Objectives: *Explain the importance of the central nervous system *Define the movements of neurons in the human body *State the function of neuron-to-neuron and neuron-to-muscle
Neural - Relating to a nerve of the nervous system. Situated in the region of the body or the side of the body as the brain and spinal cord: DORSAL Neutral - N ot helping or supporting either side in a conflict, disagreement, etc.; impartial. H aving no strongly marked or positive characteristics or features
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What is Central Nervous System?
Central Nervous System (CNS) Nervous system includes the brain, spinal cord, and a complex network of nerves. This system sends messages back and forth between the brain and the body. The brain is what controls all the body’s functions. The spinal cord runs from the brain down through the back nervous
Peripheral Nervous System Peripheral nerves reside outside the brain and the spinal cord. They relay information between the brain and the rest of the body. SENSORY (afferent) nerves carry signals to your brain or report information to the brain. MOTOR (efferent) nerves respond by sending messages from the CNS to the body for movement.
Types of Motor Nerves The AUTONOMIC nervous system controls involuntary bodily functions and regulates glands. The SOMATIC nervous system controls muscle movement and relays information.
2 division of the autonomic nervous system Sympathetic (SNS) is the division that is predominant during exercise and responding to dangerous or stressful situations. Parasympathetic (PARA SNS) is the division that is predominant at rest and responsible when there are not any stressful demands on the body.
What is NEURON??
NEURONS Neurons are information messengers. They use electrical impulses and chemical signals to transmit information between different areas of the brain, and between the brain and the rest of the nervous system.
Dendrites A dendrite (tree branch) is where a neuron receives input from other cells. Parts of Neurons Nucleus The Nucleus of a neuron is an oval-shaped membrane-bound structure found in the soma or body of the neuron Nucleolus An area inside the nucleus of a cell that is made up of RNA and proteins and is where ribosomes are made.
Nissl Bodies Nissl bodies, also called nissl substance, are granules in the cytoplasm of nerve cell bodies that are strongly stained by basic dyes and appear as basophilic clumps on light microscopy. Axon hillock Medicine Axon hillock is an axon nerve fiber that is a long projection of a neuron that carries the outbound neuronal cell signals as opposed to dendrites, which are the short protrusions from the neuronal cell body that brings in the inbound signals to the neuron. Cell body The cell body contains genetic information, maintains the neuron's structure, and provides energy to drive activities
Myelin Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. Node of Ranvier These are the gaps formed between the myelin sheath where the axons are left uncovered. NEURILEMMA Neurilemma is the plasma membrane surrounding a Schwann cell of a myelinated nerve fiber and separating layers of myelin .
Axon terminal or synaptic knob A synaptic knob is a terminal branch at the end of the post-synaptic neuron. The presynaptic neuron ends in swelling and is called the synaptic knob. Axon Each neuron in your brain has one long cable that snakes away from the main part of the cell. This cable, several times thinner than a human hair, is called an axon, and it is where electrical impulses from the neuron travel away to be received by other neurons.
Do you have any idea about SYNAPSE?
SYNAPSE (neuron-neuron) A synapse is a small gap at the end of a neuron that allows a signal to pass from one neuron to the next or a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.
Parts that are involved in synapse Presynaptic Neuron Transmits the signal toward a synapse. Postsynaptic Neuron Transmits the signal away from the synapse . Synaptic Vesicle Synaptic vesicles (SVs) are small, electron-lucent vesicles that are clustered at presynaptic terminals.
Neurotransmitter Neurotransmitters are chemical messengers that your body can't function without. Synaptic Cleft The space between neurons at a nerve synapse across which a nerve impulse is transmitted by a neurotransmitter . Postsynaptic Receptors Part of the neuron that receives a nerve impulse after it has crossed a synapse.
What do you know about the Neuromuscular junction?
Neuromuscular Junction/ NMJ (neuron – muscle) The neuromuscular junction, also called myoneural junction , site of chemical communication between a nerve fibre and a muscle cell . The neuromuscular junction is analogous to the synapse between two neurons .
Parts that are involved in Neuromuscular Junction Motor end plate A motor end plate is a chemical synapse that is formed at the sites where the terminal branches of the axon contact a target muscle cell. Motor neurons fiber Motor neurons are divided into two groups. Alpha motor neurons innervate extrafusal fibers, the high-contracting fibers that supply the muscle with its power.
Nerve fiber Branches Group A nerve fibers are one of the three classes of the nerve fiber as generally classified by Erlanger and Gasser. The other two classes are the group B nerve fibers and the group C nerve fibers. Group A is heavily myelinated, group B is moderately myelinated, and group C is unmyelinated M yofibril of muscle fiber A lso known as a muscle fibril or sarcostyle is a basic rod-like organelle of a muscle cell.
EPSPs and IPSPs
EPSPs and IPSPs
EPSPs and IPSPs
EPSPs and IPSPs APs can be either excitatory or inhibitory Excitatory Postsynaptic Potential (EPSP) Inhibitory Postsynaptic Potential (IPSP) Summation - Depolarization (EPSP) Hyperpolarization (IPSP) Axon hillock