Anatomy Of The Nervous System

p.483 The cell bodies of primary-order neurons or pain-transmitting neurons reside in the dorsal root ganglia just lateral to the spine along the sensory pathways that penetrate the posterior part of the cord. The second order neurons are found in the dorsal horn (p.484) Most nociceptive information tranvels by means of ascending columns in the lateral spinothalamic tract (also called the anterolateral funiculus). The principal target for nociceptive afferents is the thalamus (the major relay station of sensory information in general) Third order neurons project to portions of the CNS involved in the processing and interpretation of pain, the chief areas being the reticular and limbic systems and cerebral cortex. (p 484)

Movement of the deltoid begins in the cerebrum of the brain, but more specifically: in the frontal lobe, the premotor cortex is relaying instructions to the primary motor cortex. The primary motor cortex contains the upper motor neurons whose axons will travel down the pyramids of the medulla oblongata and synapse on lower motor neurons in the anterior gray horns of spinal cord segments C5-C6. From there, the ventral rami of spinal nerves C5-C6 form the superior trunk of the brachial plexus, which splits into two divisions. We will follow the posterior division that supplies to extensor muscles. This posterior division then runs into the posterior cord from which the axillary nerve is derived. The axillary nerve’s motor end innervates the deltoid through its neuromuscular junction.

The cervical spinal nerve C3-5 innervate the phrenic nerve. These are the lower motor neurons.

Together, the two sides extend neck; alone, each rotates and laterally flexes neck to that side

The nervous system is a chain of interconnected nerve fibers which is constructed by the central nervous system and Peripheral nervous system. The job of the nervous system is to send messages from the brain and spinal cord to different parts of the body.

The CNS contains the brain and spinal cord. Its main functions include: processing, integrating, and coordinating sensory information and motor instructions. The sensory data conducts information that is being processed from internal and external conditions the body is experiencing. Motor commands regulate and control peripheral organs (skeletal muscles). The brain functions under memory, emotions, learning, and intelligence. The PNS consist of the neural tissue found outside of the CNS. It functions in sending data to the CNS which motor commands are than carried out to the peripheral tissues/systems. Multiple nerve fibers send sensory data and motor commands in the PNS. The nerves that assist with transmitting data include the cranial nerves and spinal nerve. However, the PNS can be divided into afferent (to bring in) and efferent (to bring out) divisions of transferring data. The afferent division functions in bringing in sensory data to the CNS. Sensory structures are receptors that detect internal/external environmental change and adjusting accordingly. The efferent division functions in carrying out motor commands from the CNS to glands, muscles, and adipose tissue. The efferent division contains somatic

It also increases blood pressure, releases sugar from the liver into the blood and increases the blood flow to the muscles used in physical action. Further, it tells the endocrine system to release hormones into the bloodstream to strengthen these responses.

and the coccygeal. The spinal cord has 31 spinal nerves. The spinal nerves are pairs of nerves that

The nervous system in a canine is made up of these three things: Brain, spinal cord and several different kinds of nerves located throughout the body. They create complex circuits through which animals experience and respond to sensations: The central nervous system includes the spinal cord and brain. The brain has three main sections: the brain stem that controls several basic life functions. The cerebrum, which is the center of conscious decision making, and lastly, the cerebellum which involves movement and motor skills in the animal. The most common type of nervous system circuit that most people are familiar with is the reflex. Reflexes are simple networks found in the nervous system of all animals. For example, if a dog goes down in

The nervous system is responsible for a variety of tasks that are vital to everyday living, these tasks range from maintaining the bodies’ daily functions to reacting to emergency situations. There are three general functions that the nervous system carries out: motor function, sensory function, and interpretative function. The motor function consists of nerves relaying information from the central nervous to the glands and muscles of the body. Sensory nerves gather information from both inside the body and the outside environment, the information is then conveyed to the central nervous system. Information is then processed and interpreted by the central nervous system.

The vertebrae are stacked on top of each other, grouped into four regions: Cervical, Thoracic, Lumbar and Sacral. Each vertebra consists of a ventral body or centrum surmounted by a Y-shaped neural arch. The arch stends a spinous process downward and backward that may be felt as a series of bumps down the back, and two transverse processes?, one to either side, which provide attachment for muscles and ligaments. Together the centrum and the neural arch surround an opening, the vertebral foramen, through which the spinal cord passes. The centrums are separated by cartilaginous intervertebral discs. Although vertebrae range in size, cervical the smallest, lumbar the largest, vertebral bodies are the weight-bearing structures of the spinal column. Upper body weight is distributed through the spine to the sacrum and pelvis. The natural curves in the spine, kyphotic and lordotic, provide resistance and elasticity in distributing body weight and axial loads sustained during movement. The vertebrae are composed of many elements that are critical to the overall function of the spine, which include the intervertebral discs and

Starting off as a pair of parachordal cartilage, the basal region, or basal plate will grow to surround the notochord and pair with prechordal cartilages, the trabeculae cranii, that form in front of the notochord to form the ethmoid plate. The occipital region will form at the posterior end of the chondrocranium and surround the descending notochord via a segmented occipital arch, which exhibits similarly to that of a vertebral column present in vertebrates having both a neural and hemal arch (3).

First order neurons concern the initial nerve impulse from the receptor and transmission of the stimuli to the spinal cord. Interestingly, many of these neurons are psuedounipolar (2). They have two axons and a central cell body. The central bodies of these neurons are concentrated in the dorsal root ganglion, which is located in the dorsal root of a spinal nerve. This nodule allows for organization of the neurons, particularly the axons, which join to form neural fibers. The peripheral axons extend away the cell body and end where stimuli will be received. This is where the receptors are located (1).

The nervous system is split up into two parts; the peripheral (PNS) and central (CNS) nervous systems. The central nervous system consists of two main parts; the brain and spinal cord. The brain receives and processes information as well as deal with memories, thoughts, emotion, and much more. The spinal cord mainly deals with sending out signals from the brain to the rest of the body, as well as control

The human brain and a spinal cord make up the central nervous system (CNS), which is responsible for mediating our behavior; it processes the afferent sensory information carried by the peripheral nervous system (PNS) – all