Neurophysiology explaining the synapses at nerve terminal and neuromuscular junctions and the various types of neurotransmitters found in blood that mediate the flow of electrical impulses in the central nervous system.
The document discusses the structure and function of chemical synapses. It begins by defining a synapse as the junction between two nerve cells. It then describes the key anatomical components of a chemical synapse, including the presynaptic knob, synaptic cleft, and postsynaptic membrane. It explains the process of neurotransmission, including the release of neurotransmitters into the synaptic cleft, their binding to receptors on the postsynaptic membrane, and the resulting postsynaptic potentials. The document also discusses inhibition at synapses, the properties of synaptic transmission, and examples of neurotransmitters.
Synapses and synaptic transmission involve the following key points:
1. Synapses allow neurons to communicate via the release of neurotransmitters from the presynaptic neuron that bind to receptors on the postsynaptic neuron.
2. There are different types of synapses including chemical and electrical synapses. Chemical synapses use neurotransmitters while electrical synapses allow direct ion flow.
3. Neurotransmitters are released into the synaptic cleft and can have excitatory or inhibitory effects by changing the postsynaptic membrane potential via ionotropic or metabotropic receptors.
The document discusses neurohumoral transmission via the autonomic nervous system. It describes how the ANS is comprised of the sympathetic and parasympathetic nervous systems which modulate involuntary functions via neurotransmitters. The two main divisions differ in their origins, neurotransmitters, and target organ effects. Neurotransmission occurs via the binding of neurotransmitters like acetylcholine and norepinephrine to receptors, producing excitatory or inhibitory post-synaptic potentials that mediate various physiological responses. Neurotransmitters are synthesized, stored in vesicles, released upon neuronal firing, and degraded or reabsorbed to terminate synaptic transmission.
This document summarizes synaptic transmission between nerve cells. It discusses the key discoveries in the field, including that synaptic transmission can be either chemical or electrical. Chemical transmission involves the release of neurotransmitters from the presynaptic cell that bind to and activate receptors on the postsynaptic cell. The process requires calcium influx into the presynaptic terminal to trigger neurotransmitter release from synaptic vesicles.
Here are the key types of mechanoreceptors and their properties:
- Cutaneous mechanoreceptors:
- Meissner's corpuscles - detect light touch and pressure on fingertips and lips. Found in dermal papillae.
- Merkel's discs - detect sustained light touch. Found just below the epidermis.
- Pacinian corpuscles - detect deep pressure and vibration. Found in dermis and connective tissue.
- Ruffini endings - detect skin stretch and joint movement. Found in dermis and connective tissue.
- Free nerve endings - detect pain. Found throughout the dermis and epidermis.
- Proprioceptors:
- Muscle spind
neurohumoral transmission refers to the transmission of impulse through synapse and neuroeffector junction by the release of chemical (humoral) substance.
Classification and structure of synapsesAlaaAlchyad
Synapses can be classified by the type of cellular structures serving as the pre- and post-synaptic components. ... The axon can synapse onto a dendrite, onto a cell body, or onto another axon or axon terminal, as well as into the bloodstream or diffusely into the adjacent nervous tissue.
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.
The document discusses the structure and function of chemical synapses. It begins by defining a synapse as the junction between two nerve cells. It then describes the key anatomical components of a chemical synapse, including the presynaptic knob, synaptic cleft, and postsynaptic membrane. It explains the process of neurotransmission, including the release of neurotransmitters into the synaptic cleft, their binding to receptors on the postsynaptic membrane, and the resulting postsynaptic potentials. The document also discusses inhibition at synapses, the properties of synaptic transmission, and examples of neurotransmitters.
Synapses and synaptic transmission involve the following key points:
1. Synapses allow neurons to communicate via the release of neurotransmitters from the presynaptic neuron that bind to receptors on the postsynaptic neuron.
2. There are different types of synapses including chemical and electrical synapses. Chemical synapses use neurotransmitters while electrical synapses allow direct ion flow.
3. Neurotransmitters are released into the synaptic cleft and can have excitatory or inhibitory effects by changing the postsynaptic membrane potential via ionotropic or metabotropic receptors.
The document discusses neurohumoral transmission via the autonomic nervous system. It describes how the ANS is comprised of the sympathetic and parasympathetic nervous systems which modulate involuntary functions via neurotransmitters. The two main divisions differ in their origins, neurotransmitters, and target organ effects. Neurotransmission occurs via the binding of neurotransmitters like acetylcholine and norepinephrine to receptors, producing excitatory or inhibitory post-synaptic potentials that mediate various physiological responses. Neurotransmitters are synthesized, stored in vesicles, released upon neuronal firing, and degraded or reabsorbed to terminate synaptic transmission.
This document summarizes synaptic transmission between nerve cells. It discusses the key discoveries in the field, including that synaptic transmission can be either chemical or electrical. Chemical transmission involves the release of neurotransmitters from the presynaptic cell that bind to and activate receptors on the postsynaptic cell. The process requires calcium influx into the presynaptic terminal to trigger neurotransmitter release from synaptic vesicles.
Here are the key types of mechanoreceptors and their properties:
- Cutaneous mechanoreceptors:
- Meissner's corpuscles - detect light touch and pressure on fingertips and lips. Found in dermal papillae.
- Merkel's discs - detect sustained light touch. Found just below the epidermis.
- Pacinian corpuscles - detect deep pressure and vibration. Found in dermis and connective tissue.
- Ruffini endings - detect skin stretch and joint movement. Found in dermis and connective tissue.
- Free nerve endings - detect pain. Found throughout the dermis and epidermis.
- Proprioceptors:
- Muscle spind
neurohumoral transmission refers to the transmission of impulse through synapse and neuroeffector junction by the release of chemical (humoral) substance.
Classification and structure of synapsesAlaaAlchyad
Synapses can be classified by the type of cellular structures serving as the pre- and post-synaptic components. ... The axon can synapse onto a dendrite, onto a cell body, or onto another axon or axon terminal, as well as into the bloodstream or diffusely into the adjacent nervous tissue.
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.
The neuromuscular junction contains specialized anatomical structures that allow for efficient neurotransmission between a motor neuron and muscle fiber. It consists of a presynaptic nerve terminal, synaptic cleft, and postsynaptic end plate on the muscle fiber membrane. Acetylcholine is released from vesicles in the nerve terminal in response to an action potential and binds nicotinic receptors on the end plate, allowing sodium and potassium ions to flow and depolarize the membrane. This end plate potential can trigger an action potential in the muscle fiber, causing contraction. Acetylcholine is then broken down by acetylcholinesterase to allow the muscle to relax until the next action potential.
(1) Synaptic transmission occurs via either electrical or chemical synapses. (2) At chemical synapses, neurotransmitters are released from presynaptic terminals and bind to receptors on the postsynaptic cell, eliciting electrical responses. (3) The summation of excitatory and inhibitory postsynaptic potentials determines whether an action potential is generated in the postsynaptic neuron.
Synapses allow communication between neurons. The document defines a synapse and discusses its classification, functional anatomy, and electrical events. It summarizes that a synapse transmits signals from a presynaptic neuron to a postsynaptic neuron through the release of neurotransmitters. The signals can be excitatory or inhibitory, influencing whether the postsynaptic neuron fires an action potential. Synaptic transmission has properties like delay, summation, fatigue, and plasticity that influence neural signaling and functions like learning and memory.
Neurotransmitters are chemical messengers that are released by neurons to transmit signals between neurons or from neurons to effector cells. They are stored in synaptic vesicles and released into the synaptic cleft upon arrival of an action potential. Common neurotransmitters include acetylcholine, monoamines like dopamine and norepinephrine, amino acids, peptides, and gaseous transmitters. Neurotransmitters bind to receptors on the postsynaptic membrane, which can be ionotropic and directly open ion channels, or metabotropic and activate second messenger systems. Summation of excitatory and inhibitory postsynaptic potentials determines whether an action potential is initiated in the postsynaptic cell.
Nerve Impulse is defined as a wave of electrical chemical changes across the neuron that helps in the generation of the action potential in response to the stimulus. This transmission of a nerve impulse across the neuron membrane as a result of a change in membrane potential is known as Nerve impulse conduction.
Mechanism of Nerve Impulse Conduction
Nerve impulse conduction is a major process occurring in the body responsible for organized functions of the body. So, for conduction of nerve impulse there are two mechanisms:
Continuous conduction
Saltatory conduction
Synapses consist of a presynaptic ending containing neurotransmitters, a postsynaptic ending containing receptor sites, and a synaptic cleft between them. An action potential cannot cross the cleft; instead, neurotransmitters are released from vesicles in the presynaptic ending and diffuse across the cleft to bind to receptors in the postsynaptic ending. This may initiate an action potential in the postsynaptic neuron. Synapses allow neurons to communicate via chemical signaling and integrate inputs from multiple neurons.
Neurotransmitters are chemical messengers that transmit signals between neurons. The document discusses the history and criteria for classifying a substance as a neurotransmitter. Neurotransmitters are classified based on their chemical nature as amino acids, amines, or others. They are also classified based on their function as either excitatory or inhibitory. The document describes examples from each group and where they are secreted in the body. It further explains the processes of transport, release, inactivation, and reuptake of neurotransmitters at the synapse.
Neurotransmitters are chemical messengers that transmit signals between neurons. The document discusses the history and criteria for classifying a substance as a neurotransmitter. Neurotransmitters are classified based on their chemical nature as amino acids, amines, or others. They are also classified based on their function as either excitatory or inhibitory. The document provides examples of major neurotransmitters and where they are secreted in the body. It describes how neurotransmitters are transported, released, and taken back up at synapses. Finally, it discusses how neurotransmitters are inactivated after signal transmission.
This document summarizes synaptic transmission at the neuromuscular junction. It describes how one neuron communicates with another via either electrical or chemical synapses. Chemical synapses consist of a presynaptic neuron, synaptic cleft, and postsynaptic neuron. Neurotransmitters are released from the presynaptic neuron, bind to receptors on the postsynaptic neuron, and cause either excitation or inhibition via ion flow across the membrane. At the neuromuscular junction, an action potential arrives at the nerve terminal and causes acetylcholine release, binding to receptors on the muscle cell and generating an end plate potential capable of triggering an action potential in the muscle fiber.
This document discusses synaptic transmission between neurons. It describes two main types of synaptic transmission: electrical and chemical. Chemical synapses are more common and involve the release of neurotransmitters that activate receptors on the postsynaptic neuron. The key stages of chemical synaptic transmission are the synthesis and release of neurotransmitters from the presynaptic neuron, activation of receptors on the postsynaptic neuron, and termination of the synaptic signal. Glial cells and gap junctions also play important roles in coordinating neuronal activity.
The nervous system is composed of the central nervous system and peripheral nervous system. It functions to receive, store, and transmit information. The basic unit of the nervous system is the neuron, which consists of dendrites, a soma, an axon, and axon terminals. Neurons are classified based on their structure, form, and myelination. The membrane potential and action potentials allow neurons to conduct electrical signals. Synapses allow signals to pass between neurons through the release and detection of neurotransmitters. The neuromuscular junction uses acetylcholine as a neurotransmitter to transmit signals from motor neurons to muscles.
This document appears to be notes from a lecture on neuroscience physiology. It discusses various topics including connexons, electrical events at excitatory and inhibitory synapses, pain pathways, central excitatory and inhibitory states, characteristics of synaptic transmission such as forward conduction and synaptic delay, summation, and synaptic plasticity mechanisms like post-tetanic facilitation which enhances postsynaptic responses through increased calcium and vesicle release. Memory is also briefly mentioned as being the ability to recall past experience through changes in synaptic strength.
1. Synapses allow nerve impulses to pass between neurons. There are two main types - chemical synapses using neurotransmitters, and electrical synapses allowing direct ion flow.
2. At chemical synapses, neurotransmitters released by the presynaptic neuron can excite, inhibit, or modify the postsynaptic neuron. Summation occurs when multiple synaptic inputs combine temporally or spatially to trigger an action potential.
3. Synaptic transmission has properties like one-way conduction, synaptic delay, fatiguability, convergence and divergence, summation, and the ability to excite or inhibit the postsynaptic neuron. Reflexes involve a stimulus, receptor, afferent neuron, central processing, efferent neuron,
1) Synaptic transmission is the process by which neurons communicate via synapses. It involves the release of neurotransmitters from the presynaptic neuron that bind to and activate receptors on the postsynaptic neuron.
2) There are two main types of synapses - electrical and chemical. Chemical synapses, which involve the release and detection of neurotransmitters, are the most common in the nervous system.
3) The key structures that form a chemical synapse are the presynaptic terminal containing synaptic vesicles filled with neurotransmitters, the synaptic cleft, and the postsynaptic membrane containing neurotransmitter receptors.
this ppt shares what synapses are and how information of one neuron is transmitted to other through the synapses. it also includes the properties and plasticity of synaptic transmission
This document discusses synaptic transmission and neurotransmitters. It begins by defining a synapse as the contact point between neurons. It then differentiates between electrical and chemical synapses. Chemical synapses use neurotransmitters to transmit signals across the synaptic cleft in one direction, while electrical synapses allow direct ion flow between neurons. The document outlines the process of neurotransmitter release via calcium-triggered exocytosis and postsynaptic receptor activation. It discusses both ionotropic and metabotropic receptors and how they contribute to postsynaptic potentials. Finally, it covers specific neurotransmitters like glutamate and GABA, the neuromuscular junction, and clostridial toxins that impact synaptic function.
Patiwnt notes, history taking systematic screwing if patients to arrive at impression. Examination guide on assessment of patient normal anatomy and physiology by review of the body systems, central nervous system, Gastrointestinal , Cardiopulmonary , Genitourinary and Muskuloskeleal system review and examination
The anatomy of the cerebrum. External features of the CEREBRUM, sulci and gyri , folds and groves on the cerebral cortex. The cerebral hemispheres and their division s.
The neuromuscular junction contains specialized anatomical structures that allow for efficient neurotransmission between a motor neuron and muscle fiber. It consists of a presynaptic nerve terminal, synaptic cleft, and postsynaptic end plate on the muscle fiber membrane. Acetylcholine is released from vesicles in the nerve terminal in response to an action potential and binds nicotinic receptors on the end plate, allowing sodium and potassium ions to flow and depolarize the membrane. This end plate potential can trigger an action potential in the muscle fiber, causing contraction. Acetylcholine is then broken down by acetylcholinesterase to allow the muscle to relax until the next action potential.
(1) Synaptic transmission occurs via either electrical or chemical synapses. (2) At chemical synapses, neurotransmitters are released from presynaptic terminals and bind to receptors on the postsynaptic cell, eliciting electrical responses. (3) The summation of excitatory and inhibitory postsynaptic potentials determines whether an action potential is generated in the postsynaptic neuron.
Synapses allow communication between neurons. The document defines a synapse and discusses its classification, functional anatomy, and electrical events. It summarizes that a synapse transmits signals from a presynaptic neuron to a postsynaptic neuron through the release of neurotransmitters. The signals can be excitatory or inhibitory, influencing whether the postsynaptic neuron fires an action potential. Synaptic transmission has properties like delay, summation, fatigue, and plasticity that influence neural signaling and functions like learning and memory.
Neurotransmitters are chemical messengers that are released by neurons to transmit signals between neurons or from neurons to effector cells. They are stored in synaptic vesicles and released into the synaptic cleft upon arrival of an action potential. Common neurotransmitters include acetylcholine, monoamines like dopamine and norepinephrine, amino acids, peptides, and gaseous transmitters. Neurotransmitters bind to receptors on the postsynaptic membrane, which can be ionotropic and directly open ion channels, or metabotropic and activate second messenger systems. Summation of excitatory and inhibitory postsynaptic potentials determines whether an action potential is initiated in the postsynaptic cell.
Nerve Impulse is defined as a wave of electrical chemical changes across the neuron that helps in the generation of the action potential in response to the stimulus. This transmission of a nerve impulse across the neuron membrane as a result of a change in membrane potential is known as Nerve impulse conduction.
Mechanism of Nerve Impulse Conduction
Nerve impulse conduction is a major process occurring in the body responsible for organized functions of the body. So, for conduction of nerve impulse there are two mechanisms:
Continuous conduction
Saltatory conduction
Synapses consist of a presynaptic ending containing neurotransmitters, a postsynaptic ending containing receptor sites, and a synaptic cleft between them. An action potential cannot cross the cleft; instead, neurotransmitters are released from vesicles in the presynaptic ending and diffuse across the cleft to bind to receptors in the postsynaptic ending. This may initiate an action potential in the postsynaptic neuron. Synapses allow neurons to communicate via chemical signaling and integrate inputs from multiple neurons.
Neurotransmitters are chemical messengers that transmit signals between neurons. The document discusses the history and criteria for classifying a substance as a neurotransmitter. Neurotransmitters are classified based on their chemical nature as amino acids, amines, or others. They are also classified based on their function as either excitatory or inhibitory. The document describes examples from each group and where they are secreted in the body. It further explains the processes of transport, release, inactivation, and reuptake of neurotransmitters at the synapse.
Neurotransmitters are chemical messengers that transmit signals between neurons. The document discusses the history and criteria for classifying a substance as a neurotransmitter. Neurotransmitters are classified based on their chemical nature as amino acids, amines, or others. They are also classified based on their function as either excitatory or inhibitory. The document provides examples of major neurotransmitters and where they are secreted in the body. It describes how neurotransmitters are transported, released, and taken back up at synapses. Finally, it discusses how neurotransmitters are inactivated after signal transmission.
This document summarizes synaptic transmission at the neuromuscular junction. It describes how one neuron communicates with another via either electrical or chemical synapses. Chemical synapses consist of a presynaptic neuron, synaptic cleft, and postsynaptic neuron. Neurotransmitters are released from the presynaptic neuron, bind to receptors on the postsynaptic neuron, and cause either excitation or inhibition via ion flow across the membrane. At the neuromuscular junction, an action potential arrives at the nerve terminal and causes acetylcholine release, binding to receptors on the muscle cell and generating an end plate potential capable of triggering an action potential in the muscle fiber.
This document discusses synaptic transmission between neurons. It describes two main types of synaptic transmission: electrical and chemical. Chemical synapses are more common and involve the release of neurotransmitters that activate receptors on the postsynaptic neuron. The key stages of chemical synaptic transmission are the synthesis and release of neurotransmitters from the presynaptic neuron, activation of receptors on the postsynaptic neuron, and termination of the synaptic signal. Glial cells and gap junctions also play important roles in coordinating neuronal activity.
The nervous system is composed of the central nervous system and peripheral nervous system. It functions to receive, store, and transmit information. The basic unit of the nervous system is the neuron, which consists of dendrites, a soma, an axon, and axon terminals. Neurons are classified based on their structure, form, and myelination. The membrane potential and action potentials allow neurons to conduct electrical signals. Synapses allow signals to pass between neurons through the release and detection of neurotransmitters. The neuromuscular junction uses acetylcholine as a neurotransmitter to transmit signals from motor neurons to muscles.
This document appears to be notes from a lecture on neuroscience physiology. It discusses various topics including connexons, electrical events at excitatory and inhibitory synapses, pain pathways, central excitatory and inhibitory states, characteristics of synaptic transmission such as forward conduction and synaptic delay, summation, and synaptic plasticity mechanisms like post-tetanic facilitation which enhances postsynaptic responses through increased calcium and vesicle release. Memory is also briefly mentioned as being the ability to recall past experience through changes in synaptic strength.
1. Synapses allow nerve impulses to pass between neurons. There are two main types - chemical synapses using neurotransmitters, and electrical synapses allowing direct ion flow.
2. At chemical synapses, neurotransmitters released by the presynaptic neuron can excite, inhibit, or modify the postsynaptic neuron. Summation occurs when multiple synaptic inputs combine temporally or spatially to trigger an action potential.
3. Synaptic transmission has properties like one-way conduction, synaptic delay, fatiguability, convergence and divergence, summation, and the ability to excite or inhibit the postsynaptic neuron. Reflexes involve a stimulus, receptor, afferent neuron, central processing, efferent neuron,
1) Synaptic transmission is the process by which neurons communicate via synapses. It involves the release of neurotransmitters from the presynaptic neuron that bind to and activate receptors on the postsynaptic neuron.
2) There are two main types of synapses - electrical and chemical. Chemical synapses, which involve the release and detection of neurotransmitters, are the most common in the nervous system.
3) The key structures that form a chemical synapse are the presynaptic terminal containing synaptic vesicles filled with neurotransmitters, the synaptic cleft, and the postsynaptic membrane containing neurotransmitter receptors.
this ppt shares what synapses are and how information of one neuron is transmitted to other through the synapses. it also includes the properties and plasticity of synaptic transmission
This document discusses synaptic transmission and neurotransmitters. It begins by defining a synapse as the contact point between neurons. It then differentiates between electrical and chemical synapses. Chemical synapses use neurotransmitters to transmit signals across the synaptic cleft in one direction, while electrical synapses allow direct ion flow between neurons. The document outlines the process of neurotransmitter release via calcium-triggered exocytosis and postsynaptic receptor activation. It discusses both ionotropic and metabotropic receptors and how they contribute to postsynaptic potentials. Finally, it covers specific neurotransmitters like glutamate and GABA, the neuromuscular junction, and clostridial toxins that impact synaptic function.
Patiwnt notes, history taking systematic screwing if patients to arrive at impression. Examination guide on assessment of patient normal anatomy and physiology by review of the body systems, central nervous system, Gastrointestinal , Cardiopulmonary , Genitourinary and Muskuloskeleal system review and examination
The anatomy of the cerebrum. External features of the CEREBRUM, sulci and gyri , folds and groves on the cerebral cortex. The cerebral hemispheres and their division s.
Anatomy and physiology of the cardiac system
The electrocardiogram a, curves and interpretation of the first and second heart sounds. Generation of action potential within the myocardium ,the gap junctions and how they propagate electrical pilese from sinoatrial mode and ectopoic heartbeat.
Epidemiological studies ,statistics and survey research design. How to conduct a research ,steps to research ,how to design a research analysis schedule. Advantages and disadvantages of using survey research techniques and how to analyze data.
Bacteriology , Streptococcus species ,strep pyogenes, strep. Pneumoniae and strep fecalis. Diseases cause by Streptococcal microorganisms and how they can be managed. Cultural characteristics and morphology.
Cardiovascular physiology. Cardiac enzymes and their effects in the body system. Cardiac output and effects increasing and decreasing it. Calculations if Ejected fraction and other cardiac parameters.
The skin is the largest organ of the body and serves several important functions including protection, sensation, vitamin D synthesis, and thermoregulation. It is composed of three main layers - the epidermis, dermis, and hypodermis. The epidermis is made of stratified squamous epithelium with keratinocytes, melanocytes, Langerhans cells, and Merkel cells. It has five layers - stratum basale, spinosum, granulosum, lucidum, and corneum. The dermis lies below with two layers - papillary and reticular dermis. It contains collagen, elastic fibers, and fibroblasts. Skin appendages include hair follicles, sebaceous
Trypanosomiasis is a vector-borne parasitic disease caused by Trypanosoma parasites. There are two main forms: African trypanosomiasis (sleeping sickness) transmitted by tsetse flies, and American trypanosomiasis (Chagas disease) transmitted by triatomine bugs. African trypanosomiasis is found in Central and East Africa and causes a slow progression of symptoms, while American trypanosomiasis is found in Latin America and causes an initial acute phase followed by a chronic phase in some patients. Both forms require treatment with drugs to eliminate the parasites from the body.
Integrating Ayurveda into Parkinson’s Management: A Holistic ApproachAyurveda ForAll
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
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5. ANATOMICAL TYPES
Thursday, February 1, 2018
■ Axo-dendritic synapse
– between axon of one
to dendrite of other.
■ Axo-somatic – between
axon of one to
soma(body) of other.
■ Axo-axonic – between
two axons.
6. PHYSIOLOGICAL TYPES.
Thursday, February 1, 2018
■ Chemical – by
Neurotransmitter.(one
direction)
■ Electrical – transmission
through Gap junction.
(both direction)
■ Conjoint – Both chemical
& electrical transmission
co-exists.
8. STRUCTURE OF CHEMICAL SYNAPSE
Thursday, February 1, 2018
■ Synaptic knob or
button.
■ Pre synaptic
membrane.
■ Synaptic cleft.
■ Post synaptic process.
■ Post synaptic
membrane.
9. SYNAPTIC KNOB OR BUTTON.
Thursday, February 1, 2018
■
■
■
■
■
■
Axon loses myelin sheath.
End into small swellings as
knobs
Contains Mitochondria &
Neurotransmitters in vesicles
Circular – excitatory
Flat – inhibitory.
Transport –by Microtubules.
10. PRE SYNAPTIC MEMBRANE.
Thursday, February 1, 2018
■ Inner side contains
zone of dense
cytoplasm.
■ This forms
Presynaptic vesicular
grid.
12. POST SYNAPTIC PROCESS POST SYNAPTIC
MEMBRANE.
Thursday, February 1, 2018
■ Region of receiving
neuron.
■ Also contains zone of
dense cytoplasm.
■ Contains no of receptor
proteins projecting
outwards in cleft.
■ Neurotransmitter attaches
to these receptors.
13. RECEPTOR PROTEINS.
Thursday, February 1, 2018
■ Two types.
■ Ion channel receptor
proteins (Na, K, Cl)-
activation causes
opening of these
channels.
■ Enzymatic types of
receptor proteins –
■ Activation of cellular gene
■ Activation of protein
kinase.
14. TYPES OF CHEMICAL SYNAPSE
Thursday, February 1, 2018
Features Type I Type II
Structure Asymmetric Symmetric
Synaptic cleft Wider Narrower
Post synaptic
membrane thickening.
Marked Less marked
ECF in cleft Present Absent
Vesicle shape Spherical Flat
Neurotrasmitter. Ach, 5HT, Glutamate, E,
NE, DOPA, Adrenaline
GABA, Glycine
Effect Excitatory Inhibitory
Type of synapse. Axo-dendritic Axo-somatic.
15. PROCESS OF CHEMICAL SYNAPTIC
TRANSMISSION.
Thursday, February 1, 2018
■ Release of
Neurotransmitters.
■ Development of
EPSP & IPSP.
■ Removal of
Neurotransmitter
from synaptic cleft.
■ Development of
Action potential.
16. RELEASE OF
NEUROTRANSMITTERS.
Thursday, February 1, 2018
■ Nerve impulse reaches
nerve terminal
■ Depolarization of pre
synaptic membrane
■ voltage gated Ca channels
open
■ Ca permeability
■ Ca enters.
17. DEVELOPMENT OF EPSP.
■ EPSP – Depolarization
of post synaptic
membrane by
excitatory
neurotransmitter
(Glutamate)
■ Magnitude – 8mv
■ Latency – 0.5ms.
18. EPSP
Thursday, February 1, 2018
■ Ionic basis –
■ NT binds to receptors
proteins – opens ligand
gated Na & Ca channels
– Na diffuse in –
Depolarize membrane
■ Conduction of EPSP –
passively due to local
currents.
19. EPSP
.
■ Summation – EPSP is
graded response, does not
show all or none response
■ TEMPORAL – when
repeated stimuli applied in
short duration.
■ SPATIAL – when post
synaptic membrane
receives impulses
simulataneously from large
no of presynaptic terminals.
20. DEVELOPMENT OF IPSP.
Thursday, February 1, 2018
■ IPSP – Hyper polarization of
post synaptic membrane by
inhibitory neurotransmitter
(GABA)
■ Value of IPSP - -2mv
■ Summation.
■ Temporal
■ Spatial.
21. IPSP
Thursday, February 1, 2018
■ Ionic basis - Release of
inhibitory NT – open K or
Cl channels – diffusion of
K ions from neurons to
ECF or Cl from ECF into
neuron – Hyper
polarization
22. REMOVAL OF NEUROTRANSMITTER
FROM SYNAPTIC CLEFT.
Thursday, February 1, 2018
■ BY 3 WAYS.
■ Diffusion out of cleft.
■ Enzymatic
degradation –
acetylcholinesterase.
■ Active
neurotransmitter
reuptake.
23. DEVELOPMENT OF ACTION POTENTIAL.
Thursday, February 1, 2018
■ Synaptic integration
■ Generation of initial
segment spike.
■ Generation of
prolonged signals. i.
e Action Potential.
24. SYNAPTIC INTEGRATION
Thursday, February 1, 2018
■ It is phenomenon of
summation of both
EPSP or IPSP at the
post synaptic
membrane i.e
algebraically
summated potential
will determine
transmission.
25. GENERATION OF INITIAL SEGMENT SPIKE
Thursday, February 1, 2018
■ Summated potential 1st
pass to initial segment
i.e. axon hillock.
■ If potential is large
enough to depolarize
initial segment (6-10
mv) – initial spike is
generated
■ Magnitude – 30-40 mv.
26. GENERATION OF PROLONGED SIGNALS -- ACTION
POTENTIAL.
Thursday, February 1, 2018
■ Initial spike once
initiated causes further
depolarization by
opening voltage gated
Na channels on axon
hillock
■ Generate AP & travel
peripherally in axon.
28. POST-SYNAPTIC INHIBITION.
Thursday, February 1, 2018
■ Direct post synaptic
inhibition by
development of
inhibitory post synaptic
potential – by releasing
inhibitory NT.
■ Post synaptic inhibition
due to refractory period.
29. PRE-SYNAPTIC INHIBITION.
Thursday, February 1, 2018
■
■
■
By action of inhibitory
neuron (C) – releases
GABA
By opening Cl- channels of
pre synaptic terminals
produces hyperpolarization.
By activation of G protein.
■
■
By opening K+ channels
By directly blocking Ca
channels.
30. FEEDBACK INHIBITION
Renshaw cell inhibition.
Thursday, February 1, 2018
■ It occurs in spinal
alpha motor neuron
■ Neuron inhibits those
neuron which excite it.
■ It serves to limit
excitability of motor
neurons.
31. SIGNIFICANCE OF SYNAPTIC INHIBITION.
Thursday, February 1, 2018
■ Important for
restriction over
neurons & muscles to
react properly &
appropriately.
32. PROPERTIES OF SYNAPTIC
TRANSMISSION.
■ Facilitation.
■ Synaptic fatigue.
■ Synaptic plasticity &
learning.
■ Reverberation.
■ Reciprocal inhibition.
■ After discharge.
■ Effect of acidosis &
Hypoxia
■ One way conduction.
■ Synaptic delay.
■ Summation property of synapse.
■ Conversions & divergence.
■ Occlusion phenomenon.
■ Subliminal fringe effect.
33. ONE WAY CONDUCTION.
Thursday, February 1, 2018
■ Law of dynamic
polarity or Bell
Magendie law – synapse
allow only one way
conduction from pre to
post synaptic neuron.
■ Significance – For
orderly conduction of
impulse in one direction
only.
34. SYNAPTIC DELAY
Thursday, February 1, 2018
■ Time lapse between
arrival of nerve impulse
at the pre synaptic
terminal & its passage
to post synaptic
membrane.
■ 0.5 ms
35. CAUSES OF SYNAPTIC DELAY
Thursday, February 1, 2018
■ Release of
neurotransmitter.
■ Diffusion through
cleft
■ Binding with post
synaptic receptors &
opening ion channels.
■ Diffusion of ions
causing RMP.
36. SUMMATION PROPERTY OF SYNAPSE.
Thursday, February 1, 2018
■ Property of summation
is essential for
stimulation of post
synaptic membrane
either by stimulations
of large no of
Presynaptic terminals
or repeated
stimulation of single
terminal.
37. CONVERGENCE
Thursday, February 1, 2018
■ Phenomenon of
termination of signals
from many sources.
& DIVERGENCE.
■ One pre synaptic
neuron may terminate
on many post synaptic
neurons.
38. OCCLUSION PHENOMENON.
Thursday, February 1, 2018
■ Response to stimulation
of 2 pre synaptic
neurons is less than sum
total of the response
obtained when
stimulated seperately.
39. FACILITATION.
Thursday, February 1, 2018
■ When pre synaptic axon
is stimulated with
several consecutive
individual stimuli, each
evokes larger post
synaptic potential than
previous stimuli.
■ Cause – Prolonged Ca
channel opening.
40. SYNAPTIC FATIGUE.
Thursday, February 1, 2018
■ Pre synaptic neuron
when stimulated
continuously there is
Gradual Decrease &
finally disappearance of
post synaptic response.
■ Cause –
■ Gradual inactivation of
Ca
■ Accumulation of waste.
41. SYNAPTIC PLASTICITY & LEARNING.
Thursday, February 1, 2018
■ Synaptic transmission
can be increased or
decreased on the basis of
past experience
■ Post tetanic potentiation.
■ Long term potentiation
■ Sensitization
■ Long term depression.
42. REVERBERATION.
Thursday, February 1, 2018
■ Passage of impulse
from pre synaptic
neuron and again
back to presynaptic
neuron to cause
continuous
stimulation of Pre
synaptic Neuron.
43. RECIPROCAL INHIBITION.
Thursday, February 1, 2018
■ Afferent signal
activates excitatory
neurons to group of
muscles &
simultaneously
inhibitory neurons to
antagonistic muscles.
47. Objectives
• Explain how a single neurotransmitter may be excitatory at one
synapse and inhibitory at another.
• Describe the structural and functional properties of the major classes
of neurotransmitters.
• Describe the most common excitatory and inhibitory
neurotransmitters in the CNS.
48. Neurotransmitters
• They all exhibit the following effects:
• They are made in either the cell body or the axon terminal and
packaged into synaptic vesicles,
• they are released from the presynaptic neuron, they bind to their
receptors on the postsynaptic membrane, and
• finally their effects are often rapidly terminated through removal
and/or degradation
49. Nearly all neurotransmitters induce postsynaptic potentials by binding
to their receptors in the postsynaptic membrane. The type of receptor
to which a neurotransmitter binds determines the postsynaptic
response. Two types of neurotransmitter receptors have been
identified: ionotropic and metabotropic.
Ionotropic receptors
Metabotropic Receptors
50. Ionotropic
Receptors
• These are receptors that are part of
ligand-gated ion channels.
• They are called ionotropic because
they directly control the movement
of ions into or out of the neuron
when bound by a neurotransmitter.
• Neurotransmitters that bind
ionotropic receptors have very rapid
but short-lived effects on the
membrane potential of the
postsynaptic neuron.
51. Metabotropic
Receptors
• are receptors within the plasma membrane
that are connected to a separate ion
channel in some fashion.
• They are called metabotropic because they
are directly connected to metabolic
processes that begin when they are bound
by neurotransmitters.
• Most are connected through a group of
intracellular enzymes called G-proteins.
When the neurotransmitter molecule binds
to the receptor, it activates one or more G-
proteins and begins a cascade of enzyme-
catalyzed reactions that ends in the
formation of a molecule inside the
postsynaptic neuron, called a second
messenger
52. Metabotropic
receptors
• The second messenger then opens or closes an ion
channel in the plasma membrane of the
postsynaptic neuron.
• The changes that metabotropic receptors elicit in
the membrane potential of the postsynaptic neuron
occur much more slowly,but are typically longer-
lasting and more varied than those of ionotropic
receptors.
• An example of a common second messenger is the
molecule cyclic adenosine monophosphate (or
cAMP), which is derived from ATP. In the neuron,
cAMP has multiple functions, including binding a
group of enzymes that add phosphate groups to ion
channels, triggering them to open or close.
53. CRITERIA FOR
NEUROTRANSMITTER.
• Should be synthesized by pre synaptic neuron & stored in vesicle.
• Should be released by stimulation of nerve.
• Travels a short distance of synaptic cleft.
• Associated with enzyme or enzyme system for
• inactivation.
• When applied extrinsically should mimic effect of nerve stimulation.
• Regardless of the type of receptor that a neurotransmitter binds,
that binding leads to either EPSPs or IPSPs.
• Neurotransmitters that induce EPSPs in the postsynaptic neuron are
said to have excitatory effects; those that induce IPSPs have
inhibitory effects.
• A single neurotransmitter can have both inhibitory and excitatory
effects depending on which neurotransmitter it binds on the post
synaptic neuron.
54. CLASSIFICATION.
■ Neurotransmitters operating within the nervous system are
usually classified into four groups by their chemical structures.
■ Biochemical
■ Small molecule
■
■
■ Acetylcholine
Biogenic amines. (E,NE, DA,5HT, Histamine)
Amino acids (GABA, Glycine, Glutamate,
Aspartate)
■ Neuro peptide.
■ Physiological
■ Excitatory
■ Inbitory
55. ACETYLCHOLINE
Thursday, February 1, 2018
■ Principal NT released by cholinergic neurons.
■ At N-M junction.
■ Preganglionic & post-ganglionic Para-
sympathetic
■ Preganglionic Sympathetic.
■ Postganglionic sympathetic which innervates –
sweat glands & skeletal muscle blood vessels.
■ Ending of Amacrine cells of retina.
56. ACETYLCHOLINE
■ Receptors – Nicotinic &
Muscarinic.
■ Synthesis & storage – in
Mitochandria by AchCoa &
stored in vesicles.
■ Actions – most places its
excitatory but few (vagus
supplying heart) – inhibitory.
57. MUSCARINIC VERSUS NICOTINIC ACTIONS OF AcH.
FEATURES MUSCARINIC NICOTINIC
Site of action Post synaptic in Cardiac ❖All Autonomic
muscle, Smooth muscle Ganglia
& Glandular cells. ❖N-M junction in
skeletal muscles.
Characteristics of action ❖Same as Mushroom ❖Same as drug
poison – Muscarine. Nicotine.
❖Action – slow in onset. ❖Action – Quick in
❖Duration - Prolonged. onset.
❖Duration – Brief.
Actions antagonised by Atropine ❖Hexamethonium at
Autonomic Ganglia
❖Tubocurarine at
skeletal muscles.
58. BIOGENIC AMINES.
■ Catecholamines.
■ Epinephrine – mainly from
adrenal medulla.
■ Nor-epinephrine –
■ Post Ganglionic Symp
■ Cerebral cortex &
Hypothalamus.
■ Pons & Medulla.
Thursday, February 1, 2018
■ Synthesis of
catecholamine.
59. Dopamine.
• Dopamine, used extensively in the CNS, has a variety of functions.
• It helps to coordinate movement, and is also involved in emotion and
motivation.
• The receptor for dopamine in the brain is a target for certain illegal
drugs, such as cocaine and amphetamine, and is likely responsible for
the behavioral changes seen with addiction to these drugs.
60. DOPAMINE
■ Naturally acting
precursors of NE.
■ Receptors
■
■
■ D1 – Activates adenyl cyclase
via Gs protein
D2 – Inhibit adenyl cyclase
via Gi protein.
D3 – Localised to Nucleus
Accumbens.
■ Neurons – in Mid brain
to
■ Striatum
■ Olfactory tubercle
■ Nucleus accumbens
■ limbic system area.
■ Highest conc present in
Basal Ganglia, limbic
system & CTZ in medulla.
61. FUNCTIONAL ROLES OF DOPAMINE
■ Control of Movements
■ Induction of Vomiting.
■ Inhibition of Prolactin secretion & stimulation of
GnRH.
■ Retina – Inhibitory Neurons.
■ Schizophrenia type of Psychosis due to Increased
levels of D2 receptors.
62. SEROTONIN.
Thursday, February 1, 2018
■ Synthesis – from
Tryptophan.
■ Metabolism –
Inactivated by MAO to
5-hydroxy indole acetic
acid(5-HIAA)
■ Sites of secretion
■ In Brain
■ Non-neural cells.
63. SEROTONIN.
Thursday, February 1, 2018
■ Serotonin receptors –
■ 7 group of receptors
(5HT1-5HT7) with further
groups A-F.
■ Functional role in CNS
■ Regulation of carbohydrate
intake & Hypothalamic
releasing hormones.
■ Pain inhibition.
■ Hallucination
64. HISTAMINE
■ Sites of secretion
■ In Brain & Non-neural cells.
■ Histamine receptors
■ H1 – activates Phospholipase C
■ H2 – increases intracellular cAMP
■ H3 – inhibition of histamine via G protein.
■ Functional role
■ Excitatory
■ Arousal & sexual behaviour, Regulation of ant pituitary, Drinking, Pain
threshold & Itch sensation.
65. AMINO ACID
NEUROTRANSMITTERS
• Glutamate; glycine; and g-aminobutyric
acid, or GABA.
• Glutamate is the most important
excitatory neurotransmitter in the CNS—
it is estimated that over half of all
synapses in the CNS release glutamate.
• When it binds to its ionotropic
postsynaptic receptors, glutamate
triggers the opening of a type of channel
that can pass both sodium and calcium
ions.
• This elicits an EPSP in the postsynaptic
neuron.
■ Excitatory
■ Glutamate – Brain &
dorsal sensory nerve
■ Aspartate - Cortical
pyramidal cells.
■ Inhibitory
■ GABA – whole CNS
■ Glycine. – Grey matter of
spinal cord & brain stem.
66. GLUTAMIC ACID
■ Synthesis – Mainly
from Glucose via Kreb
cycle or Glutamine,
synthesized by Glial
cells & taken by
neurons.
■ Receptors – High
conc in Hippocampus
& Cerebellum.
67. GABA &
Glycine
• Receptors –
• A – Inhibition by increasing Cl conductance
• B – By K conductance
• C – in Retina.
• Glycine and GABA are the two major inhibitory
neurotransmitters of the nervous system. Both induce IPSPs in
the postsynaptic neurons primarily by opening chloride ion
channels and hyperpolarizing the axolemma. GABA use is
widespread in the CNS; as many as one-third of neurons in the
brain use it as their major inhibitory neurotransmitter. Glycine is
found in about half of the inhibitory synapses in the spinal cord;
the remainder of the synapses use GABA.
68. NEUROPEPTIDE
TRANSMITTERS.
• Mechanism of action –
• Alter ion channel function, modify cell metabolism & gene
expression.
• Types.
• Neuroactive peptides – TRH, LH releasing hormone,
somatostatin.
• Pituitary peptides – Vasopressin & Oxytocin.
• Peptides acting on the Gut and Brain – Leucine,
Enkephalin, Methionine, Sub P, Cholecystokinin, VIP,
Neurotensin, Insulin, Glucose, Opioid polypeptides.
Thursday, February 1, 2018
69. Apply What you learned
• Which neurotransmitters have largely excitatory effects?
• Which neurotransmitters have largely inhibitory effects?
• . Predict the effects of the poison strychnine, which blocks glycine
receptors on postsynaptic neurons of the CNS.
Think About it??