MINDARIE SENIOR COLLEGEMINDARIE SENIOR COLLEGE

3A/3B Human Biological 3A/3B Human Biological ScienceScience

Homeostatic DysfunctionHomeostatic Dysfunction

Hormonal causes of Hormonal causes of disruptions:disruptions:

Diabetes mellitus Diabetes mellitus Symptom:Symptom:

Hyperglycaemia: abnormally high levels of blood Hyperglycaemia: abnormally high levels of blood glucose.glucose.

Role of insulin:Role of insulin: Stimulate cells to take in glucose from blood.Stimulate cells to take in glucose from blood. Stimulate conversion of glucose into glycogen by liver Stimulate conversion of glucose into glycogen by liver

and muscle cells.and muscle cells. Dysfunction:Dysfunction:

Insufficient insulin production or cells resistant to insulin Insufficient insulin production or cells resistant to insulin effects.effects.

High levels of blood glucose.High levels of blood glucose. Large quantities of glucose excreted in urine.Large quantities of glucose excreted in urine.

Types:Types: Type 1 (insulin dependent diabetes).Type 1 (insulin dependent diabetes). Type 2 (non-insulin dependent or adult onset diabetes).Type 2 (non-insulin dependent or adult onset diabetes).

Type 1Type 1 (insulin dependent or juvenile diabetes ).(insulin dependent or juvenile diabetes ).

Cause:Cause: Fault in immune system causes destruction of beta cells in Islets of Fault in immune system causes destruction of beta cells in Islets of

Langerhans.Langerhans. No insulin produced.No insulin produced.

Treatment:Treatment: Tablets not suitable as insulin is digestible.Tablets not suitable as insulin is digestible. Regular injections of insulinRegular injections of insulin Programmable insulin pumpProgrammable insulin pump No cureNo cure

Long Term Effects:Long Term Effects: Kidney failureKidney failure Heart attackHeart attack StrokeStroke AmputationsAmputations BlindnessBlindness Nerve damageNerve damage

Type 2Type 2 (non-insulin dependent or adult onset (non-insulin dependent or adult onset diabetes).diabetes). Cause:Cause:

Insulin is produced but cells do not respond to it. Insulin is produced but cells do not respond to it. Lifestyle disease.Lifestyle disease. Risk factors:Risk factors:

InactivityInactivity ObesityObesity Energy rich/low fibre dietEnergy rich/low fibre diet HypertensionHypertension High blood cholesterolHigh blood cholesterol SmokingSmoking

Treatment:Treatment: Often no symptoms – and not diagnosed.Often no symptoms – and not diagnosed. Preventable by adopting a healthy lifestyle.Preventable by adopting a healthy lifestyle. No cureNo cure Early diagnosis can lead to successful management.Early diagnosis can lead to successful management.

Long Term Effects:Long Term Effects: Heart diseaseHeart disease strokestroke Kidney diseaseKidney disease Eye problemsEye problems Nerve damageNerve damage Skin and foot problems.Skin and foot problems.

Hormonal causes of disruptions:Hormonal causes of disruptions: Excess or deficiency of thyroid Excess or deficiency of thyroid hormones.hormones. Symptom:Symptom:

Too little or too much thyroid hormones (thyroxine and Too little or too much thyroid hormones (thyroxine and tri-iodothyronine)tri-iodothyronine)

Role of thyroxine and tri-iodothyronine:Role of thyroxine and tri-iodothyronine: Stimulate carbohydrate, protein and fat metabolism.Stimulate carbohydrate, protein and fat metabolism. Regulate basal metabolic rate.Regulate basal metabolic rate. Influence long term homeostasis of body temperatureInfluence long term homeostasis of body temperature

Dysfunction:Dysfunction: Imbalance in Thyroid Stimulating Hormone from anterior Imbalance in Thyroid Stimulating Hormone from anterior

Pituitary leads to imbalance in thyroxine.Pituitary leads to imbalance in thyroxine. Large quantities of glucose excreted in urine.Large quantities of glucose excreted in urine.

Types of dysfunction:Types of dysfunction: HyperthyroidismHyperthyroidism HypothyroidismHypothyroidism

HyperthyroidismHyperthyroidism Cause:Cause:

Too much thyroid hormone secreted.Too much thyroid hormone secreted.

Types:Types: Graves’ disease (most common form)Graves’ disease (most common form) Enlarged thyroid caused by immune system reaction.Enlarged thyroid caused by immune system reaction. Genetic predisposition.Genetic predisposition.

Effects:Effects: Overstimulation of cellsOverstimulation of cells restlessnessrestlessness Rapid heart rateRapid heart rate Weight lossWeight loss Increased appetiteIncreased appetite Anxiety/excitableAnxiety/excitable FatigueFatigue SweatingSweating Swings in mood and emotional state.Swings in mood and emotional state. Protruding eye balls – exophthalmia - (Graves’ disease)Protruding eye balls – exophthalmia - (Graves’ disease) (Pres G W H Bush suffered this condition.)(Pres G W H Bush suffered this condition.)

Treatment:Treatment: Drugs to block thyroid gland’s use of iodine.Drugs to block thyroid gland’s use of iodine. Surgery to remove all or part of thyroid glandSurgery to remove all or part of thyroid gland Radioactive iodine used to over active thyroid cells.Radioactive iodine used to over active thyroid cells.

HypothyroidismHypothyroidism Cause:Cause:

Too little thyroid hormone secreted.Too little thyroid hormone secreted. Problems with hypothalamus, pituitary gland or thyroid gland.Problems with hypothalamus, pituitary gland or thyroid gland. More common of the two conditions (6%-10% Australian females More common of the two conditions (6%-10% Australian females

suffer)suffer) Lack of iodine in diet prevents thyroid secreting sufficient hormones.Lack of iodine in diet prevents thyroid secreting sufficient hormones. Surgical removal (cancer treatment) of gland or parts of gland.Surgical removal (cancer treatment) of gland or parts of gland.

Effects:Effects: GoitreGoitre

Thyroid gland becomes enlarged in attempt to produce more hormone.Thyroid gland becomes enlarged in attempt to produce more hormone. CretinismCretinism

Deficiency of iodine in maternal dietDeficiency of iodine in maternal diet Baby severely mentally and physically retarded, impaired movement and Baby severely mentally and physically retarded, impaired movement and

hearing. hearing. Hashimoto’s diseaseHashimoto’s disease

Immune system attacks thyroid glandImmune system attacks thyroid gland

Treatment:Treatment: Inclusion of extra iodine in diet (if this is the cause)Inclusion of extra iodine in diet (if this is the cause) No cure.No cure. Carefully monitored doses of thyroid hormone (tablets)Carefully monitored doses of thyroid hormone (tablets)

Behavioural causes of Behavioural causes of homeostatic disruptionhomeostatic disruption

DrugsDrugs Non-medicinal drugs may interfere with nerve impulse Non-medicinal drugs may interfere with nerve impulse

transmission by binding to receptor sites.transmission by binding to receptor sites. CaffeineCaffeine EffectsEffects

Stimulates metabolism and CNSStimulates metabolism and CNS Increases heart rateIncreases heart rate Increases kidney blood flow, increasing urine production.Increases kidney blood flow, increasing urine production. Increases pulmonary blood flow and relaxes bronchioles, Increases pulmonary blood flow and relaxes bronchioles,

increasing pulmonary ventilation.increasing pulmonary ventilation. AlcoholAlcohol EffectsEffects

CNS depressantCNS depressant Stimulates insulin secretion, lowering blood sugar levels.Stimulates insulin secretion, lowering blood sugar levels. Inhibits secretion of ADH, increasing urine output and Inhibits secretion of ADH, increasing urine output and

dehydrationdehydration

More behavioural causes of More behavioural causes of homeostatic disruptionhomeostatic disruption

Drugs (continued)Drugs (continued) Amphetamine and methamphetamineAmphetamine and methamphetamine EffectsEffects

Cause release of noradrenaline, dopamine (hormones and Cause release of noradrenaline, dopamine (hormones and neurotransmitters) and serotonin (neurotransmitter)neurotransmitters) and serotonin (neurotransmitter)

May enhance alertness, motivation and clear thinkingMay enhance alertness, motivation and clear thinking Disrupts homeostasis by affecting appetite and weight controlDisrupts homeostasis by affecting appetite and weight control

MDMA (ecstacy)MDMA (ecstacy) Synthetic amphetamineSynthetic amphetamine

EffectsEffects Cause release of noradrenaline, dopamine and accumulation of Cause release of noradrenaline, dopamine and accumulation of

serotonin.serotonin. Initiates fight or flight syndrome, user feels more energeticInitiates fight or flight syndrome, user feels more energetic Increase heart rate and blood pressureIncrease heart rate and blood pressure Increases breathing rateIncreases breathing rate Causes sweating and dehydrationCauses sweating and dehydration Decreases appetiteDecreases appetite In high doses – rapid rise in body temp and BP, heart palpitations, In high doses – rapid rise in body temp and BP, heart palpitations,

vomiting.vomiting.

More behavioural causes of More behavioural causes of homeostatic disruptionhomeostatic disruption

Drugs (continued)Drugs (continued) CocaineCocaine EffectsEffects

Blocks removal of noradrenaline, dopamine and serotonin from synapse Blocks removal of noradrenaline, dopamine and serotonin from synapse between nerve cellsbetween nerve cells

Stimulates CNSStimulates CNS Disrupts homeostasis by increasing heart rate, blood pressure, body Disrupts homeostasis by increasing heart rate, blood pressure, body

temperature, breathing rate, dilating pupils, loss of appetite.temperature, breathing rate, dilating pupils, loss of appetite. HeroinHeroin Effects Effects

Used medicinally as strong analgesic.Used medicinally as strong analgesic. When injected recreationally, binds to brain receptors resulting in When injected recreationally, binds to brain receptors resulting in

Intense euphoriaIntense euphoria Decrease in pain perceptionDecrease in pain perception Relief from anxiety.Relief from anxiety.

Profound effects on homeostasisProfound effects on homeostasis Depresses control of breathingDepresses control of breathing Depressed control of blood pressure and body temperatureDepressed control of blood pressure and body temperature Irregular heart rateIrregular heart rate Unconsciousness, coma or death (large dose)Unconsciousness, coma or death (large dose)

More behavioural causes of More behavioural causes of homeostatic disruptionhomeostatic disruption

Excessive activityExcessive activity Well planned, monitored and not obsessively Well planned, monitored and not obsessively

over taxing exercise levels are beneficialover taxing exercise levels are beneficial Excessive activity may cause physical damage Excessive activity may cause physical damage

to tendons, muscles, ligaments, cartilages, to tendons, muscles, ligaments, cartilages, bones and joints.bones and joints.

Homeostatic dysfunction may result Homeostatic dysfunction may result If nutrition is inadequate muscle may breakdown to If nutrition is inadequate muscle may breakdown to

source energysource energy Eating disorders are strongly linked to excessive exercise.Eating disorders are strongly linked to excessive exercise.

Great stress on heart may lead to cardiovascular Great stress on heart may lead to cardiovascular problemsproblems

Loss of Calcium deposition may lead to osteoporosis. Loss of Calcium deposition may lead to osteoporosis. Amenorrhoea may occur if energy uptake is Amenorrhoea may occur if energy uptake is

inadequate.inadequate.

More behavioural causes of More behavioural causes of homeostatic disruptionhomeostatic disruption

Eating habitsEating habits Deficiency diseases may result from inadequate intake of vitamins and mineralsDeficiency diseases may result from inadequate intake of vitamins and minerals Examples of deficiency:Examples of deficiency:

IodineIodine IronIron

Causes anaemia: Causes anaemia: insufficient haemoglobininsufficient haemoglobin Reduced oxygen carrying capacity of RBC’sReduced oxygen carrying capacity of RBC’s Reduced rate of Cellular Respiration and energy release.Reduced rate of Cellular Respiration and energy release. causing weakness, fatigue, breathlessness, elevated heart rate.causing weakness, fatigue, breathlessness, elevated heart rate.

Vitamin BVitamin B causes Pernicious anaemia (stem cell divisions don’t occur)causes Pernicious anaemia (stem cell divisions don’t occur)

Vitamin K Vitamin K Produced by bacteria in large intestine.Produced by bacteria in large intestine. Lack causes reduced blood clotting ability.Lack causes reduced blood clotting ability. Homeostasis compromised if excessive blood is lost.Homeostasis compromised if excessive blood is lost.

Energy balance (intake and use) is a complex but essential element of Energy balance (intake and use) is a complex but essential element of homeostasis.homeostasis.

Alimentary canal, hormones, CNS (hypothalamus), Autonomic NS are linked.Alimentary canal, hormones, CNS (hypothalamus), Autonomic NS are linked. Imbalances may be caused physically or psychologically.Imbalances may be caused physically or psychologically. Lifestyle, eating habits and natural selection play a role in contributing to obesity Lifestyle, eating habits and natural selection play a role in contributing to obesity

epidemic epidemic

Homeostatic disruption caused by Homeostatic disruption caused by disease.disease.

A disease is any condition in which normal functioning is impaired.A disease is any condition in which normal functioning is impaired. Some diseases have direct effects on homeostasisSome diseases have direct effects on homeostasis Emphysema:Emphysema:

Alveolar walls breakdown, reducing surface area for gas exchangeAlveolar walls breakdown, reducing surface area for gas exchange results in difficulty in taking in oxygenresults in difficulty in taking in oxygen

Cause:Cause: SmokingSmoking

SymptomsSymptoms Breathlessness, initially during activity, and eventually, constantlyBreathlessness, initially during activity, and eventually, constantly

Treatment:Treatment: damage is irreversibledamage is irreversible

Fever:Fever: An elevation of body temperatureAn elevation of body temperature A symptom of a diseaseA symptom of a disease

Cause:Cause: Many infections.Many infections.

SymptomsSymptoms 1 or 2 degrees C increase in core temperature.1 or 2 degrees C increase in core temperature.

Effect:Effect: Helps immune system overcome infectionHelps immune system overcome infection Disrupts homeostasis by affecting many body reactions - increasing temp Disrupts homeostasis by affecting many body reactions - increasing temp

beyond optimal range. beyond optimal range.

More homeostatic disruption More homeostatic disruption caused by disease.caused by disease.

Hypertension:Hypertension: Cause:Cause:

Homeostatic mechanisms unable to keep blood pressure within normal Homeostatic mechanisms unable to keep blood pressure within normal rangerange

Genetic factors, Genetic factors, excessive salt intake excessive salt intake obesity obesity InactivityInactivity High alcohol intakeHigh alcohol intake Kidney diseaseKidney disease

Poor lifestyle choicesPoor lifestyle choices EffectsEffects

Significant risk factor for cardiovascular disease and kidney failureSignificant risk factor for cardiovascular disease and kidney failure Treatment:Treatment:

Adopt a healthy lifestyleAdopt a healthy lifestyle Injuries:Injuries:

Examples:Examples: Excessive blood loss limits supply of oxygen and glucose, and removal of Excessive blood loss limits supply of oxygen and glucose, and removal of

carbon dioxide and wastes.carbon dioxide and wastes. Punctured/collapsed lung impairs gas exchangePunctured/collapsed lung impairs gas exchange Immobility limits venous returnImmobility limits venous return Spinal cord injuries reduce innervation of respiratory muscles.Spinal cord injuries reduce innervation of respiratory muscles.

Hormonal treatments to Hormonal treatments to homeostatic disruptionshomeostatic disruptions

Hormone replacement therapyHormone replacement therapy To treat symptoms of menopausal womenTo treat symptoms of menopausal women

hot flushes and night sweatshot flushes and night sweats Uncomfortable skin sensationsUncomfortable skin sensations HeadachesHeadaches Thinning and dryness of walls of vaginaThinning and dryness of walls of vagina Aches and painsAches and pains Frequent urinationFrequent urination Reduced libidoReduced libido Tiredness and irritabilityTiredness and irritability Mood disturbances, loss of self esteem, depressionMood disturbances, loss of self esteem, depression Sleeping difficultiesSleeping difficulties

TreatmentTreatment May not require medical interventionMay not require medical intervention Severe symptoms may need HRTSevere symptoms may need HRT Oestrogen and progesterone prescribed to counteract loss or Oestrogen and progesterone prescribed to counteract loss or

irregularities in natural secretionsirregularities in natural secretions Carefully managed doses given as tablets, patches, gels, implants or Carefully managed doses given as tablets, patches, gels, implants or

nasal spray.nasal spray. Risks and benefits must be carefully assessedRisks and benefits must be carefully assessed May lead to side effects – bleeding, bloating, breast tenderness, slight May lead to side effects – bleeding, bloating, breast tenderness, slight

increaseincrease in risk of breast cancer, CV disease, thrombosis. in risk of breast cancer, CV disease, thrombosis.

More hormonal treatments for More hormonal treatments for homeostatic disruptionshomeostatic disruptions

Corticosteroids and treatment of Corticosteroids and treatment of rheumatoid arthritisrheumatoid arthritis Rheumatoid arthritisRheumatoid arthritis

A crippling diseaseA crippling disease Immune system attacks synovial membrane of joints, Immune system attacks synovial membrane of joints,

causing painful swelling and deformitycausing painful swelling and deformity TreatmentTreatment

Corticosteroids, closely related to cortisol (the ‘ stress Corticosteroids, closely related to cortisol (the ‘ stress hormone’ secreted by the adrenal gland)hormone’ secreted by the adrenal gland)

Act on immune system to block production of Act on immune system to block production of substances which stimulate allergic and inflammatory substances which stimulate allergic and inflammatory responsesresponses

Side effect – reduce resistance to infection due to Side effect – reduce resistance to infection due to interference to WBC’s.interference to WBC’s.

Usage of lowest possible doses must be managed Usage of lowest possible doses must be managed veryvery carefullycarefully

Behavioural treatments for homeostatic Behavioural treatments for homeostatic disruptionsdisruptions

Control of reproductionControl of reproduction Intervention in Menstrual Cycle and Ovarian CycleIntervention in Menstrual Cycle and Ovarian Cycle

Hormonal contraceptionHormonal contraception Combined Pill (synthetic progesterone and oestrogen)Combined Pill (synthetic progesterone and oestrogen)

Prevent ovulationPrevent ovulation Reduce ability of sperm to enter uterusReduce ability of sperm to enter uterus Reduce likelihood of implantationReduce likelihood of implantation

Mini Pill (progesterone substitute)Mini Pill (progesterone substitute) Thickens mucus plug in cervix preventing entry of spermThickens mucus plug in cervix preventing entry of sperm

Reliable, effective and allows personal choice.Reliable, effective and allows personal choice. Some risks involved with intervention to normal body functioningSome risks involved with intervention to normal body functioning

Combined pill - Headaches, nausea, increased appetite, breast Combined pill - Headaches, nausea, increased appetite, breast tenderness, increased incidence of heart attacks, strokes, blood tenderness, increased incidence of heart attacks, strokes, blood clotsclots

Mini Pill – fewer complications, but less reliable if not used with Mini Pill – fewer complications, but less reliable if not used with discipline.discipline.

Female infertilityFemale infertility Drugs, synthetic forms of pituitary hormones, can be used to induce ovulationDrugs, synthetic forms of pituitary hormones, can be used to induce ovulation High risk of multiple pregnancyHigh risk of multiple pregnancy Use of in-vitro fertilizationUse of in-vitro fertilization Side effects to hormones, multiple pregnancies, premature birth must be Side effects to hormones, multiple pregnancies, premature birth must be

considered.considered. Male infertilityMale infertility

Problem with up to 50% of infertile couples due to male sperm problemsProblem with up to 50% of infertile couples due to male sperm problems Treatment with gonadotrophins over several months may help. Treatment with gonadotrophins over several months may help.