Block 9 - Disease Processes (1) Flashcards
What is disease a consequence of?
Failed homeostasis
What are the two types of morphological changes?
Microscopic changes which eventually turn macroscopic
Which is the acidic and basic dye in the haematocyclin-eosin stain?
Haematocyclin = basic (purple) Eosin = acidic (pink)
4 main disease targets in a cell?
Cytoskeleton, Ionic channels, Membrane, Mitochondria
Define autophagy
The cell ‘eats’ itself
Triggered by calcium influx
Define karyorrhexis
Large fragments
Define atrophy
Decrease in cell size and number
What are the three stages of necrosis?
Coagulative –> Colliquative/Liquefaction –> Caesating
Define coagulative necrosis
Cell death but structure retained
Pale cytoplasm, decreased nuclei
Define colliquative/liquefaction necrosis
Hydrolytic enzymes from dying cells degrade tissue
Fluid-filled cavity of necrotic cells
Define caesating necrosis
Accumulation of inflamamtory cells
Structure lost but not fluid
3 structural chromosome abnormalities
Break, reattach, inverted incorrectly
Define PLOIDY
Additional chromosome
Definer restituation
When the opposite DNA strand is used as a template
Define dysplasia
Abnormal cell apperance
Define metaplasia
The cell differentiates into a different type of cell
Define immunopathology
The damage from the immune system becomes more clinically significant than the thing it was defending
Type 2 hypersensitivity:
What antibodies are involved?
Two types of tissue cytotoxicity?
6 examples
IgG or IgM
Antibody or complement dependent cytotoxicity
Goodpasture, Myasthenia gravis, Grave’s disease, Rhesus disease, Drug allergies, Drug induced haemolytic anaemia
Type 3 hypersensitivity:
What antibody is involved
3 examples
IgG
Arthur’s reaction (vaccination)
Serum sickness
Lupus
Type 4 hypersensitivity:
Explain the primary and secondary response
What is a Hapten?
What class of diseases also come under this?
4 examples
Primary: Sensitisation and memory cell production when APC presents Haptens (sensitising agents that bind to self-proteins in the epidermis –> neoantigens)
Secondary: APC with hapten presents to CD4+ cells –> T cell and macrophage activation
Autoimmune diseases
Contact sensitisation, Rheumatoid arthritis, MS, Allergen skin tests
What layer of skin is found in thick skin but not in thin skin?
2 characteristics
Stratum lucidium
Thin, transparent layer between the granulosum and corneum
What is different about the stratum corneum and hypodermis in thick skin?
Corneum is thicker
Hypodermis has more angualtion
What epithelium is the skin?
Stratified squamous
What are the 4 layers of the epidermis?
Stratum corneum –> Stratum granulosum –> Stratum spinosum –> Stratum basale
What happens at the stratum corneum?
How are the cells arranged?
What is the main property of the cells?
Apoptosis
Tight junctions form a barrier
Lipids and insoluble proteins = hydrophobic
What two things are found in the stratum granulosum?
Lamellar bodies: Lipids for hydrophobic barrier
Reratohyalingranules: Proteins which bind to keratin
How many layers are in the stratum spinosum?
What pigment is present?
What protein structures are present?
Many layers
Keratin
Tonofibrils: Cytoplasmic protein structures that meet at desmosomes
What 2 cells are found in the stratum basale?
Single layer of cuboidal cells
Stem cells which proliferate in a 40 day cycle
What are the four cells found in the skin?
Which is the most abundant?
What are their roles?
Keratinocytes - most abundant, more in high layers
Langerhans - Dendritic APC
Merkel - Fine touch
Melanocytes - more in low layers
What causes scaling
Imbalance between loss and renewal
Shedding of the cornified layer
What causes blisters
Breakage of the cell-cell junctions
3 roles of the dermis?
Protection
Thermoregulation
Touch
Papillary dermis:
Thickness
Type of connective tissue
3 properties
Thinnest
Loose connective tissue
Fine collagen and elastin
Squiggles to provide blood
Reticular dermis:
Thickness
Type of connective tissue
2 properties
Thickest
Dense and irregular connective tissue
Thick collagen fibre
Immune cells and cell appendages
How are nails produced?
What is their structure?
Nail root cells in the basal layer proliferate to form the nail matrix
Similar to the straum corneum and contains keratin
Where is hair produced?
Hair follicle from the acini in the basal layer
What is the structure of hair?
Medulla - Cortex - Cuticle
What are the three phases of hair growth?
Anagen - Growth phase
Catagen - Transition phase
Telogen - Resting phase
What type of glands are sebaceous glands?
What do they secrete?
How do they secrete?
Branched acinar
Secretes sebum: A lipid which keeps hair soft and waterproof
Holocrine secretion: Increased lipid concentration causes rupture of cell membrane
What type of glands are eccrine and apocrine glands?
Where are they?
How do they secrete?
Coiled tubular
Reticular dermis
Merocrine secretion: Secrete directly onto skin
Which glands become active in puberty?
Apocrine
What are the 5 stages of healing of deeper wounds?
Haemostasis: Fibrin clot Inflammation Fibroplasia: Fibroblasts --> collagen Epithelialisation: Keratinocytes create new layers Remodelling
2 examples of liquid-filled lesions
Where are they found?
Blister, pustule
Epidermis
3 examples of solid lesions
3 causes
Plaque, nodule, wheal
Increased epidermal thickness, tumour, oedema
2 examples of lesions in skin colour
2 causes
Patch, erythema
Changes in blood flow, melanocytes
What causes a callus?
Hyperplasia of the epidermis following pressure/friction
What causes an ulcer?
Loss of epidermis and papillary dermis
3 requirements of fluid homeostasis
Intact vessels, osmolarity and constant pressure
How much blood do you need to lose to go into hypovolemic shock?
20%
What are the three stages of haemostasis?
Haemorrhage: Bleeding
Thrombosis: Clotting
Fibrinolysis: Clot dissolution
2 causes of a decrease in plasma proteins
Liver cirrhosis
Malnutrition
4 causes of lymphatic obstruction
Parasitic worm
Malignancy
Surgery
Radiation therapy
What causes the formation of a thrombus?
Inappropriate haemostasis caused by endothelial injury, abnormal blood flow and hypercoagulability
Main component of an arterial and venous thombus
Arterial: Platelets
Venous: Fibrin and electrolytes
2 reasons why there is an increase in blood flow to a tissue
Hyperaemia
Congestion
When does hyperaemia occur?
What are the two types?
A change in environment
Reactive: Vasodilation due to decreased oxygen or increased waste
Active: Vasodilation due to exercise
What is congestion?
What are the two types?
Decreased blood removal due to impaired venous return
Local: Vessel compression
Systemic: Heart failure, oedema
How does shock cause cell injury and damage?
Decreased blood flow (systemic hypoperfusion) due to decreased cardiac output causes decreased nutrients to cells
Define cardiogenic shock
3 examples
Failure of the heart to pump sufficient blood to damage
e.g. MI, Arrhythmia, Pulmonary oedema
Define neurogenic shock
CNS damage –> loss of systemic stimulation of blood vessels –> blood pooling
Define sepsis
Uncontrolled systemic reaction to the infection causes organ dysfunction
Define septic shock
Profound circulatory, cellular and metabolic abnormalities which increase mortality
Pathophysiology of sepsis
> Bacteria activate neutrophils and macrophages
Systemic release of cytokines causes systemic vasodilation, hypotension and vascular leakage
Oedema decreases blood pressure more and decreases blood flow to organs, decreasing nutrient exchange
Complement activated
Dysregulation of immune and haemostatic systems causes respiratory distress and multiple organ failure
Are parasites eukaryotes or prokaryotes?
Eukaryotes
What are the two classes of prokaryotes?
Archaea: Virus and prion
Bacteria
3 ways to classify bacteria?
Cell wall
Morphology
Nutritional and biochemical properties
What is found on the peptidoglycan layer?
Tecchoic acid
What do you use to stain Gram+ and Gram- bacteria?
Crystal violet
Retained in Gram+, lost in Gram -
Stain with counterstain
Not seen in Gram+ but seen in Gram-
Which class of bacteria can make spores?
Gram positive
Define microaerophilic
Requires some oxygen but not a lot
How do you identify bacteria?
PCR and genome sequencing
What are the 4 methods of horizontal gene transfer?
Transformation: DNA released into environment and taken up
Transduction: Phage transfers non phage DNA
Conjugation: Bacteria have sex
Transposons: Genetic units which jump
What are the 4 phases of bacterial replication?
- Lag phase: Bacteria make the right conditions
- Growth phase: Optimum multiplication
- Stationary phase: Nutrients decrease (can remain here for a while)
- Death: Non nutrients
What bacteria causes Lyme disease?
Borrella burgdorferi
What is in tears which provides a barrier to infection?
Lysozyme
Microbe free areas? (7)
Blood, Urine, CSF
Muscles, glands, inner ear, brain
What are the three types of pathogen?
Overt/Strict: Disease causing
Opportunistic: Causes disease when they end up where they’re not supposed to be
Faculative: Survives in host normally
What is the role of virulence factors?
Facilitate colonisation, growth, spread and immune evasion
Give 5 examples of virulence factors and their roles
Adhesions: Fimbriae, pili, membrane proteins Flagella: Mobility and penetrate mucin Capsule: Prevents phagocytosis Type 3 secreted molecules Toxins
What 3 diseases does streptococcus pneumoniae cause?
Pneumonia, Sepsis, Meningitis
Give 5 virulence factors of streptococcus pneumoniae
Capsule Surface adhesions Secretory IgA protease (cleaves IgA) Neuraminase Spore formation
Endotoxin: Which bacteria release it? How does it react to heat? What does it cause? (2) Toxicity?
Gram negative
Heat stable
Fever, D+V
Weak toxicity
Exotoxin: Which bacteria release it? How does it react to heat? What does it target? Toxicity? Intracellular or extracellular?
Gram positive and negative Heat fluctuation Specific targets High toxicity Extracellular
Define toxoid
Inactivated toxin used as a vaccine
Give 2 examples of enterotoxins
What do they cause
Cholera and E.coli
Permeability change and D+V
What type of bacterium is clostridium botulinum? Type of respiration? Spore former or not? Mechanism of entry? 3 clinical uses of botulinum toxin
Gram positive Anaerobic Spore former Ingestion Bladder, migraine, sweat
What type of bacterium is lysteria monocytogenes?
Where is it found
2 people at increased risk
What other disease can it cause?
Gram positive
Found in food
Pregnancy, immunosuppressed
Can cause meningitis
What type of bacterium is vibrio cholerae?
What type of toxin is it?
How does it change the osmotic gradient?
Gram negative
Exotoxin
Increased adenylate cyclase and cAMP
What type of bacterium is salmonella?
How does it cause cell lysis?
Gram negative
Modifies the phagosome pathway
Define ‘pathogenicity factors’
Extra genome sequences unique to a set of related pathogens
What are black holes
Deleted information
Give 7 strategies for bacterial immune evasion
> Stay intracellular
Antigen and phage variation (changing immunogenicity)
Molecular mimicry
Modify/block the host immune response (e.g. IgA, protease, Type 3 factors)
Avoid complement activation
Avoid phagocytosis (capsule, anti-phagocytic toxins, resist killing in the phagocytes via enzymes, pH and toxic O2 metabolites)
Inhibit host signalling
Give 6 examples of bacteria which are part of the normal flora
H. influenzae S. epidermidis S. aureus S. pneumoniae L. species E. coli
4 roles of the microbiome
Develops the immune system
Prevents pathogens colonising (directly competes with them for nutrients and room and indirectly induces the immune system)
Metabolises toxins
Produce beneficial nutrients
What does more species in the microbiome NOT mean?
More genes
7 things the microbiome is dependent on
Age - Diet - Environment - Immune response - Lifestyle - Host genetics - Microbial co-adaptation
3 reasons why the microbiome can cause infection
Spread into sterile body parts
Expand their population
Disrupt their normal balance
Explain the pathogenesis of C.diff
Microbiome bacteria convert 1 –> 2 bile salts
2 bile salts stop c.diff growth
less bacteria mean less 2 bile salts and growth of c.diff
What is the technical name for diahorrheoa
Pseudomemranous colitis
What type of bacterium is Clostridiumm Difficile?
Why is it hard to combat in hospitals?
Gram positive
It is a spore former
Define dysbiosis
Imbalance of the normal gut microbiome composition leading to problems in the host (e.g. metabolism and distribution)
Define prebiotics
Non-digestable food which helps the microbiome develop healthily and improves host health
Define probiotics
Living, non-pathogenic organisms used as food to improve host health
Define selective toxicity
Exploiting differences between prokarytic and eukaryotic cells
4 properties of antibiotics
Bacterial selective
Kills bacteria (not just inhibits growth)
Slow emergence of resistance
Narrow spectrum
Give 2 examples of narrow spectrum antibiotics
Older penicillins
Macrolides
Give 4 examples of broad spectrum antibiotics
Aminoglycosides
Synthetic penicillin
Quinolones
2nd and 3rd generation Cephlasporins
What does antibiotic resistance relate to?
The sensitivity of a bacterial agent at a certain concentration
What are the 4 types of acquired bacterial resistance?
Modification of the antibacterial target (e.g. change surface protein shape)
Enzymatic inactivation of the antibiotic (e.g. create enzyme to break antibiotic)
Limited access of antibiotic (e.g. stop entry/efflux)
Bypass pathway
Define the MIC
What 3 things does it depend upon?
Minimum concentration of antibacterial agent below which bacteria growth is not inhibited
Depends on the species, isolate and drug
What are the 3 stages of antibiotic resistance?
Resistant - Intermediate - Sensitive
2 methods of beta lactam resistance
Bacteria produce beta-lactamase to degrade the antibiotic
Bacteria alter penicillin binding proteins
7 ways that doctors can decrease antibiotic resistance rates?
Individual patient Prevent overuse, misuse and abuse Decrease infection risk Improve hygiene Know local guidelines Shortest course possible Single use when possible
What are the 3 shapes of viruses?
Icosahedral
Spherical
Filamentous
Which virus is it harder to find a vaccination for?
Non-enveloped
How is an enveloped virus transmitted?
Droplets
What protrudes from the surface of an enveloped virus?
What are their roles?
Protein structures
Adhesion and enzymes
2 examples of non-enveloped viruses
Rotavirus
Norovirus
3 examples of enveloped viruses
Influenza
HIV
Ebola
What type of genome does norovirus have?
How is it transmitted?
Positive strand RNA
Transmitted though food, water and surfaces
What is the genome in:
DNA viruses?
RNA viruses?
Reteroviruses?
DNA viruses: single or double strand DNA
RNA viruses: single or double strand RNA
Reteroviruses: single strand RNA / double strand DNA
What 3 proteins do viruses make?
Proteins for new viruses
Enzymes for genome replication
Proteins to interfere with the immune response
5 examples of negative single strand RNA viruses
Where is their lifecycle?
Influenza Mumps Measles Ebola Rabies
Outside the nucleus
3 examples of positive single strand RNA viruses
Where is their lifecycle?
Poliovirus
Dengue
Hepatitis C
Outside the nucleus
2 examples of double strand DNA viruses
Where is their lifecycle?
Rotavirus
Gastroenteritis
Outside the nucleus
Define burst size
Yield of the infectious virus/cell
What does the response to the virus depend upon?
The type of cell infected (e.g. liver or skin)
Give 2 examples of DNA viruses
Where is their lifecycle?
How do they replicate?
Herpes
Epstein-Barr
Inside the nucleus
Use normal cell functions to assemble the virus in the nucleus and release it by cell lysis
Give 3 classes of viral drugs
Nucleoside analogues (inhibit polymerase)
Nucleoside antimetabolite
Protease and fusion inhibitors
Define lytic infection
Latent/persistant
2 ways by which viruses can cause cancer
Introduction of viral oncogenes
Transcribing/translating proteins which have never been used before
Give an example of a reterovirus
Where is its lifecycle?
How do they replicate?
HIV
Inside the nucleus
Viral genome integrates with DNA, reverse transcriptase used and virus packaged in cytoplasm then released by budding
What are the 6 main ways of virus transmission
Respiratory Zoonoses (animal) Enteric Contact Percutaneous Mother - Child
What do viruses not infect which bacteria do?
Wounds
Give 5 examples of respiratory viruses
Flu RSV Coranovirus Rhinovirus Parainfluenza
Give 3 examples of rash causing diseases
Measles
Rubella
Chickenpox
Give 2 examples of respiratory viruses transmitted by saliva
Epstein-Barr
CMV
Give 3 examples of methods by which viruses can be transmitted by animals
Ingestion of meat e.g. Hepatitis E
Bites e.g. Rabies
Insects e.g. Mosquitos or Ticks (tick bourne encephalitis)
Define arbovirus
Virus transmitted by insects
Give 5 examples of viruses transmitted by the faecal-oral route
Hepatitis A Hepatitis E Norovirus Rotavirus Gastroenteritis
Give 3 examples of contact viruses
How are they actually transmitted?
HIV (mucosal)
Herpes simplex (mucosal)
HPV (skin)
3 examples of viruses transmitted during pregnancy
3 examples of viruses transmitted during birth
CMV, Rubella, Varicella
HIV, Hepatitis B, Herpes simplex
3 methods of percutaneous tranmission
Arbovirus
Mother - baby
Injection
Why is it hard to make anti-viral drugs
Hard without host damage
Give 3 prevention methods for viruses
Physical e.g. condoms and DEET
Passive e.g. antibodies
Active e.g. vaccination
What part of the immune system less important for viruses?
Adaptive
What leads to the production of interferons?
How do they work?
Fibroblasts and leukocytes produce them
Stimulate genes –> Host restriction factors –> NK, macrophages, cytokines
What leads to the production of lymphocytes?
How do they work?
Early: antigens presented by MHC1 –> CD8+
Late: B cells produce IgM and IgG
What is the role of IgM?
Aggregation in the initial response
What is the role of IgG?
Neutralising in the later response
Involved in the secondary infection (immunity)
A clinical sign of a reactivated latent virus?
Specific T cells to the virus
Is HIV latent?
No
What inflammatory cells are seen in chronic inflammation?
Lymphocyte, Macrophage, Plasma cells
What is the difference between exudate and pus?
Exudate: Increased fluid with plasma proteins
Pus: Exudate with dying cells and bacteria
Explain the process of the C3 and C5 inflammatory cascade
Pathogen binds to C3 causing release of histamine and chemoattractant
C3a and C5a: cell recruitment
C3b: interaction
C5a: cascade producing the membrane attack complex
Give 3 examples of cell derived inflammatory mediators
What do they release?
2 other roles of inflammatory cells
Platelets –> serotonin
Mast cells and basophils –> histamine
Inflammatory cells –> Lymphokines and monokines
Inflammatory cells also activate arachidonic acid metabolites and platelet activating factor
3 examples of plasma derived inflammatory mediators
What system do they arise from?
Kinin (kallikrenin system)
D-dimers/fibrin degradation products (clotting and fibrinolytic system)
Complement compnents (complement system)
What 3 things produce Hageman factor (XII)
Plasmin from the fibrinolytic system
XI from the clotting system
Kallikrenin system
What are the two pathways which arachidonic acid is a precursor to?
What do these pathways produce?
What is the role of them?
Cyclo-oxygenase pathway produces prostaglandins
Prostacyclin –> platelet aggregation and vasodilation
Thromboxane –> platelet aggregation and vasoconstriction
Lipo-oxygenase pathway produces leukotrines
Increase vascular permeability, vasoconstrict, chemotaxis, neutrophil adhesion and vasodilation
What are ‘acute phase reactions’
9 examples
Systemic effects of acute inflammation
e.g. fever, rigors, tachycardia, decreased bp, reduced appetite, vomiting, aching, skeletal weakness, altered liver metabolism
What are the 5 stages of tissue repair after inflammation?
Congestion: Tissue filled with proteins and fibrin (firm)
Consolidation: Inflammatory cells infiltrate (red hepatization)
Grey hepatization: Macrophages digest neutrophils and fibrin
Resolution: Restoration of tissue
Repair/reorganisation: Decreased structural integrity forms a scar
What causes fever?
Pyrogens reset the temperature control system in the hypothalamus
How does the HPA axis cause illness?
Alters metabolism
Give 5 diseases where there is chronic inflammation
Arthritis, Alzheimers, Atherosclerosis, Dementia, Depression
Give 4 types of chronic inflammation
Chronic suppurative
Autoimmune
Non-specific
Granulomatous
Explain what happens in chronic suppurative inflammation
Why is it also acute?
Why is it hard to treat?
2 examples
Neutrophils are walled off by fibrin and surrounded by macrophages and fibroblasts
Acute inflammation due to neutrophils but a chronic condition
Hard to treat with antibiotics as poor blood supply –> surgery
e.g. Abscess or osteomyelitis
What cell indicates an inflammatory condition
Eosinophils
When does non-specific inflammation occur?
What is the characteristic of it?
What 2 cells does it contain?
After the initial inflammation due to a specific infection
No structure or obvious drive
Plasma cells and lymphocytes
Explain what gramulomatous is and what happens
What causes more damage?
Two examples of this
The immune systems response to agents which hare hard to destroy
Granulomas form around the agent
The host immune response causes more damage
TB, Chron’s
Give two ways how macrophages can have increased numbers of nuclei
Fusion of many
Replication without cytokinesis
What is the difference between Langerhan giant and Touton giant cells
Which is caused by chronic measles?
Langerhan giant: Nuclei in a line
Touton giant: Nuclei in a circle (measles)
What is the morphology of Warthin-Finkeldey cells?
What are they caused by?
Small dots in the nuclei or cytoplasm
Chronic measles
What does immunostaining identify?
How does it work?
Identifies cells by molecules not morphology
Uses histochemistry and antibody probes to make coloured images
What are the 4 receptors involved in the HIV infection?
gp120 (on HIV) binds to the CD4 receptor then the CCR5 co-receptor (on the host)
gp41 is also found on HIV
What are the 3 enzymes in HIV?
Reverse transcriptase
Integrase
Protease
What are the two stages of the HIV infection?
Primary infection: Virus localised at infection site then spread to lymph nodes causing CD4+ infection (esp in gut)
Secondary infection: Defects in gut mucus causes apoptosis and bystander killing of non-infected CD4+
Give 5 stereotypical HIV infections
Karposi’s sarcoma: Cancer caused by herpes (red nodules)
Pneumocytes pneumonia: Thick infiltrates in lungs
CNS toxoplasmosis
CMV retinitis: Necrosis and bleeding
Pneumocystis jiroveci: Fungus cysts in the alveoli
Treatment of pneumcystis jiroveci?
IV Trimethoprim
Sulphaethoxazole
Steroids
How are HIV resistance patterns measured?
PCR creates a profile which is compared to a database
Define quasi-species
Easily resistant as mutations are high
Define epitope
Proteins which initiate immune response
B and T cells can discriminate between these
Which antibodies are transferred via the mothers placenta and milk?
Placenta = IgG Milk = IgA
What are the two methods of giving a living vaccination
Naturally weakened (giving a related strain) Artificially weakened
What is the genome of the smallpox virus?
Double strand DNA virus
What is the genome of the polio virus?
Positive single strand RNA virus
Which vaccination (dead or alive) is better for transport? Which vaccination (dead or alive) is safer? (for who) Which vaccination (dead or alive) needs a booster? Which vaccination (dead or alive) is inactivated/attenuated? Which vaccination (dead or alive) produces which antibodies?
Dead is more stable for transport
Dead is safer for immunodeficient
Dead needs a booster
Dead is inactivated but living is attenuated
Dead produces IgG but living produces IgG and IgA
Define a subunit vaccination
What do they need?
Made from components of an organism
Need an adjuvant (increases the immune response)
2 reasons why there is not a vaccination for HIV?
Too many people with it
It cannot leave your body
Are fungi acellular or multicellular?
Both
How does mould grow?
Growth by filaments (hyphae) - asexual
Growth by spores - sexual
What is the most common yeast to cause human infection?
Candida albicans
How does yeast grow?
Reproduces by budding
Grows by pseudo-hyphae
Where does yeast live?
Lives in mucus membranes
Normal flora of the mouth and female GU tract
What is the prefix for diamorphic fungi?
Coccidiodes
How are diamorphic infections acquired?
What are the two stages of the infection?
Through spores
Early infection can last a while
Late can cause chronic lung infection and spread to organs
Define mycotoxins
Byproducts of fungi on food
Causes neurological, renal and hepatic problems
Define ergotism
Poisoning by eating food contaminated with an ergot
Give 2 other examples of superficial mycoses
Tinea pedia: Athlete’s foot
Baby’s bottom: urea damages the skin so fungi can easily penetrate
Define geophilic
Define zoophilic
Define anthrophilic
Geophilic: soil
Zoophilic: animal
Anthrophilic: insect
Explain the four levels of fungal infection?
Superficial mycoses: Ringworm/Tinea
Subcutaneous mycoses: Fungus invades bone, muscles, nerves and vessels –> amputation
Deep/systemic mycoses: Inhalation of spores –> blood
Mucormycoses: Brain
How do you diagnose fungal infections?
Yeast: Microscopy on culture plates (fast), PCR and antigen
Mould: Culture plates (slow), Antigen tests, Radio and histopathology
What temperature do you have conscious intelligence?
35-40C
What is the most reliable measure of temperature?
When is it used?
Oesophagus
ICU/Operations
What temperature do we measure?
CORE temperature
Why do elderly people struggle to shiver?
It requires increased oxygen and many have
pneumonia
Where in the body are temperature receptors found?
Conscious: Skin
Subconscious: Organs, GI tract, Great veins, Hypothalamus
What are the two pain neurones?
A delta (myelinated) C (unmyelinated)
What branch of the nervous system causes piloerection?
Sympathetic system
What are the two neuroendocrine controls of temperature?
Catecholamines –> increased metabolic rate –> heat increase
Thyroxine
What does acclimatisation do to the production of sweat?
Why is this a problem?
Increases production
Huge sodium loss
Define hypothermia
When is it severe?
Below 35C
Severe below 28C
Give an active treatment of hypo/hyperthermia?
Cardiac bypass to warm/cool the blood
Define PUO
Pyrexia of Unknown Origin