1. Students Biology 1110 Principles of Biology
Please spend a little time becoming familiar with PowerPoint operations. Running the PowerPoint is quite simple. Follow the guidelines below.
1. To begin left click the slide show screen icon, or go to Slide show on the toolbar and click From Beginning.
2. A left click of the mouse will continue to advance you through the presentation. You can also navigate forward and backward within the presentation using your keyboard arrows.
3. A right mouse click will allow you to end the presentation and provide you with additional navigation options.

2. Biology 1110 Principles of Biology
Biology 1110 Laboratory
Laboratory # 2 Beginning Histology
Vascular Tissue
Support/Review Materials
All of the micrographs in this presentation were photographed in the MnWest Biology laboratory unless otherwise noted.
The microscope symbol that you see indicates a change in microscope power. A left mouse click on the microscope most often increases the viewing magnification. Give it a try.

3. Histology –the study of tissues.
A tissue is an association of similar cells united in structure and function.
The major animal tissue groups include:
Epithelial
Connective – this includes the vascular tissue, studied in this presentation.
3. Muscle
4. Nervous

4. Vascular tissue – general information
All blood, regardless of source, contains two categories of blood cells. They are:
Erythrocytes (which means red cells), or red blood cells (RBCs). These are always the most abundant blood cell, and perform the important function of oxygen transport.
Leukocytes, or white blood cells (WBCs). There are a number of different types of leukocytes. They all help to defend the body and prevent disease.

5. Vascular tissue – general information
In addition to erythrocytes (RBCs) and leukocytes (WBCs), human blood contains small cell fragments called platelets. We will cover platelet function later.
All of the blood cells and the platelets together are said to make up the formed elements. About 45% of your blood is formed elements.
The remaining 55% of you blood is the straw-colored, liquid portion called plasma. The plasma contains many important things including water, electrolytes, nutrients, numerous proteins, wastes, hormones, some respiratory gases, and buffers.

6. Vascular tissue – general information
If you centrifuge (spin) a sample of your blood, it quickly separates into the components previously discussed and demonstrated on this slide.
55%
Plasma
Leukocytes (WBCs) & platelets
The formed elements – 45% of the blood sample.
Erythrocytes (RBCs)

7. Vascular tissue - A circulating tissue made up of a number of different cell types.
In this lab we will briefly study the vascular tissue of an amphbian (frog) before emphasizing mammalian (human) blood.
Amphibian Blood
Human Blood

8. Amphibian Blood
In this stained sample of amphibian blood we can see the many erythrocytes (RBCs).
These RBCs have a nucleus, and they are the largest of the blood cells.
The micrograph also demonstrates a number of leukocytes (WBCs).
Take a look on a higher power.

9. A WBC called a heterophil
Abundant erythrocytes (RBCs)
A WBC called a heterophil
A thrombocyte – another type of WBC

10. Amphibian Blood
This amphibian blood smear contains the expected, high number of erythrocytes (RBCs).
Can you spot and identify the leukocytes (WBCs)?

11. Thrombocyte
Thrombocyte
Heterophil

12. Amphibian Blood Take a closer look
This micrograph of amphibian blood demonstrates a number of different blood cells.
We can identify erythocytes (RBCs), a heterophil, a lymphocyte, and three thrombocytes. Remember that the leukocytes (WBCs) are helping, in some way, to protect the animal.
Note the three thrombocytes that appear to be sticking to each other.
This gives us a suggestion regarding their function.
Take a closer look

13. The Function of Amphibian Thrombocytes
These “football-shaped” and “sticky” cells are protective in that they are necessary for the formation of blood clots.

14. These two micrographs demonstrate all of the amphibian blood cells that you are responsible for.
If you cannot identify all cells, please return and review the previous slides.

15. Human Blood Cell types, number, and function
Erythrocytes (RBCs) dominate the formed elements.
In a normal sample of human blood there would be about 5 million RBC/mm3
For every single leukocyte (WBC), there are erythrocytes (RBCs).
Erythrocytes (RBCs) are produced in your red bone marrow at a rate of well over two million per second.
Why do you need so many RBCs? What do they do?
Plasma
55%
Leukocytes (WBCs)
& platelets
Erythrocytes (RBCs)

16. Human Blood
This smear of human blood has been stained and appears typical.
The great majority of blood cells are erythrocytes (RBCs). Remember that your RBCs outnumber your WBCs around to 1.
You need this great number of RBCs to transport oxygen to all of your living cells.
Like most creatures, we are aerobic (oxygen-requiring).

17. Human Blood Cell types, number, and function
Mammalian RBCs, are the smallest of all blood cells.
They are biconcave, and thus very thin in the middle.
This is demonstrated nicely in this micrograph.
Lets take a close look.

18. Human Blood Cell types, number, and function
Notice the light, central area of the RBCs in this micrograph. They are thin in the middle so more light passes through.
The RBCs are also anucleate (without a nucleus). That is why they stain lighter than the WBCs.
RBCs are flexible “bags” filled with millions of hemoglobin molecules. It is hemoglobin that attaches to the oxygen for transport.

19. Human Blood Cell types, number, and function
The two human blood smears appear somewhat different due to different staining techniques. They both, however, nicely demonstrate larger, nucleated, leukocytes (WBCs). The nuclear material of these WBCs has a great attraction for the biological stain applied.
A quick look at these micrographs reveals leukocytes (WBCs) of different kinds. Regardless of kind, they all play an important role in your bodies protective system. Leukocytes fight certain microorganisms and help prevent disease.

20. Human Blood Cell types, number, and function
Leukocytes (WBCs) in human blood.
Neutrophils
Lymphocytes
Monocytes
Eosinophils
Basophils
Platelets – these are cell fragments.
Plasma
55%
Leukocytes (WBCs)
& platelets
Erythrocytes (RBCs)

21. Human Blood Cell types, number, and function
Leukocyte (WBC) types and %.
Neutrophils – 70 %
Eosinophils – 3 %
Basophils – 1 %
Lymphocytes – 35 %
Monocytes – 6 %
Leukocytes (WBCs)
& platelets

22. Human Blood Cell types, number, and function
Leukocytes (WBCs) are classified into two main groups. Neutrophils, eosinophils, and basophils are granulocytes. These cells have granules in their cytoplasm.
The remaining two WBCs, lymphocytes and monocytes are agranulocytes. These cells lack the cyoplasmic granules.
Eosinophil
lymphocyte
monocyte
neutrophil

23. Human Blood Smear
This stained sample of human blood demonstrates a number of the formed elements.
We recognize the many erythrocytes (RBCs) as well as a number of small, darkly stained platelets.
Increase the magnification and focus in on the large, centrally located blood cell.

24. Human Blood Smear
This high power microscopic view demonstrates a human neutrophil.
The single nucleus has multiple lobes. This particular neutrophil, with its many nuclear lobes is sometines called a hypersegmented neutrophil.
Neutrophils are your most abundant white blood cells.

25. A single, mature eosinophil is demonstrated in this micrograph.
Human Blood Smear
A single, mature eosinophil is demonstrated in this micrograph.
These WBCs make up only about 1-3% of your total WBC number.
Take a look on higher magnification.

26. Human Blood Smear
When stained, eosinophils usually take on a distivtive coloration.
Note the very granular cytoplasm and remember they are classed as granulocytes.
A mature eosinophil will have two distinct lobes making up the nucleus.

27. Human Blood Smear
In addition to the many erythrocytes (RBCs), this micrograph nicely demonstrates two leukocytes (WBCs).
These two WBCs are classed as granulocytes and should be easily recognizable.
If you are having problems identifying these WBCs, please review the previous slides.

28. Human Blood Smear
Both micrographs below demonstrate a single monocyte. These large white blood cells (leukocytes) have a single nucleus that seems to often resemble the letter C.
Monocytes normally make up about 4-6% of your WBCs. They are very important in fighting infection and preventing disease.

29. Human Blood Smear
In this micrograph we again recognize the many red blood cells (erythrocytes).
As we finish our study of white blood cells (leukocytes) we focus on the two very similar, and deeply stained cells.
These two WBCs are lymphocytes.

30. Human Blood Smear
Below you will see the same blood smear at different magnifications. Note the lymphocyte at the pointer. These abundant WBCs play very important protective roles in your bodies immune system.
Note that these small, WBCs have a very large nucleus and little cytoplasm. They make up 25-35% of your WBCs.

31. Human Blood Smear
A close look at the human blood samples below reveals small, dark stained “specks” visible among the blood cells. Some of these are identified with a pointer. These are cell fragments known as platelets.
Platelets play a number of roles in the process of hemostasis. Hemostasis is the cessation of bleeding ( blood clotting).

32. Matching Exercise – the formed elements of blood
Matching Exercise – the formed elements of blood. Identify the correct matches. When complete, push the down arrow to check your answers.
Eosinophil
Monocyte
Lymphocyte
Neutrophil
Erythrocytes (RBCs)
RBCs with scattered platelets

33. The End

34. Left click the scope again to return to the previous slide.