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Kerri's Part 1 Biomed Slides > 9. Endocrine System > Flashcards

9. Endocrine System Flashcards

1
Q

Describe the main function of the endocrine system.

A

Coordinates the activities of the organs through hormones which are produced in glands and send chemical messengers through the blood

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2
Q

How do cells alter their sensitivity to a hormone?

A

With the number of receptors that it displays for a given hormone. The cell can change the number of receptors

This is known as up regulation and down regulation

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3
Q

Describe ‘down regulation’ and name ONE example.

A

If a hormone is present in excess, the number of target cell receptors may decrease. This is because if a hormone message is loud we don’t need as many cell receptors to get the message out.

Eg: during puberty when hormones are raging

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4
Q

Describe ‘up regulation’ and name ONE example.

A

If a hormone is in short supply, the number of receptors on target cells will increase to ensure all of what is there is received.

Eg: Oxytocin receptors increase in the 3rd trimester of pregnancy because this hormone is involved in milk production and labour contractions.

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5
Q

We have a lot of endocrine glands in the endocrine system but we also have endocrine tissues. They are not regarded as glands but they have the ability to produce hormones.

Name three of these and what they produce

A

Skin - A precursor to Vitamin D when exposed to UV light

Kidneys - erythropoieten for blood cell production when it experiences hypoxia

The stomach releases grehlin and gastrin for satiety and gastric emptying respectively.

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6
Q

Name two endocrine glands

A

Hypothalamus
Pituitary
Pineal
Thyroid
Parathyroid (4)
Adrenal
Pancreatic: Islets of langerhan
Thymus
Ovaries
Testes

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7
Q

Name FOUR endocrine tissues.

A

Some tissues of the body are not considered glands but have endocrine functions in that they produce hormones.

Adipose tissue
Heart
GIT
Liver
Placenta
Kidneys
Skin

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8
Q

Define what is meant by a hormone?

A

A chemical messenger (created by glands) that travels in the blood and acts on cells with the correct receptor.

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9
Q

What are the two control systems in the body for homeostatis?

What are their features:
Speed of Change:
Precision:
Duration:
Messenger:
Control Centre:

A

Autonomic Nervous System:
Speed of Change: Fast
Precision: Less precise
Duration: Shorter
Messenger: Neurotransmitter
Control Centre: Central Vernous System

Endocrine System:
Speed of Change: Slower
Precision: More precise
Duration: Longer
Messenger: Hormone
Control Centre: Endocrine Ssytem

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10
Q

Hormone secretions are regulated in three ways. What are these?

A
  1. Nervous system signals
  2. Chemical changes in the blood
  3. Other hormones
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11
Q

Hormones are controlled through positive and negative feedback loops.

Give an example of each of these.

A

Negative: Output reverses the input:
Kidney detects lacxk of oxygen in the blood and releases erythropoieten to to trigger production of new blood cells

Positive: Amplifies and strengthens a resaponse. For example Oxytocin in childbirth to stimulate

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12
Q

Delete

What is in charge of the endocrine system of the body?

A

Hypothalamus and pituitary gland act as a unit regulating the activity of most of the endocrine glands.

Activities such as growth, devleopment, metabolism and homeostatis.

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13
Q

What is a gland?
Compare the two types of gland found in the body

A

Glands are collections of tissue that makes some kind of secretion or hormone.

Endocrine - These glands have a really good blood supply and release hormones directly into the blood.
eg: Pituitary, adrenals, thyroid

Exocrine - Gland that produces a secretion that goes out of a duct either onto a surface (eg: skin) , into an organ or cavity.
Eg: saliva glands (saliva), gastric glands (digestive enzymes), mammary glands

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14
Q

Explain how the hypothalamus and the pituitary gland are connected.

A

The pituitary gland is connected to the hypothalamus by a stalk of nerve fibres and network of capillaries.

The Hypothalamus and Pituitary glands are composed of nervous tissue.

They represent the major link between the NERVOUS AND ENDOCRINE SYSTEMS.

The hypothalamus communicates with
- the anterior pituitary lobe via hormones though the netowrk of capillaries
- the posterior lobe through nerve impulses.

Together the hypothalamus and pituitary control almost entirely growth, development, metabolism and homeostasis.

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15
Q

Describe the difference between ‘exocrine’ and endocrine’ glands.

A

A gland is a collection of tissue that makes some kind of secretion or hormone.

Exocrine = outside. Characterised by
a. A duct
b. Secretion onto a surface, into a cavity or into an organ

Endocrine = inside/within. Characterised by
a. Ductless
b. Surrounded by a really good capillary network
c. Secretions are hormones that go directly into circulation through the blood.

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16
Q

With regards to the autonomic nervous system and the endocrine system, complete the following table:

Speed of change?

Precision?
ANS- Less precise ES - More precise

Duration?

Messengers?

Control centre?

A

Speed of change?
ANS - rapid
ES : Slower

Precision?
ANS- Less precise ES - More precise

Duration?
ANS - Shorter duration ES - Longer duration

Messengers?
ANS -Neurotransmitters ES - Hormones

Control centre?
ANS - Central Nervous System
ES - Hypothalamus

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17
Q

Describe how the Hypothalamus works with the anterior pitiutary gland

A

Hello anterior pituatary. I have made some hormones that I am sending to you to instruct you to make some hormones to send to a gland to take some action.

Here is an example:
(i) H sends Thryotrophin releasing hormone ** (TRH)** to AP
(ii) AP responds by making Thyroid stimulating hormone (TSH)
(iii) This will dock on the receptors of the target tissue, the Thyroid.
(iiii) The thyroid gland produces hormones

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18
Q

Name the master endocrine gland.

A

The pituitary Gland is often named the master endocrine gland as it controls many of the other endocrine glands in the body

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19
Q

Name the 5 releasing hormones and the 2 inhibiting hormones released by the Hypothalamus into the anterior pituitary.

What is the response by the AP?

What is the target tissue?

A

GHRH – Growth Hormone Releasing and GHIH – Growth Hormone Inhibiting Hormone &raquo_space;»» GH - Growth Hormone &raquo_space;»> most body tissue

TRH – Thyrotropin Releasing Hormone&raquo_space;»»Thyroid stimulating hormone (TSH)&raquo_space;»> Thyroid gland

**CRH - Corticotropin **&raquo_space;»» ACTH - Adrenocorticotropic Hormone &raquo_space;»»> Adrenal Cortex

CRH - Corticotropin&raquo_space;»» MSH - Melanocyte Stimulating Hormone &raquo_space;»»> Skin

GnRH (Gonadotropin)&raquo_space;»> FSH - Follicle stimulating hormone and
LH - Luteinising hormone&raquo_space;»>Ovaries and testes

PRH – Prolactin Releasing Hormone and
PIH – Prolactin Inhibiting Hormone&raquo_space;»»> Prolactin&raquo_space;»> breasts

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20
Q

What are two functions of growth hormone?

A

** Regulates METABOLISM in many organs**

  • PROMOTES GROWTH AND DIVISION OF MOST BODY CELLS but particularly the bones and muscles.
  • Stimulates release of insulin-like growth factors (IGF’s)
  • Causes us to utilise our stored energy and breaks down fats and glycogen
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21
Q

Name TWO factors that stimulate production of Growth Hormone

A
  • NIGHT TIME sleep
  • Hypoglycaemia
  • Exercise
  • Highest in childhood and adolescence
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22
Q

Name a function for Thyroid Stimulating Hormone

A

GROWTH AND ACTIVITY OF THE THYROID GLAND which is involved in metabolic rate and growth.

Increases /triggers thyroid hormone production T4 and T3

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23
Q

State when levels of TSH are at their:

a. Lowest
b. Highest

A

a. Lowest - early evening
b. Highest – during the night

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24
Q

Name a function of Adrenocorticotropic Hormone

A

Adrenocorticotropic hormone (ACTH) is a hormone your pituitary gland releases that plays a large role in how your body responds to stress. The release of ACTH triggers your adrenal glands to produce cortisol, the “stress hormone,” and androgens (a group of sex hormones).

  • Circadian rhythm (sleep/wake cycle)
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25
Q

Name ONE function for Melanocyte Stimulating Hormone

A

Skin, hair and eye pigmentation

  • Can be excessively produced as part of some pathologies such as Hyperpigmentation of skin in Addisons Disease
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26
Q

Name a factor that stimulates production of MSH - Melanocyte Stimulating Hormone

A

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

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27
Q

What is the functions of prolactin?

A

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
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28
Q

Name TWO factors that stimulate production of Prolactin

A
  • AFTER BIRTH
  • Breast suckling
  • Emotional STRESS
  • Adequate Sleep
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29
Q

Name TWO functions of Follicle stimulating Hormone

A
  • All about stimulating PRODUCTION OF GAMETES (sex cells) IN MALES AND FEMALES
  • Increase oestrogen production
  • Increasing testosterone production
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30
Q

Name TWO functions of Luteinising Hormone

A
  • TRIGGERS OVULATION
  • Increase oestrogen secretion
  • Increasing testosterone secretion
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31
Q

Where are hormones secreted by the posterior pituitary gland produced. What are the names of these TWO hormones?

A

They are produced/created in the hypothalamus and released on demand by the posterior pituitary gland.

  1. Oxytocin
  2. Antidiuretic Hormone (ADH)
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32
Q

Give three functions of the hormone Oxytocin

A

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

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33
Q

How does ADH prevent the loss of fluid in the body

A

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.

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34
Q

Name the hormone that is deficient in diabetes insipidus

A

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

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35
Q

What does the number next to the thyroid hormones T3 and T4 reflect?

A

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.

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36
Q

What is the name of the thyroid hormone that is the more active form.

A

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.

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37
Q

What do parafollicular cells produce?

A

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.

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38
Q

List four symptoms of hypothyroidism

A

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

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39
Q

State two signs of hyperthyroidism

A

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

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40
Q

A patient completed a Barnes temperature test with an average temperature of 37.3°C. Explain what this might indicate

A

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

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41
Q

State two causes of hypoparathyroidism

A

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.

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42
Q

What is the effect of hypoparathyroidism on muscles

A

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.

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43
Q

What effect might hyperparathyroidism have on the bone

A

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

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44
Q

Explain the difference between receptors for protein-based hormones and lipid hormones.

A

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.

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45
Q

Name TWO hormones released from the posterior pituitary gland.

A

Oxytocin
Antidiuretic Hormone (ADH)

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46
Q

section 2

A
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47
Q

Name TWO functions of oxytocin.

A
  • CONTRACTS LACTATING BREAST
  • CONTRACTS UTERUS IN CHILDBIRTH
  • BONDING HORMONE with baby
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48
Q

List TWO factors (not suckling) that stimulate oxytocin production.

A
  • 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
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49
Q

What is colostrum?

A

The first breast fluid.

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50
Q

Describe the main function of colostrum.

A
  • The main function is to pass on immunity because it contains ANTIBODIES.
  • It also acts as a LAXATIVE for the baby to remove bilirubin.
51
Q

Describe how ADH prevents loss of fluid from the body.

A

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

52
Q

Name ONE factor that stimulates production of ADH and one factor that inhibits production of ADH

A

Increased osmotic pressure due to reduced fluid intake, thirst, vomiting.

Decreased osmotic pressure due to uncreased fluid intake. ALCOHOL unnaturally inhibits ADH

53
Q

last section

A
54
Q

Pituitary Gland pathology:

Using definitions, explain the difference between acromegaly and gigantism.

A

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

55
Q

Pituitary Gland pathology:

List TWO signs / symptoms of acromegaly.

A
  • 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
56
Q

Pituitary Gland pathology:

Explain why Type 2 diabetes is a potential complication of acromegaly and gigantism.

A

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

57
Q

Pituitary Gland pathology:

Name the following pathology and list ONE cause:

“Galactorrhoea, amenorrhoea, decreased libido / sexual dysfunction and sub-fertility”

A

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)

58
Q

Pituitary Gland pathology:

What is meant by galactorrhoea?

A

Flow of milk from the breast but not associated with childbirth

59
Q

Pituitary Gland pathology:

Using definitions describe the difference between diabetes insipidus and Type 2 diabetes.

A

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

60
Q

Pituitary Gland pathology:

List TWO causes of diabetes insipidus.

A

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

61
Q

Pituitary Gland pathology:

Name TWO signs / symptoms of diabetes insipidus.

A

Extreme thirst
Excessive urination – very diluted

62
Q

Pituitary Gland pathology:

With regards to diagnostic tests for diabetes insipidus, describe what you would expect to find with:

a. Urine volume over 24 hours

b. Urine concentration (urine specific gravity)

c. Sodium levels (blood biochemistry)

A

a. Urine volume over 24 hours
High

b. Urine concentration (urine specific gravity)
low

c. Sodium levels (blood biochemistry)
High

63
Q

Pineal gland:

What does the pineal gland produce?

A

Melatonin

64
Q

Pineal gland:

Describe how age affects melatonin levels.

A

Levels are highest in children and decline with age

65
Q

Pineal gland:

Name ONE factor that stimulates melatonin.

Name TWO factors that reduces melatonin levels.

A

Increase: Night, darkness

Decrease: Daylight, irregular sleep patterns like night shifts

66
Q

Pineal Gland:

State TWO functions of melatonin.

A

Setting of circadian rhythm
DNA protection
Antioxidant

67
Q

Thyroid:

What is the function of the thyroid gland in a nutshell?

A

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.

68
Q

Thyroid:

State THREE functions of thyroid hormones.

A
  • Increased metabolic rate and heat production.
  • Essential for central nervous system function
  • Essential for normal growth and development
69
Q

Thyroid:

With regards to iodine atoms, describe the difference between thyroxine and triiodothyronine.

A

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

70
Q

Thyroid:
Name the thyroid cell which store the following:

A

a. Iodine – Thyroid follicular cells trap and store Iodine

b. Calcitonin - Parafollicular cells secrete the hormone calcitonin which functions to lower blood calcium levels

71
Q

Thyroid:

Name ONE amino acid needed for production of thyroid hormones.

A

Tyrosine

72
Q

Thyroid:

Name TWO minerals which are essential for the conversion of T4 to T3.
Selenium and Zinc is needed for the conversion of T4 to T3.

A

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.

73
Q

Thyroid:

Name the most biologically-active thyroid hormone.

A

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

74
Q

Thyroid:

Describe how thyroid hormones are measured.

A

They are measured in terms of free T4 and T3

75
Q

Thyroid:

List TWO factors that:

a. Stimulate thyroid hormone production

b. Reduce thyroid hormone production

A

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

76
Q

Thyroid:

Explain why TSH levels are measured in the morning.

A

Most reliable in the morning when it is lower.

77
Q

Thyroid:

Name ONE antibody used to identify autoimmune thyroid disease.

A

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

78
Q

Thyroid:

List TWO signs of hypothyroidism.

A
  • 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
79
Q

Thyroid:

List FOUR symptoms of hypothyroidism.

A

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

80
Q

Thyroid:

Name TWO causes of hypothyroidism.

A
  • 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
81
Q

Thyroid:

Define Grave’s disease and its pathophysiology.

A

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.

82
Q

Thyroid:

List FOUR signs / symptoms of Grave’s disease.

A

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

83
Q

Thyroid and Parathyroid:

Describe in detail how blood calcium levels are affected by the following hormones:

a. Calcitonin
b. Parathyroid hormone

A

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

84
Q

Parathyroid:

What is Hyperparathyroidism characterised by?

A

Elevated blood levels of parathyroid hormone and improper calcium regulation.

The usual cause would be a tumour of the parathyroid gland.

85
Q

Parathyroid:

TWO signs / symptoms of hyperparathyroidism.

A

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

86
Q

Parathyroid:

What is Hypoparathyroidism characterised by?

A

Hypo-metabolism and reduced serum levels of parathyroid hormone

87
Q

Parathyroid:

Name TWO signs / symptoms of hypoparathyroidism.

A

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
88
Q

Adrenals:

Name TWO hormones produced by the adrenal cortex and state the main function.

A

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

89
Q

Adrenals:

Name two hormones produced by the medulla cortex and state the main function.

A

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.

90
Q

Adrenals:

Name TWO factors that stimulate adrenaline and noradrenaline.

A
  • Exercise
  • Fasting
  • Shock
  • Elevated temperature
  • Infection
  • Disease
  • Emotional stress
  • caffeine
91
Q

Adrenals:

Name TWO factors that inhibit adrenaline and noradrenaline.

A

Eating
Sleeping
Calmness
Diaphragmatic breathing

92
Q

Adrenals:

Name FOUR functions of cortisol.

A

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
93
Q

Adrenals:

State TWO functions of aldosterone.

A

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.
94
Q

Adrenals:

Name ONE factor that stimulates aldosterone production and one factor that inhibits Aldesterone production

A

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

Inhibits:
Low blood Potassium

95
Q

Adrenals:

Using definitions, explain the difference between Cushing’s syndrome and Addison’s disease.

A

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

96
Q

Adrenals:

Name TWO causes of Cushing’s syndrome.

A
  • Corticosteroid therapy
  • Adrenal adenoma – adrenal tumour creating excessive production of cortisol
  • Pituitary adenoma (cushings disease) – Pituitary tumour creating excessive production of cortisol
97
Q

Adrenals:

List THREE signs / symptoms of Cushing’s syndrome.

A

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
98
Q

Adrenals:

List ONE cause of Addison’s disease.

A
  • Atrophy of the adrenal gland (often auto immune)
  • Secondary to a disease
  • Abrupt cessation of steroids
99
Q

Adrenals:

List TWO signs / symptoms (not skin pigmentation) of Addison’s disease.

A

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

100
Q

Adrenals:

Explain why hyperpigmentation occurs in Addison’s disease.

A

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.

101
Q

Adrenals:

Name TWO functions of androgens.

A

Sex hormones are primarily androgens.

  • Produce pubic and axillary hair
  • Growth (including muscle mass)
  • Converted to testetosterone and then oestrogen.
102
Q

Adrenals:

List ONE factor that stimulates androgen production.

A

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

103
Q

Pancreas:

What is the function of the pancreas?

Describe the difference between ‘alpha cells’ and ‘beta cells’ in the pancreas.

A

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

104
Q

Pancreas:

State the normal blood glucose range.

A

4-7mmol

105
Q

Delete

Pancreas:

Name TWO functions of insulin.

A

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

106
Q

Adrenals:
State TWO functions of aldosterone.

A

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.
107
Q

Delete

Pancreas:

List ONE function of glucagon.

A

Acts on the liver to elevate blood glucose levels

108
Q

Pancreas:

Name TWO factors that:

a. Stimulate insulin production

b. Inhibit insulin production

A

a. Stimulate insulin production
High blood glucose
Elevated amino acids

b. Inhibit insulin production
Low blood glucose
Glucagon when active

109
Q

Adrenal;

Name FOUR functions of cortisol.

A

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
110
Q

Pancreas:

Name TWO factors that:

a. Stimulate glucagon production

b. Inhibit glucagon production

A

a. Stimulate glucagon production
Low Blood sugar
Exercise
Stress (SNS)

b. Inhibit glucagon production
Insulin
Hyperglycaemia

111
Q

Pancreas:

Using definitions compare Type I diabetes with Type 2 diabetes.

A

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.

112
Q

Pancreas:

Name ONE cause of secondary diabetes.

A

Use of the drug Cortisone
Pancreatitis

113
Q

Pancreas:

Which type of diabetes is a woman with gestational diabetes at higher risk of developing post childbirth?

A

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

114
Q

Pancreas:

State TWO dietary causes of Type I diabetes.

A

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

115
Q

Pancreas:

Name ONE viral cause of Type I diabetes.

A

Polio
rotavirus

116
Q

Pancreas:

List THREE signs / symptoms of Type I diabetes.

A

Thirst
Need to urinate frequently
Glucose in urine

117
Q

Pancreas:

State TWO lifestyle factors that contribute to the development of Type 2 diabetes.

A

Obesity
Low fibre
High glycaemic index diet
Lack of exercise

118
Q

Pancreas:

Name TWO diagnostic tests for identifying diabetes mellitus.

A

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

119
Q

Pancreas:

Name THREE complications of diabetes mellitus.

A

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

120
Q

Pancreas:

Describe specifically how ketoacidosis develops.

A

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

121
Q

Pancreas:

Name FOUR signs / symptoms of hypoglycaemia.

A

Shaking
Sweating
Headache
Slurred speech, confusion
Ketoacidosis and coma

122
Q
A
123
Q

Where is thyroid stimulating hormone (TSH) released from?

A

Anterior Pituitary

Kerri's Part 1 Biomed Slides (13 decks)

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