The document defines arterial blood pressure and its components: systolic, diastolic, pulse, and mean arterial pressure. It discusses factors that regulate blood pressure, including the nervous system's vasomotor center and reflexes, the kidneys' regulation of fluid volume and renin-angiotensin system, and hormonal factors. It also covers hypertension and hypotension, defining each and describing primary vs. secondary causes, manifestations, and treatment approaches.
1) The document discusses the rhythmicity and automaticity of the heart, which refers to the heart's ability to beat regularly and generate impulses without external stimuli.
2) It originates from within the heart itself (myogenic, not neurogenic) and several factors can influence the heart rate such as the autonomic nervous system, temperature, drugs, blood gases, and inorganic ions.
3) The sinoatrial node acts as the pacemaker for the heart and has membrane properties that allow it to spontaneously depolarize, initiating the heartbeat via an action potential involving sodium, calcium, and potassium ion fluxes.
DNA replication is the process whereby a cell makes an identical copy of its DNA before cell division. It ensures faithful inheritance of genetic material during cell division. DNA replication is semi-conservative and bidirectional, occurring simultaneously on both strands of the DNA double helix to produce two identical copies. It involves unwinding of the DNA double helix by helicase, synthesis of new strands by DNA polymerases along leading and lagging strands using existing strands as templates, and ligation of fragments by DNA ligase. DNA replication is tightly regulated during the S phase of the cell cycle and is essential for accurate transmission of genetic information from parent to daughter cells.
The document summarizes key aspects of neurons and nerve impulses. It describes the basic structure and function of neurons, including dendrites that receive signals, axons that conduct signals, and axon endings that relay signals to other neurons or effector cells. It explains how nerve impulses are generated and conducted via changes in sodium and potassium ion concentrations, and how myelin sheaths allow faster signal transmission. Chemical synapses are described, where action potentials trigger neurotransmitter release that can generate new action potentials in receiving neurons. Several types of neurotransmitters are also listed.
The document discusses various aspects of protein structure, including:
1) Proteins have primary, secondary, tertiary, and quaternary levels of structure that determine their shape and function.
2) Secondary structures like alpha helices and beta sheets involve hydrogen bonding between amino acids in the protein chain.
3) Tertiary structure refers to a protein's final 3D shape after folding. Quaternary structure involves interactions between protein subunits.
4) Techniques like X-ray crystallography and NMR spectroscopy can be used to determine protein structures at high resolutions.
DNA replication is the process where a cell makes an identical copy of its DNA before cell division. It involves unwinding the DNA double helix into single strands, and using DNA polymerase to add complementary nucleotides to each strand to make two new double helix DNA molecules. It is semiconservative, starting at the origin of replication and proceeding bidirectionally. The leading strand is synthesized continuously while the lagging strand makes short Okazaki fragments that are later joined. DNA replication occurs with high fidelity to maintain genetic integrity as cells divide.
1) The cardiac cycle describes the events of one complete heartbeat, including atrial contraction, ventricular contraction and relaxation.
2) The cardiac cycle begins with mid-to-late diastole as blood flows into the ventricles, followed by ventricular systole where the ventricles contract and push blood out.
3) Cardiac output is the amount of blood pumped by the heart per minute and is calculated by multiplying heart rate by stroke volume, which is the amount of blood pumped per ventricular contraction.
The document defines arterial blood pressure and its components: systolic, diastolic, pulse, and mean arterial pressure. It discusses factors that regulate blood pressure, including the nervous system's vasomotor center and reflexes, the kidneys' regulation of fluid volume and renin-angiotensin system, and hormonal factors. It also covers hypertension and hypotension, defining each and describing primary vs. secondary causes, manifestations, and treatment approaches.
1) The document discusses the rhythmicity and automaticity of the heart, which refers to the heart's ability to beat regularly and generate impulses without external stimuli.
2) It originates from within the heart itself (myogenic, not neurogenic) and several factors can influence the heart rate such as the autonomic nervous system, temperature, drugs, blood gases, and inorganic ions.
3) The sinoatrial node acts as the pacemaker for the heart and has membrane properties that allow it to spontaneously depolarize, initiating the heartbeat via an action potential involving sodium, calcium, and potassium ion fluxes.
DNA replication is the process whereby a cell makes an identical copy of its DNA before cell division. It ensures faithful inheritance of genetic material during cell division. DNA replication is semi-conservative and bidirectional, occurring simultaneously on both strands of the DNA double helix to produce two identical copies. It involves unwinding of the DNA double helix by helicase, synthesis of new strands by DNA polymerases along leading and lagging strands using existing strands as templates, and ligation of fragments by DNA ligase. DNA replication is tightly regulated during the S phase of the cell cycle and is essential for accurate transmission of genetic information from parent to daughter cells.
The document summarizes key aspects of neurons and nerve impulses. It describes the basic structure and function of neurons, including dendrites that receive signals, axons that conduct signals, and axon endings that relay signals to other neurons or effector cells. It explains how nerve impulses are generated and conducted via changes in sodium and potassium ion concentrations, and how myelin sheaths allow faster signal transmission. Chemical synapses are described, where action potentials trigger neurotransmitter release that can generate new action potentials in receiving neurons. Several types of neurotransmitters are also listed.
The document discusses various aspects of protein structure, including:
1) Proteins have primary, secondary, tertiary, and quaternary levels of structure that determine their shape and function.
2) Secondary structures like alpha helices and beta sheets involve hydrogen bonding between amino acids in the protein chain.
3) Tertiary structure refers to a protein's final 3D shape after folding. Quaternary structure involves interactions between protein subunits.
4) Techniques like X-ray crystallography and NMR spectroscopy can be used to determine protein structures at high resolutions.
DNA replication is the process where a cell makes an identical copy of its DNA before cell division. It involves unwinding the DNA double helix into single strands, and using DNA polymerase to add complementary nucleotides to each strand to make two new double helix DNA molecules. It is semiconservative, starting at the origin of replication and proceeding bidirectionally. The leading strand is synthesized continuously while the lagging strand makes short Okazaki fragments that are later joined. DNA replication occurs with high fidelity to maintain genetic integrity as cells divide.
1) The cardiac cycle describes the events of one complete heartbeat, including atrial contraction, ventricular contraction and relaxation.
2) The cardiac cycle begins with mid-to-late diastole as blood flows into the ventricles, followed by ventricular systole where the ventricles contract and push blood out.
3) Cardiac output is the amount of blood pumped by the heart per minute and is calculated by multiplying heart rate by stroke volume, which is the amount of blood pumped per ventricular contraction.
The document summarizes key aspects of nerve impulse propagation. It describes neurons as the basic unit of the nervous system that transmit electrical or chemical impulses. It discusses the structure of neurons including the cell body, dendrites, myelin sheath, Schwann cells, and nodes of Ranvier. The presence of myelin speeds up impulse transmission along axons via saltatory conduction. Neurons are classified anatomically based on their structure and functionally based on their sensory, motor, or interneuron roles. Properties of nerve fibers that are described include excitability, conductivity, refractory period, all-or-none law, rheobase, and chronaxie.
The cardiac cycle describes the repeating sequence of events in the heart during one heartbeat. It begins with atrial systole which fills the ventricles with blood. This is followed by ventricular systole where the ventricles contract and eject blood out of the heart. The cardiac cycle is regulated by the heart's conduction system which coordinates the contractions of the atria and ventricles. It ensures the atria contract before the ventricles so blood is pumped efficiently through the heart and circulatory system with each heartbeat.
Cardiac innervation seminar by Dr Manish Ruhela, SMS Medical College,jaipurmanishdmcardio
The document discusses the innervation of the heart. It notes that the heart receives nerve supply from the cardiac plexus, formed by sympathetic and parasympathetic fibers. The sympathetic fibers originate from the spinal cord and travel through the sympathetic trunk. They have long postganglionic fibers. The parasympathetic fibers originate from the brainstem and travel through the vagus nerve. They have short postganglionic fibers and more localized effects. Baroreceptors in the carotid sinus and aortic arch detect blood pressure changes and trigger the baroreceptor reflex to maintain blood pressure homeostasis.
Blood pressure is regulated through both short-term and long-term mechanisms. Short-term regulation involves neural mechanisms like the autonomic nervous system and baroreceptor reflexes which sense changes in blood pressure and heart rate. It also involves vascular mechanisms like changes in capillary fluid and stress relaxation as well as hormonal mechanisms like catecholamines and renin-angiotensin system. Long-term regulation is controlled by the kidneys and renal mechanisms as well as hormones like aldosterone, ADH, ANP and the renin-angiotensin-aldosterone system. Together these mechanisms tightly control blood pressure and ensure adequate perfusion to tissues.
The document discusses the cardiac cycle, cardiac blood flow, and the intrinsic conduction system of the heart. It explains that the sinoatrial node initiates impulses that travel through the atrioventricular node and bundle of His to stimulate ventricular contraction. It also reviews factors that influence stroke volume and cardiac output, such as preload, contractility, and the autonomic nervous system.
Cardiac muscle (The Guyton and Hall Physiology)Maryam Fida
In the heart there is Atrial muscle and Ventricular muscle which are separated from each other by the fibrous AV Rings containing Valves.
ATRIAL MUSCLE: thin walled. There are two sheets, superficial and deep sheet. Superficial sheet is common over both atria. Deep sheet is separate for each atrium. Muscle fibers in the deep sheet are at right angle to the muscle fibers in the superficial sheet.
FUNCTIONS OF THE ATRIUM:
1. Receive venous blood from large veins. So atria act as reservoir.
2. Conduct the blood into the ventricles.
3. Atrial contraction is responsible for last 25 % of ventricular filling.
4. In the right atrium there is SA Node(Pace maker) and AV node.
5. In the wall of the atria, there are low pressure stretch receptors and these are involved in various reflexes like brain bridge reflex and left atrial reflex.
6. Atria also produce a hormone i.e. Atrial Natriuretic Hormone. Whenever NaCl increases in ECF, it causes release of ANH which causes natriuresis.
VENTRICULAR MUSCLE:
Much thicker than atrial muscle. Thickness of right ventricle wall is 3-4 mm and thickness of left ventricle is 8 – 12 mm.
1.Involuntary
2.Has cross striations
3.Each cardiac muscle fiber consists of a number of cardiac cells, united at ends in series. Where as in skeletal muscle each muscle fiber is individual cell.
4.Cardiac muscle cells are branching and interdigitate.
5.Single central nucleus in each cell.
6. Atrial muscle and ventricular muscle act as separate functional syncytium and impulses from atria are conducted to ventricles through the AV Node and AV Bundle.
7. Sarcoplasmic system is present. In skeletal muscle triad is at the junction of A and I bands. In cardiac muscle T Tubules are much large and thus in cardiac muscle if we take a section it may form a diad or a triad. And these diads and triads are present at the level of Z Disks.
8.Between adjacent cardiac cells there are side to side and end to end connections and these are the intercellular junctions. These junctions are Gap Junctions. Or intercalated discs
9.When one part of myocardium is excited the whole muscle is excited.
10.Whole myocardium obeys all or none law as a whole.
11.No spike potential but action potential with plateau.
12.Has got long refractory period.
Absolute refractory period in ventricular muscle is 250 – 300 milli sec.
In atrial muscle Absolute refractory period is 150 milli sec
Because of long refractory period cardiac muscle cannot be tetanized.
The document provides an overview of the physiology of the autonomic nervous system (ANS). It discusses the history and definitions of the ANS, as well as the anatomy and functions of the sympathetic and parasympathetic nervous systems. Specifically, it describes how the sympathetic nervous system is involved in the "fight or flight" response while the parasympathetic nervous system governs "rest and digest" functions. It also summarizes the autonomic innervation of the heart.
This document discusses and compares chemical and electrical synapses. It defines a synapse as a junction between two neurons. There are three types of synapses: chemical, electrical, and conjoint. Chemical synapses use neurotransmitters for impulse transmission across the synaptic cleft in one direction, while electrical synapses have direct connections through gap junctions that allow for faster two-way transmission. Key differences are that chemical synapses exhibit synaptic properties and delay, while electrical synapses do not.
The autonomic nervous system maintains homeostasis and contains efferent and afferent fibers that supply visceral organs, muscles and blood vessels. It has two divisions - the sympathetic and parasympathetic systems. The sympathetic system activates the fight or flight response and includes ganglia that extend from the spinal cord into the trunk. The parasympathetic system causes localized responses and has cranial and sacral outflows that target the head, neck and pelvic regions respectively. Both systems contain two neurons and have different effects on target organs.
Neuroglia, also known as glial cells, provide support and insulation to neurons in the central and peripheral nervous systems. There are two main types of neuroglia: microglia and macroglia. Microglia are small phagocytic cells found throughout the central nervous system, while macroglia include astrocytes, oligodendrocytes, Schwann cells, and other larger glial cells. Astrocytes help form the blood-brain barrier and regulate neurotransmitters. Oligodendrocytes and Schwann cells are responsible for myelination in the central and peripheral nervous systems respectively. Nerve fibers have properties like excitability, conductivity, following the all-or-none principle, and
1. The document describes the ascending tracts of the spinal cord which transmit sensory information to the brain. It discusses tracts like the lateral and anterior spinothalamic tracts that carry pain, temperature and touch sensations and the posterior white columns that carry proprioceptive information.
2. It provides details on the neurons involved in transmitting sensory information from the receptors via the spinal cord to the thalamus and sensory cortex. It includes a diagram of the sensory homunculus map in the cortex.
3. The tracts transmit different sensory modalities and project to different areas of the brain like the thalamus, cerebellum and reticular formation to process sensory information and maintain consciousness.
This document provides an overview of the contractile mechanism of smooth muscle. It discusses:
1. The physical basis of smooth muscle contraction including the arrangement of actin and myosin filaments.
2. The chemical basis being similar to skeletal muscle but without a troponin complex.
3. Key differences from skeletal muscle including slower cycling of myosin cross-bridges, lower energy requirements, and a "latch mechanism" allowing prolonged contraction.
4. The role of calcium ions and proteins like calmodulin in activating phosphorylation of the myosin head and initiating contraction.
Neurons communicate with each other via electrical and chemical signals. At the synapse, an electrical signal in the presynaptic neuron causes it to release neurotransmitters like acetylcholine or glutamate. These chemicals bind to and open ion channels in the postsynaptic neuron, generating an electrical signal there. This transmission allows neurons to form complex communication networks and coordinate the functions of the nervous system.
Nervous control of blood vessels regulation of arterial pressureAmen Ullah
The main function of the circulatory system is to give local blood flow to the tissue. There arespecial need of the tissue which is:
delivery of oxygen to the tissue
delivery of nutrients to the tissue
removal of carbon dioxide from tissue
maintaining of normal concentration of ions
transform of hormones and other substance to tissue
The resting membrane potential of neurons and muscle cells is maintained around -70 mV due to selective permeability of ions across the cell membrane. The sodium-potassium pump actively transports 3 Na+ ions out and 2 K+ ions into the cell, contributing to the negative interior potential. When the membrane potential reaches the threshold, voltage-gated sodium channels open rapidly, causing a sharp depolarization as sodium ions rush in. Subsequently, voltage-gated potassium channels open more slowly, repolarizing the membrane as potassium ions efflux from the cell. This generates an action potential that propagates by local current flow between adjacent areas of the membrane. The sodium-potassium pump then restores ion gradients in preparation for the next action potential
The document discusses synaptic transmission in the central nervous system. It describes the cellular organization of the brain including neurons and support cells. It then focuses on synapses, explaining that they allow chemical communication between neurons through neurotransmitters. There are two main types of synapses - electrical synapses which allow direct electrical coupling, and chemical synapses which use chemical messengers. Chemical synapses are more numerous and involve neurotransmitters being released into the synaptic cleft, binding to receptors and causing excitation or inhibition of the postsynaptic neuron. The properties of synaptic transmission include one-way conduction, synaptic delay, fatigue, convergence and divergence, summation, and facilitation.
Anatomy & physiology of the Autonomic nervous systemRafid Rashid
Provides a good description of the anatomy & physiology of the autonomic nervous system for undergraduate medical students. It goes over the parts & functions of the sympathetic & parasympathetic nervous system respectively & compares the differences between them.
1) A synapse is a junction that transmits signals between neurons. It contains a presynaptic terminal that releases neurotransmitters and a postsynaptic membrane with receptors.
2) When an action potential reaches the presynaptic terminal, calcium ions enter and cause neurotransmitter vesicles to fuse and release their contents across the synaptic cleft.
3) Neurotransmitters bind to and open ion channels on the postsynaptic membrane, producing an electrical effect that may trigger another action potential.
This document provides an overview of membrane potentials and resting membrane potential by Dr. Rashid Mahmood. It defines key terms like excitation, stimulus, and excitable tissues. It explains that the Nernst potential is the diffusion potential level that opposes net ion diffusion through a membrane. Diffusion potentials are +61 mV for sodium and -94 mV for potassium. The Goldman equation is used to calculate diffusion potential when multiple ions are involved. The resting membrane potential of large myelinated nerve fibers is approximately -90 mV, contributed to by the potassium diffusion potential of -94 mV, sodium diffusion potential of +61 mV, and the sodium-potassium pump of -4 mV.
The document summarizes key aspects of nerve impulse propagation. It describes neurons as the basic unit of the nervous system that transmit electrical or chemical impulses. It discusses the structure of neurons including the cell body, dendrites, myelin sheath, Schwann cells, and nodes of Ranvier. The presence of myelin speeds up impulse transmission along axons via saltatory conduction. Neurons are classified anatomically based on their structure and functionally based on their sensory, motor, or interneuron roles. Properties of nerve fibers that are described include excitability, conductivity, refractory period, all-or-none law, rheobase, and chronaxie.
The cardiac cycle describes the repeating sequence of events in the heart during one heartbeat. It begins with atrial systole which fills the ventricles with blood. This is followed by ventricular systole where the ventricles contract and eject blood out of the heart. The cardiac cycle is regulated by the heart's conduction system which coordinates the contractions of the atria and ventricles. It ensures the atria contract before the ventricles so blood is pumped efficiently through the heart and circulatory system with each heartbeat.
Cardiac innervation seminar by Dr Manish Ruhela, SMS Medical College,jaipurmanishdmcardio
The document discusses the innervation of the heart. It notes that the heart receives nerve supply from the cardiac plexus, formed by sympathetic and parasympathetic fibers. The sympathetic fibers originate from the spinal cord and travel through the sympathetic trunk. They have long postganglionic fibers. The parasympathetic fibers originate from the brainstem and travel through the vagus nerve. They have short postganglionic fibers and more localized effects. Baroreceptors in the carotid sinus and aortic arch detect blood pressure changes and trigger the baroreceptor reflex to maintain blood pressure homeostasis.
Blood pressure is regulated through both short-term and long-term mechanisms. Short-term regulation involves neural mechanisms like the autonomic nervous system and baroreceptor reflexes which sense changes in blood pressure and heart rate. It also involves vascular mechanisms like changes in capillary fluid and stress relaxation as well as hormonal mechanisms like catecholamines and renin-angiotensin system. Long-term regulation is controlled by the kidneys and renal mechanisms as well as hormones like aldosterone, ADH, ANP and the renin-angiotensin-aldosterone system. Together these mechanisms tightly control blood pressure and ensure adequate perfusion to tissues.
The document discusses the cardiac cycle, cardiac blood flow, and the intrinsic conduction system of the heart. It explains that the sinoatrial node initiates impulses that travel through the atrioventricular node and bundle of His to stimulate ventricular contraction. It also reviews factors that influence stroke volume and cardiac output, such as preload, contractility, and the autonomic nervous system.
Cardiac muscle (The Guyton and Hall Physiology)Maryam Fida
In the heart there is Atrial muscle and Ventricular muscle which are separated from each other by the fibrous AV Rings containing Valves.
ATRIAL MUSCLE: thin walled. There are two sheets, superficial and deep sheet. Superficial sheet is common over both atria. Deep sheet is separate for each atrium. Muscle fibers in the deep sheet are at right angle to the muscle fibers in the superficial sheet.
FUNCTIONS OF THE ATRIUM:
1. Receive venous blood from large veins. So atria act as reservoir.
2. Conduct the blood into the ventricles.
3. Atrial contraction is responsible for last 25 % of ventricular filling.
4. In the right atrium there is SA Node(Pace maker) and AV node.
5. In the wall of the atria, there are low pressure stretch receptors and these are involved in various reflexes like brain bridge reflex and left atrial reflex.
6. Atria also produce a hormone i.e. Atrial Natriuretic Hormone. Whenever NaCl increases in ECF, it causes release of ANH which causes natriuresis.
VENTRICULAR MUSCLE:
Much thicker than atrial muscle. Thickness of right ventricle wall is 3-4 mm and thickness of left ventricle is 8 – 12 mm.
1.Involuntary
2.Has cross striations
3.Each cardiac muscle fiber consists of a number of cardiac cells, united at ends in series. Where as in skeletal muscle each muscle fiber is individual cell.
4.Cardiac muscle cells are branching and interdigitate.
5.Single central nucleus in each cell.
6. Atrial muscle and ventricular muscle act as separate functional syncytium and impulses from atria are conducted to ventricles through the AV Node and AV Bundle.
7. Sarcoplasmic system is present. In skeletal muscle triad is at the junction of A and I bands. In cardiac muscle T Tubules are much large and thus in cardiac muscle if we take a section it may form a diad or a triad. And these diads and triads are present at the level of Z Disks.
8.Between adjacent cardiac cells there are side to side and end to end connections and these are the intercellular junctions. These junctions are Gap Junctions. Or intercalated discs
9.When one part of myocardium is excited the whole muscle is excited.
10.Whole myocardium obeys all or none law as a whole.
11.No spike potential but action potential with plateau.
12.Has got long refractory period.
Absolute refractory period in ventricular muscle is 250 – 300 milli sec.
In atrial muscle Absolute refractory period is 150 milli sec
Because of long refractory period cardiac muscle cannot be tetanized.
The document provides an overview of the physiology of the autonomic nervous system (ANS). It discusses the history and definitions of the ANS, as well as the anatomy and functions of the sympathetic and parasympathetic nervous systems. Specifically, it describes how the sympathetic nervous system is involved in the "fight or flight" response while the parasympathetic nervous system governs "rest and digest" functions. It also summarizes the autonomic innervation of the heart.
This document discusses and compares chemical and electrical synapses. It defines a synapse as a junction between two neurons. There are three types of synapses: chemical, electrical, and conjoint. Chemical synapses use neurotransmitters for impulse transmission across the synaptic cleft in one direction, while electrical synapses have direct connections through gap junctions that allow for faster two-way transmission. Key differences are that chemical synapses exhibit synaptic properties and delay, while electrical synapses do not.
The autonomic nervous system maintains homeostasis and contains efferent and afferent fibers that supply visceral organs, muscles and blood vessels. It has two divisions - the sympathetic and parasympathetic systems. The sympathetic system activates the fight or flight response and includes ganglia that extend from the spinal cord into the trunk. The parasympathetic system causes localized responses and has cranial and sacral outflows that target the head, neck and pelvic regions respectively. Both systems contain two neurons and have different effects on target organs.
Neuroglia, also known as glial cells, provide support and insulation to neurons in the central and peripheral nervous systems. There are two main types of neuroglia: microglia and macroglia. Microglia are small phagocytic cells found throughout the central nervous system, while macroglia include astrocytes, oligodendrocytes, Schwann cells, and other larger glial cells. Astrocytes help form the blood-brain barrier and regulate neurotransmitters. Oligodendrocytes and Schwann cells are responsible for myelination in the central and peripheral nervous systems respectively. Nerve fibers have properties like excitability, conductivity, following the all-or-none principle, and
1. The document describes the ascending tracts of the spinal cord which transmit sensory information to the brain. It discusses tracts like the lateral and anterior spinothalamic tracts that carry pain, temperature and touch sensations and the posterior white columns that carry proprioceptive information.
2. It provides details on the neurons involved in transmitting sensory information from the receptors via the spinal cord to the thalamus and sensory cortex. It includes a diagram of the sensory homunculus map in the cortex.
3. The tracts transmit different sensory modalities and project to different areas of the brain like the thalamus, cerebellum and reticular formation to process sensory information and maintain consciousness.
This document provides an overview of the contractile mechanism of smooth muscle. It discusses:
1. The physical basis of smooth muscle contraction including the arrangement of actin and myosin filaments.
2. The chemical basis being similar to skeletal muscle but without a troponin complex.
3. Key differences from skeletal muscle including slower cycling of myosin cross-bridges, lower energy requirements, and a "latch mechanism" allowing prolonged contraction.
4. The role of calcium ions and proteins like calmodulin in activating phosphorylation of the myosin head and initiating contraction.
Neurons communicate with each other via electrical and chemical signals. At the synapse, an electrical signal in the presynaptic neuron causes it to release neurotransmitters like acetylcholine or glutamate. These chemicals bind to and open ion channels in the postsynaptic neuron, generating an electrical signal there. This transmission allows neurons to form complex communication networks and coordinate the functions of the nervous system.
Nervous control of blood vessels regulation of arterial pressureAmen Ullah
The main function of the circulatory system is to give local blood flow to the tissue. There arespecial need of the tissue which is:
delivery of oxygen to the tissue
delivery of nutrients to the tissue
removal of carbon dioxide from tissue
maintaining of normal concentration of ions
transform of hormones and other substance to tissue
The resting membrane potential of neurons and muscle cells is maintained around -70 mV due to selective permeability of ions across the cell membrane. The sodium-potassium pump actively transports 3 Na+ ions out and 2 K+ ions into the cell, contributing to the negative interior potential. When the membrane potential reaches the threshold, voltage-gated sodium channels open rapidly, causing a sharp depolarization as sodium ions rush in. Subsequently, voltage-gated potassium channels open more slowly, repolarizing the membrane as potassium ions efflux from the cell. This generates an action potential that propagates by local current flow between adjacent areas of the membrane. The sodium-potassium pump then restores ion gradients in preparation for the next action potential
The document discusses synaptic transmission in the central nervous system. It describes the cellular organization of the brain including neurons and support cells. It then focuses on synapses, explaining that they allow chemical communication between neurons through neurotransmitters. There are two main types of synapses - electrical synapses which allow direct electrical coupling, and chemical synapses which use chemical messengers. Chemical synapses are more numerous and involve neurotransmitters being released into the synaptic cleft, binding to receptors and causing excitation or inhibition of the postsynaptic neuron. The properties of synaptic transmission include one-way conduction, synaptic delay, fatigue, convergence and divergence, summation, and facilitation.
Anatomy & physiology of the Autonomic nervous systemRafid Rashid
Provides a good description of the anatomy & physiology of the autonomic nervous system for undergraduate medical students. It goes over the parts & functions of the sympathetic & parasympathetic nervous system respectively & compares the differences between them.
1) A synapse is a junction that transmits signals between neurons. It contains a presynaptic terminal that releases neurotransmitters and a postsynaptic membrane with receptors.
2) When an action potential reaches the presynaptic terminal, calcium ions enter and cause neurotransmitter vesicles to fuse and release their contents across the synaptic cleft.
3) Neurotransmitters bind to and open ion channels on the postsynaptic membrane, producing an electrical effect that may trigger another action potential.
This document provides an overview of membrane potentials and resting membrane potential by Dr. Rashid Mahmood. It defines key terms like excitation, stimulus, and excitable tissues. It explains that the Nernst potential is the diffusion potential level that opposes net ion diffusion through a membrane. Diffusion potentials are +61 mV for sodium and -94 mV for potassium. The Goldman equation is used to calculate diffusion potential when multiple ions are involved. The resting membrane potential of large myelinated nerve fibers is approximately -90 mV, contributed to by the potassium diffusion potential of -94 mV, sodium diffusion potential of +61 mV, and the sodium-potassium pump of -4 mV.
Zhang, Qiangzhe, Junjie Jiang, Pengcheng Han, Qi Yuan, Jing Zhang, Xiaoqian Zhang, Yanyan Xu et al. "Direct differentiation of atrial and ventricular myocytes from human embryonic stem cells by alternating retinoid signals." Cell research 21, no. 4 (2011): 579.
Zhang, Qiangzhe, Junjie Jiang, Pengcheng Han, Qi Yuan, Jing Zhang, Xiaoqian Zhang, Yanyan Xu et al. "Direct differentiation of atrial and ventricular myocytes from human embryonic stem cells by alternating retinoid signals." Cell research 21, no. 4 (2011): 579.
http://rfumsphysiology.pbworks.com/w/page/12566771/Electrical%20Activity%20of%20the%20Heart
Shih, Hue-Teh. "Anatomy of the action potential in the heart." Texas Heart Institute Journal 21, no. 1 (1994): 30.
Zhang, Qiangzhe, Junjie Jiang, Pengcheng Han, Qi Yuan, Jing Zhang, Xiaoqian Zhang, Yanyan Xu et al. "Direct differentiation of atrial and ventricular myocytes from human embryonic stem cells by alternating retinoid signals." Cell research 21, no. 4 (2011): 579.
Zhang, Qiangzhe, Junjie Jiang, Pengcheng Han, Qi Yuan, Jing Zhang, Xiaoqian Zhang, Yanyan Xu et al. "Direct differentiation of atrial and ventricular myocytes from human embryonic stem cells by alternating retinoid signals." Cell research 21, no. 4 (2011): 579.
Yaniv et al. Front. Physiol. 2015, Weisbord et al. Proc. Natl. Acad. Sci. 2013
The whole process.
Maltsev, Victor A., and Edward G. Lakatta. "Dynamic interactions of an intracellular Ca2+ clock and membrane ion channel clock underlie robust initiation and regulation of cardiac pacemaker function." Cardiovascular research 77, no. 2 (2007): 274-284.
Maltsev, Victor A., and Edward G. Lakatta. "Dynamic interactions of an intracellular Ca2+ clock and membrane ion channel clock underlie robust initiation and regulation of cardiac pacemaker function." Cardiovascular research 77, no. 2 (2007): 274-284.
Ashley, E. A., and J. Niebauer. "Conquering the ECG." In Cardiology Explained. Remedica, London, England, 2004.
https://www.ncbi.nlm.nih.gov/books/NBK2214/
Ashley, E. A., and J. Niebauer. "Conquering the ECG." In Cardiology Explained. Remedica, London, England, 2004.
https://www.ncbi.nlm.nih.gov/books/NBK2214/