Cardiovascular Slides Flashcards
What typs of artery?
What type of stain?

Muscular artery (named artery/distributing artery)
- Elastic stain
shows:
- t. intima undulating appearance
- distinct IEL
- t.media circularly arranged smooth m. (8-40 layers) - less visable
- distinct EEL
- elastic fibers in t. adventitia ,dense ct; (type I collagen, vasa vasorum + nerves)
What type of artery?
What type of stain?

Muscular artery (named artery/distributing artery)
- H&E stain
shows:
- t. intima undulating appearance
- distinct IEL
- t.media circularly arranged smooth m. (8-40 layers)
- distinct EEL
- t. adventitia dense ct, type I collagen, elastic fibers; vasa vasorum + nerves
What type of artery?
What type of stain?

Elastic Artery (Conducting artery) = A
- elastic stain
shows:
- thin t. intima (endothelial cells + subendothelial ct)
- smooth m nuclei in t. media (40-70 layers elastic lamellae; Type III collagen)
- t. adventitia (dense irregular ct)
CANNOT RECOGNIZE IEL/EEL
- elastic does not stain well w. H&E
What type of vein?
What do arrows indicate?

Medium Vein
* arrows = VALVES
shows:
- t. intima endothelium + sparse subendo. CT; contain unidirectional VALVES
- t.media few layers of smooth m.
- t. adventitia = more developed that t. media
* valve malfunction = blood backflow to sm. veins = varicose veins
Tunica Adventitia
(contents)

- Mainly collagen type I fibers + a few elastic fibers = loose network
l- Contains nerves (nervi vascularis), vasa vasorum (vessel of vessels) & lymphatics
- In smaller vessels, merges with surrounding connective tissue
Nutrient supply:
- T. intima & inner half of the T. media from blood in the lumen
- T. adventitia & the outer half of T. media from vasa vasorum
What type of vein?

MUSCULAR VEIN (Ex: VENA CAVA)
shows:
- t. intima endothelium + sparse subendo. CT; NO VALVES
- t.media circularly arranged layers of smooth m. + CT
- t. adventitia = more developed that t. media; longitudinal smooth m. bundles*
*Continuous “milking” of blood towards heart, against gravity
What type of Capillary?
Where is it located?

Sinusoid Capillary (Discontinuous capillaries)
- location: spleen, liver*
- basal lamina = discontinuous; no tight junctions; Gap junctions
- Fenestrations = large openings
*(do NOT have 3 tunics; only endothelium + basal lamina)
- in sinusoids (spleen, liver, bone marrow)

Internal Elastic Lamina
- *- Separates t. intima from t. media**
- Fenestrated elastic membrane : diffusion of materials through the layers to reach underlying cells
What type of artery?
What is the arrow indicating?

Elastic artery
- H&E stain
arrow = peripheral nerve (dots = sectioned axons); only in tunica adventitia
Identify the types of capillaries:

Left = CONTINUOUS
middle = FENESTRATED
right = SINUSOIDAL
What type of artery?
Identify 2 stains:

Elastic artery (Aorta):
Left = Elastic stain (elastic visiable –> t. media)
Right = H&E stain (smooth m. nuclei visable –> t. media)
What type of Capillary?
Where is it located?

Fenestrated Capillary (visceral capillaries)
- location: choroid plexus*
- basal lamina = continuous; tight junctions
- Fenestrations = around cytoplasm of endothelial cells (some w. diaphragm)
*(do NOT have 3 tunics; only endothelium + basal lamina)
- peptide-secreting endocrine organs, kidney glomerulus, gut capillaries, etc.

What type of vein?

Small Vein
shows:
- t. intima endothelium + subendo. CT
- t.media few layers of smooth m., circular arrange.
- t. adventitia more developed than t. media
* Arteriole + Small Artery to the right
Vein or Artery?

VEIN
can see:
- collapsed walls
- t. intima extensions into lumen = VALVES
External Elastic Lamina (EEL)

- separates T. media from T. adventitia
- feature of muscular arteries
What type of artery?
What type of stain?

Small artery
- H&E stain
shows:
- t. intima endothelium + minimal subendo. CT
- IEL (not very visable with this stain)
- t.media 3-8 layers smooth m.; more developed than t. adv
- NO distinct EEL
- t. adventitia, CT with Type I collagen
Tunica Media
(contents)

- Primarily circumferential layers of smooth muscles; secrete the ECM components of this layer
- Interspersed with layers of overlapping elastic fibers, Type III collagen fibers and proteoglycans
What type of artery?
What type of stain?

Muscular artery (named artery/distributing artery)
- H&E stain
shows:
- t. intima undulating appearance
- distinct IEL
- t.media circularly arranged smooth m. (8-40 layers)
- distinct EEL
- t.adventitia dense ct, type I collagen, elastic fibers; vasa vasorum + nerves
What type of artery?
What type of stain?

Elastic Artery (Conducting artery)
- elastic stain
shows:
- thin t. intima (endothelial cells + subendothelial ct)
- elastic filled t. media (40-70 layers; smooth m.; Type III collagen)
- t. adventitia (dense irregular ct); vasa vasorum + arteriole visable
CANNOT RECOGNIZE IEL/EEL (they are present)
What are these 2 types of fibers?
Where are they found?

dark red = Myocardium fibers
pink = Purkinje fibers
found in the heart
PERKINJE:
- modified cardiac tissue
- conducting, NOT contracting
- no intercalated discs; DO have gap junctions, FA, desmosomes
Tunica Intima
(contents)

Endothelium
- Simple squamous epithelium (endothelium) + basal lamina
Subendothelial CT
- Loose CT (Type IV collagen, elastin and GS) + smooth muscles: for support
What type of Capillary?
Where is it located?

Continuous Capillary (classical/somatic capillaries)
- location: skeletal m.*
- basal lamina = continuous w. tight junctions
- Fenestrations = NONE
*(do NOT have 3 tunics; only endothelium + basal lamina)
- controls diffusion + transcytotic processes

What type of artery?
What type of stain?

Arteriole (
- Trichrome stain ??
shows:
- t. intima endothelium
- t.media 1-2 layers smooth m.
- t. adventitia = ill-defined; blends w surrounding CT
- RBC in lumen
Identify 3 types of tissues here:
Where is this located?

Heart tissue

What type of vein?
What are arrows indicating?

Post Capillary Venuoles (High Endothelial Venuoles)
- arrows = High cuboidal endothelium*
- loosest junctional complexes; facilitate entry of immune cells from lumen into CT
(during inflammation or normal phenomenon in locations such as lymph nodes)
- Inflammation: leukocyte exudation
Important in “homing effect” = HEV is site where lymphocytes enter a lymph node from circulation
What type of capillary is this?

lymphatic capillary
start of lymphatic system = blind- ended lymphatic capillaries
- empty into the circulation : (unidirectional) valves
- Not present in Nervous tissue, Bone marrow and Cartilages
- Impaired function = edema (ascitis in abdomen)
What is this structure?
What are arrows indicating?

Lymph node
black arrows = afferent lymph entering
green arrows = efferent lymph exiting