Nervous System Part I

BIOELECTRIC

Biolistrik there is electricity in living things. Voltage is different from the body that we imagine an electric power in households. Electricity on the body related to the ion composition can be contained within the body.

Ion composition of different cell an extra intra-cell ion composition. In the extra cells more Na and Cl ions, while the intra cell K ions and anions are proteins. The cell walls have doors - doors ion the gap - a gap that can be opened or closed by the influence of certain stimuli. In the resting state in the electric voltage is lower than the outside of the cell about 70 mVolt.

If there is pain stimuli, the pain receptors of the tip - do not bermielin exposed nerve endings stimulated Na ion door open   Na ions enter quickly so that there is a difference in the charge outside the cell is very small and can even be reversed, meaning that the positive charge in the cell over the next occurred receptor potential / voltage receptors. It stimulates the action potential in nerve cell axons. This action potential propagates along the axon is called impulse. Once the nerve to nerve connections (synapses) with muscle or nerve connections (neuromial junction) there occurs the crossing of the nerve impulses and transmitted to the next or to the muscle cells. So if the pain that damage the skin will be forwarded in the form of impulses to the brain until we feel pain and there was a reflex reaction is to avoid muscle pain.

BRAIN

The brain is divided into two large brain (cerebrum) and a small brain (cerebellum). Cerebrum consists of the frontal lobe, parientalis lobe, occipital lobe and temporal lobe. Bergelumbang brain surface and grooved to form such a curve is called a gyrus.

Large brain is the center of:

- Motor: received impulses transmitted by the nerve cells and then towards the center of the muscle contraction

- Sensory: every sensory impulse is delivered via the axons of nerve cells which then reaches the brain including the cerebral cortex.

- Reflex: the reflex activities centered in the brain and brain stem most other parts of the spinal cord.

- Awareness: the brain stem called the reticular formasio with other parts of the cerebral cortex at the center of the major awareness.

- Function of the sublime: the center of thinking, speaking and numeracy another - another. In the anterior part of the central sulcus is the motor driving the muscles.

SEREBLUM

The cerebellum is the center of balance and movement kooardinasi. In the area of ​​the cerebellum are the circle of Willis, at the base of the brain surrounding the pituitary gland, an arterial circle formed between a series of internal carotid arteries and vertebral, the circle is called the circle of Willis is formed from branches of the internal carotid artery, anterior and middle cerebral arteries and arterial connecting the anterior and posterior. Arteries in the circle of Willis provide an alternative to blood flow if one of the major artery blood flow is blocked.

Cerebrospinal fluid

Fluid is a clean and colorless with a density of 1.007. Produced in the ventricles and circulates around the brain and spinal cord through the ventricular system.CSS fluid produced in the choroid plexus in the lateral third and fourth ventricles, the organic and non organic liquid CSS the same but have different plasma konsenterasi.

CSS-containing protein, glucose and chloride, and immunoglobulin. CSS normally contain only a few white blood cells and does not contain red blood cells.CSS in the body fluid is absorbed by villiarakhnoid.

The spinal cord

- Is central reflexes that were there

- Successor to the sensory nerves of the brain and where the entry of the sensory

- Successor of motor impulses from the brain to motor nerve

- Center geraka simple pattern that has been long in the study sample step.

Somatic NERVE:

Peripheral nerve is a sensory nerve from the central and peripheral motor saaf from the center to the periphery. Based on the exit is divided into the brain and spinal nerves.

Spinal cord

Pairs of nerves exit the spinal cord left and right vertebrae:

- 8 pairs of cervical nerves

- 12 pairs of thoracic nerves

- 5 pairs of lumbar nerves

- Sara sacrum / sacral 5 pairs

- 1 pair of nerves koksigeal

Spinal nerve contains sensory and motor nerve, sensory fibers enter the spinal cord through the cord and roots kaluar motor fibers of the spinal cord through the front of the then united to form the roots of spinal nerves.

These nerves form a plexus some groups (woven) and formed a variety of neural (nerve) as iskiadikus nerve for sensory and motor area of ​​the lower leg. Thoracic region did not form a braid, but each - one straight bone between the ribs (nerve inter kostalis). Generally in these nerve fibers also contain autonomic, mainly sympathetic fibers to blood vessels leading to the appropriate area. Nerve fibers from the center in the cerebral cortex to the periphery occurs crossing (contra lateral) that is located at the crossing left to right and vice versa. So if there is damage in the center of the left motor is broken limb on the right.

AUTONOMIC NERVOUS

The nervous system has a capability of autonomous work, such as heart, lung, and digestive tract. Influenced by the autonomic nervous system sympathetic and parasympathetic.

Increased sympathetic activity shows:

- Preparedness to increase

- Heart rate increased

- Respiratory increased

- Muscle tone - increased muscle

- Movement of the gastrointestinal tract decreased

- Increases the body's metabolism.

All of these individuals prepare for fight or flight, it appears in humans when facing problems, work, exercise, anxiety and other - other, in these circumstances an increase in energy peggunaan / catabolism.

Showed an increase in parasympathetic activity:

- Preparedness to decline

- The pulse slowed jentung

- Respiratory quiet

- Decreased muscle tone

- Movement of the gastrointestinal tract increases

- Decreased metabolism

This is the case of energy storage (anabolism) and look if the individual is resting.

Sympathetic nerve center of the spinal cord at the thoracic and lumbar, while the parasympathetic is at the center of the medulla oblongata and sacral spinal cord.Center - the center is still influenced by higher centers in the hypothalamus as the center of emotion.

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