TOPIC 3 Flashcards
Is skin an organ
Yes
Looking at diagram How can you distinguish the glands?
Eccrine sweat gland it the worm looking duct, Subaceous gland is lumpy protrusion on follicle
What are the layers on the basic skin diagram
epidermis,
dermis ( papillary and reticular-made up of dense irregular connective tissue),
subcutaneous tissue ( hypodermics- not part of skin SUB= under)
What are the yellow wirey things and spirals on skin diagram?
Wirey things nerve endings
Spirals lamellar corpuscles
Does the epidermis have a blood supply?
No but Dermis has blood supply
Does dermis layer have blood supply
Dermis has blood supply epidermis does not
Does subcutaneous tissue have blood supply?
Subcutaneous tissue has a lot of blood supply
Layers of epidermis in order deep to superficial
‘BSGLC- Beck said go little caterpillar ‘
Stratum basale- produces keratinocytes
Stratum spinosum- Several cell layers thick, with intermediate filaments, keratinocytes and dendritic (Langerhans) cells
Stratum granulosum- consists of one to five cell layers in which keratinocyte appearance changes drastically, and the process of keratinization (in which the cells fill with keratin) begins. These cells flatten, their nuclei and organelles begin to disintegrate, and they accumulate keratohyaline and lamellar granules.
( stratum lucidem -only I thick skin Eg. Palms, soles, fingertips. thin, translucent band consisting of a few rows of flat, dead keratinocytes.)
Stratum corneum - consists of many layers of dead, keratin filled cells.
Cells of the epidermis?
Keratinocytes which produce keratin.
melanocytes which produce melanin pigment.
dendritic cells which patrols around and look for anything that shouldn’t be there and alert the immune system.
Merkel/ tactile cells also there which detect touch
which layer of the epidermis are keratinocytes too far from the dermal capillaries to survive?
Stratum granulosum
Characteristics of the dermis?
friction ridges which are genetically determined.formed in uterus by baby moving around.
Cleavage lines- seperations between underlying collagen fibre bundles in the reticular dermis
Flexure lines from where dermis is closely attached to the underlying structures
Cutaneous glands in dermis
Eccrine sweat glands
Apocrine sweat glands
Sebaceous glands
Eccrine sweat glands function and secretion type/ method / location
Eccrine sweat glands - Seperate to hair follicle
function: temperature control, some antibacterial properties
Type of secretions: hypotonic filtrate of blood plasma
Method of secretion: merocrine (exocytosis) at skin surface
Body location- everywhere especially palms, soles and forehead
Apocrine sweat glands function and secretion type/ method / location
apocrine-attached to hair follicle
Function: may act as sexual scents
Type of secretions: filtrate of blood plasma with added proteins and fatty substances
Method of secretion: merocrine ( exocytosis)
Secretions exiting duct at… usually upper part of hair follicle; rarely, skin surface
Body location: mostly auxiliary and anogenital regions
Sebaceous glands function and secretion type/ method / location
Functions- lubricants skin and hair, helps prevent water loss, antibacterial properties
Type of secretions: sebum ( an oily secretion) holocrine, with secretions exiting duct usually at upper part of hair follicle; sometimes, skin surface
Functions of skin?
protection physical ( lots of skin layers, keratinocytes) and chemical barriers ( acidic nature of sweat, chemicals in sebum and sweat. That acts like natural antibiotics)
Temperature regulation- sweat, piloerection -hair standing up
Sensation- touch ( Merkel cell, receptors on hair) , vibration (lamellar corpuscles), pain (nerve endings)
Metabolic function- converting modified epidermal cholesterol to a vitamin D precursor important to calcium metabolism , steroid hormones
Blood reservoir- shunting due to vasoconstriction
Excretion- nitrogen waste products
Types of microorganisms/ pathogens?
Bacteria
Fungi
Protozoa- single cell organisms
Helminths ( worms)- pretty large and can be seen with the human eye
Viruses
Prions tinyyyyyyy and very rare so don’t need to know in much detail
T or f, most microorganisms in body are beneficial
True
87% beneficial, 10% are opportunistic ( cause disease if given an opportunity), 3% pathogenic ( can cause disease in a healthy person)
What is virulence?
capacity to cause disease
What is resident flora
Flora residing/ living in body, replicating etc
What are transient flora
come across by touching others, soil and environment. Usually don’t replicate. They come and go but if they start replicating and decide to become resident it is called COLONISATION
How are bacteria named
Shape, colour
Shape, location
Who discovered it, location
T or false, species can have different strains, some good some bad?
True
Are bacteria prokaryotes or eukaryotes?
Prokaryotes, they have no nucleus
Do bacteria have a cell wall
Yes, some also have a capsule
How can bacteria protect themselves from hostile environments?
Can form an endospore which is like a copy of the bacteria within the bacteria that can survive tough hostile conditions
Different cell shapes include…
Cocci Eg. Staphylococcal
Rods Eg. E. coli
Spiral
Difference between gram positive and negative bacteria
Gram positive - have thick double wall/ peptidoglycan, pick up colour and show as purple/ violet in dye
Gram negative - have thin peptidoglycan, show pink/ red in dye
Importance of knowing whether gram positive or negative
Significant as if we want to treat a patient, we need to find what sort of bacteria we are dealing with as some antibiotics work better for gram positive and some work better for gram negative.
Bacteria ‘growth cycle’
Bacteria multiply very quickly, then go into stationary stage ( as only so many nutrients) then start dying off when they’ve run out of nutrients
Factors that help bacteria grow?
water, they are temperature dependant ( depending on the type of bacteria), they like specific PH ( depending on the bacteria), specific pressure, oxygen for some/ no oxygen for some
What are fungi?
yeasts
Mould
Mycosis
Can happen in various areas of the body.
Eg. Athletes foot
What are Protozoa
Protozoa
single cell organisms
Have a nucleus (eucaryote)
Eg. Malaria
What are helminths
Helminths
tapeworm
Roundworms
Many types, weird life cycles, can cause a lot of damage but easily treatable
What are viruses?
Viruses
RNA or DNA as genetic material
Can not replicate or synthesise proteins by themselves
Need a host cell to replicate
Many different ones Eg. Influenza, HIV, hepatitis
Some preventable with vaccinations
Viruses do not react to antibiotics
Most respiratory tract infections are viral
Host cells are SPECIFIC most of the time
What is the chain of infection
- Aetiological agent (Microorganism)
- Reservoir (Source)
- Portal of exit from reservoir
- Method of transmission
- Portal of entry to the susceptibile host
- Susceptible host
All steps required for an infection to occur
Factors increasing susceptiblity to infection
Age- young and old
Hereditary - genetic predisposition and race
Stress- cortisol release, altered immune response
Nutrition- micronutrient deficiency and metabolic derangement
Treatment- immunodeficiency drugs and breaching defensive barriers
Disease- altered immune response and metabolic derangement
Methods of transmission of communicable disease
Direct- skin to skin touch, droplets, vertical ( mother to baby)
Indirect- airborne, vehicle Bourne( finite transmission), vector Bourne- mechanical( agent doesn’t multiply of undergo any change in vector) or biological ( agent undergoes change in vector)
Standard precautions of infection control
hand hygine PPE when risk of bodily fluid exposure Use and dispose of sharps safely Perform routine environmental cleaning Clean and reprocess shared patient equipment Respiratory hygine and cough etiquette Aseptic technique Handle and dispose of waste and used linen safely
…Standard precaution assumes that every patient is infectious …
5 moments of hand hygine
5 moments of hand hygine
Before touching patient ( including file)
Before procedure.
After procedure or body fluid exposure risk
After touching a patient
After touching a patients surroundings
What is a Parasite relationship?
one partner benefits from the other one.
Parasites are different to normal flora
What is colonisation
Colonisation: microorganisms are multiplying on host but not causing disease
What is chronic infection
Chronic infection - slow and not eliminated
What is a Mutualistic relationship
- both partners benefitting
Eg. Normal flora feed from you who’s also defending you
Is the immune system an anatomical system or a functional system
Immune system is not an anatomical system but is a functional system