401002 Short Answer Questions: Importance of Maintaining Healthy Lifestyle Assessment Answer
Short answer questions
The cardiac conduction system is composed of nodes and different conduction cells. The nodes and cells are initiated and co-ordinated the conduction of heart muscles and cardiac cycle.
- Sino-artial node
SA node is composed of specialised cells known as pacemaker cells and it is situated in the upper wall of the right atrium. SA node is found in the junction of the right atrium and superior vena cave (Bailey, 2018). The impulses created by the SA node can be influenced by the sympathetic nervous system and parasympathetic nervous system.
- Atrio-ventricular Node
Electrical impulses from SA node can spread across the atria and reach the AV node which is situated within the atrioventricular septum. It is also located near to the coronary sinus (Human Cardiac Anatomy, 2019).
- Artio-ventricular bundle
It is a continuation of specific tissues of the AV node and helps in the transmission of electrical impulses from the AV node to the Purkinje fibres of the ventricles. The purkinje fibres descend down into the interventricular septum before dividing into right bundle branch and left bundle branch.
- Purkinje fibres
The network of specialised cells creates purkinje fibres which are abundant with glycogen and have gap junction. The Purkinje fibres situated in the subendocardial surface of the ventricular walls can help in the transmission of cardiac impulses to the myocardium of the ventricles from the bundle of atrio-ventricular (White, 2017).
Heart chamber contractions
Cardiac conduction is considered as rate of electrical impulses which cause the heart to contract and relax. It has been isolated that specialised cells in the SA node can instinctively produce electrical impulses which spread to both atria via gap junction. The incident is responsible for contraction of atria, as a result, the blood moves from atria to the ventricles (Bailey, 2018). SA node causes contraction of both atria. Consequently, the AV node is delaying the impulse and ensuring that the atria have sufficient time before the ventricular systole to eject the blood into ventricles. Thus the valve between the atria and ventricles close when the atria are empty. In addition, the right bundle branch can help in conducting the impulses to the Purkinje fibres situate in the right ventricles (Bailey, 2018) and the left bundle branch can conduct the electrical impulses to the purkinje of the left ventricle. Thus, the rapid conduction of Purkinje fibres can allow the contraction of ventricular and blood is moved in the pulmonary artery and aorta from both ventricles. Hence, the right ventricle uses pulmonary artery to send blood to the lungs and left ventricle send blood to the aorta.
Sources of vitamin B12
The richest sources of vitamin B12 are clams (3 ounces contains 84 mcg) and liver (3 ounces contains 70.7 mcg).
- Vitamin B12 can help in the normal functioning of the brain and nervous system. It plays an important role in the formation of red blood cells and regulates the DNA.
- Vitamin B12 can regulate cell metabolism and play a crucial role in energy and fatty acid production process (O’Leary & Samman, 2010).
- It can help to release energy by absorbing folic acid.
- In addition, Vitamin B12 can help in multiplication and maturation of red blood cells. Lack of B12 can precipitate anaemia due to insufficient production of a red blood cell.
- Vitamin B12 plays an important role in the synthesis of serotonin which is regulating the mood of individuals. Therefore, a lack of B12 can interfere with serotonin production and increase chances of depression (O’Leary & Samman, 2010).
- In non pregnant
Deficiency of vitamin B12 can cause weight loss, constipation, diarrhoea, menstrual disturbance, nerve and brain damage, dementia, irregular heartbeat, fatigue and shortness of breath along with sore mouth and anaemia (Carter, 2017).
- In pregnant
Lack of vitamin B12 during pregnancy can increase the risk of premature delivery, anaemia, neural defects in newborn, and spina bifida (Carter, 2017).
It has been isolated that vegetarian people have the maximum chance of B12 deficiency compared to others. Vegan diet during pregnancy and lactation can increase the risk of deficiency as it is deficient in vitamin B12. In addition, people with diabetes, alcoholic, Crohn’s disease, and celiac disease are vulnerable to develop vitamin B12 deficiency as such condition can interfere with vitamin B12 adsorption (Carter, 2017).