Week 8 - Pneumonia Flashcards
what happens to sympathetic innervation in high core body temperatures?
Sympathetic innervation is decreased, reducing the vasomotor tone in the AVAs.
More blood flows through the AVAs and reaches the superficial venous plexus (near the skin’s surface). This increases heat loss and reduces core temperature.
what happens to sympathrtic innervation in low core body temperatures?
Sympathetic innervation is increased, increasing the vasomotor tone in the AVAs.
Less blood flows to the apical skin (of nose, lips, ears, hands and feet). This reduces heat loss and increases the core temperature.
what medications can be used to manage pyrexia?
paracetamol
NSAIDs
what adverse effects does paracetamol have?
few
in overdose it can cause liver failure so dose should be reduced if patient has liver toxicity
what is the action of paracetamol?
weak COX inhibitor
COX is involved in prostaglandin metabolism
what is the action of NSAIDs?
inhibits prostaglandin synthesis from arachidonic acid by inhibiting COX
what are the adverse of effects of NSAIDs?
GI toxicity
renal impairment
increased risk of CV events
high BP
headaches + dizziness
when should NSAIDs be avoided?
severe renal impairement
heart failure
liver failure
what are the types of polymorphonuclear leukocytes?
AKA granulocytes
Neutrophils
Eosinophils
Basophils
Mast cells
what is the innate immune system?
the cells don’t need to learn to recognise the invaders, they attack anything that the body considers foreign
what is the acquired immune response?
specialised immune cells learn to recognise specific invaders
what is the function of neutrophils?
- First-line defence against bacteria, viruses and fungal infections
Tissue injury → body release chemotactic factors to attract neutrophils
what is the function of eosinophils?
- Involved in allergic reactions & also fight parasitic infections
- High levels of eosinophils can result from other conditions → including drug reactions or immune system disorders like eosinophilic esophagitis
what is the function of basophils?
- Involved in allergic reactions
- Also secrete histamine and other compounds that cause inflammation
- Basophils → the bloodborne equivalent of mast cells
what is the function of mast cells?
- Live in tissues and play an important role in respiratory and digestive conditions
- Two major subtypes:
○ Connective tissue mast cells → trigger inflammation
○ Mucosal mast cells → keep the gut in balance - Histmaine and other substances within these PMNs (such as heparin) help regulate the immune response
- Two major subtypes:
what is the difference between M1 and M2 macrophages?
- M1 → aka classically-activate macrophages. Activate by pathogen invasion and play a large role in the immune response to foreign pathogens e.g. bacteria
detect, engulf and destroy bacteria. They do this through phagocytosis.
○ Phagocytosis → process by which cells ingest or engulf other cells or particles
○ M1 macrophrages promote inflammation, extracellular matrix destruction, apoptosis of invading cells by releasing various cytokines and nitric oxide to aid in cellular destruction, as well as antigen presentation- M2 → aka alternatively-activated macrophages. Play a role in wound healing, tissue repair, and have an anti-inflammatory role
needed for regeneration of connective tissue during wound healing.
○ Produce vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-Β1 which allows for vascular stability and wound repair
○ Also function to phagocytose bacteria and damaged tissue around the wound
- M2 → aka alternatively-activated macrophages. Play a role in wound healing, tissue repair, and have an anti-inflammatory role
what are the 5 clinical signs of inflammation?
pain
heat
redness
swelling
loss of fucntion
what factors can stimulate an acute inflammatory response?
- Microorganisms (viruses and bacteria)
- Physical agents
- Chemicals
- Inappropriate immunological responses (autoimmune responses)
Tissue death
what causes heat in inflammation?
- Immune system releases inflammatory mediators such as bradykinin and histamine.
- Blood vessels in the injured tissue vasodilate.
More blood flow leads to the area becoming inflamed (swelling), red, and hot.
what is the cause of pain in inflammation?
- Increased blood flow to injured area results in inflammation
- Release of both histamines and bradykinin triggers neurons to send pain signals to the brain
- Injured area feels painful
what is tissue repair?
restoration of tissue architecture and function after an injury. This is a process that involves both of the below two processes, and the predominance of one over the other depends on the site of injury, extent of damage, and the tissue that needs to be repaired.
what is tissue regeneration?
where new growth completely restores portions of damaged tissue to their normal state. replacing damaged cells functioning identical copies
what is labile tissue? give examples
continuously dividing tissue
e.g. bone marrow cells, skin, hair, GIT epithelium
what is stable tissue? give examples?
quiescent tissue
non-dividing but are capable of entering the cell cycle and replicating again
e.g. parenchymal liver, kidney, pancreas cells, lymphocytes
what are permanent tissues? give examples
consist of cells that dont proliferate anymore
e.g. RBC, cardiac muscle, skeletal muscle, neurones
what does gram -ve bacteria stain like?
pink
what does gram +ve bacteria stain like?
purple
which bacteria type has a thicker peptidoglycan wall?
gram +ve