Sunday, February 27, 2011

Chapter Six The Skeletal System (Blog 6)

The Skeletal System is composed of bones and bone tissue. The skeletal system has four main components, bones, tendons, cartilage and ligaments. The major functions of the skeletal system are support, protection, movement and storage.  In supporting the body, the bones are used for bearing the weight of the body and is the major supporting tissue of the body. In protecting the body, bone protects the organs it surrounds. Skeletal muscle provides the body with movement in that it attaches muscle to bone by tendons. The contractions of skeletal muscles allows the bones to move therefore producing movements within the body. When providing storage, the skeletal system stores minerals within blood that are then taken into the bones. The essential minerals that are stored in bones are calcium and phosphorus. Both calcium and phosphorus are essential for many physiological processes within the body.

There are three types of cartilage involved in bone, hyaline cartilafge, fibrocartilage and elastic cartilage. Hyaline cartilage is the type of cartilage that is mostly associated with bone because it is the main cartilage that provides  the skeletal system with the  ability to help lengthen and strengthen the bones. Hyaline cartilage consists of specialized cells called chondroblasts(meaning the beginning ) that produces a matrix surrounding themselves. When matrix surrounds a chondroblast, it becomes a chondrocyte (a cell) that occupies a space called a lacuna.

The histology of bones begins with the bone matrix and the bone cells. Bone consists of extracellular bone matrix and bone cells. The bone cells produce the bone matrix, become entrapped within it and break it down so that the new matrix can replace the old matrix. The composition of the bone matrix is responsible for the characteristics of bone. The bone matrix is is thirty five percent organic and sixty five percent inorganic material. The organic material consists primarily of collagen and proteoglycans and the inorganic material consists of  a calcium phosphate crystal called hydroxyapatite. Bones are composed of three types of cells osteoblasts, osteocytes and osteoclasts.  Osteoblasts are the bone forming cells that release matrix vesicles, osteocytes are the cells of bone and osteoclasts are responsible for the reabsorption or breakdown of bone.There are four types of bone classifications, woven bone, lamellar bone, spongy bone and compact bone. Woven bone the collagen fibers randomly oriented in many directionsand lamellar bone is the mature bone that dervies from woven bone that is organized into thin sheets or layers with the collagen fibers being parallel to one another.  Spongy bone is composed of interconnecting rods or plates of bone called trabeculae and compact bone is denser and has fewer spaces than spongy bone. Compact bone contains blood vessels and loose connective tissue.

In understanding chapter six, I was able to grasp that without the skeletal system is the most important component within the body and that without the body would be unable to move and provides its essential full function of the body. Without calcium and phosphorus contained in the bones, the bones will not grow and will therefore result in the absence of bone growth and bone disease.

The questions that I developed based on my reading of chapter six were:

(1) How would bones function without all of the four types of bone working together (Woven, Lamellar, Spongy and Compact Bone)

(2) If calcium and phosphorus were absent from the bones, would the bones be able to function at their full potential?

(3)What role does fibrocartilage and elastic cartilage provide in the skelatal system?

(4) Where does the matrix vesicles lie within the bone?

(5) Why do all bones not contain sinus cavities?

Thursday, February 17, 2011

My Review Of Chapters' Eight, Fourteen, Fifteen And Sixteen

My review of chapter's eight, fourteen, fifteen and sixteen is that together the joints, the  special senses of the body, the autonomic nervous system and the functions of the nervous system all work together as a whole in order to facilitate and uphold the correct and proper functioning of the body. The most difficult chapters for me to interpret and understand while studying were chapter's fourteen and fifteen. Chapter fourteen was difficult for me to understand because the nervous system functions contained so many different and diverse components all of which provided a role in the functioning of the nervous system. In chapter fourteen the difficult components for me to understand were the functions of the cerebellar comparator and the anterolator system. I was able to understand that the anterolateral system was the spinothalamic tract that conatined primory, secondary and tertiary neurons, however the part that confused me the most was that  how could the spinothalamic tract help convey pain, temperature, light touch, pressure, tickle and itch.

Based on my reading of chapter fourteen, there were numerous types of receptors listed whose specific functions were related to the recognition ability of detecting the senses of pain, temperature, light touch, tickle and itch. For example, the mechanoreceptors, the nociceptors and the thermoreceptors were the receptors solely responsible for allowing the body to recognize the senses of the body and being able to detect when a stimuli is present upon the body surface. The direct and indirect pathways divided the descending motor parts into two distinctive groups, known as the pyramidal system and the extrapyramidal system. The difficult concept of understanding this material was that although both pathways contributed to the movement and control of the body's muscular system, each system controlled the opposite portion of the body. For example the direct pathways controlled the upper portion of the body, that being the movement of the head and the neck, however direct pathways contained a corticospinal tract and a cortibulbar tract. The corticospinal tract provided movements below the head, from my understand it provided neck movement, and the cortibulbar tract provided the direct movement in the head and neck, this concept originally confused me, however I was able to understand the concept of it by relating to an injury of the spinal cord, that being if either the cevical or thoracic lumbar is damaged , then therefore the direct and indirect pathways will be unable to function.

In chapter fifteen, the most dificult concept for me to understand was the process of olfaction and all of its components. The process involved in olfaction adaptation was largely confusing to me. I understood that olfaction was the sense of smell in response to the stimulation of sensory receptors in the olfactory region of the nose. In understanding the taste preception of the taste senses, I was able to fully understand all of the components involved with taste and the three types of nerves that helped carry out the function of taste. The visual system of chapter fifteen was an easy concept for me to grasp because I was able to understand that each component of the inner eye each contributed to a vital role as to how the eye was able to function at its full potential.

Chapter eight focused on all of the joints within the body and explained how each joint functioned throughout the body in order to provide movement of the body. Based on my reading there are numerous types of movement involved in the moving of the joints and that if a joint is overextended or stretched well beyond its limit, an injury may occur as a result. In dealing with the joints of an older adult, beacuse the cartilage tends to decrease as age increases, they are the most at risk for obtaining a decrease in the range of motion o f their bodies and should obtain a daily regimen of exercise to prevent the aging of their joints.

As a whole, studying the material for all four of the chapters was alot of information for me to process at one time and was difficult to understand in the beginning because I was trying to study the  material together and at the same time try to figure out how all of the information contained within these four chapters all related to one another and how they all aided in the function of the nervous system. I was able to gain a better understanding of the material by going back and rereading the material of each chapter and focusing on one chapter at a time, instead of overwhelming myself with all of the information at one time.

The questions that I was able to come up with to help me gain a clear understanding of the material were:

What role did the functions of the nervous system play in the muscular system, the special senses and the autonomic nervous system?

How did the incorrect functioning of the nervous system negatively effect the joints and the autonomic nervous system of the body?

If damage occured to the autonomic and somatic nervous system would it have an impact on the nervous system altogether and the joints within the body?






 

Saturday, February 5, 2011

The Brain And The Cranial Nerves

The focus of chapter thirteen was the brain  and the various parts contained within the brain. The brain is a component of the central nervous system. The brain contains four essential parts in order to function, those parts being the brainstem, the cerebellum, the diencephalon, and the cerebrum. I was able to understand that together these four essential parts of the brain worked together with one another in order to function, however I learned that the brainstem is the most important component within the brain. The brainstem attaches the spinal cord to the remainder of the body and is responsible for numerous body functions.

The brainstem is composed of the medulla oblongata, the pons, and the midbrain. In relation to one another each component of the brainstem must work correctly amongst each other in order for the brainstem to function noramlly.  In relevance to health if any part of the brain stem is damaged it can cause death, because the brainstem contains the reflexes that play a vital role in survival.

The diffucult concepts of chapter thirteen for me were understanding how the diencephalon operated within the brain, and learning the main purpose and role of the cerebrum. The diencephalon is composed of four parts, the thalamus,  the subthalamus, the epithalamus and the hypothalamus, that concept I wa able to grasp, however I was having trouble understanding that if the diencephalon consisted of those four parts, why was is that both the thalamus and the hypothalamus  were the main focus points of the diencephalon?

I was able to understand that  the thalamus  played a vital role in the emotional responses of the bodyand that the hypothalamus played a vital role in  the autonomic system, the endocrine system, and the regulation of food and water intake. This helped me realize that if the thalamus or hypothalamus were to stop performing their functions various systems of the body would shut down. For example if the hypothalamus stopped working, it would cause an interuption in the autonomic nervous system which would stop the function of the kidneys, leading to kidney failure, and it would result in the loss of muscle control which will create an imbalance of the muscles within the body,resulting in issues with swallowing and controlling the movement of the body.

The cranial nerves were somewhat a difficult concept for me because I was unable to understand how each cranial nerve coincided with one another. There are twelve pairs of cranial nerves, and I was able to grasp that each of the twelve nerves works together in conjunction with one another in order for their parts to keep amd maintain the intended function of their nerve. For example the optic canal consists of an optic nerve and an oculomotor nerve. The optic nerve aids in allowing vision to occur and the oculomotor nerve moves the eyeball and the muscles of the eye. In the case of a birth defect if a muscle within the eye does not develop, the oculomotor nerve will be unable to carry out its full function of controlling the eye muscles.

The questions that I created this week that helped me think more clearly about the concept of the brain and cranial nerves were:

Is it possible for the brain to carry out its full function without the aid of the cranial nerves?
How would the thalamus negatively affect the hypothalamus if it were to stop functioning?
Do all twelve of the cranial nerves within the brain have to function at the same time?
What would happen if one or more of the cranial nerves stopped working all together and how would it impact the brain?

Friday, February 4, 2011

The Spinal Cord And The Spinal Nerves

The concepts that I learned from studying the spinal cord and the spinal nerves was that the spinal cords main function was to process the communication between the brain and the peripheral nervous system and that the spinal cord brings together the information entering the brain with the reflex responses.

Both the spinal cord and the spinal nerves are housed in two separate nervous systems, the spinal cord is housed in the central nervous system and the spinal nerves is housed in the peripheral nervous system, meaning that the two systems must work together to provide communication between the brain and the body as a whole. My interpretation of this is that if one of the nervous systems' of the body stops working it will negatively impact the function of the other nervous system. For example if the central nervous system suffers damage from an injury, it will cause damage to the peripheral nervous system because the injury to the central nervous system will cause damage to the spinal cord nerves.

The difficult concept of the spinal cord for me was understanding how the spinal cord  was able to produce a response through the reflex mechanisms. I was able to grasp the concept of the spinal cord producing a response by understanding that the nervous system functioned under the control of a reflex arc( the basic functional unit of the nervous system) The reflex arc receives stimuli and therefore produces a response through reflex mechanisms (Seely's Anatomy And Physiology 9th Edition, Page 411).


The spinal cord contains four types of nerves, the cervical, thoracic, lumbar and sacral nerves. In understanding the spinal nerves, I related my interpretation of the spinal nerves to that of a paraplegic. When an individual becomes paralyzed from an accident or a medical misphap, damage occurs to either the cervical nerves, the thoracic nerves, the lumbar nerves or the sacral nerves.  If damage occurs to the cervical nerves a paraplegic will suffer nerve damage to their upper limbs, such as paralysis from the neck down to the waist. If damage occurs to the thoracic nerves the paraplegic will not be able to breathe or their own and if damage occurs to the lumbar nerves the paraplegic will suffer paralysis from their waist down, however if damage occurs to the entire spinal column, damaging every nerve the result would cause paralysis to the entire body resulting in a quadraparaplegic.

The significance of the spinal cord and the spinal nerves is that togther both work in conjunction  with each other. Without the use of or damage to the spinal nerves, the spinal cord will be permanently damged and therefore cause certain parts of the body to stop functioning all together.

The questions that I have created this week that helped me think more clearly about the concepts and really learn them were:
What would happen to the spinal cord if one of the 31 spinal nerves were damaged? 
How would damage to one or more of the spinal cord nerves affect the peripheral nervous system? Would the spinal cord be able to provide its full function if one of the three vertebral nerves were damaged? (Such as if the cervical veterbrae nerves were damaged, could the thoracic and lumbar vertebrae nerves still carry out their functions within the body.)

Tuesday, February 1, 2011

Bio-207 Ethics Paper Review

Tracey R. Walker
Biology 207
Ethics Paper
Biology 207 Ethics Paper Review
The article, “Ethical dilemmas in nursing” provided an insight on the ethical dilemmas that nurses were faced with involving the care of their patient’s. The article provided a glance into the ethical rights that nurses are entitled to while providing care to their patients.  In the article, three examples of ethical dilemmas were presented as a means to review the firsthand look at what purpose ethics serve within the fundamentals of nursing.  The article expressed the main point of that too often nurses are faced with asking the difficult question of what is the right thing to do regarding the best interest of their patients.

The article discussed the dilemma of nurses being directly involved in the treatment decisions concerning the patient’s well being. The main point of the article is that nurses were not acknowledged nor perceived as important in the overall ethical issues surrounding their patient’s. In order to resolve this issue, I believe that a nurse’s opinion is greatly needed in the ethical issues relating to a patient. Nurses are the individuals who provide primary care to the patient and therefore they have a vast amount of knowledge relating to the patient’s ethics. In resolving the ethical dilemmas within this paper, at all times nurses should be given the right to express their main concerns in reference to the health of their patients, and in the end a nurse’s input into any situation will ultimately determine the fate of a patient.

The insights that I have gained on bioethics from reading the article are that first and foremost bioethics is not considered as a critical component in the medical profession and that the role of a nurse is overlooked in the medical profession in regards to the best interest of a patient. The second insight that I have gained on bioethics from reading the article was that the ethical dilemmas of nurses will continue to remain unaddressed simply because of the way a nurses role is viewed according to the medical profession, being that they provide care to a patient, but does not necessarily know what is best for the patient when faced with an ethical issue. In my opinion bioethics should apply to everyone that is involved in the direct care of the patient, not just the doctors who have an in-depth knowledge of the patient’s medical history.  The third insight that I gained on bioethics from reading the article was that bioethics takes into consideration a matter of life and death, pain and suffering, and rights and responsibilities involving the ethical issues of patients. The ethical dilemmas of nursing should become a number one priority in medical ethics in order to provide nurses with a better mechanism of coping with and their addressing their concerns during the rise of an ethical dilemma.