The organization of the vertebrate nervous system is different from invertebrates. Vertebrates have a well-organized hollow dorsal nervous system. The central nervous system included a brain and spinal cord. The peripheral nervous system comprise peripheral nerves extending from spinal cord and peripheral ganglia. nervous
Showing posts with label nervous system. Show all posts
Showing posts with label nervous system. Show all posts
vertebrate nervous system
basal ganglia
Basal ganglia is composed of some nuclei in the diencephelon; caudate nucleus, putamen, globus pallidus and substantia nigra. These are neural structure is related with motor function. Basal ganglia receive afferents from motor cortex and send efferents to the thalamus and then to the cortex. Basal ganglia controls the motor impulses conducted from cortex to the spinal cord. The complex fine movements is coordinated by the nasal ganglia. In the failure of the nasal ganglia, spontenous contraction occur in the extremity muscle.
autonomic nervous system
in simple animal autonomic fibers directly originate the segmentally arranged nerve cord and travel to the visceral organ as like peripheral nerves. In higher vertebrate and mammals, there are postganglionic ganglia in the periphery near to the inervated organ. Autonomic nerves innervate involuntary internal organs of the body.
After they emerge from spinal cord, it relays on a ganglia and the postganglionic fibers goes to the organ. When the autonomic nerves of a smooth muscle are cut, the smooth muscle continue to contruct and no athropy seen. But somatic nerve is destroyed, atrophy occur in the innervated organ. Autonomic nervous system is divided into two functional branches: the parasymphatetic branch and symphatetic branch. The preganglionic fibers of the parasymphatetic system exit the central nervous and synapse at the peripheral organs. Nervous system
The preganglionic fibers of symphatetic nerves leave the spinal cord via throracic and lumbar spinal nerves and synaplse on to the ganglia close to the spinal cord or synapse in more peripheral sympathetic ganglia. The symphatetic and parasymphatetic systems have antoganistic actions. In general the symphatetic nervous system preparres the body for response to stressful or dangerous situations; it initiates the fight of flight reactions, elevation of heart rate and increased force of contruction, peripheral vasoconstriction, and sweating.
In contrast, the parasymphatetic nervous system controls general bodily functions such as digestion. The neurotransmitter of postganglionic parasymphatetic synapse is acetylcholine, so the postsynaptyic receptors of these synapses are cholinergic.. http://nervous-system-info.blogspot.com/
The neurotransmitter of the symphatetic postganglionic synapse is usually norepinephrine, so there are adrenergic. The symphatetic neurotransmitter is epinephrine rather than norepinephrine rather than norepnephrine in some vertebrates. The neurotransmitter at the preganglionic synapse of both the parasymphatetic and symphatetic branches is acetylcholine.http://nervous-system-info.blogspot.com/
chemical synapses
The sequence of events during chemical synaptic transmission is :
1- the presynaptic action potential depolarizes the presynaptic membrane. 2- Ca+ permeability increase through the presynaptic membrane.
3-the elevated intracellular Ca+ concentration causes the release of neurotransmitter from synaptic vesicles in to synaptic cleft.
4- Neurotransmitter molecules diffuse across the synaptic cleft to the postsynaptic membrane and they reversibly bind to the specific receptors on the postsynaptic membrane.
Ca is very important in neurotransmitter release . The neuromucular junction is a typical chemical synapse. In this case two acetylcoline molecule are required to open the sodium channel. Postsynaptic membrane include acetycholine esterase to remove ACh.
In each postsynaptic end, a small depolarization is generated. That is called as end plate potential (EPP) or postsynaptic endplate potential.
These mini EPPs reflect the spontaneous release of one, or a few synaptic vesicles. Single EPPs does not generate in chemical synapsis . This ranges from 0.5 msec to 2.0 msec or even more.
electrical synapses
Electronic conduction is provided by gap junction between two neuronal membrane. these gap junctions are composed of numerous connections that allow direct movement of ions and small molecules. The direct electrical coupling of neurons is often observed when there is a requirement for the closesyncronization of effector organs. Examples are the cells of lobster heart, the electronic organ of mormyrid fish. the sound production muscle of toadfish and the escape response of some invertebrates.
http://nervous-system-info.blogspot.com/
There is no time delay, or latency in transmission of electrical depolarization in electrical synapses. The normal direction of synaptic transmission is from the presynaptic membrane to the postsynaptic membrane. Some electrical synapsis are inhibitory.
Synaptic Transmission
Action potentials are transmitted from one cell to another. There are two different mechanism for transfer of electrical from one cell to another .
1) electrical synapsis
2)chemical synapses
in electrical synapses, the action potential jumps electrotonically from the presynaptic cell membrane to the postsynaptic cell membrane. In the chemical synapsis, neurotransmitter released from one cell provide transmission of impulses.
Nervous System general
do you want to explore the nervous system ? this is general nervous system video.. there is a biochemical communications network of the human body, Revealing visuals are supported by informative features in which a neurologist discusses the chemistry of a nerve impulse.
The Nervous System video
The Nervous System video Animation from youtube . very great animation how nervous system works?
NUTRITIONAL SUGGESTIONS BY BODY SYSTEM
The Nervous system is an internal communication system, relaying signal with short electrical impulses. The central nervous system is composed of the brain and spinal cord. The peripheral nervous system extends to all other parts of the body. Health problems related to the nervous system include stress, insomnia, depression, nervous disorders, headaches and multiple sclerosis. click here to read full article
huntington's disease nervous system
what is Huntington disease ? it is shortly called HD and it is a genetic disorder of the central nervous system with symptoms usually appearing in adults within the third or fourth decade of life, although symptoms can occur in individuals younger or older than this.
Within the same family, the symptoms vary both in their rate of progression and in the age of onset. Symptoms may include involuntary movements and loss of motor control. In addition, personality changes may occur, with loss of memory and decreased mental capacity. Symptoms in individuals, as well as confirmation of diagnosis in other family members, are used to determine the diagnosis.
Huntington disease is inherited as an autosomal dominant condition.
interesting facts about brain
A newborn baby's brain grows almost 3 times during the course of its first year.
The left side of human brain controls the right side of the body and the right side of the brain controls the left side of the body. The total surface area of the human brain is about 25, 000 square cm. Only four percent of the brain's cells work while the remaining cells are kept in reserve. There are about 13, 500,00 neurons in the human spinal cord. As we get older, the brain loses almost one gram per year. The base of the spinal cord has a cluster of nerves, which are most sensitive.
An average adult male brain weighs about 1375 grams and for female brain is about 1275 grams.
Sense organs
The sense organs are highly specialized structures that receive information from the environment. Sense organs contain special sense receptors ranging from complex structures, such as eyes and ears, to small localized clusters of receptors, such as taste buds and olfactory epithelium. Smell and taste are chemical senses, which contain chemoreceptors that respond to chemicals in solution. Food chemicals dissolved in saliva stimulate taste receptors in taste buds. The nasal membranes produce fluids that dissolve chemicals in air. These chemicals stimulate smell receptors in olfactory epithelium. The chemical senses complement each other and respond to many of the same stimuli.
nervous system video
Very good video about nervous system, review for Structure and Function Nervous System. Nervous system video below :
central peripheral autonomic nervous systems
Central Nervous System which has has the responsibility for issuing nerve impulses and analyzing sensory data, and includes the brain and spinal cord,
Peripheral Nervous System which is responsible for carrying these nerve impulses to and from the body and many structures, including the many craniospinal nerves which branch off the brain and the spinal cord, and the
Autonomic nervous system which is composed of the sympathetic and parasympathetic systems and is responsible for regulating and coordinating the functions of vital organs in the body.
Location of emotions and brain
With all the other things we do, are you surprised that the brain is responsible for your emotions? Maybe get the toy you wanted for your birthday and you're very happy. Or your friend is sick and you feel sad. Or your little brother you have the messy room and are very angry! Have you ever wondered where they come from those feelings? All come from the brain that controls all the emotions you feel.
The brain has a small group of cells on each side called the amygdala. The word "amygdala" comes from the Latin word for "nuts" and that is the aspect that has this area. Scientists believe that the tonsils are responsible for emotions. So when you're sad about a friend who moves, your tonsils are working hard. But not everything that makes the amygdala is bad - also makes you feel excited when you win your soccer game.
It's normal to feel all sorts of emotions, good and bad. Sometimes you can feel a bit sad and ask why. And sometimes you can feel scared, silly or happy. These feelings are part of what makes us human
The pituitary gland
The pituitary gland is very small - is about the size of a pea! His job is to produce and release hormones in your body. If the clothes of last year I was very young, it is because the pituitary gland has released special hormones that you have made it grow. This gland also plays an important role during puberty. This is the time when the bodies of boys and girls go through major changes as they slowly become men and women - all thanks to hormones released by the pituitary gland. This small gland is involved with many other hormones, such as those that control the amount of sugar and water in the body. And keep your metabolism asset - your metabolism is everything that happens in your body to keep it alive and growing and to give you energy, like breathing, digesting food, and circulating blood
The brainstem
The brainstem
Another part of the brain that is small but powerful is the brainstem that is located below the cerebral cortex and cerebellum ahead. The brainstem connects the rest of the brain to the spinal cord, which covers your neck and back. The brainstem handles all the functions necessary to ensure that your body is alive, such as breathing, digestion of food and blood circulation.
Part of the role of the brainstem is to control involuntary muscles - those that run automatically, without thinking what. There are involuntary muscles in the heart and stomach, and is the brainstem who tells your heart to pump more blood when you go by bicycle or on your stomach to digest this piece of birthday cake you just eat. (Remember the cortex that controls voluntary muscles. Monitor all the muscles of the body is too big a task for part of the brain!). The brainstem also classifies the millions of messages that the brain and the rest of the body are sent. Uf! It's enough work to be the secretary of the brain!
The cerebellum
The cerebellum
The next part is the cerebellum. The cerebellum is in the back of the brain, below the crust. It is much smaller than the cerebral cortex, only 1 / 8 of its size. But do not let the small size of the cerebellum fool you - is working hard between racks, controlling the balance, movement and coordination (how your muscles work together). Thanks to the cerebellum can stop you erect, maintain balance and move from side to side. Think of a surfer uploaded to your table on the waves. What is it that more needs to maintain balance? The best table? The suit cooler? None of this - you need your cerebellum!
nervous system
The nervous system controls everything you do, for example, breathing, walking, what you think and what you feel. This system consists of the brain, spinal cord and all the nerves of the body. The brain is the control center and the spinal cord is the main highway that connects with him. Nerves transmit messages to the body and from the brain to interpret and act accordingly.
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