Rise in temp
Stable
Thermoreceptors on skin detect change
Signal is sent to hypothalumas
Signal sent to peripheral nervous system
Sweating, vasoconstriction
Fall in temp
Stable
Thermoreceptors on skin detect change
Signal is sent to hypothalumas
Signal sent to peripheral nervous system
Shivering, vasodilation
Rise in BGL
Stable
Rise in BGL
Sensor cells in pancreas detect the change
Beta cells in pancreas release insulin
Glucose is absobed by the liver
Fall in BGL
Stable
Fall in BGL
Sensor cells in pancreas detect change
Alpha cells in pancreas release glucagon
Glucagon converted into glucose
Structural adaptation example
Australian Fur Seal
Fur
Wooly underfur traps in heat, insulating internal temperatures, preventing heat from escaping
Physiological adaptation example
Fairy Penguin
Restricts blood flow to feet
Heat moves from hot to cold, so heat would be lost
Behavioural Adaptation
Spinifex Hopping mouse
Dig burrow in desert as habitat
By seeking shelter, sun exposure is reduced, thus maintaining homeostasis
Internal Systems that maintain homeostasis
Nervous system
- A nerve impulse is sent from a sensory nerve to the CNS which coordinates a response
- A nerve impulse is sent from the CNS via motor neurons to effector organs which carry out a response
Endocrine system
–> the pituitary gland is the master gland controlling the release of hormones
Hormone is released and will interact with target cell to regulate cell activity (eg. growth/metabolism)
Mechanisms in plants that allow for water to be maintained
- smaller leaves, reduces surface area to volume ratio
- movement, angling leaves away from the sun
- drops leaves during summer and droughts
Genetic disease
- define
- causes
Definition
Altered or incorrect gene expression due to mutation of inherited, causing disruption to protein production
Causes
Gene abnormality - changes to the DNA sequence via mutation
Chromosomal - incorrect number or structure of chromosomes
Example of genetic disease
Cystic Fibrosis
Accumulation of mucus membrane in the lungs causing difficulty breathing and frequent lung infections –> can also occur in other organs
Cause: CFTR gene mutation, disrupts CFTR production
Management:
- Physiotherapy
- Inhales meds
- IPPB (intermitted positive pressure breathing)
- Transplant
Future Treatment
- Gene therapy: delivery of functional CFTR genes into patients cells and/or tissue to replace mutated or altered genes
Environmental disease
- define
- causes
Definition
- A disease caused by mutations and reactions as a result of environmental factors
Causes
- Mutagens –> Alter DNA eg. radiation exposure
- Allergen –> Immune system overreaction to an antigen that is not harmful eg. an allergic reaction (hypersensitivity reaction)
Example of environmental disease
Hypersensitivity Reaction
Exaggerated immunologic responses occurring in response to an antigen or allergen
allergen or antigen –> IgE antibodies –> IgE attach to surface of mast cell –> the next time exposes, the mast cells release histamines causing symptoms
Management:
AntihistaminesL: block impact - reduce itchiness
Allergen immunotherapy: inject with allergen multiple times, increase tolerance
Nutritional Diseases
- define
- causes
Definition
- A disease developed when a person’s dietary intake does not contain the required amount of nutrients for healthy functioning
Causes
- Undernutrition, over nutrition or an incorrect balance of nutrition
Example of nutritional disease
Scurvy
A lack of vitamin C leading to exhaustion, anaemia and swelling
Vitamin C –> found in fruits such as oranges and grapefruit
Management:
Ensure patient consumes a balanced diet including Vitamin C
Cancer
- define
- cause
Definition
- Cancer involves a group of diseases due to abnormal cells division an uncontrollable way. Can invade body tissue consequently spreading and disrupting normal body function
Example of cancer
Lung Cancer
Cause
- environmental factors such as smoking (80%) of cases
- genetic factors
Treatment
- surgery
- chemotherapy
- radiation therapy
- targeted therapy
Future treatment
- immunotherapy –> activates the immune system to fight off cancer
Incidence
Prevalence
Mortality
Morbidity
Incidence - number of new cases of a disease reported over a specific time period
Prevalence - number of people in a particular population with a disease
Mortality - number of deaths within a time period
Morbidity - number of cases of the disease (incidence and prevalence)
Epidemiology
Aim
Validity
Aims to establish disease cause, guide development of strategies to improve health and evaluate effectiveness of current strategies
Validity
- Use large sample size
- Have a number of variables
- Allow for analysis of risk factors
- Control group
Possible causes of dementia
Plaques - beta-amyloid clumps
Tangles - tau protein threads
What is Alzheimer’s
A progressive, non infectious brain disease that slowly destroys the brains ability to remember, problem solve and carry out day to day tasks
Benefits of an epidemiology study
- identify causes
- allows public health authorities to manage, evaluate and plan to control diseases
- predicts possible future outbreaks
Education Campaigns
- designed to control and present disease
- provides information and education
- saves money –> cheaper to run campaign than to provide medical assistance and treatment
- also may result in long term disability and are often relient on the government for assistance
