Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
M 7.1
| Question | Answer |
|---|---|
| What is the primary function of a control system in the body | Maintains body homeostasis. |
| What does a control system regulate | Variables like blood glucose and body temperature. |
| What level does a control system maintain variables at | An optimal level. |
| What does a control system establish for each variable | A specific or near set point. |
| What are the three main components of a control system | Receptor, Control centre, Effector. |
| What is the role of the receptor in a control system | To sense the signal or variable. |
| What is the role of the control centre in a control system | Monitors variables and adjusts them accordingly. |
| What is the role of the effector in a control system | To carry out the adjustment. |
| What is the role of the Receptor (sensor) in a control system | To monitor the controlled variable, e.g., thermoreceptors. |
| What must a control system be able to do regarding actual and set values | Compare the actual value with what it should be. |
| What is an example of a Control centre | The hypothalamus (control of the endocrine system). |
| What is the function of the Effector in a control system | To change the controlled variable. |
| What is an example of an Effector | Sweat glands. |
| What is the stimulus in the feedback loop example | Body temperature exceeds $37^{\circ} \mathrm{C}$. |
| What acts as the sensor when body temperature exceeds $37^{\circ} \mathrm{C}$ | Nerve cells with endings in the skin and brain. |
| What is the control center for body temperature regulation | Temperature regulatory center in brain. |
| What is the effector in the body temperature regulation feedback loop | Sweat glands throughout body. |
| What process is being regulated by this feedback loop | Body temperature regulation. |
| What is essential for a control system to work | Effective communication between its components. |
| How do components communicate when they come into contact | Via cell surface chemicals (e.g., immune cells). |
| How do components communicate when they are close | Local diffusion of chemical messengers (paracrine via hormones). |
| How do components communicate when they are far apart | Chemical messengers in the bloodstream (endocrine via hormones) or neurotransmitters. |
| What is an example of communication via cell surface chemicals | Immune cells. |
| What type of chemical messengers are involved in local diffusion | Paracrine via hormones. |
| What type of chemical messengers are involved in communication over long distances via blood | Endocrine via hormones. |
| Besides hormones in the bloodstream, what else facilitates communication over long distances | Neurotransmitters. |
| What are hormones | Chemical signals produced in endocrine glands. |
| What are the three types of effects hormones may have | Endocrine, paracrine, or autocrine effect. |
| How do hormones travel to affect other tissues | They travel in the bloodstream. |
| Can hormones have different effects in different places | Yes, they can have different effects. |
| What determines the effect a hormone has on a target cell | Its concentration in the bloodstream. |
| Are hormones normally present at high or low concentration in the bloodstream | Normally present at low concentration. |
| What hormones does the HYPOTHALAMUS produce | ADH, oxytocin, and regulatory hormones. |
| What hormone do the PARATHYROID GLANDS produce | Parathyroid hormone (PTH). |
| What hormones does the HEART produce | Natriuretic peptides: ANP and BNP. |
| What hormones does the THYROID GLAND produce | Thyroxine (T4), Triiodothyronine (T3), Calcitonin (CT). |
| What hormones does the KIDNEY produce | Renin, Erythropoietin (EPO), Calcitriol. |
| What hormone does the THYMUS produce | Thymosins. |
| What hormones does ADIPOSE TISSUE produce | Leptin, Resistin. |
| What hormones do the PANCREATIC ISLETS produce | Insulin, glucagon. |
| What hormone does the PINEAL GLAND produce | Melatonin. |
| What hormones does the Anterior lobe of the PITUITARY GLAND produce | ACTH, TSH, GH, PRL, FSH, LH, and MSH. |
| What hormones does the Posterior lobe of the PITUITARY GLAND release | Oxytocin and ADH. |
| What hormones does the Adrenal medulla produce | Epinephrine (E), Norepinephrine (NE). |
| What hormones does the Adrenal cortex produce | Cortisol, corticosterone, aldosterone, androgens. |
| What hormones do the Testes (male) produce | Androgens (especially testosterone), inhibin. |
| What hormones do the Ovaries (female) produce | Estrogens, progestins, inhibin. |
| What is the core chemistry/structure of Peptide/Polypeptide hormones | Single-chain peptides; variable length (3-191 aa). |
| How are Peptide/Polypeptide hormones stored and released | Synthesized as prohormones; stored in vesicles; released by exocytosis. |
| What is the solubility of Peptide/Polypeptide hormones | Hydrophilic. |
| What is the mechanism/receptors for Peptide/Polypeptide hormones | Bind cell-surface (membrane) receptors $\to$ second messengers. |
| Name a representative example of a Peptide/Polypeptide hormone.aa). | TRH (3 aa), Glucagon (29 aa), Insulin (51 aa), GH (191 |
| What is the core chemistry/structure of Glycoprotein hormones | Two polypeptide chains ($\alpha$ and $\beta$) with carbohydrate side chains. |
| How are Glycoprotein hormones stored and released | Synthesized and stored; secreted on demand. |
| What is the solubility of Glycoprotein hormones | Hydrophilic. |
| What is the mechanism/receptors for Glycoprotein hormones | Cell-surface receptors; $\beta$-subunit confers specificity. |
| Name a representative example of a Glycoprotein hormone. TSH, FSH, LH, hCG. | |
| What is the core chemistry/structure of Amino acid derivatives (tyrosine-derived) hormones | Derived from tyrosine. |
| How are Amino acid derivatives hormones stored and released | Mixed: some stored in vesicles; thyroid hormones stored bound to thyroglobulin. |
| What is the solubility of Amino acid derivatives hormones | Mixed: catecholamines hydrophilic; thyroid hormones lipophilic. |
| What is the mechanism/receptors for Amino acid derivatives hormones | Catecholamines $\to$ membrane receptors; thyroid hormones $\to$ nuclear receptors. |
| Name a representative example of an Amino acid derivative hormone. | T3, T4, Adrenaline. |
| What is the core chemistry/structure of Steroid hormones | Synthesized from cholesterol; not stored. |
| How are Steroid hormones stored and released | Produced on demand from cholesterol esters. |
| What is the solubility of Steroid hormones | Hydrophobic (lipophilic). |
| What is the mechanism/receptors for Steroid hormones | Intracellular (cytosolic/nuclear) receptors $\to$ gene transcription. |
| Name a representative example of a Steroid hormone. | Cortisol, Aldosterone, Oestrogen, Testosterone. |
| What primarily stimulates endocrine cells to release hormones | Chemical stimulation, mainly by another hormone. |
| What mechanism controls hormonal secretion | A negative feedback loop. |
| What stimulates parathyroid hormone (PTH) secretion | Decreased blood calcium levels. |
| What organs does PTH act on to increase blood calcium | Bone and kidney. |
| What effect does increased blood calcium have on PTH secretion | It reduces its own secretion. |
| What are tropic hormones controlled by | The hormones they control. |
| How does the hypothalamus control pituitary gland hormone secretion | Via hypothalamic releasing and inhibiting hormones. |
| What is an example of a hypothalamic releasing hormone | TRH (Thyrotropin-releasing hormone). |
| What does TRH stimulate the release of | TSH (Thyroid-stimulating hormone). |
| Which hormones are soluble enough to travel in simple solution in the blood | Peptide/polypeptide, glycoprotein, and adrenaline hormones. |
| What type of hormones are adrenaline | Amino acid derivative hormones. |
| Which hormones must bind to proteins in the blood | Steroids and thyroid hormones. |
| Where can hormone inactivation occur | Target tissues and other tissues, especially the liver. |
| How are peptides/polypeptides and glycoprotein hormones inactivated | Degraded to amino acids. |
| What happens to amino acids from degraded peptide/polypeptide hormones | Reused for protein synthesis. |
| How are steroid hormones and amino-acid derivatives inactivated | Small changes in structure. |
| What happens to inactivated steroid hormones and amino-acid derivatives | Recycled or excreted. |
| What are the two main systems the pancreas is part of | Digestive and endocrine systems. |
| What is the approximate weight of a healthy adult pancreas | $\sim 200-300 \mathrm{~g}$. |
| What is the approximate length of a healthy adult pancreas | $\sim 15-20 \mathrm{~cm}$. |
| What are the anatomical divisions of the pancreas | Head, body, and tail. |
| What percentage of the pancreas is endocrine tissue | $2 \%$. |
| What hormones are produced by the endocrine part of the pancreas | Insulin, glucagon, somatostatin, pancreatic polypeptide, ghrelin, and amylin. |
| What percentage of the pancreas is exocrine tissue | $98 \%$. |
| What does the exocrine part of the pancreas produce | Digestive enzymes (amylases, lipases, proteases). |
| What are the anatomical divisions of the pancreas | Tail, Body, Head. |
| Which duct is associated with the pancreas | Pancreatic duct. |
| What is the main artery supplying the pancreas | Celiac trunk. |
| Which artery branches from the celiac trunk to supply the pancreas | Splenic artery, Common hepatic artery. |
| What artery branches from the common hepatic artery | Gastroduodenal artery. |
| Which artery is located dorsally to the pancreas | Dorsal pancreatic artery. |
| What is the large artery supplying the pancreas | Pancreatica magna artery. |
| What is the major artery inferior to the pancreas | Superior mesenteric artery. |
| What type of branch connects arteries in the pancreatic vasculature | Anastomotic branch. |
| What is the name of the duct associated with the dorsal pancreas | Duct of dorsal pancreas |
| What structure develops from the hepatic outgrowth | Bile duct |
| Which bud is located dorsally in the developing pancreas | Dorsal pancreatic bud |
| Which bud is located ventrally in the developing pancreas | Ventral pancreatic bud |
| What part of the duodenum is mentioned in the context of pancreatic development | Second part of duodenum |
| What is the name of the duct associated with the ventral pancreas | Duct of ventral pancreas |
| What process involves the ventral duct during development | Rotation of the ventral duct |
| What is an abnormality of buds fusion | Annular Pancreas |
| What is the consequence of buds forming a ring around the duodenum | Bowel obstruction in infancy |
| What is the process called when the dorsal and ventral buds merge | Fusion of buds |
| What is the exocrine component of the pancreas | Acini |
| What is the endocrine component of the pancreas | Islets of Langerhans |
| Which cells are found in the Islets of Langerhans | \(\alpha\)-cells and \(\beta\)-cells |
| What percentage of Islet of Langerhans cells are glucagon-secreting $\alpha$-cells | 20-25% |
| What do $\beta$-cells in the Islet of Langerhans secrete | Insulin |
| Which cells in the Islet of Langerhans secrete somatostatin | $\delta$-cells |
| Which cells are responsible for the regulation of appetite | Ghrelin-secreting $\varepsilon$-cells and Pancreatic Polypeptide-secreting PP cells |
| What hormone raises blood sugar | Glucagon |
| What organ releases glucagon | Pancreas |
| What does glucagon stimulate in the liver | Glycogen breakdown |
| What hormone lowers blood sugar | Insulin |
| What does insulin promote | Glucose uptake from blood |
| What is the half-life of insulin | ~5 minutes |
| What cells release glucagon | a-cells |
| What cells release insulin | B-cells |
| What tissues are insulin sensitive | Adipose, skeletal muscle, liver |
| What is the physiologic state associated with insulin | Feeding (post-prandial) |
| What is the physiologic state associated with glucagon | Fasting / low glucose |
| What is the overall role of insulin | Anabolic - promotes storage |
| What is the overall role of glucagon | Catabolic - mobilises stores |
| What are the primary targets of insulin | Liver, skeletal muscle, adipose tissue |
| What are the primary targets of glucagon | Liver, adipose tissue |
| How does insulin affect glycogen synthesis | Increases glycogen synthesis (liver, muscle) |
| How does glucagon affect glycogen breakdown | Increases glycogen breakdown (liver) |
| How does insulin affect hepatic gluconeogenesis | Decreases hepatic gluconeogenesis |
| How does glucagon affect hepatic gluconeogenesis | Increases hepatic gluconeogenesis |
| How does insulin affect lipolysis | Decreases lipolysis |
| How does glucagon affect lipolysis | Increases lipolysis |
| What is the net effect of insulin on blood glucose | Decreases |
| What is the net effect of glucagon on blood glucose | Increases |
| What is the first form of insulin synthesized | Preproinsulin |
| What does preproinsulin process into | Proinsulin |
| What does proinsulin process into | Insulin |
| What is removed during the conversion of preproinsulin to proinsulin | Signal peptide |
| How many amino acids are in preproinsulin | 109 a.a. |
| How many amino acids are in proinsulin | 86 a.a. |
| How many amino acids are in mature insulin | 51 a.a. |
| What chains are present in preproinsulin | Signal peptide, B chain, C chain, A chain |
| What chains are present in proinsulin | B chain, C chain, A chain |
| What chains are present in mature insulin | A chain and B chain |
| What type of bonds connect the A and B chains in mature insulin | Inter-chain disulfide bridges |
| What type of bond is found within the A chain of insulin | Intra-chain disulfide bridge |
| What is the role of the C chain in insulin synthesis | It is removed during maturation from proinsulin to insulin. |
| What is the first step in insulin secretion | mRNA production and preproinsulin gene transcription in the nucleus. |
| Where is preproinsulin synthesized and disulfide bonds formed | Endoplasmic reticulum. |
| What happens to proinsulin in the Golgi apparatus | Proinsulin is converted to insulin and packaged into granules. |
| What structures are involved in transporting proinsulin to the Golgi | Transfer vesicles. |
| What role do microtubules play in insulin secretion | Secretory vesicles move along microtubules towards the plasma membrane. |
| What stimulates the \(\beta\)-cell to release insulin | Glucose, which causes calcium to enter the cell. |
| What do calcium ions induce in the \(\beta\)-cell | Contraction of microfilaments. |
| What is the final step of insulin release from the \(\beta\)-cell | Exocytosis of insulin and peptide C from vesicles. |
| What happens when vesicle membranes fuse with the plasma membrane | Insulin and peptide C are released. |
| What is the function of transfer vesicles | Transport of proinsulin to the Golgi. |
| How does glucose enter the $\beta$-cell | Facilitated diffusion via GLUT2. |
| What happens to glucose inside the $\beta$-cell | It is utilized to produce ATP. |
| What is the effect of ATP on $\mathrm{K}^{+}$ channels | ATP closes the $\mathrm{K}^{+}$ channels. |
| What does increased intracellular $\mathrm{K}^{+}$ levels cause | Membrane depolarization. |
| What follows membrane depolarization in $\beta$-cells | Influx of extracellular $\mathrm{Ca}^{2+}$. |
| What triggers the release of insulin from secretory granules | Increased intracellular $\mathrm{Ca}^{2+}$. |
| What are sulphonylureas used for | To treat type 2 diabetes. |
| How do sulphonylureas work | They are insulin secretagogues. |
| What type of receptor is the insulin receptor | Tyrosine kinase receptor. |
| Where is the insulin receptor located | On the target cell. |
| What is the structure of the insulin receptor | A transmembrane dimer. |
| How many identical monomers make up the insulin receptor | Two. |
| What does each monomer of the insulin receptor consist of | One $\alpha$-subunit and one $\beta$-subunit. |
| What connects the $\alpha$-subunit and $\beta$-subunit in a monomer | A single disulfide bond. |
| Where is the $\alpha$-subunit located and what is its function | Extracellular and insulin binding. |
| Where is the $\beta$-subunit located | Intracellular. |
| What activity does the $\beta$-subunit possess | Tyrosine kinase activity. |
| What does the insulin receptor span | The plasma membrane. |
| What is the first step in insulin receptor activation | Dimerization. |
| What happens after dimerization of the insulin receptor | Phosphorylation. |
| What does an active relay protein facilitate | Cellular response. |
| What is consumed during the activation of the insulin receptor | ATP is converted to ADP. |
| What is the first step in glucose uptake via GLUT4 | Insulin binds to receptor. |
| What happens after insulin binds to the receptor in glucose uptake | Glucose entry is permitted. |
| What follows the signal cascade in glucose uptake via GLUT4 | Glucose utilisation. |
| What is the final step in glucose uptake via GLUT4 after glucose utilisation | Exocytosis. |
| Where is glucagon synthesized | In \(\alpha\)-cells. |
| What is the large precursor of glucagon | Pre-proglucagon. |
| How many amino acids are in a single polypeptide chain of glucagon | 29 amino acids. |
| Does glucagon have di-sulfide bridges | No, it has a flexible structure. |
| Where is glucagon synthesized within the cell | In the RER. |
| Where is glucagon transported after RER synthesis | To the Golgi. |
| How is glucagon packaged after the Golgi | In secretory vesicles. |
| How do secretory granules release glucagon into the blood | By exocytosis. |
| What is the full length of Proglucagon | 1-160. |
| What does glucagon bind to | G-protein coupled receptor (GPCR). |
| Which subunit activates adenylate cyclase | The $\alpha$-subunit. |
| What does adenylate cyclase produce | cAMP. |
| What does cAMP activate | PKA. |
| What does PKA activation lead to | Signalling cascade and metabolic effects. |
| What is a clinical sign of high insulin levels | High insulin levels result in hypoglycaemia. |
| What is a clinical sign of low insulin levels | Low insulin levels result in hyperglycaemia (diabetes mellitus). |
| What is a clinical sign of insulin resistance | Insulin resistance results in hyperglycaemia and hyperinsulinaemia. |
| What is a clinical sign of high glucagon levels | High glucagon levels worsen diabetes. |
| What is a clinical sign of low glucagon levels | Low glucagon levels may contribute to hypoglycaemia. |
| Which endocrine glands are located in the head and neck | Pituitary, pineal, thyroid, and parathyroid glands. |
| Which two parts make up the pituitary gland | The anterior and posterior pituitary. |
| What links the nervous system to the endocrine system | The hypothalamus. |
| How does the hypothalamus link the nervous and endocrine systems | Via the pituitary gland. |
| Which endocrine glands are located in the abdomen | Adrenal glands, pancreas, kidney, and gut. |
| What are the two parts of the adrenal glands | Cortex and medulla. |
| Which endocrine glands are found in the pelvis | Gonads (ovaries, testes), uterus, and placenta. |
| Name the gonads that are endocrine glands. | Ovaries and testes. |
| Where is adrenaline stored | In vesicles in adrenal medulla (chromaffin cells). |
| Is adrenaline hydrophilic or hydrophobic | Hydrophilic. |
| How are thyroid hormones stored | As thyroglobulin (prohormone) extracellularly in follicles in the thyroid gland as colloid. |
Created by:
holaaloo