated?Regular injections of insulin
- 44How is type 2 diabetes treated?Regulating diet and excercise
- 45What are the advantages of producing insulin from genetically modified bacteria?Produced in a pure form so less likely to cause allergic reactions, can be produced in much higher quantities, production costs cheaper, no ethical concerns
- 46What are the advantages of using stem cell therapy for treating type 1 diabetes?Stem cells can produce an unlimited amount of beta cells so readily available, reduced likelihood of rejection, no longer have to monitor blood glucose
- 47Draw a flow diagram to show the coordination of the fight or flight response
- 48Describe the action of adrenaline1) Adrenaline fuses to receptor site on cell surface membrane
2) This activates the adenylyl cylase inside the membrane
3) The activated adenylyl cyclase converts ATP to cyclic AMP, which acts as a second messenger that activates protein kinases. These enzymes phosphorylate other enzymes which become activated and trigger the conversion of glycogen to glucose. This is a cascade effect. - 49What part of the brain is responsible for controlling heart rate?Medulla oblongata
- 50What do the the two centres in the medulla oblongata do?One increases heart rate by sending impulses through the sympathetic nervous system - transmitted by the accelerator nerve
The other decreases heart rate by sending impulses through the parasympathetic nervous system - transmitted by the vagus nerve - 51What are the two types of receptor which provide information that affects heart rate?Baroreceptors and chemoreceptors
- 52What do chemoreceptors detect to control heart rate?pH of the blood - when more carbonic acid is formed from increased carbon dioxide concentration, the pH of the blood decreases and vise versa. The chemoreceptors detect the change in pH and respond by increasing heart rate when pH decreases and decreasing when pH increases
- 53How do baroreceptors control heart rate?They detect changes in blood pressure - if blood pressure is too high, impulses are sent to the medulla oblongata to decrease heart rate and vise versa
Informationen
- Beschreibung
- AS - Level AS Biology Karteikarten am Hormonal Communication, erstellt von Kayla Price am 12/01/2017.
- Erstellt von
- Kayla Price
- Aufrufe
- 0
- Bewertung