9. Endocrine System Flashcards

Question

Name ONE function for Melanocyte Stimulating Hormone

Answer 1

Skin, hair and eye pigmentation * Can be excessively produced as part of some pathologies such as Hyperpigmentation of skin in Addisons Disease

Answer 2

Can be excessively produces as part of some pathologies such as Hyperpigmentation of skin in Addisons Disease

Answer 3

Prolactin acts on the breast tissue. It is involved in milk production. * STIMULTES LACTATION: Prolactin + Oxytocin = lactation * PREVENTS PREGNANCY (most of the time) DURING LACTATION by inhibiting the menstrual cycle and GnRH * BREAST MATURATION after childbirth

Answer 4

* AFTER BIRTH * Breast suckling * Emotional STRESS * Adequate Sleep

Answer 5

* All about stimulating PRODUCTION OF GAMETES (sex cells) IN MALES AND FEMALES * Increase oestrogen production * Increasing testosterone production

Answer 6

* TRIGGERS OVULATION * Increase oestrogen secretion * Increasing testosterone secretion

Answer 7

They are produced/created in the hypothalamus and released on demand by the posterior pituitary gland. 1. Oxytocin 2. Antidiuretic Hormone (ADH)

Answer 8

Contracts the uterus in childbirth Contracts the lactating breast for milk release Bonding - mother with baby but also social bonding.

Answer 9

ADH - Antidiuretic hormone As the name suggests it is 'against urination'. If the hypothalamus senses that the concentration of sugar, salts, plasma protein in the blood is too high it releases ADH which reduces urine output by stimulating reabsorption of water into the kidneys so that the fluid is retained in the blood stream thus increasing blood volume.

Answer 10

This is a deficiency of ADH production or recognition causing the kidneys to over excrete water. ADH stands for antidiuretic hormone and it is excreted from the Posterior pituitary

Answer 11

The thyroid gland, which influences metabolic rate, produces thyroxine (T4) and triiodothyronine (T3). The 4 and 3 represent the number of iodine atoms in the molecule.

Answer 12

T3 We have T3:T4 in the ratio of 1:20 because T3 is more biologically active and therefore powerful. T4 is converted to T3.

Answer 13

Parafollicular cells are situated between follicles in the thyroid and secrete the hormone calcitonin. Calcitonin functions to lower blood calcium levels. It has the opposite effect to parathyroid.

Answer 14

Hypo = Low Hypothyroidism Is a condition caused by a deficiency in the thyroid hormone. The main function of the thyroid is to in fluence metabolic rate. With this condition everything runs slower. Symptoms of hypothyroidism include tiredness, malaise, weight gain, cold intolerance, constipation and depression. In fact anything that is a symptom of slowing down of metabolic function such as slow cognition, poor memory, low libido. Also deep voice, menstrual changes, muscle aches and arthralgia (joint pain), dry skin and hair

Answer 15

Hyper = High Hyperhyroidism Is a condition caused by an excess in the thyroid hormone. The main function of the thyroid is to in fluence metabolic rate. With this condition everything runs faster. Signs include: * Goitre - Overstimulating the thyroid leads to the thyroid continuing to grow leading to an enlarged thyroid and creating a visible palpable mess in the throat area * Exophthalmos - bulging, staring eyes * Tachycardia * Tremor * Fast reflexes * Lid lag

Answer 16

The Barnes test measures core body temperature because thyroid controls metabolism and is therefore linked to core temperature. Anything above an average of 37 might indicate hyperthyroidism. Anything below 36.6 might indicate hypothyroidism

Answer 17

The parathyroid gland is involved with calcium management and specifically increasing calcium. Therefore hypoparathyroidism is when there is not enough parathyroid end therefore not enough calcium. Given the calcium is essential for muscle contraction, nerve transmission and blood clotting this can lead to signs and symptoms such as muscle cramps and spasms, tingling lips fingers and toes, dry hair and nails skin etc The main causes are surgery or radiation often in connection with treating a thyroid problem.

Answer 18

One of the essential functions of calcium is muscle contraction. As the parathyroid is involved in regulating calcium to make sure that we have enough, a condition in which there is not enough parathyroid will lead to muscle cramps and spasms.

Answer 19

CHECK THIS With this condition the parathyroid is elevated Leading to an elevation of calcium in the blood (hypercalcaemia). This leads to an increased risk of osteoporosis or osteopenia because of the overstimulating of osteoclasts that reduces bone density

Answer 20

The receptors for protein based water soluble hormones are part of the cell/plasma membrane Lipid hormones can glide thought the cell membrane so receptors are within the cell.

Answer 21

Oxytocin Antidiuretic Hormone (ADH)

Answer 22

* CONTRACTS LACTATING BREAST * CONTRACTS UTERUS IN CHILDBIRTH * BONDING HORMONE with baby

Answer 23

* Childbirth (positive feedback system) * Emotional state – Fear or anxiety may inhibit release of Oxytocin and emotions such as hearing a baby cry can trigger it

Answer 24

The first breast fluid.

Answer 25

* The main function is to pass on immunity because it contains ANTIBODIES. * It also acts as a LAXATIVE for the baby to remove bilirubin.

Answer 26

Antidiuretic hormone acts on the kidneys retaining water so there is less loss of water in the urine.

Answer 27

Increased osmotic pressure due to reduced fluid intake, thirst, vomiting. Decreased osmotic pressure due to uncreased fluid intake. ALCOHOL unnaturally inhibits ADH

Answer 28

Both are caused by excess growth hormone released from the pituitary gland. - Gigantism is excess growth hormone whilst still developing and results in the person growing to massive heights - Acromegaly is excess growth hormone post puberty and in this case the patient grows outwards as opposed to upwards. So the difference between the two is when in our lifetime we have them

Answer 29

- Overgrowth of bone making the jaw more prominent and creating a more masculine appearance - Overgrowth of soft tissue such as nose and lips and tongue creating large, prominent facial features - Increased size hands and feet, tongue and soft tissue - Tiredness, deep voice, impotence, joint pain, bone deformities, soft tissue swellings

Answer 30

Growth hormone increases blood glucose levels which in turn leads to insulin resistance

Answer 31

Hyperprolactinaemia caused by Pituitary rumour, acromegaly and antipsychotics Galactorrhoea – Flow of milk from the breast but not associated with childbirth Amenorrhoea – Absence of menses because prolactin inhibites GnRH (Gonadotropin Releasing Hormone)

Answer 32

Flow of milk from the breast but not associated with childbirth

Answer 33

Diabetes is a disease that causes excess thirst and urination. Not all diabetes disease involves blood sugar. Diabetes Insipidus is due to over excretion of water from the kidneys and it is caused by a deficiency in ADH – Anti Diuretic Hormone. The body has lost the ability the send a signal to the kidneys to retain water, Type 2 Diabetes is impaired glucose tolerance. Insulin resistance where glucose cannot enter the cells

Answer 34

Cranial: Brain trauma, tumour, encephalitis Renal (kidney): Chronic kidney disease

Answer 35

Extreme thirst Excessive urination – very diluted

Answer 36

a. Urine volume over 24 hours High b. Urine concentration (urine specific gravity) low c. Sodium levels (blood biochemistry) High

Answer 37

Levels are highest in children and decline with age

Answer 38

Increase: Night, darkness Decrease: Daylight, irregular sleep patterns like night shifts

Answer 39

Setting of circadian rhythm DNA protection Antioxidant

Answer 40

Influences metabolic rate and is an important growth hormone early in life. Most body cells have receptors for thyroid hormones. This is because the thyroid is involved in controlling metabolism. The chemical activity of just about every single one of our cells.

Answer 41

- Increased metabolic rate and heat production. - Essential for central nervous system function - Essential for normal growth and development

Answer 42

These are both follicular cells produced by thyroid hormones. - Thyroxine (T4) has four iodine atoms. - Triiodothyronine (T3) Has 3 iodine atoms. We have much more T4 circulating them T3. Thyroid hormone levels are measured in terms of free T4 and T3

Answer 43

a. Iodine – Thyroid follicular cells trap and store Iodine b. Calcitonin - Parafollicular cells secrete the hormone calcitonin which functions to lower blood calcium levels

Answer 44

Therefore if someone is low in out of these essential minerals they might experience the signs of and symptoms of an under active thyroid, not due to a lack of production of T4 but due to a lack of conversion to the more potent T3.

Answer 45

T3 – it is 3 times more potent than T4 (which explains why we produce less of it)

Answer 46

They are measured in terms of free T4 and T3

Answer 47

a. Stimulate thyroid hormone production - Thyroid stimulating hormone - Exercise - Stress - Low blood glucose - Low conversion of T3 to T4 Also note that you will have higher levels of production during adolescence, pregnancy and female reproductive years b. Reduce thyroid hormone production - Low thyroid stimulating hormone - High T3

Answer 48

Most reliable in the morning when it is lower.

Answer 49

Anti-thyroglubulin antibodies (TgAb) is often found in patients with autoimmune thyroid disease - Hashimoto’s or graves)

Answer 50

- Goitre - the thyroid starts to grow because it cannot make enough T3 and T4 and recruits more resource is - Dry and brittle skin, thin hair, loss of outer third of eyebrow - swelling around the eyes - Myxoedema

Answer 51

Think about what slow metabolism looks like - - Tiredness, malaise, weight gain, cold intolerance, constipation, depression - Slow cognition, poor memory, low libido

Answer 52

* The most common reason is Hashimoto's Thyroiditis which is an autoimmune condition. * Iodine deficiency which could be lacking in the diet and is needed for the production of T3 and T4. * Thyroid destruction through surgery or tumour

Answer 53

An autoimmune disease that is the most common reason for an overactive thyroid - hyperthyroidism. The immune system is producing antibodies (IgG) that mimic TSH. The antibodies dock onto the TSH receptors sending a message to the thyroid to say more TSH is needed, even though it isn't. This causes the thyroid gland to grow and the thyroid follicles to increase synthesis of thyroid hormone.

Answer 54

Signs – Goitre, exophthalmos, tachycardia, tremor Think about what overstimulated metabolism looks like - nervousness, irritability, hyperactivity, unexplained weight loss - Fatigue - Increased sweating, heat sensitivity

Answer 55

a. Calcitonin The thyroid gland makes a third hormone called calcitonin. It lowers blood calcium by packaging it away in our bones. Production of calcitonin is stimulated by increased blood calcium levels. As calcium goes up it is detected by parafollicular cells and they will release calcitonin either in the urine or packaged up into bones. It lowers blood calcium by: i. Inhibiting calcium reabsorption from the bone and kidneys ii. inhibiting osteoclast activity and thus bone resorption and facilitating the depositing of calcium and building bone density b. Parathyroid hormone Increases blood calcium by: o Increasing osteoclast activity causing us to breakdown bone and send it back to the bloodstream (aka resorption) o Increasing kidney reabsorption of calcium and magnesium o increasing production of calcitriol, the active form of vitamin D, which increases calcium absorption in the digestive tract

Answer 56

Elevated blood levels of parathyroid hormone and improper calcium regulation. The usual cause would be a tumour of the parathyroid gland.

Answer 57

Often there are no symptoms or very few symptoms but what we do see in some cases are: - Hypercalcaemia - which is an elevation of blood in the calcium. It can lead to an increased risk of kidney stones because we need to get rid of calcium in the urine, osteoporosis because we are stimulating osteoclasts and reducing bone density, low energy, depression - In some cases you might see nausea, vomiting, Constipation, anorexia and muscle paralysis

Answer 58

Hypo-metabolism and reduced serum levels of parathyroid hormone

Answer 59

What would you see if you had low calcium levels? What is calcium for? - We need calcium for muscle contraction therefore without it we might get muscle cramps and spasms - we need calcium for nerve transmission if we might get tingling lips, fingers and toes

Answer 60

Adrenal glands divide into Adrenal Medulla and Adrenal Cortex. **The cortex** is the outer part and **produces three groups of steroid hormones**: **Glucocorticoids** – Regulate metabolism and resistance to stress. **It is mostly cortisol** Cortisol stimulates gluconeogenesis. It does this by basically breaking down stored forms of energy and turning them into sugar in the bloodstream to fuel our fight and flight reactions. **Mineralocorticoids** – Maintains water and electrolyte balance. **It is mostly aldosterone** - Aldosterone’s main function is to cause us to retain and reabsorb sodium in the kidneys because where there is sodium water will follow. If we keep sodium in the blood we cause our cells to hold onto more water which increases blood volume, which increases blood pressure. - Aldosterone also stimulates excretion of potassium in urine which remove H+ (acidity) through urine. **Sex Hormones** – Responsible for male and female characteristics in childhood and later years

Answer 61

Adrenal glands divide into Adrenal Medulla and Adrenal Cortex. **The medulla** is the inner part and called the** ’initial alarm response to stress’.** It is made up of nervous tissue and is **part of the autonomic nervous system.** It produces - **Adrenaline** (80%) – Main role is to increase the heart rate and contraction - **Noradrenaline** (20%) – Main role is vasodilation in heart, brain, skeletal muscles - **Dopamine** **Adrenaline and noradrenaline both intensify the sympathetic response**. They are released by chromaffin cells which contribute to a quick response.

Answer 62

* Exercise * Fasting * Shock * Elevated temperature * Infection * Disease * Emotional stress * caffeine

Answer 63

Eating Sleeping Calmness Diaphragmatic breathing

Answer 64

Cortisol in glucocorticoids 1. Stimulates gluconeogenesis – new glucose 2. Calatabolic processes – breaking down amino acids and fats to be turned into energy 3. Production of glucose by the liver 4. Anti inflammatory (reduces immune response as resources needed elsewhere) which is why steroids are used medically

Answer 65

Mineralocorticoids are primarily Aldosterone. - Aldosterone’s main function is to cause us to **retain and reabsorb sodium in the kidneys** because where there is sodium water will follow. If we keep sodium in the blood we cause our cells to hold onto more water which increases blood volume, which increases blood pressure. - Aldosterone also stimulates excretion of potassium in urine which remove H+ (acidity) through urine.

Answer 66

Stimates: Reduction in blood pressure or blood volume – dehydration, haemorrhage High blood potassium Inhibits: Low blood Potassium

Answer 67

Too much cortisol Vs too little Cushings syndrome is defined as a cortisol excess from any cause. This could be excessive amount of glucocorticoids. Addisons Disease is adrenal insufficiency. Hypo functioning of the adrenal cortex causing deficiency of mineralocorticoids and glucocorticoids

Answer 68

- Corticosteroid therapy - Adrenal adenoma – adrenal tumour creating excessive production of cortisol - Pituitary adenoma (cushings disease) – Pituitary tumour creating excessive production of cortisol

Answer 69

If we think about cortisol as the ‘tearing down’ hormone (catabolic) then lots of tissues become weak and the immune system depressed. - Central weight gain/ Moon face/ Buffalo hump (excess fat behind the neck) - Easy bruising - Signs of reduced immunity because cortisol suppresses the immune system - Osteoporosis/ bone fractures

Answer 70

- Atrophy of the adrenal gland (often auto immune) - Secondary to a disease - Abrupt cessation of steroids

Answer 71

Weakness, fatigue and hypotension Diarrhoea, weight loss, anorexia, malaise, muscle weakness Impotence

Answer 72

In Addison's disease the negative feedback loop producing adrenal hormones is broken due to adrenal failure. The hypothalamus will be desperately trying to get adrenals to work by producing excessive quantities of Corticotropin Releasing Hormone (CRH). The pituitary gland can become confused and it can start to produce excess Melanocyte Stimulating Hormone (MSH). This causes the skin colour to darken, hence hyperpigmentation.

Answer 73

Sex hormones are primarily androgens. - Produce pubic and axillary hair - Growth (including muscle mass) - Converted to testetosterone and then oestrogen.

Answer 74

Corticotropin Releasing Hormone (CRH) to release Adrenocorticotropin )ACTH)

Answer 75

The job of the pancreas is to regulate blood sugar levels. Alpha and Beta cells work in opposition to each other to achieve this aim. Both are cells within the Islets of Langerhans in the Pancreas. Alpha cells produce glucagon which acts on the liver to elevate blood glucose levels. They are: - stimulated by low blood sugar, exercise and stress. - Reduced by insulin and hyperglycaemia. Beta cells produce Insulin which acts on the pancreas to lower blood glucose levels, amino acids and fatty acids by - Stimulating cells to uptake glucose from the blood - Promote synthesis of proteins, glycogen and fats

Answer 76

Lowers blood glucose levels, amino acids and fatty acids by - Stimulating cells to uptake glucose from the blood - Promote synthesis of proteins, glycogen and fats

Answer 77

Mineralocorticoids are primarily Aldosterone. - Aldosterone’s main function is to cause us to retain and reabsorb sodium in the kidneys because where there is sodium water will follow. If we keep sodium in the blood we cause our cells to hold onto more water which increases blood volume, which increases blood pressure. - Aldosterone also stimulates excretion of potassium in urine which remove H+ (acidity) through urine.

Answer 78

Acts on the liver to elevate blood glucose levels

Answer 79

a. Stimulate insulin production High blood glucose Elevated amino acids b. Inhibit insulin production Low blood glucose Glucagon when active

Answer 80

Cortisol on glucocorticoids 1. Stimulates gluconeogenesis – new glucose 2. Calatabolic processes – breaking down amino acids and fats to be turned into energy 3. Production of glucose by the liver 4. Anti inflammatory (reduces immune response as resources needed elsewhere) which is why steroids are used medically

Answer 81

a. Stimulate glucagon production Low Blood sugar Exercise Stress (SNS) b. Inhibit glucagon production Insulin Hyperglycaemia

Answer 82

Type 1 Diabetes is an autoimmune disease that attacks the pancreas Beta cells and therefore impacts on insulin production. A deficiency in insulin leads to hyperglycaemia. It has a genetic factor triggered thought to be triggered by environmental factors. Type 2 Diabetes is caused by a resistance to insulin which controls blood sugar levels. It is not due to a lack of insulin, it is that Insulin receptors are downregulated and become unresponsive to insulin. Therefore glucose cannot get into the cell and result is high sugar levels in the blood.

Answer 83

Use of the drug Cortisone Pancreatitis

Answer 84

Seven fold increase in risk of Type 2 diabetes later in life

Answer 85

**Vitamin D deficiency** Infant exposure to cows milk Omega 3 deficiency Early exposure to gluten

Answer 86

Polio rotavirus

Answer 87

Thirst Need to urinate frequently Glucose in urine

Answer 88

Obesity Low fibre High glycaemic index diet Lack of exercise

Answer 89

Oral glucose tolerance test – large glass of sugared water. How fast does it come down? Glycated haemoglobin - HbA1c – gives a longer term view over 48 hours looking at the accumuluation of sugar molucelues in Hb and red blood cells

Answer 90

Sugar damages blood vessels large and small so, - Heart disease - Hypertentsion - Retinopathy - Peripheral nueropathy

Answer 91

Mitochondria can use ketones to make energy when glucose is not available. Ketones are derived from the breakdown of fatty acids. They are acidic and can be toxic if accumulated at excessive levels resulting in coma and death

Answer 92

Shaking Sweating Headache Slurred speech, confusion Ketoacidosis and coma

Answer 93

Anterior Pituitary