Blood

1
Stephen E. Fish, Ph.D. Mitchell L. Berk,
Ph.D. Marshall University J. C. E. School of
Medicine
2
Note to instructors I use these PowerPoint
slides in histology lectures that I give to first
year medical students. Copy the slides, or just
the images into your own teaching media. We all
know that teaching science often requires
compromises and simplification for specific
student populations, or the requirements of a
specific course. Please feel free to offer
suggestions for improvements, corrections, or
additional illustrations. I would be pleased to
hear from anyone who finds my work useful, and am
always willing to make it better. Also, the
images have been compressed to screen resolution
to keep PowerPoint file size down, and I can
provide them at any resolution. Contact me about
the illustrations and Mitchell L. Berk about the
photomicrographs. Stephen E. Fish,
Ph.D. Fish_at_Marshall.edu Berk_at_Marshall.edu
3
Blood lymph vessels
4
Vessels have a common plan of layers
5
A little about elastin in the media

• It is made by the smooth muscle cells
• Elastin fibers predominate in small arteries
• Elastic laminae predominate in large arteries
• They are like inner tubes, one inside another
• But they are perforated to allow access to O2
  nutrients
• They appear wrinkled in most slides because the
  smooth muscle often contracts in death

6
Very large arteries- aorta
Artifactual crack
Intima
Adventitia
Media
Vasa vasorum
7
Aorta detail This is so dark because it is
stained for elastin (Intima is missing on many
slides)
Intima
Internal elastic lamina hard to see, look
for others in the media
Endothelium
Media
8
Aorta detail
Dense irregular CT of adventitia with elastic
stain
Media
Vasa vasorum
External elastic lamina
Crack
9
Muscular arteries (medium size)
Media- elastic lamina faint or nonexistent,
mostly elastin fibers
Intima very thin
Internal elastic lamina
Adventitia
10
Arterioles

• Minimal intima 1- 3 muscle layers
• In media a few elastin fibers no laminae
• Normal constriction (vasomotor response) is
  important for regulating capillary blood flow

11
Capillaries supplying sweat glands with water
proteins

• Capillaries consist of endothelial cells their
  basement membrane
• The only layer is the intima

12
Type 1 Capillary
13
Type 2 (for type 3, covered in kidney lectures,
just imagine there are no diaphragms)
14
One example of a sinusoid
15
Capillary bed
16
Low flow (pressure) in a capillary bed
17
High flow in a capillary bed
18
Lymphatic vessels
19
Medium artery vein compared
20
How veins look on slides
21
Vena cava