Functions of the Spinal Cord Essay
The spinal cord performs the conductor and reflex functions.
The conductor function is carried out by the ascending and descending paths passing through the white matter of the spinal cord. They connect individual segments of the spinal cord to each other, as well as to the brain.
Reflex function is performed by unconditioned reflexes closing at the level of certain segments of the spinal cord and responsible for the simplest adaptive reactions. Neck segments of the spinal cord (C3 – C5) innervate the movements of the diaphragm, thoracic (T1 – T12) – external and internal intercostal muscles; Cervical (C5 – C8) and thoracic (T1 – T2) are the centers of movement of the upper limbs, lumbar (L2 – L4) and sacral (S1 – S2) – the centers of movement of the lower limbs. Functions of the Spinal Cord Essay.
In addition, the spinal cord participates in the exercise of autonomic reflexes – the response of internal organs to the irritation of visceral and somatic receptors. Vegetative centers of the spinal cord located in the lateral horns are involved in the regulation of blood pressure, cardiac activity, secretion and motility of the digestive tract and the function of the genitourinary system.
In the lumbosacral spinal cord is the center of defecation, from which the parasympathetic fibers in the pelvic nerve are impulses that enhance the rectal motility and provide a controlled act of defecation. Functions of the Spinal Cord Essay.An arbitrary act of defecation takes place due to the descending effects of the brain on the spinal center. In the II-IV sacral segments of the spinal cord there is a reflex center of urination providing a controlled urine compartment. The brain controls the urination and ensures a hundred randomness. In a newborn baby, urination and defecation are involuntary acts, and only as the regulatory function matures, the cerebral cortex becomes arbitrarily manageable (usually in the first 2-3 years of a child’s life).
The brain – the most important department of the central nervous system – is surrounded by the medullary membranes and is located in the cavity of the skull. It consists of the brainstem : the medulla oblongata, the bridge, the cerebellum, the midbrain, the midbrain, and the so-called strong brain, consisting of subcortical, or basal, ganglia and large hemispheres (Figure 11.4). The upper surface of the brain in shape corresponds to the inner concave surface of the cranial vault, the lower surface (the base of the brain) has a complex relief corresponding to the cranial fossa of the inner base of the skull.
Fig. 11.4. The structure of the brain
The brain is intensively formed during embryogenesis, its main parts are allocated already by the 3rd month of intrauterine development, and by the 5th month the main furrows of the large hemispheres are clearly visible. In a newborn, the mass of the brain is about 400 g, its ratio with the body weight is significantly different from the adult – it is 1/8 of the body weight, while in the adult it is 1/40. The most intensive period of growth and development of the human brain occurs during early childhood, then the rate of its growth is somewhat reduced, but continue to be high up to 6-7 years, by this time the brain mass reaches already 4/5 of the brain mass of an adult.Functions of the Spinal Cord Essay. The final maturation of the brain ends only by 17-20 years, its mass increases in comparison with the newborn by 4-5 times and is on average in men 1400 g, and in women – 1260 g (the mass of the adult brain varies from 1100 to 2000 g ). The length of the brain in an adult is 160-180 mm, and the diameter is up to 140 mm. Further, the mass and volume of the brain remain the maximum and constant for each person. Interestingly, the mass of the brain does not directly correlate with a person’s mental abilities, but with a decrease in brain mass below 1000 g, a decrease in intelligence is natural.
Changes in the size, shape and mass of the brain during development are accompanied by a change in its internal structure. The structure of neurons, the form of inter-neural connections becomes more complicated, the white and gray matter become clearly delineated, and various conduction pathways of the brain are formed. Functions of the Spinal Cord Essay.
The development of the brain, like other systems, is heterochronous (uneven). Earlier, others mature those structures on which the normal vital activity of the organism at a given age stage depends. Functional usefulness is first achieved by stem, subcortical and cortical structures regulating the autonomic functions of the body. These departments in their development are approaching the brain of an adult person by the age of 2-4.
The brain is the center of human body’s control. All feelings, thoughts and actions are conditioned by the work of the central nervous system. The brain controls the body by sending electrical signals through the nerve fibers, which first combine into the spinal cord, and then spread out through various organs (along the peripheral nervous system). According to Ciccarelli and White (2016), the spinal cord is a “cord” of nerve fibers and is located in the middle of the spinal column. The brain and spinal cord form together the central nervous system (CNS).
The functions of the brain include the processing of sensory information, which comes from the senses. The speech is going about positive and negative emotions, process of planning, coordination and movement control, decision-making process, memory and attention. The highest function that is thinking is also performed by the human brain. In addition, understanding and speech generation are also important functions of the brain.
The spinal cord has a rather complex structure and provides transmission of nerve impulses from the brain to the peripheral structures of the nervous system, and also carries out its own reflex activity. Normal breathing, palpitation, digestion, urination, sexual activity, and any movements in the limbs are impossible without the functioning of the spinal cord. Functions of the Spinal Cord Essay.
The spinal cord is endowed with two important functions – the reflex and the conductive. Presence of the simplest motor reflexes is caused by the reflex function of the spinal cord. The connection of the spinal cord to the skeletal muscles is possible due to the reflex arc, which is the pathway of nerve impulses. The conducting function consists in transferring nerve impulses from the spinal cord to the brain (with the help of ascending paths of movement), as well as from the brain along descending paths to the organs of various body systems.
The structure of the brain and spinal cord has much in common. This becomes clear with a detailed examination of the white substance of the medulla oblongata. The white matter of the brain is represented by long and short nerve fibers. The gray matter is represented in the form of nuclei. This brain is responsible for coordination of movement, balance, regulation of metabolism, circulation and respiration. It is also responsible for coughing and sneezing. Moreover, downward impulses allow the brain to “manage” the body. Thus, everything the person has conceived is carried out with the help of the spinal cord, while normal functioning of the spinal cord provides all the vital activity of man. It serves as an intermediate link between the brain and various parts of the body, transmitting information in the form of impulses in both directions.Functions of the Spinal Cord Essay.