CZZ101 revision baby

• The cross bridge cycle occurs when actin binds to myosin
• thin filaments are composed of actin
• thick filaments are composed of myosin
• Cells of the innate immune system, such as macrophages, monocytes, neutrophils, eosinophils, basophils and natural killer cells
• Macrophages main function, monocytes leave the body and turn into macrophages, the remove- organisms and debris from blood and lymph , they are typically located in the liver, spleen, lymphnodes and bone marrow
• Neutrophils main function - is the most common white blood cell in the blood, it is a major phagocytic cell, which enters infected tissues from the blood, and only lasts a few hours.
• Natural killer cells - can kill cancer cells with MHC on their surface
• MHC is the major histocompatibility complex
• The MHC complex signals to the immune system when a cell is infected. The cell kills by releasing perforin which crates perforations in the cell membrane. This allows for the entry of grazymes to enter which leads to apoptosis
• Mast cells are non motile
• Mast cells are involved in allergy response, releasing large amounts of histamines when allergens is contacted.
• Eosinophils are relatively rare
• Eosinophils are involved in damage to airways and control parasitic infections
• Neuromuscular junction


  Nerve synapse between the nerve terminal and a specialised area of muscle cell membrane (motor endplate)
• Stimulation of muscle fibres

  1. Action potential reaches the nerve terminal

  2. Causes the release of the neurotransmitter acetylcholine

  3. Acetylcholine binds to nicotinic receptors (ligand-gated ion channels) on the end plate

  4. Nicotinic receptors bind to the acetylcholine which causes them to open and allows the Sodium ions to depolarises the inside and reduces the end plate potential

  5. Action potential is generated in the muscle cell only when the end plate potential threshold is reached to be able to created sodium-gated channels outside of the cell

  6. Voltage gated potassium channels open for the K to move out

  7. Action potential spreads, to voltage gated channels, it also runs deep into the fibre via t-tubules to reach the sarcoplasmic reticulum, which releases calcium
• Somatic nervous system consists of the - skeletal muscle
• Autonomic nervous system consists of the - smooth and cardiac muscle
• PNS - nerves projecting to different parts of the body
• The functional unit of the nervous system is the neuron
• Neuron

  • the neuron receives information from its surroundings via the dendrites
  • The soma or the cell body then integrates this Information
  • Once it has been integrated it propagates along the axon
  • Once it reaches the axon terminal it is able to pass on information to other cells or neurons
• Nociceptors - are pain receptors (the detect pain)
• Epithelial tissue can NOT detect pressure
• Layers of the epithelial tissue

  Stratum Corneum - stratum lucidium (only in thick skin) - stratum granulosum - stratum spinosum - stratum basal
• Blood type O is the universal donor
• blood type A can receive blood types A&O
• blood type B can receive blood types B &O
• The sequence of events in haemostasis

  Vasoconstriction (vessel spasm) - Platelet plug formation - Coagulation - Clot retraction and Clot dissolution
• Acquired immune response is coordinated by Helper T cells
• The antibody responsible for protecting us against bacteria and virus, in the secondary or late innate response is IgG
• Unbroken skin is NOT a part of the innate immune response
• Macrophages express MHC-II) on their surface
• A patient with an immune deficiency experiencing reoccurring infections is likely to have a T-lymphocyte defect
• The most abundant protein in normal blood plasma is Albumin
• The most abundant protein within the hyalin cartilage matrix is Type II collagen
• Elastic cartilage can be found in the core of the external ear
• The small channels that run within the cytoplasmic processes of osteocytes is called lacunae
• Osteoclasts brake down bone, which releases calcium and phosphate
• Osteoclasts can be found in the lacunae between lamellae
• Irregular bone example - vertebrae, scapula.
• Axial skeleton - skull, ribs, sternum