unit 1 pre-release Flashcards
(71 cards)
1
Q
what is the scientific term for high blood pressure?
A
hypertension
2
Q
what are the causes of high blood pressure?
A
- lifestyle choices
- underlying medical conditions
- genetics
- obesity
- high salt intake
- lack of exercise
3
Q
what is the method to measure blood pressure?
A
- using a sphygmomanometer, inflatable cuff connected to a pressure gauge, and a stethoscope to listen to blood flow sounds
- cuff - inflates to temporarily stop blood flow, then slowly released, allowing the measurement of systolic and diastolic pressures
4
Q
what is systolic pressure?
A
when the heart beats
5
Q
what is diastolic pressure?
A
when the heart rests
6
Q
what are the main reasons for conducting a clinical trial?
A
- looks at new ways to prevent, detect or treat disease
- assess the effectiveness and side effects compared to existing treatments
- develop knowledge that improves human health or increases understanding of human biology
7
Q
what is a placebo?
A
- a substance or treatment that appears real but contains no active ingredient
- often used in clinical trials to compare effects of a new treatment against the possibility of a psychological or physiological response to the belief of receiving treatment
- fake treatment (usually pill or injection), its inactive, contains no active drug or therapeutic substance
8
Q
why are placebos used in clinical trials?f
A
- establish a baseline comparison
- help determine if a new treatment is truly effective by the controlling for the ‘placebo effect’
- facilitate outcome blinding
- assess if any ingredients used would cause allergic reactions to people
- measure safety of the treatment
9
Q
what is the independent variable in the investigation?
A
whether the participants took the blood pressure drug or not
10
Q
what was the dependent variable in this investigation?
A
acne severity / improvement - how much the participants’ acne improved over the 12 weeks
11
Q
what were the control variables in this investigation?
A
- dosage and timing of the drug
- participant group
- duration of treatment (12 weeks)
- measurement method (how acne improvement was assessed)
- participants’ weight
- participants’ age
- participants’ health
12
Q
what were some extraneous variables in this study?
A
- diet
- stress levels
- use of other skincare or medications
- hormonal changes (menstrual cycle)
13
Q
what would the null hypothesis for this investigation be?
A
the blood pressure drug has no effect on acne severity in women with persistent acne
14
Q
if the t value or chi squared value was above the critical value, what would this mean?
A
- results are statistically significant
- reject null hypothesis
- conclude that the drug likely doesn’t have an effect on reducing acne
15
Q
if the t value or chi squared value was below the critical value, what would this mean?
A
- results are not statistically significant
- fail to reject null hypothesis
- suggest any observed improvement could be due to chance, not the drug
16
Q
in what ways could the investigation be improved / extended?
A
- include larger and more diverse sample size (include men / different age groups)
- run the trial over a longer period to test the long term effects and safety
- compare the drug to other acne treatments, not just a placebo
- include a double-blind set up to reduce bias
- measure other outcomes, such as psychological impact or quality of life improvements
- investigate hormonal changes before and after treatment to confirm the mechanism
17
Q
why would the patient have been given the contraceptive pill to control acne?
A
- helps regulate hormones
- reduces levels of androgens like testosterone, which leads to less oil production and fewer acne breakouts
- often prescribed to women with hormone-related acne, especially if acne worsens around their menstrual cycle
18
Q
what ethics need to be considered during research studies?
A
- informed consent - must be fully informed of nature, aim, risks and benefits & must be given without pressure / deception
- confidentiality - keeping personal and medical info private and secure, comply with laws and protect participant data
- right to withdraw - aware of option to leave study at anytime without penalty
- working with vulnerable individuals - such as children, disabled individuals, elderly etc
19
Q
what are 2 common visible symptoms of acne that a GP may observe during diagnosis?
A
- pimples - (aka pustules or papules) red, inflamed spots filled with pus
- blackheads and whiteheads - (aka comedones) clogged pores appearing small dark or white bumps on skin
— typically found on face, back or chest
20
Q
describe how sebum contributes to the development of acne
A
- sebum is an oily substance produced by sebaceous glands in the skin
- it plays a key role in the development of acne through the following process:
OVERPRODUCTION:
- during puberty or hormonal changes, sebum production can increase
- this excess oil can clog hair follicles (pores)
CLOGGED PORED:
- dead skin cells that normally shed from the skin’s surface can mix with excess sebum, forming a plug that blocks the pore
- results in comedones (whiteheads or blackheads)
BACTERIAL GROWTH:
- the clogged pore creates an ideal environment for cutibacterium acnes (formerly propionibacterium acnes), a bacteria naturally present on the skin
- it thrives in the oxygen-poor, oily environment and multiplies
INFLAMMATION:
- as the bacteria grow, they trigger an immune response, leading to inflammation, redness, swelling, and the formation of papules, pustules, or cysts.
- while sebum is important for keeping skin moisturised, its overproduction and interaction with dead skin cells and bacteria are central to acne development
21
Q
give 3 reasons why overusing topical acne treatments can increase skin sensitivity
A
- DISRUPTION OF THE SKIN BARRIER:
- many acne treatments (like benzoyl peroxide or salicylic acid) are drying and exfoliating.
- overuse can strip away natural oils and damage the skin’s protective barrier, making it more vulnerable to irritation and environmental aggressors. - INCREASED IRRITATION AND INFLAMMATION:
- excessive application can lead to redness, stinging, peeling, and inflammation, especially in sensitive or already-compromised skin.
- this can worsen acne rather than improve it - CHEMICAL OVERLOAD:
- using too many active ingredients at once (or too frequently) can overwhelm the skin, leading to sensitisation or allergic-like reactions
- this may cause sensitivity not just to the treatments, but also to previously well-tolerated skincare products
22
Q
outline 4 lifestyle recommendations that may help reduce acne symptoms
A
- MAINTAIN A CONSISTENT SKINCARE ROUTINE:
- use gentle, non-comedogenic products to cleanse, moisturise, and treat the skin
- avoid over-washing or harsh scrubs, which can irritate the skin and worsen acne - EAT A BALANCED DIET:
- reduce intake of high-glycemic foods (like sugary snacks and refined carbs) and dairy, which have been linked to individuals
- focus on whole foods rick in antioxidants, omega-3 fatty acids, and zinc - MANAGE STRESS LEVELS:
- chronic stress can trigger hormonal fluctuations that increase oil production and inflammation, leading to breakouts
- practices like exercise, meditation, or adequate sleep can help manage stress - KEEP HANDS AND HAIR AWAY FROM THE FACE:
- touching your face frequently or letting hair oils transfer to your skin can introduce bacteria and clog pores
- keep your hands clean and hair away from your face, especially during workouts or sleep
23
Q
explain how hormonal factors contribute to the development of acne in adult women
A
- INCREASED SEBUM PRODUCTION:
- androgens (like testosterone) stimulate the sebaceous glands to produce more sebum
- excess sebum can clog pores, creating an environment for acne to develop - MENSTRUAL CYCLE FLUCTUATIONS:
- hormone levels naturally shift throughout the menstrual cycle
- many women experience breakouts in the days leading up to their period, when oestrogen drops and androgens become more dominant - CONDITIONS LIKE PCOS:
- polycystic ovary syndrome (PCOS) and other hormonal disorders can cause chronic elevation in androgens, leading to persistent acne, often along the jawline and chin - STRESS AND HORMONAL IMBALANCE:
- chronic stress can affect hormone levels, increasing cortisol and potentially impacting androgen production, which can worsen acne
24
Q
compare the use of topical treatments and oral antibiotics in treating moderate to severe acne
A
- MECHANISM OF ACTION:
~ topical treatments:
— working directly on the skin to reduce oil production, unclog pores, kill acne-causing bacteria, and reduce inflammation
— common examples include benzoyl peroxide, retinoids ( like adapalene) and topical antibiotics (like clindamycin)
~ oral antibiotics:
— work systemically to reduce C. acnes bacteria and inflammation from within the body
— common options include doxycycline, minocycline, or erythromycin - EFFECTIVENESS:
~ topical treatments:
— effective for mild to moderate acne, and often used in combination for moderate cases
— may no be sufficient alone for severe or widespread acne
~ oral antibiotics:
— more effective for moderate to severe or inflammatory acne, especially when lesions are deep or widspread - ONSET OF ACTION:
~ topical treatments:
— may take 4-8 weeks to show improvement, irritation can occur early in treatment
~ oral antibiotics:
— often work faster than topicals, with noticeable improvement in 4-6 weeks, though full results may take a few months - SIDE EFFECTS:
~ topical treatments:
— can cause dryness, peeling, redness, and sensitivity, especially in the beginning
~ oral antibiotics:
— may cause gastrointestinal issues, yeast infections, photosensitivity, and with long term use, antibiotic resistance - LONG-TERM USE:
~ topical treatments:
— safe for long-term use and often part of maintenance therapy
~ oral antibiotics:
— not recommended long-term due to risk of resistance
— typically used for a few months alongside topical treatments, then tapered off
CONCLUSION:
- topical treatments are generally first-line and essential for maintenance
- oral antibiotics are valuable for controlling more severe acne quickly but should be used short-term and combined with topicals to prevent resistance and maintain results
25
describe the role of sebaceous glands in acne formation
- sebaceous glands play a central role in acne formation by producing sebum, an oily substance that helps keep skin moisturised
- these glands are most abundant on the face, chest, and back which are areas commonly affected by acne
1. SEBUM OVERPRODUCTION
- when sebaceous glands produce too much sebum, it can mix with dead skin cells and clog hair follicles (pores)
- this creates a plug that traps oil and bacteria inside
2. CLOGGED PORES:
- the blocked follicle forms a comedone > a whitehead if closed, or a blackhead if open
- this trapped material creates an environment where acne-causing bacteria (cutibacterium acnes) can thrive
3. INFLAMMATION:
- as the bacteria multiply, the immune system responds, leading to inflammation
- this results in red, swollen pimples or deeper nodules and cysts in more severe acne quickly
26
how do hormonal changes influence their activity?
- androgens (male hormones present in both males and females) are the main hormones that affect sebaceous gland activity
- during puberty, pregnancy, the menstrual cycle, or conditions like PCOS, androgen levels can rise
- increased androgens stimulate sebaceous glands to enlarge and produce more sebum, which increases the risk of clogged pores and acne
27
discuss the possible benefits of using hormonal treatments, such as co-cyprindiol, for managing acne
1. REDUCES ANDROGEN ACTIVITY:
- cyproterone acetate is an anti-androgen that blocks the effects of male hormones (androgens) on the sebaceous glands, leading to reduced sebum production and fewer breakouts
2. IMPROVES HORMONAL ACNE:
- particularly effective for acne linked to menstrual cycles, PCOS, or excess androgen levels
- it helps treat persistent acne or areas like the jawline, chin, and lower face
3. DUAL BENEFIT:
- co-cyprindiol also acts as a contraceptive, which may benefit beneficial for women seeking birth control and acne management in one treatment
4. LONG-TERM IMPROVEMENT:
- with consistent use, many users experience significant reduction in acne, often maintained with ongoing hormonal balance
28
discuss the possible risks of using hormonal treatments, such as co-cyprindiol, for managing acne
1. INCREASED RISK OF BLOOD CLOTS:
- co-cyprindiol has a higher risk of venous thromboembolism (VTE) compared to some other contraceptive pills
- this risk is especially important for women who smoke, are over 35, or have a family history of clotting disorders
2. SIDE EFFECTS:
- may cause nausea, breast tenderness, mood changes, or weight fluctuations
- some women may also experience spotting or irregular bleeding
3. DELAYED RESULTS:
- it can take 2-3 months before noticeable improvements in acne are seen, which requires patience and adherence
4. NOT SUITABLE FOR EVERYONE:
- women with certain condition (e.g. history of blood clots, liver disease, migraines with aura) may not be good candidates for co-cyprindiol
29
evaluate the effectiveness of using a blood pressure drug as a treatment for persistent acne
BENEFITS:
- reduces the need for long-term antibiotics, helping to prevent antibiotic resistance
- targets hormone-driven acne by lowering androgens stimulate sebaceous effects
- provides an affordable and accessible treatment option
- may offer additional cardiovascular benefits for patients who also have high blood pressure
- shown to provide long-lasting acne clearance in some patients
DRAWBACKS:
- risk of side effects such as low blood pressure, dizziness and electrolyte imbalance
- requires careful dose adjustment and regular monitoring, especially in people without blood pressure issues
- limited long-term safety dats available for use especially in acne treatment
- ethical need for informed consent because it is an off-label use
30
how are papules and pustules different?
PAPULES:
- small, raised, red bumps
- solid
- do not contain pus
- form when pores become clogged and inflamed, but without infection spreading enough to create pus
- red, inflamed, NO pus
PUSTULES:
- similar to papules, but they have a white or yellow centre filled with pus
- they form when inflammation causes the clogged pore to fill with white blood cells (pus) as the body fights infection
- red, inflamed, WITH pus
31
how could we tell the difference between nodules and papules?
PAPULES:
- small (usually less than 5mm)
- red and raised, but not filled with pus
- can feel slightly firm to the touch
- often go away with topical treatments
- usually closer to the surface of the skin
NODULES:
- larger and deeper than papules (over 5mm)
- very firm or hard lumps under the skin
- can be painful or tender
- often do not come to a head or contain visible pus
- more likely to leave scars and need stronger treatments like oral medications
- develop deep in the skin, not just on the surface
small, red, on the surface > papule
large, deep, painful > nodules
32
how are whiteheads and pustules different?
WHITEHEADS (CLOSED COMEDONES):
- small, flesh-coloured or white bumps
- caused by clogged pore (oil + dead skin cells)
- not inflamed > no redness or swelling
- no pus > the white appearance comes from the trapped material under the skin
- usually painless
- clogged pore, no pus, no inflammation
PUSTULES:
- red, inflamed bumps with a visible white or yellow centre
- contain pus (a mix of bacteria and immune cells)
- caused by infection and inflammation in a clogged pore
- often tender or sore
- inflamed, red, pus-filled spot
33
list 3 risk factors causing acne:
1. HORMONAL CHANGES:
— such as during puberty, menstrual cycles, pregnancy, or conditions like PCOS, which increases oil (sebum) production
2. USE OF COMEDOGENIC PRODUCTS:
— skincare or makeup that clogs pores can trigger breakouts
3. GENETICS:
— a family history of acne increase your likelihood of developing it
34
how are whiteheads (closed comedones) formed?
- formed when a hair follicle (pore) becomes clogged with oil (sebum) and dead skin cells
- the top of the pore closes, trapping everything inside
- since the blockage is under the skin, it looks like a small white bump
35
how are blackheads (open comedones) formed?
- also form from a clogged pore (sebum + dead skin)
- but the top of the pore stays open
- when the trapped material is exposed to air, it oxidises and turns black (not dirt)
36
how are papules formed?
- form when a clogged pore becomes inflamed (red and swollen) but without pus
- caused irritation and the immune system reacting to trapped bacteria
37
what are pustules formed?
- develop from papules when the body sends white blood cells to fight infection
- this create pus inside the pore, leading to a red bump with a white / yellow centre
38
how are nodules formed?
- occur when a clogged pore causes deeper, more severe inflammation under the skin
- nodules are large, hard, painful lumps that form deep within the dermis
- they do not contain pus like pustules
39
how are cysts formed?
- form when a severe infection causes massive inflammation deeper under the skin
- they are large, soft, pus-filled lumps, often very painful
- cysts can scar if treated properly
40
what is a hormone?
- chemical messengers in the body
- made by endocrine glands (e.g. pituitary, thyroid and adrenal glands
- travel through the bloodstream to reach organs and tissues
- help body functions like:
— growth and development
— metabolism (how your body uses energy)
— mood and emotions
— sexual function and reproduction
— sleep cycles
- works by binding to receptors on target cells to trigger specific responses
41
what is the role of sebum?
- sebum is a oily substance produced by sebaceous glands in the skin
- it helps to moisturise and protect the skin and hair
- form a barrier that prevents too much water from leaving the body (prevents dryness)
- has antibacterial properties, helping protect against harmful microbes
- keeps the skin soft, flexible, and waterproof
42
what is a gene?
- a gene is a small section of DNA (your genetic material)
- it carries instructions for making proteins, which do important job in the body
- genes help determine traits, like eye colour, height, and even risks for some diseases
- you inherit genes from your parents > half from each
- if a condition like acne runs in the families, it may be because of inherited genes that affect how your skin works
43
how does semi-conservative replication occur?
- DNA replication is the process of making an exact copy of DNA
- its called semi-conservative because each new DNA molecule has one old strand and one new strand
STEPS:
1. unwinding > an enzyme called helicase unwinds the double helix and separates the two DNA strands
2. base pairing > free DNA nucleotides in the nucleus pair up with their complimentary bases on each original strand (A-T, C-G)
3. bonding > an enzyme called DNA polymerase helps join the new nucleotides together to form a new strand
4. result > two identical DNA molecules are formed, each with one original (parent) strand and one newly made strand
44
how does transcription occur?
- transcription is the first step of making a protein, it copies a gene’s DNA sequence into mRNA
- it happens in the nucleus of a cell
STEPS:
1. DNA unwinds > the double helix opens up at the gene that needs to be copied
2. RNA polymerase > binds to the start of the gene
3. base pairing > RNA polymerase matches RNA nucleotides to the DNA template strand (A pairs with U in RNA, C with G)
4. mRNA strand forms > the RNA nucleotides join together to make a single strand of messenger RNA (mRNA)
45
how does translation occur?
- translation is the second step of protein synthesis, it turns the mRNA message into a protein
- it happens in the ribosome, in the cytoplasm of the cell
STEPS:
1. mRNA attaches to the ribosome
2. ribosome reads the mRNA in sets of three bases called codons
3. tRNA (transfer RNA) brings the correct amino acid for each codon
4. the amino acids link together to form a polypeptide chain (a protein)
5. when the ribosome reaches a stop codon, the process ends and the protein is complete
46
describe the difference between mild, moderate and severe acne
MILD ACNE:
- few spots > mostly whiteheads, blackheads and small pimples
- usually appears on the face
- little to no inflammation or redness
MODERATE ACNE:
- more spots > including papules (red bumps) and pustules (pus-filled pimples)
- can appear on the face, back or chest
- noticeable redness and inflammation
SEVERE ACNE:
- many painful, deep spots (nodules and cysts)
- large areas of skin affected
- high risk of scarring and long-term skin damage
- often requires medical treatment a
47
what type of data is being collected in this test?
QUANTITATIVE:
- includes measurable improvements in acne over 12 and 24 weeks (like the number of spots, severity rating, etc)
QUALITATIVE:
- comes from patient experiences and descriptions, like how the woman explained feeling embarrassed or how her confidence was affected
48
over-the counter treatments (e.g. gels, creams, face washes)
HOW IT WORKS:
- contain benzoyl peroxide, which reduces bacteria, unplugs pores, and decreases inflammation
PROS:
- easily available without a prescription
- reduces bacteria and inflammation
- helps with blackheads and whiteheads
CONS:
- can make the skin sensitive to UV light (sunburn risk)
- dryness and irritation are common
- requires consistent use (6-weeks course)
49
topical retinoids
HOW IT WORKS:
- removes dead skin cells, preventing them from plugging hair follicles
- helps new skin grow properly
PROS:
- helps prevent clogged pores
- encourages skin turnover
- often effective in mild to moderate acne
CONS:
- increases sensitivity to sunlight
- not safe during pregnancy (birth defects risk)
- can initially irritate the skin
50
topical antibiotics
HOW IT WORKS:
- kills bacteria on the skin that infect plugged hair follicles
PROS:
- reduces bacteria causing acne
- helps calm inflamed spots
- suitable for short-term use
CONS:
- risk of antibiotic resistance (must be limited to 8 weeks)
- possible minor irritation and burning
- best used with other treatments
51
azelaic acid
HOW IT WORKS
- clears dead skin and kills bacteria, available as a cream or gel
PROS:
- alternative if benzoyl peroxide or retinoids are too harsh
- also helps lighten pigmentation from acne
- generally well tolerated
CONS:
- can cause burning, stinging, dryness, and redness
- takes time (usually a month) to see improvements
- may still irritate sensitive skin
52
antibiotic tablets
HOW IT WORKS:
- systemic treatment for severe acne, usually combined with a topical treatment
PROS:
- useful for more severe or widespread acne
- treats inflammation and infection internally
- 6-week course with ongoing treatment as needed
CONS:
- sensitivity to UV light
- can make birth control pills less effective initially
- risk of antibiotic resistance
53
hormonal treatments (e.g. co-cyprindiol)
HOW IT WORKS:
- reduces the production of sebum (oil) and helps when acne does not respond to antibiotics
PROS:
- good for hormone-related acne
- reduces oil production
- can be effective for women with PCOS or hormonal imbalance
CONS:
- risk of side effects like headaches, weight changes and mood swings
- increased risk of thrombosis (blood clots)
- small increased risk of breast cancer with long-term use
54
if we had a teenage girl with severe acne, which treatment would you recommend and why?
TOPICAL RETINOIDS + TOPICAL ANTIBIOTICS:
- possibly also with azelaic acid if the skin is sensitive, and possibly antibiotic tablets if its very severe
WHY?
- teenagers often have increased oil production due to hormones, leading to clogged pores and bacterial infection
- topical retinoids will help prevent pores from clogging
- topical antibiotics will reduce bacteria
- if the acne is very severe and widespread, oral antibiotic tablets can control deeper infections
- hormonal treatments like co-cyprindiol could be an option if acne doesn’t improve, but usually started after trying other treatments
55
if we had a polycystic woman of age 45 with sensitive skin, which treatment would you recommend and why?
AZELAIC ACID:
- possibly hormonal treatment (co-cyprindiol) if appropriate (depending on hormone levels and doctor’s advice)
WHY?
- azelaic acid is gentler and less irritating for sensitive skin compared to benzoyl peroxide or retinoids
- hormonal treatments can help because PCOS often causes increased androgen (testosterone) levels, leading to acne
- however, because of her age and potential health risks (e.g. blood clots, breast cancer risk), hormonal treatments must be carefully considered by a doctor
56
if you have a pregnant woman of 25 with severe acne, which treatment would you recommend and why?
AZELAIC ACID
WHY?
- it is safe to use during pregnancy (unlike topical retinoids, which can cause birth defects)
- it kills bacteria and removes dead skin, helping to treat severe acne
- it is less irritating compared to benzoyl peroxide and topical retinoids
- it has anti-inflammatory effects to reduce redness and swelling
57
explain why taking antibiotics when not needed can lead to antibiotic resistant bacteria
- when antibiotics are used unnecessarily, some bacteria survive because they may naturally resist the drug
- these surviving bacteria can multiply and spread, passing on their resistance to other bacteria
- over time, more bacteria become resistant, meaning that antibiotics become less effective at treating infections
- this can make future infections harder to treat, requiring stronger or more complex medications
58
explain what photodynamic therapy is
- a treatment where special light and a light-sensitive medication are used together
- it helps kill bacteria, reduce inflammation, and shrink oil glands in the skin, improving acne
59
explain what a comedone extractor is
- a small tool used to remove blackheads and whiteheads (comedones) from the skin
- it works by applying gentle pressure around the clogged pore to clear it safely
60
explain what chemical peels are
- a treatment where a chemical solution is applied to the skin to remove the top layers
- it helps to reduce acne scars, improve skin texture, and clear blocked pores
61
why might squeezing blackheads, whiteheads or spots make the issue worse?
- it can push bacteria deeper into the skin, causing more inflammation and infection
- it can damage the skin, leading to scarring or dark marks
- it can spread bacteria to nearby areas, causing more spots to form
62
why is drying up the spots using toothpaste not effective?
- toothpaste is not designed for the skin and can cause irritation, redness, and dryness
- it can upset the skin’s natural balance, making acne worse instead of better
- some ingredients in toothpaste may clog pores, leading to more spots
63
why might there be more acne sufferers in cities than in rural areas?
- air pollution in cities can clog pores and irritate the skin, leading to more acne
- stress levels are often higher in cities, which can worsen acne
- diet in cities may include more processed and sugary foods, which can trigger breakouts
- lifestyle factors like lack of sleep and less outdoor activity can also affect skin health
64
state two conclusions that can be made from the figure 4 graph?
1. in the teenage years, more males have acne compared to females
2. after the teenage years (20s to 50+), more females suffer from acne than males, and the overall percentage of people with acne decreases with age
65
why might the number of males with acne fall faster than women with acne?
- hormonal changes in ,ales after puberty often stabilise more quickly, leading to fewer breakouts
- in women, hormonal fluctuations continue into adulthood (due to periods, pregnancy, and menopause), which can keep triggering acne
- women may also be more affected by hormonal conditions like polycystic ovary syndrome (PCOS), which can cause ongoing acne
66
why is there a higher prevalence of acne among teens in comparison with other age groups?
- during puberty, there is a surge in hormones (especially androgens) that increase sebum (oil) production in the skin
- excess sebum can clog pores, leading to more blackheads, whiteheads and inflamed spots
- teenagers also experience faster skin cell turnover, which can block hair follicles and contribute to acne
67
why does the prevalence of acne decrease with age?
- hormone levels stabilise after puberty, leading to less sebum (oil) production
- skin cell turnover slows down, so pores are less likely to get blocked
- adults often adopt better skincare routines and healthier lifestyles, which can help reduce acne
- oil glands shrink slightly with age, making the skin less oily and reducing the chance of acne
68
how many times more likely is a person from the US to not have acne than a person from botswana?
- from figure 4, about 60% of people in the US do not have acne
- in botswana, only about 20% of people do not have acne
- so, a person from the US is 3 times more likely to not have acne than someone from botswana
69
what are the types of white blood cells and their action?
1. NEUTROPHILS:
- most common type
- first responders to infection, especially bacterial
- they ‘eat’ bacteria and damaged cells (a process called phagocytosis)
2. LYMPHOCYTES:
- includes B cells, T cells, and natural killer (NK) cells
- B cells make antibodies
- T cells kill infected cells and help coordinate the immune response
- NK cells attack virus-infected and cancerous cells
3. MONOCYTES:
- largest type of white blood cell
- they also do phagocytosis and can become macrophages (big eaters) in tissue
4. EOSINOPHILS:
- attack parasites and are involved in allergic reactions
5. BASOPHILS:
- least common
- release histamine during allergic reactions and help with inflammation
70
outline the humoral immunity response (antibody-mediated immune response)
MAIN CELLS INVOLVED:
- B cells (specifically plasma cells after activation)
- helper T cells (especially T helper 2 cells, or Th2)
PROCESS:
1. B cells recognise specific antigens (either directly or via help from helpers T cells)
2. B cells get activated and differentiate into plasma cells
3. plasma cells produce antibodies specific to the antigen
4. antibodies circulate in blood and lymph, binding to antigens
5. this neutralises pathogens, marks them for destruction (opsonisation), or activates the complement system
MAIN TARGET:
- extracellular pathogens (like bacteria, viruses before they enter cells)
- toxins
71
outline the cell-mediated immunity response (T cell-mediated immune response)
MAIN CELLS INVOLVED:
- cytotoxic T cells (CD8 + T cells)
- helper T cells (especially T helper 1 cells, or Th1)
- macrophages, dendritic cells (as antigen-presenting cells)
PROCESS:
1.antigen-presenting cells (SPCs) show antigens on MHC molecules
2 helper T cells recognise the antigen and activate cytotoxic T cells
3. cytotoxic T cells kill infected cells directly (especially virus-infected or cancer cells)
4. activated macrophages and other immune cells help destroy pathogens inside cells
MAIN TARGET:
-intracellular pathogens (like viruses, some bacteria inside host cells)
- cancerous cells
- transplanted tissues (can be attacked if recognised as foreign
