Biology Mod 8 - Non-infectious Disease

Pinna

Outer part of the ear that collects sound waves, made of cartilage and skin

Tympanic Membrane

Eardrum that vibrates in response to sound and passes on vibrations to ossicles; converts sound waves to mechanical vibrations

Ear Ossicles

Three bones in the middle ear that transmit vibrations from eardrum to oval window.

Oval Window

Structure that amplifies and passes vibrations to the cochlea

Round Window

Membrane that allows vibrations to escape from the cochlea and prevents ringing in cochlea

Cochlea

Spiral structure filled with fluid for sound transmitted to produce pressure waves

Basilar Membrane

Part of the cochlea where specific fibers vibrate

Organ of Corti

Structure containing hair cells stimulated by pressure waves to send signals to auditory nerve to brain

Auditory Processing Disorder and Cause

Inability of the brain to understand speech due to sound transmission issues, caused by birth defect or brain injury

Conductive Hearing Loss and Cause

Impairment in mechanical conduction of sound vibrations through outer and middle ear, caused by impacts to outer middle ear e.g. ear infection

Sensorineural Hearing Loss and Cause

Disruption in the pathway from the inner ear to the brain due to cochlear damage, caused by exposure to loud sounds, head injury, damage to cochlea hairs

Mixed Hearing Loss

Combination of conductive and sensorineural hearing loss

Cochlear Implant Function and Process

• Device to stimulate the auditory nerve directly for hearing improvement in response to sensorineural hearing loss

• External speech processor captures sound and transmits it to receiver, which conveys sound to electrical signal and passed to auditory nerve. alternative to damaged cochlea

Iris Composition and Function

Muscle tissue controlling pupil size and volume of light entering eye

Lens Composition and Function

Transparent biconvex protein disk adjusts thickness to bend light directly on the retina (accommodation)

Retina Composition and Function

Layer of photoreceptor cells at back of the eye which detect light and send electrochemical signals to brain

Hyperopia, its Cause in relation to the Lens and Treatment

• Far-sightedness, inability to focus on close objects

• Lens of eye can no longer assume round shape required for viewing nearby objects, image falls behind retina

• Glasses with convex () lens, rays bend inward to ensure they hit retina (focal point correction)

Myopia, its cause in relation to the Lens and Treatment

• Short-sightedness, inability to focus on distant objects

• Light from distant objects bent more than necessary, image falls before retina

• Glasses with concave )( lens, rays bend outward, image falls on retina (focal point correction)

Explain the three key functions of the kidney and where they occur

• Filtration (occurring in bowman’s capsule and glomerulus) to remove toxins and liquids from the blood. Non-selective

• Reabsorption (occuring in the tubules) to filter essential substances e.g. salts back into the bloodstream from the filtrate via semi-permeable membranes

  • Filtrate → bloodstream

  • Osmoregulation → reabsorbs water for body

• Secretion (occuring in the tubules) to remove toxic and unnecessary substances from blood and create urine to send to bladder 

  • Bloodstream → filtrate and urine

Bone Conduction Implant Function and Process

• Aids conductive hearing loss by transmitting vibrations to cochlea

• External sound processor outside of ear detects and converts sounds to vibrations transferred directly through bone to cochlea

Hearing Aids Function and Process

• Amplify sound for various types of hearing loss

• Microphone detects sound waves which is converted to electrical energy, amplifier strengthens signals, and a receiver converts electrical signals back to sound and is directed into the auditory canal louder

Laser Eye Surgery Process and What It Helps

• Uses lasers to correct refractive errors in the cornea by changing cornea curvature

• can correct myopia, hyperopia

Dialysis

Machine filtering blood when kidneys fail; Removes metabolic wastes by diverting blood out of arteries into tubes with artificial semi-permeable membranes

Haemodialysis vs Peritoneal Dialysis

• H —> Cannula (needle) in the arm, blood flows into the machine through a series of semi-permeable membranes. Toxins removed, clean blood returned

• P —> Catheter placed in abdomen. dialysate flows through here and absorbs waste and extra fluids from body, and the solution is emptied from body every few hours

Describe the order sound travels through the ear

• pinna

• auditory canal

• tympanic membrane (eardrum)

• ear ossicles

• oval window

• cochlea

  • basilar membrane

  • organ of corti

• auditory nerve

• round window (vibrations escape from cochlea)

Auditory Canal

transmits sound waves from pinna to tympanic membrane

Label the eye

Label the ear

Label the nephron

Label the kidney

Describe the order light travels through the eye

• pupil

• iris

• lens

• retina

Pros Cons Cochlear Implants

PROS: effective

CONS: invasive surgery, expensive

Pros Cons Bone Conduction Implants

PROS: comfortable, no blocking ear canal

CONS: expensive, inflammation risk, invasive

Pros Cons Hearing Aids

PROS: inexpensive, no surgery

CONS: visible, uncomfortable, all sound amplified

Pros Cons Renal Dialysis

PROS: efficient (done at home), effective (clean blood returned), no surgery

CONS: time consuming, expensive, uncomfortable

Explain the functions of the parts of the nephron

• Bowman’s capsule → encapsulates glomerulus and collects filtrate from glomerulus to sends it to rest of nephron 

• Glomerulus → set of tight capillaries designed to increase pressure of blood and squeeze out unnecessary substances and plasma through non-selective filtering from blood into Bowman’s capsule

• Proximal Tubule, Loop of Henle, Distal Tubule → semi-permeable tubules responsible for reabsorption and secretion of filtrate into and out of blood to reabsorb necessary substances and clean blood further from toxins

• Collecting duct → semi-permeable tube that reabsorbs water from filtrate via osmosis and manipulation of salt levels

Kidney Pelvis Function

collects urine from calyces (small tubes collecting urine) to send to ureters to bladder

Describe the movement of blood through the kidney

• renal artery —> capillaries

• nephron

  • glomerulus

  • tubules

• capillaries —> renal vein

Glomerulonephritis Definition and Cause

• Infected inflamed glomeruli → cause, results in kidney failure

• Toxins and wastes not properly filtered into urine, therefore excess fluid moves into body via osmosis

  • Too much waste that cannot be excreted → “full of shit”

Define homoestasis

the body maintaining a stable internal environment despite external environment changes by detecting change and counteracting it

Define Negative Feedback Loop

A self-regulating system that counteracts a change in the internal or external environment to maintain homeostasis

How does the negative feedback loop work?

• disturbance occurs

• receptor recieves change in variable and sends message to control centre (e.g. hypothalamus)

• control centre sends orders to effector organs, e.g. muscles

• effector organs correct issue

• message sent back to control centre to stop once homeostasis is reached

Compare endotherms and ectotherms

• endotherms: generate body heat metabollically (atp from consumed food goes toward creating heat)

• ectotherms do not control body temp, rely on external sources (e.g. lizards on hot rocks)

Explain thermoregulation

- The process of regulating optimal body temp for enzymes
- Change detected by thermoreceptors in hypothalamus (control centre)
- Regulated by electrical impulses and nervous system

Outline how negative feedback loops respond to hot external environments

- thermoreceptors detect decreased body temperature
- receptors send message to hypothalamus
- hypothalamus sends message to effector organs
- vasodilation and sweating occurs to cool body temp
- receptors send message back to hypothalamus to stop once homeostasis is reached

Outline how negative feedback loops respond to cold external environments

- thermoreceptors detect decreased body temperature
- receptors send message to hypothalamus
- hypothalamus sends message to effector organs (muscles)
- muscles shake and shiver to heighten body temp
- receptors send message back to hypothalamus to stop once homeostasis is reached

Define vasodilation

Blood vessels dilate to transfer heat from body to
surrounding environment to decrease body temp

Define vasoconstriction

Blood vessels constrict to retain heat within body to increase body temp

Identify a behavioural response to temperature

- removing clothing
- seeking shade
- seeking shelter
- increasing amount of clothes worn

Identify a physiological response to temperature

- vasodilation and vasoconstriction
- sweating
- changes in metabolism and rate of cellular respiration
- piloerection
- shaking/shivering

Explain glucoregulation

- changes monitored and controlled by pancreas
- glucose changes with carbohydrates consumption

Identify response to high glucose in blood

Release of insulin from beta cells in pancreas, which causes liver to absorb glucose to store out of blood

Identify response to low glucose in blood

Glucagon released from alpha cells in pancreas, which causes liver to convert glycogen to glucose and release into bloodstream

Identify a behavioural adaptation in endotherms

- Animals move to shade (maintain suitable temp)
- Animals lick forearms (cools body temp through evaporative cooling
- Panting in hot temps (quick breathing evaporates water from tongue)
- Animals e.g. penguins huddle in cold (Decrease body surface exposed to cool temperature)

Identify a physiological adaptation in endotherms

- Vasodilation (dilate to transfer heat to external environment)
- Vasoconstriction (constrict to save body heat)
- Thirst (encourages body to drink water to protect from dehydration)
- Metabolism (maintains body temp, metabolism = heat)
- Hibernation (body temp drops and metabolism slowed to conserve energy in cold and low food sources)

Identify a structural adaptation in endotherms

- Liver → glucoregulation
- Body insulation e.g. fur, blubber,feathers (trap air/heat against skin to increase heat retention)
- Ear shapes (larger ears = hotter climate for heat loss)

Explain the endocrine system as an internal coordination system that allow homeostasis to be maintained

• Secretes hormones (chemical signalling molecules produced by glands) to send messages through bloodstream to body that coordinate slower but long-lasting responses, e.g. reproduction 

• Transported by blood and diffusion through extracellular fluid/space

Explain the nervous system as an internal coordination system that allow homeostasis to be maintained

• Central nervous system → brain and spinal cord; gathers info from body and coordinates responses

• Peripheral nervous system → all other nerves; connect CNS to rest of body

• Neutral pathways → direct for max speed

• Neurons → high concentration of mitochondria for enough energy  to maintain ion balance across cell membrane

Identify similarities between the nervous and endocrine systems

• Shared homeostatic processes, different ways of going about them

• Thermoregulation → endocrine system responds with secreting hormones to adjust cell metabolism for heat generation, nervous system coordinates piloerection, shivering, vasoconstriction/dilation

• Osmoregulation → nervous system triggers thirst, endocrine adjusts ADH hormone

Identify differences between the nervous and endocrine systems

- neurons vs glands
- electrical impulses vs chemical hormones
- neurons vs blood carries signals
- high vs low speed
- localised smaller response vs systematic larger response
- temporary vs long lasting

Define Hydrophytes and identify a mechanism to maintain water balance

• Plants in freshwater environments (lots of available water) —> Internal enviro has low water and water moves into plant, plant must regulate to prevent tissue floods

• High number of stomata + leaves with high SA

Describe 2 general mechanisms in plants which allow water balance to be maintained

• stomata —> maintain water balance by opening and closing

  • High no of stomata → max loss of water (freshwater enviro)

  • Low no of stomata → minimum water loss (dry enviro)

• Leaves hanging vertically → reduce sun exposure and therefore water loss via evaporation and overheating (e.g. eucalyptus)

• Extensive root systems → max surface area for water absorptions from soil (dry enviro)

• Guard cells → control opening and closing of stomata, close to prevent water loss

Explain the four causes of genetic disease

• Single gene inheritance —> one gene is affected

• Multifactorial inheritance —> multiple genes involved in a feature, comes from defects from multiple chromosome regions

• Chromosomal abnormalities —> Errors in cell division leading to deletion, duplication, inversion, translocation or substitution of genes.

• Mitochondrial inheritance —> Gene variants in the DNA found in mitochondria, which is provides instructions for proteins and energy creation

Explain environmental exposure as a cause for disease

• Lifestyle choices influence the body and disease

• for example, high exposure to the sun and UV rays can cause skin cancer

• allergies are also triggered by certain environments

Explain the causes of nutritional diseases

• Imbalanced diet lacks or is excessive nutrients

• e.g. scurvy is due to a lack of vitamin C

• overnutrition, malnutrition, undernutrition

Describe cancer and its causes

• Large group of diseases involving rapid creation of abnormal cells which invade adjoining parts of body and spread to other organs

• Caused by carcinogens (factors that mutate DNA), smoking, obesity, family history

Define incidence

The number of new cases within a period

Define prevalence

The number of individuals who survive a disease at the end of a period

Define mortality

The amount of individuals that die from a disease in a time period

How do nutritional diseases relate to incidence, prevalence and mortality?

- imbalanced diet or excessive nutrients = increase prevalence and incidence
- Non infectious disease is the cause of 70% of deaths globally
lifestyle diseases responsible for 63% of these
- Incidence and mortality rates decrease as knowledge of nutrition becomes widespread
• importance of fruit/vegetable nutrients → decreases prevalence

How do environmental exposure diseases relate to incidence, prevalence and mortality?

• Mortality rates decrease as public health programs are created to control/prevent disease

  • e.g. slip slop slap campaign for use of sunscreen to prevent UV rays mutating DNA

  • E.g. quit campaign for effects of smoking to decrease chance of mutating DNA —> Decreased prevalence

Explain one form of treatment for cancer

- Chemotherapy - deliberately kills cancerous cells, but can kill healthy cells
- Radiation therapy - deliberately damages cell DNA, killing them, but kills healthy tissue
- Surgery - removes cancerous tumours, but difficult to remove all cancerous cells in just one surgery
- Monoclonal antibody therapy - mass production of antibodies which are injected into the body to aid the immune response.

Identify the three types of epidemiological studies

Analytical, Descriptive, Intervention

Explain how analytical studies work

• Case control studies - compare those with disease to those without and look for differences in exposure to possible disease causes (e.g. age, diet, gender, lifestyle, occupation, location)

• Cohort studies - studying two similar groups of people who are free of disease, one group exposed to possible cause of disease and other is not, and these groups followed over long period of time to compare resulting incidence of disease (tests mortality and morbidity)

Explain how descriptive studies work

Find patterns in disease, e.g. occupation → car mechanics are exposed to fumes are therefore more susceptible to cancer. Consider frequency, age, gender, location, time period, etc

Explain how intervention studies work

Tests effectiveness of treatments/campaigns to change behaviour of population to decrease incidence of disease

Explain what features enhance the effectiveness of an epidemiological study

• Conducted over long period

• Study large samples (consider if the population of Australia is 28 million and a study for aus is 20,000, it's not the largest possible sample. Relative 'large')

• Include people of wider population

• Evaluation of treatment and control methods

• Collect range of relevant data from large group of affected and unaffected population

  • These help grant a study validity especially

Describe benefits of epidemiological studies

- understanding causes and effects of disease
- potential prevention of exposure to disease causing elements
- early detection and treatment
- higher chance of saving lives
- save govt money and medical resources
- clear up hospitals potentially

Describe the role of educational campaigns in preventing disease

Define the function of neurons and then each part of the neuron (dendrite, axon, axon terminal, cell body, synapse)

Function → nerve cells which carry electrical signals; sending, receiving, and transmitting electrochemical signals throughout the body

• Dendrites —> receptors, receive info from other neurons; branch out from cell body, carry info to cell body

• Axon → tail, carries info away from cell body and has terminal area where other neurons pick up information via their dendrites; covered by myelin sheath like rubber encircles a wire

• Cell body → spherical, contains nucleus

• Synapse → gap between axon terminals

Define Mesophytes and identify a mechanism to maintain water balance

• Land plants, adequate supply of water

• Regular stomata numbers, stomata often open

Define Xerophytes and identify a mechanism to maintain water balance

• Dry climates, adaptations focus on conserving water

• Few stomata, thick waxy cuticles, small SA on leaves

Identify factors used to evaluate methods of epidemiological studies

Requirements for Effective Study

• Conducted over long period

• Study large samples (consider if the population of Australia is 28 million and a study for aus is 20,000, it’s not the largest possible sample. Relative ‘large’)

• Include people of wider population

• Evaluation of treatment and control methods

• Collect range of relevant data from large group of affected and unaffected population

  • These help grant a study validity especially

Evaluate genetic engineering as a strategy to prevent disease

• Genetic Engineering → insertion of genes from one organism to another; modification of an organism's genes to prevent or treat diseases, e.g. replacing faulty gene

• Genetically engineering other animals (e.g. mice) to produce high volumes of monoclonal antibodies which will specifically kill cancer cells

  • Ethical concerns

• Effectiveness: moderate (technology has not reached full potential and is not a foolproof method of eradicating cancer)

  • Good because reducing requirement for donors and no issues with tissue and organ rejection

Describe lung cancer as a non-infectious disease

• Abnormal cells grow and multiply in an uncontrolled way, either beginning in or spreading to the lungs

• Caused by carcinogens in smoking for example or exposure to chemicals

• Can be treated in ways similar to other cancers - surgery, chemotherapy, radiation therapy

• High prevalence amongst lower socioeconomic groups and rural populations due to greater rates of smoking

Identify an analytical study on lung cancer

• Case control study by Richard Doll (1947) to compare smoking habits of patients with and without lung cancer → showed people with lung cancer were smokers suggesting a link

• Cohort study by A Hill (1951) where 1 group of doctors were smokers and the others were non-smokers over 10 years → showed smokers had lung cancer and more cigarettes = more chance of lung cancer

Describe and evaluate an intervention study relating to lung cancer

Provide an example of a specific epidemiological study

• The Quit campaign was an intervention epidemiological study through the form of an educational campaign in mass media which raised awareness of the effects of smoking to reduce the prevalence of smoking related diseases in the population

• Understanding cause of lung cancer → encouraging prevention of exposure to mutagens in smoking

• Used slogans, graphic images in the media and on cigarette packets, helpline and non-smoking areas

• Positives: large sample size, control of variables (e.g. age, gender), long period, accurate/reliable studies

• Cons: Can reliability be assessed? It wasn’t repeated

• considered highly successful in decreasing smoking rates and thus the prevalence of lung cancer