Nt1310 Unit 8 Assignment

SC/121
Leslie Boyle
Unit 8: Assignment
July 06, 2015

The human body is everything that makes up, well, you. The basic parts of the human body are the head, neck, torso, arms, and legs. Our bodies consist of a number of biological systems that carry out specific functions necessary for everyday living. The following paragraphs are going to explain the functions of two different body systems.
The nervous system controls both voluntary action (like conscious movement) and involuntary actions (like breathing) and sends signals to different parts of the body. The central nervous system includes the brain, spinal cord, sensory organs, and all of the nerves that connect these organs to the rest of the body. Together, these organs are responsible for the control of the body and communication among its parts. The brain and spinal cord form the control center, also known as the central nervous system, where information is

evaluated and decisions made. The peripheral nervous system consists of nerves that connect every other part of the body to the central nervous system. The sensory nerves and sense organs of the peripheral system monitor conditions inside and outside the body and send this information to the central nervous system. Efferent nerves in the peripheral nervous system carry signals from the control center to the muscles, glands, and organs to regulate their functions.
The majority of the nervous system is made up of two classes of cells: neurons and neuroglia. Neurons, also known as nerve cells, communicate within the body by transmitting electrochemical signals. Neurons look quite different from other cells in the body due to the many long cellular processes that extend from their central cell body. The cell body is the roughly round part of a neuron that contains the nucleus, mitochondria, and most of the cellular organelles. Small tree-like structures called dendrites extend from the cell body to pick up stimuli from the environment, other neurons, or sensory receptor cells. Long transmitting processes called axons extend from the cell body to send signals onward to other neurons or effector cells in the body.
The brain is a soft, wrinkly, 3 pound organ that is located inside the cranial cavity, where the bones of the skull surround and protect it. The approximately 100 billion neurons of the brain form the main control center of the body (Zimmerman, 2015). The brain and the spinal cord together form the central nervous system. Here information is processed and responses are originated. The brain is responsible for planning, consciousness, memory, and voluntary actions and it also controls the lower body functions such as the maintenance of respiration, heart rate, blood pressure, and digestion.
The spinal cord is a long, thin mass made of up neurons that carry information through the vertebral cavity of the spine beginning at the medulla oblongata of the brain on its superior end and continuing inferiorly to the lumbar region of the spine. The white matter of the spinal cord functions as the main conduit of nerve signals to the body from the brain. The grey matter of the spinal cord integrates reflexes to the stimuli.
Since the nervous system does not store nutrients, it must receive a continuous supply from blood. The nervous system maintains homeostasis by controlling and regulating the other parts of the body. A deviation from a normal set point acts as a stimulus to a receptor, which sends nerve impulses to a regulating center in the brain. For example, the deviation was a lowering of body temperature, the effector acts to increase body temperature. The adaptive response returns the body to a state of normalcy. Since the effector is regulated by the very conditions it produced, this process is called control by negative feedback.
The role of the immune system is a collection of structures and processes within the body—is to protect against diseases or other potentially damaging foreign bodies.

When functioning properly, the immune system identifies a variety of threats, including viruses, bacteria and parasites, and distinguishes them from the body’s own healthy tissue. The major components of the immune system include: lymph nodes, bone marrow, spleen, lymphocytes, thymus, and leukocytes. Lymph nodes are small bean shaped structures that produce and store cells that fight infection and disease and are part of the lymphatic system. The lymphatic system and the immune system are very closely related. Lymph nodes also contain a clear fluid that carries cells to different parts of the body. When the body is fighting off infection lymph nodes can become enlarged and swollen and even feel sore. For example, when the body is trying to fight off an infection you may notice that the lymph nodes around your neck which are located under your ears become

inflamed.
The largest lymphatic organ in the body is the spleen which is located on your left side under your ribs and above your stomach. It contains white blood cells that fight infection and disease. According the National Institutes of Health (NIH), the spleen also helps control the amount of blood in the body and disposes of old or damaged blood cells. Bone marrow is the yellow tissue in the center of the bones that produce white blood cells. Lymphocytes are small white blood cells that play a role in defending the body against disease. There are two types of lymphocytes: B cells, which make antibodies that attack bacteria and toxins, and T-cells which help destroy infected or cancerous cells. Killer T-cells which are a subgroup of T-cells, kill cells that are infected with viruses and other pathogens or are otherwise damaged. The thymus is a small organ where T-cells mature. The thymus is located beneath the breastbone and can trigger and maintain the production of antibodies that result in muscle weakness. Leukocytes are white blood cells that fight disease and identify with and eliminate pathogens and are second arm to the innate immune system. A white blood cell count is referred to as leukocytes, according to the Mayo Clinic.
A homeostatic feedback mechanism in the immune system would be the spleen. The spleen works to fight off the disease and viruses and restore the body to its original state. The nervous system and the immune system work together to maintain the body in a homeostatic state. Every system within the body works together to keep the human body functioning. For example, the immune system cannot do its job without the nervous system. The brain influences the whole body and sends signals to the body in making decisions.

References:
National Institutes of Health. (2012). The Human Body. Retrieved from http://www.nih.gov

Mayo Clinic. (2015). Functions of the Human Body. Retrieved from http://www.mayoclinic.org

Zimmerman, K. (2015). Live Science. Nervous System: Facts, Functions, and Diseases. Retrieved from http://www.livescience.com)