Bioscience 1 Assessment 2 (Part B)

This document provides answers to short answer questions on the components and conduction pathway of the cardiac conduction system of the heart, as well as the functions and consequences of vitamin B12 deficiency. It also includes in-text references.

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: There are five components of the conduction pathway of the cardiac conduction
system of the heart. They include the Purkinje fibres, the left bundle branches, the right
bundle branches, the bundle of His, the atrioventricular node and finally the Sino-atrial
node. Each of the five components has a unique role to play in the heart. The function of
the purkinje fibres is to receive signals from the atrioventricular node and then activates
the left and right ventricles by stimulating the ventricular myocardium. The bundle of his
transmit signals from AVN to ventricles (Kennedy et al., 2016). The Sino atrial node on
the other hand is the natural pacemaker of the heart sending out signals from the atrium
to ventricles. The AV node is the electrical relay station that regulates or slows down an
impulse sent by the SA node before it is allowed to reach the ventricles. Finally the left
and right bundle branches transmit cardiac action potentials from the bundle of his to the
Purkinje fibres.
Relate the conduction system to the corresponding sequence of heart chamber
contractions. (200 words, 5 marks)
Answer: The Sino atrial node, a mass of specialized tissue found in the atria of the heart
generate an electrical stimulus. Studies elaborate that the SA produce the electrical
between 60 and 100 times a minute under normal circumstances. The electrical signal
moves down the conduction pathways which makes the ventricles to contract and

Bioscience 1 Assessment 2 (Part B)
effectively pump blood out (Van Weerd & Christoffels, 2016). The signal normally delay
for some time so that the atria have enough time to pump blood into the ventricles. Once
the atria are empty, the valves between atria and ventricles close and this makes it
possible for the stimulus to move to the AV node, bundle of His, to the bundle of
branches and finally to the Purkinje fibres. The process goes on repeatedly as the
ventricles contract and pump out blood. A single contraction is equal to a single
heartbeat. However, the contraction vary with age where elderly people experience low
rates of contractions as opposed to the younger 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 (Smith, Warren, & Refsum, 2018).
.
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 (Moll & Davis, 2017).

Bioscience 1 Assessment 2 (Part B)
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: According to different studies, results show that vitamin B12 deficiency
among pregnant women leads to birth defects such as neural tube defects.
Furthermore, spontaneous abortions are also a common occurrence (Moll &
Davis, 2017). Among the non-pregnant individuals, deficiency of vitamin 12 leads
to anaemia since less RBC s will be produced. They can also experience fatigue
due to impaired cellular metabolism.
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: The group of people likely to be at risk of vitamin B12 deficiency are
vegans. This are people who only feed on plant matter. Therefore, there only
source of vitamin B12 is fortified breakfast (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