Bioscience 1 Assessment 2 (Part B): Heart Conduction and Vitamin B12

This assignment, part of Bioscience 1 Assessment 2 (Part B), addresses the cardiac conduction system and vitamin B12. It begins with a feedback review of a previous assignment, emphasizing referencing and paraphrasing. The main part comprises short answer questions. The first question describes the components and conduction pathway of the heart's electrical system, including the sinoatrial node, atrioventricular node, bundle branches, bundle of His, and Purkinje fibers, relating them to heart chamber contractions. The second question focuses on vitamin B12, asking for food sources, functions in the body, consequences of deficiency in pregnant and non-pregnant individuals, and groups at risk of deficiency. The assignment requires complete sentences, in-text references, and adherence to word limits. The student provides answers supported by cited sources, demonstrating understanding of the topics. The assignment highlights the importance of academic integrity and proper citation practices.

Bioscience 1 Assessment 2 (Part B)
Do NOT delete any part of the template
Due Monday 6th May 2019, midnight
Student Name:
Student ID:
Task 1- Feedback review on Part A
This activity is to be completed and submitted as part of Assessment 2 (Part B).
This activity should bring to your attention the importance of referencing and
paraphrasing and help to improve your marks awarded for Academic Style and
Referencing.
Use your submitted Assessment 2 (Part A) when considering the following
questions. Please highlight or underline your chosen answer.
a) Did you include in-text references in your answer and a reference list at the end?
a) Yes
b) No
b) What is the purpose of including in-text references and a reference list in an
assessment?
a) Provide evidence for the source of the information
b) Allows information to be included without paraphrasing
c) Permits information to be directly copied without rewriting
c) What is the purpose of submitting your assessment through Turnitin?
a) Allows you to identify material that needs to be referenced
b) Allows you to identify material that needs to be paraphrased
c) Allows you to identify incorrect information that should be removed
d) Which of the following Turnitin similarity percentages best represents an
assessment that has been well paraphrased?
a) 80-95%
b) 50-60%
c) 10-30%
Make sure you include in-text references in every answer and check your Turnitin
similarity % at least three days before the due date so you have time to paraphrase
your answers.

Bioscience 1 Assessment 2 (Part B)
Task 2- Short answer questions.
Note: Answers must be in complete sentences and include in-text references
Answer the following questions:
Question 2-
Describe the components and conduction pathway of the cardiac conduction
system of the heart. (200 words, 5 marks)
Answer: Basically, there are five major components of the conduction pathway and the
electrical conduction system of the human heart. The five include sinoatrial node
otherwise abbreviated as SA, The Atrioventricular Node normally abbreviated as AV, the
right and left bundle branches, the bundle of His and finally the Purkinje fibres. Each of
these components plays a unique role to ensure that the heart is bale to contract to pump
blood to other parts of the body. The Sino-atrial node is the one that generates the
electrical signal and it is the natural pacemaker of the heart. The function of the purkinje
fibres is to receive the stimulus from the SA (Kennedy et al., 2016). After receiving the
signal, they activate both the left and right ventricles through activating the myocardium.
The function of the bundle of His is to transmit the signal from the Atrioventricular node to
the ventricles. The Atrioventricular node acts as the regulator of the signal. It regulates
the rate at which the signal reach the ventricles. The right and left bundle branches
transmit cardiac action potentials in between the bundle of His and the purkinje fibres.

Bioscience 1 Assessment 2 (Part B)
Relate the conduction system to the corresponding sequence of heart chamber
contractions. (200 words, 5 marks)
Answer: The Sino atrial node, which is made up of specialized tissues located in the
atrium of the heart is the source of the electrical stimulus. Once the SA generates the
stimulus, it moves down through the conduction pathways that makes it possible for the
ventricles to pump out blood. Studies suggest this electrical signal delays for few
seconds so as the left and right atrium can empty blood to the respective ventricles (Van
Weerd & Christoffels, 2016). Once the atria have emptied blood to the ventricles, the
valves in between close to complete the circuit and the signal thus moves to the
Atrioventricular Node. From the AVN, it moves through the bundle of His, then to the
bundle of branches and eventually to the purkinje fibres. The cycle then goes on in that
manner repeatedly. Studies indicate that the SA produce between 60 to 100 signals per
minute that is equivalent to heartbeats. However, it depends on age with the signals
being produced at low rates in the elderly as compared to the young generation.
Question 3- Vitamin B12 is an essential nutrient that is important for normal
development and health. Please answer the following:
a) Name two food sources high in vitamin B12 (20 words; 0.5 mark)
Answer: Animal sources such as meat and poultry products and fortified plant
products are vitamin rich foods (Moll & Davis, 2017).

Bioscience 1 Assessment 2 (Part B)
b) Describe the functions of vitamin B12 in the body (60 words; 1.5 marks)
Answer: vitamin B12 has important role in protein metabolism, erythrocytes
production and proper functioning of brain and spinal cord which constitutes
central nervous system (Smith, Warren, & Refsum, 2018).
c) Describe the possible consequences to the body if there is a deficiency in
vitamin B12 in pregnant and non-pregnant individuals (80 words; 2 marks)
Answer: Vitamin B12 has several functions among pregnant women. Studies
elaborate that deficiency of Vitamin B12 in pregnant women leads to abortion of
the foetus (Moll & Davis, 2017). Furthermore, birth defects have also been
reported with the notable being neural tube defects. Deficiency of vitamin B12
among non-pregnant individuals is also risky leading to anaemia due to low
production of Red Blood Cells.
d) Name one group of people that is more likely to be at risk of becoming
deficient in vitamin B12 and why. (40 words; 1 mark)
Answer: Since majority of the food sources of Vitamin B12 are animal products
and partly fortified breakfast, the group of people who are at risk to suffer from

Bioscience 1 Assessment 2 (Part B)
vitamin B12 deficiency are vegans since they are only limited to fortified breakfast
as the only source of vitamin B12 (Smith, Warren, & Refsum, 2018).

Bioscience 1 Assessment 2 (Part B)
References
Kennedy, A., Finlay, D. D., Guldenring, D., Bond, R., Moran, K., & McLaughlin, J. (2016).
The Cardiac Conduction System. Critical Care Nursing Clinics of North America,
28(3), 269-279. doi:10.1016/j.cnc.2016.04.001
Moll, R., & Davis, B. (2017). Iron, vitamin B 12 and folate. Medicine, 45(4), 198-203.
doi:10.1016/j.mpmed.2017.01.007
Smith, A. D., Warren, M. J., & Refsum, H. (2018). Vitamin B12. Advances in Food and
Nutrition Research, 215-279. doi:10.1016/bs.afnr.2017.11.005
Van Weerd, J. H., & Christoffels, V. M. (2016). The formation and function of the cardiac
conduction system. Development, 143(2), 197-210. doi:10.1242/dev.124883