B1 - Physiology

• There are chemical and electrical synapses for communication between a neuron and another cell • Chemical synaptic transmission is mediated by neurotransmitter: – often produced in the presynaptic terminal – released in the synaptic cleft in a Ca2+ dependant manor, and – binds to postsynaptic receptors – Degraded/reuptaken and recycled • NT receptor activation results in the opening of channels that depolarise or hyperpolarise the postsynaptic membrane, thereby altering its excitabil

• Describe the sequence of events involved in skeletal muscle contraction starting from synaptic transmission at the neuromuscular junction to the shortening of the sarcomere. • Outline the key proteins involved in contraction and their role in the cross-bridge cycle • Recognise the role of Ca2+ in muscle contraction • Outline the different skeletal muscle types • Describe the mechanisms by which Ca2+ enters and exits skeletal and cardiac muscle cells, and explain how smooth muscle

Be cognisant of a few physical principles that relate flow, pressure, and velocity, among them Ohm’s law. Realise that arteries are cardiofugal and veins cardiopetal vessels. Know the notion of blood pressure Appreciate factors determining resistance, pressure, flow, and its characteristics Understand the distal impact of a resistance change Recognise why some vascular beds display different characteristics

understand the shape of the Hb saturation curve and know which factors modify it; appreciate resting and max. O2 consumption rates; be aware of where O2 and CO2 are metabolised; understand the O2 partial pressure in mitochondria; grasp how diffusion rates change along capillary; be aware of how CO2 is removed from periphery; recognise the central role of EC in CO2 removal; and be able to state the differences between O2 and CO2 saturation curves.