2016NURS1004: Laboratory report

Week11:Part 1—Blood and blood vessels

Learning Objectives

  • List the different types of blood vessels by size and function.
  • Describe the layers of an artery and vein
  • Understand the differences in the function of arteries and veins
  • Explain how basic blood types are determined and the implications for nurses when administering a blood transfusion.

Part 2—Aqueous solutions

Learning Objectives

  • Describe the process of osmosis in then body
  • Describe the process of diffusion and how body fluids are affected
  • Describe the process of dialysis compared to osmosis and diffusion
  • Explain the nursing implications of the three types of fluid movement in the human body

Part 1—Blood and blood vessels

Preliminary work (complete before attending the laboratory session)

Read and note

Part 1:Martini et al. (2015), chapters 19 and 20, pp. 690-693, on blood typing; pp.750–761 on blood vessels.

Part 2 Martini et al. (2015), chapter 3, pp. 118–120, on osmosis and osmotic pressure.

Activities
  1. List and describe the function of the different arterial blood vessels.

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  1. List and describe the function of the different venous blood vessels.

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On the following three pages are diagrams of blood vessels for you to complete.

Nurses are often the first health professional to assess the patient when problems related to blood vessels occur. Nurses frequently assess the patient’s insertion sites into peripheral veins associated with intravenous infusions. Nurses will also be involved in assessing, for the presence of deep vein thrombosis (DVT) (blood clot), lower limbs of patients who are resting in bed.

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  1. Identify the following structures.Drag and drop the labelsto complete thetwo diagrams below(Martini et al. 2015, p. 753).

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  1. Drag and drop to complete the following diagram about the function of leg veins(Martini et al. 2015, p. 759).

Laboratory activities

Activity 1

  1. What are the anatomical differences between arteries and veins?

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  1. Why does the aorta mainly have elastic tissue, and why does an arteriole mainly have smooth muscle?

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  1. Which type of blood vessels regulate blood pressure and are responsible for blood distribution throughout the body and why?

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Activity 2(20 minutes)

Blood typing

Surface antigensare cell surface proteins that identify cells to the immune system. Normal cells are ignored and foreign cells attacked.

Blood typesare genetically determined by the presence or absence of RBC surface antigens A, B, Rh (or D). There are Four Basic Blood Types:

  1. A (surface antigen A)
  2. B (surface antigen B)
  3. AB (antigens A and B)
  4. O (neither A nor B)

Agglutinogens are antigens on the surface of RBCs, screened by the immune system. Plasma antibodies attack and agglutinate (clump) foreign antigens.

Blood plasma antibodies

  1. Type A has Type B antibodies
  2. Type B has Type A antibodies
  3. Type AB has neither A nor B antibodies
  4. Type O has both A and B antibodies

Cross-reactions in blood transfusions, also called transfusion reactions,occur when the plasma antibody (from the person receiving [recipient] the transfusion) meets its specific surface antigen (on the blood cells of the donor’s blood). The recipient’s blood will agglutinate and haemolyse; this will occur if donor and recipient blood types are not compatible. Death results.

Activity

Whole class activity:Students can determine their own blood grouping using a small blood sample.You tutor will guide you through the process and will dispense the Anti A and Anti B agglutinins on to each student’s slide.

Relevance to nursing practice

  1. What nursing duties does a nurse need to follow when administering blood products to patients? When might a nurse be required to administer a blood product?

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Part 2—Aqueous solutions

Objectives for this part of the workshop

To understand, observe and distinguish between osmosis and dialysis.

Equipment

Anti A and Anti B test serum (Tutor to dispense)

Plastic tubes & standCentrifuge

Dialysis tubingGlucose test strips

Microscopes, slides, coverslipsPrepared slide of blood smear

Iodine solution, Starch solution, 100 ml beakers1% sodium chloride solution

Horse blood

Distilled water

Section 1: Osmosis

Introduction

Cells must constantly exchange materials with their surroundings. This exchange involves movement across the plasma (cell) membrane, which is selectively-permeable (it allows some substances to pass through and not others). In this part of the workshop you will observe the process by means of which red blood cells exchange water with their surroundings (osmosis). In the next part you will observe the process by means of which cells exchange solutes with their surroundings (dialysis). Both processes occur without the need for an energy input and are referred to as passive processes. The importance of these processes cannot be over emphasised: they are essential for the maintenance of life.

Red blood cell haemolysis

A common intravenous solution is 0.9% Na+Cl- solution because it is isotonic with blood (i.e. will not cause net movement of water into or out of rbc). If rbc are placed into an environment that is hypotonic, water will move (osmosis will occur) across the plasma membrane into the rbc and cause it to expand. If the expansion is great enough, the plasma membrane will tear and the contents will spill out—the rbc has haemolysed.

Activity 2

We will investigate what happens to rbc when they are placed into progressively more hypotonic saline solutions.

You are provided with a rack containing eight clean test tubes. Label the tubes 1-8 and place the specified number of drops (see table) of 1% Na+Cl- solution in each tube.

Then place the specified number of drops of water in each tube to produce the required solution % concentrations.

Tube no. / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
1% NaCl
(Drops/tube) / 36 / 32 / 28 / 26 / 24 / 22 / 20 / 18
Water
(Drops/tube) / 4 / 8 / 12 / 14 / 16 / 18 / 20 / 22
% NaCl resulting
(mosmol/L) / 0.9%
(300) / 0.8%
(267) / 0.7%
(233) / 0.65%
(217) / 0.6%
(200) / 0.55%
(183) / 0.5%
(167) / 0.45%
(150)

Place a drop of horse blood into each tube and invert to mix.

If left for long enough and haemolysis does NOT occur, the rbc will sink to the bottom of the tube leaving clear saline above them.

If some haemolysis has occurred, the saline will be tinged with red haemoglobin (and there will be some cells at the bottom of the tube).

If haemolysis is complete, the fluid will be uniformly red (and there will be no cells at the bottom of the tube).

To speed the process of cell sedimentation, we will centrifuge the tubes for five minutes at 3000 rpm. Present your tubes to the tutor for centrifugation and answer the following questions.

Questions

  1. What is meant by a hypotonic solution?

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  1. Why are solutions that are isotonic (or close to isotonic) rather than hypotonic solutions used for intravenous infusions?

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  1. At which saline concentration does haemolysis begin and at which concentration is it complete?

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Activity 3

Demonstration of osmosis

Observe the dialysis tubing containing glycerol, submerged in a beaker of distilled water. Measure and record the height of the liquid in the dialysis tubing.

You can also weigh the dialysis tubing before and after one hour.

Repeat your measurement in one hour.

Questions

  1. What is the difference in height of liquid level between your two readings?

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  1. Why has the level changed?

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Section 2: Dialysis

Introduction

In the previous section you observed the process by means of which cells exchange water with their surroundings (osmosis). In this exercise you will observe the process known as dialysis through which cells exchange small solute molecules with their surroundings.

Activity 4

  1. Clamp (or tie a knot in) one end of a length of dialysis tubing and partly fill the tubing with starch solution. Now tie the other end of the tubing to create a closed bag filled with starch solution. Rinse the outside of the bag with water to remove any starch solution which may have been accidentally spilled over it.
  2. Place about 20 ml of iodine solution in a 100 ml beaker and immerse the bag of starch solution in the iodine. (Take care as the iodine solution will stain anything it spills on.) Observe the contents of the beaker and of the bag over a period of 5-10 minutes.
  3. Repeat part 1 but enclose glucose instead of starch in the dialysis tubing and immerse it in water (not iodine). Immediately test the water for the presence of glucose using one of the test strips provided. Using a fresh strip each time, test the water at five minute intervals after this.
  4. Record your observations and provide an explanation for them.

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Questions

  1. Describe and explain what happened to the starch and iodine combination.

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  1. Describe and explain what happened to the glucose and water combination.

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Well done .You have covered many concepts in A&P in these activities.

You have completed the Laboratory report for week11. Save the file and submit via FLO in the week 11 section.

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