Random Question Generator for Revision MSA Flashcards
What are the chemical barriers to infection belonging to the innate immune response
-Fatty Acids on skin
-Low pH of stomach
-Secretion of antibacterial peptides like defensins (in gut and skin) and cryptidins ( in gut)
What are the mechanical barriers to infection belonging to the innate immune response?
-Air and fluid flow across epithelium
-Movement of mucus by cilia
-Tight junctions between cells
What compounds are present in eosinophils granules?
-Histamines, RNases, DNases, peroxide, Major Basic Protein, lipase and plasminogen
What are Gap junctions?
What’s their structure?
Site of low electrical resistance that electrically links cardiomyocytes(allowing diffusion of ions) so they contract simultaneously.
They are composed of 6 connexons subunits
What is the role of junctions in smooth muscle structure
Gap junctions electrically links cells
Focal adhesions structurally links cells
Describe muscle development
Embryonic mesoderm cells called myoblasts proliferate and enlarge.
Myoblasts then fuse together forming myotube.
Myotube matures and becomes a skeletal muscle fiber
Name and describe the supporting proteins of sarcomere
Alpha actinin- maintains actin in place attaching it to Z disks
Titin- Involved in recoil of muscle
Nebulin- provides structural and regulatory support to actin
Dystrophin- maintains integrity of muscle. Stabilizes muscle during contraction to avoid injury or damage
Describe structure of myosin
Made up of:
- 2 interwined chains of MHC
-2 light chains of MLC-1 that sustain myosin head
-2 light chains of MLC-2 that regulates ATPase activity of myosin
Describe the process of Calcium release for contraction
-When depolarisation travel down T tubules, the DHPR located in the T tubules membrane changes conformation and associates with the Ryanodine receptor of the SR.
-The Ryanodine receptor opens, allowing outflow of calcium ions out of the Sarcoplasmic Reticulum.
-Calcium ions then bind to TnC which will expose the actin-myosin binding sites.
Describe the properties of SERCA
What is the role of calsequestrin in muscle relaxation
SERCA is Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase. It pumps intracellular calcium ions back into the Sarcoplasmic reticulum after contraction of muscle. 2 Ca 2+ in SR per ATP.
Calsequestrin binds to Calcium ions at high concentrations and releases it at low intracellular concentrations. It acts as a calcium store during relaxation. It binds to 43 Calcium ions per molecule of calsequestrin.
Aside from SERCA and Calsequestrin what other proteins are involved in cardiac muscle relaxation.
Calcium-Sodium exchanger- Pumps 3 Na+ into cell for every 1 Ca2+ out.
Na+/K+ pump which brings the cell to resting potential, preventing the unwanted depolarisation of cell after so much Na+ is pumped in.
Name the roots that supply each terminal nerve
Musculocutaneous nerve- C5,C7
Axillary nerve-C5,C6
Median nerve-C6-T1
Radial nerve- C5-T1
Ulnar nerve C7-T1
Formation of creatinine phosphate
How does creatine phosphate provide ATP?
-ATP+ creatinine= Creatine phophate+ ADP
-Creatine Phosphate+ ADP= creatinine kinase= creatine +ATP
Craetine phosphate has a slightly higher energy level than ATP, so it gives off phophate groups more readily
Muscle fibre types and properties
-Slow Oxidative(Type Ia fibres): slow myosin ATPase activity, high oxidative capacity
-Fast oxidative-glycolytic(Type IIa) fibres: fast mATPase activity, intermediate, high oxidative capacity, intermediate glycolytic capacity
-Fast-glycolytic(type IIb/IIx fibres): fasr myosin ATPase activity, fast glycolytic capacity
Difference muscle tension and load
Muscle tension- force exerted by a contracting muscle
Load- force exerted by an object to be moved
Regulating factors of smooth muscle contraction
-Spontaneous electrical activity from pacemaker cells
-Ion concentration
-Acidity
-Stretch
-Hormones
4 muscles of pectoral region and their innervation
-Subclavius- innervated by subclavius nerve( C5 and C6)
-Pectoralis Major- innervated by median pectoral nerve (C8, T1) and lateral pectoral nerve(C5,C6,C7)
-Pectoralis minor- innervated by median pectoral nerve (C8,T1)
-Serratus anterior- innervated by Long thoracic nerve( C5,C6,C7)
Function of the 4 muscles of pectoral region
-Subclavius- moves clavicle
-Pectoralis major- moves humerus
-Pectoralis minor and serratus anterior- move scapula
What drugs can inhibit ACh release?
-Local Anesthetics
-Calcium inhibitors like Magnesium ions and antibiotics that bind to calcium like gentrimicin and tetracycline
-Neurotoxins like botulinum toxin and beta-bungarotoxin.
When can NMJ blocking drugs be used?
-Endotracheal intubation
-During operative procedures to ensure immobility- general anaesthetics
-In intensive care when patient placed on mechanical ventilator
-in electroconvulsive therapy
Action of non-depolarising blockers and example
They are AChR antagonists
-Binds to ACh receptors causing it to remain closed. ACh can’t bind
-Decreases the End Plate potential
-Decrease the depolarisation of motor end plate region
-No action potential generated in muscle as threshold not reached
Examples: atracurium(medium onset, medium duration), rocurorium( fast onset, medium duration)
Action of depolarising blockers and example
They are AChr agonists
-Binds to ACh receptor, triggering influx of Na+ and allowing depolarisation
-Persistent depolarisation of motor end plate
-Prolonged End Plate Potential and depolarisation of muscle
-Membrane reaches threshold
-Sodium channels remain refractory- electrically inactive
-More action potentials can’t be generated.
Example: suxamethonium( fast onset, slow duration)
Name the NMJ depolarising drugs, their onset and duration.
Which of these are aminosteroidal, and which are benzylisoquiolinium?
Pancuronium: medium, long
Vecuronium;medium, medium
Rocurorium: fast, medium
Atracurium: medium,medium
Mivacurium: Fast, short
Suxamethonium: Fast, short
P,V,R are aminosteroidal. A and M are benzylisoquiolinium
What can kinetic energy be transformed into?
Light, chemical, sound and heat energies