Assessment Task 5 FST Year 11 ATAR Course 2024 PDF

**\*\*Glycogenesis (\*\*stimulated by insulin)** **Formation of glycogen from other carbohydrates, especially glucose (Glucose → Glycogen)** \*\*Glycogenolysis (\*\*Stimulated by glycogen) **Breakdown** of glycogen to glucose (Glycogen → glucose) **Gluconeogenesis** **Conversion** of fats or pr...

**\*\*Glycogenesis (\*\*stimulated by insulin)** **Formation of glycogen from other carbohydrates, especially glucose (Glucose → Glycogen)** \*\*Glycogenolysis (\*\*Stimulated by glycogen) **Breakdown** of glycogen to glucose (Glycogen → glucose) **Gluconeogenesis** **Conversion** of fats or proteins into glucose (Fat/Protein →Glucose) **Endocrine system** ==================== - The body system involved in chemical communication between cells are made of endocrine glands. - Endocrine system generally coordinated the body in order to maintain homeostasis through the release of chemical messenger called hormones. - Hypothalamus - Pineal gland - Pituitary gland - Thyroid and parathyroid - Thymus - Liver - Stomach - Adrenal - Stomach - Pancreas - Ovary - Testes - Uterus **Endocrine glands** **Exocrine glands** ------------------------------------------------------------------------------------- ----------------------------------------------------------------------------- Secrete hormones. Secretes other than hormones. Secrete the extracellular fluid then hormone passes in the blood to be transported. Secrete into a duct which carries secretion to body surface or body cavity. Secretions have altered cell metabolism. Secretions have extracellular effects such as the digestion of food. E.g. thymus, thyroid, pancreas E.g. sweat glands, pancreas **Steroid** **Lipid derived from cholesterol** **Lipophilic - can cross cell membrane** **Testosterone, Estrogen, progesterone** ------------- ------------------------------------ ---------------------------------------------- ------------------------------------------ **Peptide** Short polypeptide chains Hydrophilic - cannot cross the cell membrane Insulin, hGH, glucagon, oxytocin, ADH **Amine** Derived from aromatic amino acids Hydrophilic - cannot cross the cell membrane Thyroxine **Protein & amine** **Steroid** -------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------- **Mode of** Amino acid Cholesterol **Solubility** Water soluble Lipid soluble **Transport in blood** dissolved in blood plasma Attached to carrier protein diffuses across the cell membrane **Location of receptor** Hormones cannot pass through the cell membrane they bind to a particular or a matching receptor on surface of target cell membrane to form a hormone receptor complex. therefor hormones don\'t enter the cell Hormones bind to a receptor either in the cytoplasm or in the nucleus to form hormone receptor complex as the hormones enter the cell. (intercellular) **Mechanism of action** Binding of hormone to receptor triggers a secondary messenger/ response inside the cell The complex enters the nucleolus and bind to DNA altering the gene expression therefore it produces protein. **Effect** secondary m **Speed of action** Faster - they don't depend on the cell to synthesize protein Slower - as they depend on the cell to synthesize protein **Longevity** Short lasting Long lasting **Break down time** Fast Slow **Example** ADH, FSH, LH, protecting Estrogen, testosterone **FIRST** & **SECOND** messengers in water soluble hormones - The hormone is the first messenger. - The second messenger is inside the cell and is activated by the presence of the first messenger binding receptors that is in the cell membrane. - It then initiates cell activity/ enzymes inside the cell. ### **Hormones and receptors** - They are specific - Hormones are only able to influence cells that have the correct receptor. These receptors are either on cell membrane, cytoplasm or nucleus. - Saturations can occur when all receptors ae filled. In this case adding more hormones do not increase the rate of reaction ### **Different cells, different number of receptors, different variation of sensitivities** - hormones have wide range of targets. - e.g. sex hormones - which affect most of the tissues of the body - Glucagon from the pancreas - only have few kinds of target cells - e.g. liver and fat cells for glycogen some hormones have other endocrine glands as their target cells. e.g. LH and FSH to ovaries \ 💡 graph TD\ A\[High Blood Glucose\] \--\> B{Pancreas}\ B \--\>\|Releases Insulin\| C\[Glucose to Glycogen\]\ C \--\> D\[Lowers Blood Glucose\]\ \ E\[Low Blood Glucose\] \--\> F{Pancreas}\ F \--\>\|Releases Glucagon\| G\[Glycogen to Glucose\]\ G \--\> H\[Raises Blood Glucose\]\ \ D \--\> I\[Normal Blood Glucose Level\]\ H \--\> I\ \ style I fill:\#90EE90,stroke:\#333,stroke-width:2px This diagram illustrates the roles of insulin and glucagon in regulating blood glucose levels: - Insulin promotes the conversion of glucose to glycogen, lowering blood glucose. - Glucagon stimulates the breakdown of glycogen to glucose, raising blood glucose. - Both hormones work together to maintain blood glucose homeostasis. \ ### **Enzyme amplification** - Enzyme amplification is the process whereby those of enzyme molecules are activated by one hormone molecule. - This means that a very small stimulus can produce a very large effect. - once a hormone has produced a required affect it can be turned off - Some hormone's effect recuses further hormone release - some hormones are broken down by enzymes in the liver or kidney - some target cells reduce the number of receptors when the hormone level is high - hormones are excreted via urine or bile **Hypothalamus** ================ - The region of the brain that controls an immense number of bodily functions - Body temperature - Food & water intake - Patterns of walking and sleeping - Releasing hormones - Controlling appetite - Emotional responses - It is located at **the base of the brain, near the pituitary glands** - The hypothalamus is a selection of the rain that links the nervous and endocrine system in order to maintain homeostasis - The hypothalamus receives information from nerves through the body and other parts of the brain and initiates endocrine responses. - Neurosecretory cells within the hypothalamus secrets releasing factors or inhibiting factors into the hypophysial portal system where it stimulates the anterior pituitary. \ 💡 Releasing Function - Thyrotrophin releasing hormone - stimulates the secretion of TSH and Prolactin from the anterior pituitary gland. - Corticotrophin releasing hormone - promotes the secretion of ACTH. - GnRH - stimulates FSH and LH - GnRH - produces growth hormone. \ - Neurosecretory cells within the hypothalamus produces both ADH and oxytocin - These hormones move alone the neurosecretory cells to the posterior pituitary where they are stored - They are only secreted from the posterior pituitary when the neurosecretory cells in the hypothalamus are stimulated. This is neural. **Anterior pituitary gland** ============================ - Anterior pituitary gland is glandular and is connected to the hypothalamus via the **hypothalamic-hypophysial portal system.** - The release of hormones from the anterior pituitary gland stimulate/ initiate via chemical hormonal stimulation. - manufacture/ produce hormones - The hormones in here are regulated by two classes of hormones/ factors - These hormones are secreted from the hypothalamus are factors that stimulate the secretion of hormones from the anterior pituitary and the inhibiting hormones that inhibit secretion. - These releasing and inhibiting factors are carried by hypophyseal system to the Anterior Pituitary. **Posterior Pituitary** ======================= - The posterior pituitary or **neurohypophysis** is not a separate organ, but an extension of the hypothalamus. - It's composed largely of an **extension of the hypothalamus**. - It's composed largely of the **axons from hypothalamus neurons** which extend downwards as a large bundle behind the anterior pituitary. - It also forms the pituitary stalk, which appears to suspend the anterior gland from the hypothalamus. - The posterior pituitary is **lighter in color** than the anterior pituitary. This is because anterior pituitary has more blood capillaries in it than the anterior pituitary and the posterior pituitary have the large bungle of **axons which are white.** - The posterior pituitary gland **doesn't produce any hormones**. It stores the hormones produces from the hypothalamus (Oxytocin & ADH) and stores it in the vesical of the axons and secrete them when the hypothalamus sends signals. \ ❓ The process of releasing oxytocin/ADH from neurosecretory cells and targeting the receptors in the target cells - Oxytocin/ADH is held in the vesicles - Nerve impulse/ action potential from the hypothalamus causes their release from the vesicles - Ca2+ gated channels open and resulting an influx of Ca2+ - Release of chemicals is by the process of exocytosis - Oxytocin/ADH diffuse across synopses/ into the intracellular fluid - Both oxytocin and ADH target receptors on other cells. \ \ ❓ **hGH is released from the pituitary gland. State from which lobe of the pituitary this hormone is secreted and explain the relationship between this section of the pituitary gland and the hypothalamus.** - It if secreted from the anterior pituitary gland - The hypothalamus is connected to the anterior pituitary by the hypothalamic-hypophysial portal system. - Secretion of hGH happens by the releasing + inhibiting factors from the hypothalamus. - The releasing factors are transported through vein - They also produce inhibiting factors to inhibit activity of the pituitary. \ \ ❓ **Describe how hypothalamus and posterior pituitary work together to achieve their main function.** - Hormones are produces in the hypothalamus. - These hormones are transported by the neurosecretory cells. - Hormones are stored in the posterior lobe - Oxytocin and ADH are stored in axon terminals in the posterior pituitary. - These stored hormones are released via nervous stimulation \ \ ❓ **Describe how hypothalamus and anterior pituitary work together to achieve their main function.** - Hormones are produces in the anterior lobe - These hormones are released by the releasing factors' signals from the hypothalamus - The hypothalamus and the anterior pituitary are connected by a blood vessel. \ \ ❓ **Describe the response of the hypothalamus to a decreasing metabolic rate** - The hypothalamus detects a decreased in metabolic rate - The hypothalamus sends TSH releasing factors to the anterior pituitary - Through blood vessels in the infundibulum - The anterior pituitary gland secretes TSH - TSH travels through the blood stream - Attaching to TSH receptors proteins on the thyroid - The thyroid gland secreted thyroxine - Thyroxine travels through the blood stream - Attaches to all cells that have thyroxine receptor proteins on the surface - Causing cells to increase metabolic rate/ rate of reaction/ respiration. \ **OTHOR ENDOCRINE ORGANS** ========================== **Pineal gland** ---------------- - Pineal gland is located in the Epithalamus - After puberty it decreases in size - It secreted melatonin - Regulates sleep patterns. - It is stimulated by darkness and inhibiting light **Thyroid gland** ----------------- - Is located in the neck- two lobes in either side of the trachea joined by narrow piece of tissue. - **Thyroxine (T4)** and **Triiodo thymine (T3)** are the thyroid hormones. - **T4 -** contains 4 iodine molecules - **T3 - contains 3 iodine molecules** - These thyroid hormones is responsible for metabolism, both anabolism and catabolism - The overall effect of thyroxine is to bring about the release of energy, because some metabolic reactions such as catabolic reactions release energy in form of heat and this is used to **maintain body's temperature.** - This gland also maintains the body's calcium and phosphate levels in the blood through the release of calcitonin **Calcitonin (thyroid gland)** -------------------------------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Increase in calcium in blood Calcium in the blood when increased above **10ml of calcium every 100ml of blood**, the **calcitonin** is secreted from the thyroid gland. This sends signals to the kidney to **reduce the reabsorption of calcium back in to the blood and the breakdown of bone.** Increase in phosphate in blood When phosphate in the blood is increase, Calcitonin acts and move the extra phosphate into the bone, and reduce the reabsorption of phosphate back into the blood. ***Parathormone and calcitonin are antagonistic hormones*** **Parathyroid glands** ---------------------- - There are 4 located in the rear surface of the thyroid gland. - Secretes parathyroid hormone (PTH) or parathormone. - The parathormone does the opposite of what calcitonin does. **Parathormone** --------------------------------------- ----------------------------------------------------------------------------------------------------------------------------- Calcium level in the blood decrease When the blood calcium level is too low parathormone increase the reabsorption of calcium in the kidney and bone breakdown. Phosphate level in the blood decrease When the blood phosphate level is too low parathormone increase the reabsorption of phosphate in the kidney. **Thymus** ---------- - Gets smaller as you grow up - Secretes a group of hormones calls **thymosin** - These hormones influence the maturation of disease fighting **T-lymphocytes** **Adrenal glands** ------------------ - Located on top of the kidney ### **Adrenal Medulla** - Stimulates my **nerve signals** - Forms **adrenalin** and **nor-adrenalin** - **Adrenalin** is **released in threatening situations**. - They give the fight-or-flight responses - **Noradrenalin** increases the rate and force of the heartbeat at fight-or-flight situations ### **Adrenal Cortex** - Stimulated by hormonal signals - 20 different hormones are produces here - Aldosterone and cortisol are the once we learn now - Aldosterone - acts on kidney and reduces the amount of sodium in increase the amount of potassium in urine - Cortisol - related hormones, promotes normal metabolism, help the body to withstand stress and repair damages tissue **Pancreas** ------------ - Is both an exocrine and endocrine gland - The endocrine part is made of **islets of Langerhans** - **Alpha islets of Langerhans** secret **glycogen** - This increases the blood glucose levels why breaking down fat and turning glycogen into glucose - In **liver** - insulin cause the glucose convention to glycogen and fat - In **skeletal muscles** - insulin cause the glucose to form into glycogen - In **fat** - insulin cause glucose to be stored as fat. - **Beta islets of Langerhans** secret **insulin** - this decreases the blood glucose level by breaking down glucose into glycogen - In **liver** - breakdown the glycogen to glucose - Stimulate the breakdown of fat in the liver and fat storage tissues **Gonads** ---------- - Male sex hormones released are called **Androgens. e.g.** testosterone - Female sex hormones produce in the ovaries are E**strogen** and **Progesterone** **Other endocrine tissues hormones** ------------------------------------ - These hormones are **not released from an organ.** - They are released from **tissues** - Stomach and small intestine - secrete hormones that coordinate with exocrine glands of digestive system - Kidney - secreted a hormone to stimulate production of red blood cells by the bone marrow - Heart - secretes a hormone to help reduce blood pressure - Placenta - secrete a number of hormones during pregnancy to helps maintain the pregnancy, stimulate development of fetus and stimulate the mothers' mammary glands