Biology module 8

Inquiry Question 1: What is the normal function of the body's systems?

How do body systems maintain homeostasis?

Homeostasis

The maintenance of a relatively stable internal environment despite external changes.

Internal environment

The conditions inside the body that surround cells, including tissue fluid and blood plasma.

Stimulus

A change in the internal or external environment that triggers a response.

Response

A reaction to a stimulus that helps maintain homeostasis.

Receptor

A specialised cell or organ that detects changes in the internal or external environment.

Effector

A muscle or gland that carries out a response to restore homeostasis.

Negative feedback

A regulatory mechanism in which a change from the normal state triggers responses that reverse the change.

Positive feedback

A regulatory mechanism in which a change from the normal state is amplified until a specific outcome is achieved.

Set point

The normal value or range maintained by homeostatic mechanisms.

Nervous system

A body system that coordinates rapid responses using electrical impulses.

Central nervous system (CNS)

The brain and spinal cord, responsible for processing information.

Peripheral nervous system (PNS)

The nerves outside the brain and spinal cord that connect the CNS to the rest of the body.

Sensory neuron

A neuron that carries impulses from receptors to the CNS.

Motor neuron

A neuron that carries impulses from the CNS to effectors.

Interneuron

A neuron located within the CNS that connects sensory and motor neurons.

Reflex action

A rapid, automatic response to a stimulus without conscious thought.

Endocrine system

A body system that regulates body functions using hormones.

Hormone

A chemical messenger released by endocrine glands and transported in the blood.

Target cell

A cell with receptors specific to a particular hormone.

Target organ

An organ that responds to a specific hormone.

Insulin

A hormone produced by the pancreas that lowers blood glucose concentration.

Glucagon

A hormone produced by the pancreas that raises blood glucose concentration.

Pancreas

An organ that produces digestive enzymes and the hormones insulin and glucagon.

Blood glucose concentration

The amount of glucose present in the blood.

Thermoregulation

The maintenance of a stable internal body temperature.

Vasodilation

The widening of blood vessels to increase heat loss.

Vasoconstriction

The narrowing of blood vessels to reduce heat loss.

Sweating

The production of sweat to cool the body through evaporation.

Shivering

Rapid involuntary muscle contractions that generate heat.

Kidney

An organ that filters blood, regulates water balance and removes metabolic wastes.

Nephron

The functional unit of the kidney where filtration, reabsorption and secretion occur.

Filtration

The movement of water and small solutes from the blood into the nephron.

Selective reabsorption

The movement of useful substances from the nephron back into the blood.

Secretion

The movement of substances from the blood into the nephron for excretion.

Urine

A liquid waste produced by the kidneys.

Osmoregulation

The regulation of water and solute concentrations within the body.

Antidiuretic hormone (ADH)

A hormone that increases water reabsorption in the kidneys.

Inquiry Question 2: What happens when homeostasis fails?

How do disorders affect normal body function?

Disease

An abnormal condition that impairs normal body function.

Disorder

A disruption to the normal structure or function of an organ or system.

Non-infectious disease

A disease that cannot be transmitted between individuals.

Cancer

A group of diseases involving uncontrolled cell division.

Tumour

An abnormal mass of cells produced by uncontrolled cell division.

Benign tumour

A non-cancerous tumour that remains localised.

Malignant tumour

A cancerous tumour capable of invading surrounding tissues and spreading.

Metastasis

The spread of cancer cells from the original site to other parts of the body.

Carcinogen

A substance or agent capable of causing cancer.

Mutation

A permanent change in the DNA sequence.

Oncogene

A mutated gene that promotes uncontrolled cell division.

Tumour suppressor gene

A gene that normally prevents uncontrolled cell division.

Apoptosis

Programmed cell death.

Diabetes mellitus

A disorder in which blood glucose regulation is impaired.

Type 1 diabetes

An autoimmune disorder in which pancreatic beta cells are destroyed.

Type 2 diabetes

A disorder characterised by insulin resistance and reduced insulin effectiveness.

Insulin resistance

A reduced response of body cells to insulin.

Cardiovascular disease

A group of disorders affecting the heart and blood vessels.

Atherosclerosis

The buildup of fatty deposits within artery walls.

Hypertension

Persistently high blood pressure.

Stroke

The interruption of blood flow to part of the brain.

Risk factor

A characteristic or behaviour that increases the likelihood of disease.

Lifestyle factor

A behavioural factor influencing disease risk, such as diet or exercise.

Genetic predisposition

An inherited increased likelihood of developing a disease.

Inquiry Question 3: How are non-infectious diseases investigated?

How is epidemiology used to identify disease patterns?

Epidemiology

The study of the distribution and causes of disease in populations.

Incidence

The number of new cases of a disease within a specified period.

Prevalence

The total number of cases of a disease within a population at a given time.

Morbidity

The rate of illness within a population.

Mortality

The rate of death within a population.

Life expectancy

The average number of years an individual is expected to live.

Correlation

A relationship between two variables.

Causation

A relationship in which one factor directly produces another.

Confounding variable

A factor that influences both the independent and dependent variables.

Case-control study

An observational study comparing individuals with and without a disease.

Cohort study

An observational study following groups over time to determine disease development.

Longitudinal study

A study that follows participants over an extended period.

Cross-sectional study

A study examining a population at one point in time.

Primary data

Data collected directly by researchers.

Secondary data

Data collected by others and used for analysis.

Validity

The extent to which an investigation measures what it is intended to measure.

Reliability

The consistency of results when an investigation is repeated.

Bias

A systematic error that affects the validity of an investigation.

Sample size

The number of individuals included in a study.

Inquiry Question 4: How are disorders prevented and treated?

What strategies are used to manage non-infectious diseases?

Prevention

Actions taken to reduce the risk of disease before it occurs.

Treatment

Medical intervention used to manage or cure disease.

Screening

The testing of individuals for disease before symptoms appear.

Early diagnosis

The identification of disease in its initial stages.

Chemotherapy

The use of drugs to destroy cancer cells.

Radiotherapy

The use of ionising radiation to destroy cancer cells.

Immunotherapy

A treatment that stimulates the immune system to fight disease.

Targeted therapy

A treatment that specifically attacks cancer cells while minimising damage to healthy cells.

Surgery

The physical removal or repair of diseased tissue.

Lifestyle modification

Changes in behaviour to reduce disease risk or improve health outcomes.

Rehabilitation

The process of restoring health and function after illness or injury.

Inquiry Question 5: How can technologies be used to assist people who experience disorders?

How do medical technologies improve quality of life for people with disorders?