Explain the following terms :
(a) Motor nerve .............................
(b) Autonomic nervous system .....................
(c) Conditioned reflex .............................
(d) Association neuron ..........................
(e) Grey matter .............................
Explain the following terms :
(a) Motor nerve .............................
(b) Autonomic nervous system .....................
(c) Conditioned reflex .............................
(d) Association neuron ..........................
(e) Grey matter .............................
(a) Motor nerve: Depending on their function, nerves are known as sensory, motor, or mixed. Motor nerves or efferent nerves, transmit impulses from the brain and spinal cord to the muscles.
Technically, a motor nerve is a macroscopic cord-like structure of the body comprising a collection of nerve fibres that convey impulses between a part of the central nervous system and some other body region.
(b) Autonomic Nervous System. The autonomic nervous system (ANS) is a division of the peripheral nervous system that influences the functioning of internal organs. It is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, papillary response, urination, etc. This system is the primary mechanism in control of the fight-or-flight response and the freeze and dissociates response.
Within the brain, the autonomic nervous system is regulated by the hypothalamus. Autonomic functions include vasomotor activity (the vasomotor centre, and certain reflex actions such as coughing, sneezing, swallowing and vomiting.
Those are then subdivided into other areas and are linked to ANS subsystems and nervous systems external to the brain. The hypothalamus, just above the brain stem, acts as an integrator for autonomic functions, receiving ANS regulatory input from the limbic system to do so.
(c) Conditioned reflex. It is an acquired response that is under the control of (conditioned on the occurrence of) a stimulus. It is brought about by a condition totally different from the direct initial stimulus. It is developed by experience or learning. For this reason, it differs in different individuals (subject to learning and experience).
(d) Association neuron. An association neuron (also called relay neuron, connector neuron or local circuit neuron) is one of the 3 classifications of neurons found in the human body. Association neurons create neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They have been found to function in reflexes, neuronal oscillations and neurogenesis in the adult mammalian brain. Interneurons, Local interneurons have short axons and form circuits with the nearby neutrons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons on one region of the brain with those in other regions. The interaction between interneurons allows the brain to perform complex functions such as learning, and decision making.
(e) Grey matter. It is the major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and myelinated system as well as unmyelinated axons), glial cells, synapses, and capillaries. Grey matter is distinguished from white matter, in that it contains numerous cell bodies and relatively very few cell bodies and is composed chiefly of long-range myelinated axon tracts. The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies.
(a) Motor nerve: Depending on their function, nerves are known as sensory, motor, or mixed. Motor nerves or efferent nerves, transmit impulses from the brain and spinal cord to the muscles.
Technically, a motor nerve is a macroscopic cord-like structure of the body comprising a collection of nerve fibres that convey impulses between a part of the central nervous system and some other body region.
(b) Autonomic Nervous System. The autonomic nervous system (ANS) is a division of the peripheral nervous system that influences the functioning of internal organs. It is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, papillary response, urination, etc. This system is the primary mechanism in control of the fight-or-flight response and the freeze and dissociates response.
Within the brain, the autonomic nervous system is regulated by the hypothalamus. Autonomic functions include vasomotor activity (the vasomotor centre, and certain reflex actions such as coughing, sneezing, swallowing and vomiting.
Those are then subdivided into other areas and are linked to ANS subsystems and nervous systems external to the brain. The hypothalamus, just above the brain stem, acts as an integrator for autonomic functions, receiving ANS regulatory input from the limbic system to do so.
(c) Conditioned reflex. It is an acquired response that is under the control of (conditioned on the occurrence of) a stimulus. It is brought about by a condition totally different from the direct initial stimulus. It is developed by experience or learning. For this reason, it differs in different individuals (subject to learning and experience).
(d) Association neuron. An association neuron (also called relay neuron, connector neuron or local circuit neuron) is one of the 3 classifications of neurons found in the human body. Association neurons create neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They have been found to function in reflexes, neuronal oscillations and neurogenesis in the adult mammalian brain. Interneurons, Local interneurons have short axons and form circuits with the nearby neutrons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons on one region of the brain with those in other regions. The interaction between interneurons allows the brain to perform complex functions such as learning, and decision making.
(e) Grey matter. It is the major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and myelinated system as well as unmyelinated axons), glial cells, synapses, and capillaries. Grey matter is distinguished from white matter, in that it contains numerous cell bodies and relatively very few cell bodies and is composed chiefly of long-range myelinated axon tracts. The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies.
