Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histo second semester 23-24 > Histo block I: gen circulatory sys/blood vess struct & endothelial cell structure & fucntion > Flashcards

Histo block I: gen circulatory sys/blood vess struct & endothelial cell structure & fucntion Flashcards

1
Q

The circulatory system consists of?

A
  1. blood vessels
  2. lymphatic vessels
  3. heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the major functions of the circulatory system?

A
  1. Circulate blood carrying:
    oxygen, nutrients, metabolites, hormones and other signaling molecules to the tissues.
  2. Removes CO2 and waste products form tissues to the: lungs liver and kidneys for disposal or removal from body.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Blood vessels can be divided into two systems:

A

Macrovascular and microvascular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the macrovascular system?

A

The larger arteries and veins that are visible with eye and serve as major conduits to trasnport blood between the heart and organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some of the components of the macrovascular system?

A
  1. Elastic arteries
  2. Muscular arteries
  3. Small veins
  4. Medium veins
  5. Large veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the microvascular system?

A

The smaller branches of the arteries and veins only visible in the microscope, which carry and distribute blood at the tissue level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some of the components of the microvascular system?

A
  1. Arterioles
  2. Metarterioles
  3. Capillaries
  4. Venules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The wall of blood vessels can be divided into 3 major concentric layer:

A
  1. Tunica intima
    2.Tunica media
  2. Tunia Adventitia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the tunica intima consists of?

A
  1. Endothelial layer
  2. Basal lamina
  3. Subendothelial layer (loose CT)
  4. Internal elastic membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the tunica media consists of?

A
  1. Circular (concentric) layers of smooth muscle & fenestrated elastic lamella
  2. External elastic membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the tunica adventitia consists of?

A

Dense irregular CT and in some cases longitudinally oriented smooth muscle. Both small vessels and nerves may be present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

memorize the layers

A

memorize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Do all vessels have the 3 concentric layer?

A

no, and not all of the components either.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

identify

A

muscular artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are arteries histologically compared to veins?

A
  1. arteries in general have a better organized thicker wall (relative to lumen diameter) in general as compared to veins. This is consistent with their being higher pressure vessels as compared to the veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do arteries look in cross-sections?

A

Arteries in cross-section often appear more rounded while the accompanying veins are often more flattened appearing in section. Again this is consistent with the arteries having a relatively thicker wall and being higher pressure vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which layer is the thickest in arteries and in veins>?

A

arteries: tunica media
veins: tunica adventitia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

identify

A

Micrograph of small muscular artery compared to small vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe de histological characteristics of endothelial cells

A
  1. Are present as a simple squamous epithelia lining the lumen of all blood vessels.
  2. The cells are typically elongated along the direction of blood flow.
  3. Both tight junctions and gap junctions are typically present between the cells (depending upon location and vessel type).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

identify

A

Venule with endothelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

identify

A

TEM of arteriole

22
Q

identify

A

Diagram and scanning EM of endothelial cells

23
Q

Do endothelial cells only function as lining for the blood vessels? explain

A

No; They play an important role in blood homeostasis, and their functional properties change in response to various stimuli (endothelial activation)

24
Q

What are some of the endothelial activation inducers?

A
  1. Bacterial and viral antigens
  2. Cytotoxins
  3. Complement products (fragments of protein)
  4. Lipid products
  5. Hypoxia and various types of cellular stress
25
Q

identify

A

Venule lined by endothelial cells

26
Q

What happens to activated endothelial cells in response to the inducing agents?

A

can exhibit new surface adhesion molecules, and produce different classes of cytokines, lymphokines, growth factors, vasoconstrictors and vasodilator molecules, and molecules that control blood coagulation.

27
Q

In what vascular pathology does endothelial activation may play a role?

A

atherosclerosis

28
Q

What are the functions of the endothelial cell?

A
  1. Maintenance of a selective permeability barrier
  2. Maintenance of a non-thrombogenic barrier
  3. Secretion of von Willebrand factor(coagulating factor VIII)
  4. Synthesis of growth factors and inhibitors
  5. Regulation & modulation of immune responses
  6. Inactivation or conversion of compounds
  7. Control of blood pressure
29
Q

How does endothelial cell maintain a selectively permeable barrier?

A

They regulate the exchange of gases (O2 and CO2), metabolites, waste products) with the tissues. They regulate the movement of many molecules.

30
Q

What molecules can diffuse across the membrane?

A

Small hydrophobic molecules and gases

31
Q

How do large charged molecules need to pass the membrane?

A

must pass across the endothelium through fenestations (pores) or by pinocytosis, receptor mediated endocytosis, or by passage across the zonula occludens

32
Q

How does endothelial cells maintain a non-thrombogenic barrier?

A

through production of anticoagulants (e.g. thrombomodulin) that prevent blood coagulation and antithrombogenic substances that prevent platelet aggregation and the formation of clots on endothelial cell surfaces (e.g. prostacyclin and tissue plasminogen activator).

33
Q

Does normal endothelium prevent adherence of platelets to its surface? Explain

A

Yes; and prevents formation of clots on its surface. It is probably the only true non-thrombogenic barrier

34
Q

identify

A

TEM of Endothelial cells lining capillary

35
Q

Explain the secretion of von Willebrand factor

A

Endothelial cells secrete (coagulating factor VIII) and other prothrombogenic agents) to promote platelet aggregation in response to damage to the endothelial barrier

36
Q

What are some growth and inhibitory factors that endothelial cells synthesize, why they synthesize them?

A

growth: hemopoietic colony stimulating factors, fibroblast growth factor, platelet derived growth factor

inhibitory: heparin and transforming factor B

They are important for regulation in the body

37
Q

How do endothelial cells play a role in regulation and modulation of immune responses?

A

by controlling interaction of white blood cells with the endothelial surface by synthesis of specific adhesion molecules and receptors (regulates white blood cells from entering or exocytosing); and by secretion of 3 classes of interleukins – IL-1, IL-6, and IL-8.

38
Q

What are some compounds that endothelial cells inactivate or convert?

A

norepinephrine, thrombin, prostagladins, bradykinin, and serotonin to inactive forms

39
Q

How do endothelial cells control blood pressure?

A

through secretion of vasodilators and relaxing factors and through secretions of vasoconstrictors.

40
Q

What are some vasodilators and relaxing factors synthesized by endothelial cells to reduce blood pressure?

A
  1. Endothelial-derived relaxing factor (EDRF)
  2. Prostacyclin (PGI2)
  3. Endothelium-derived hyperpolarizing factor (EDHF)
41
Q

What are some vasoconstrictors synthesized by endothelial cells to produce an increase in blood pressure?

A
  1. Endothelins
  2. Thromboxane A2 and prostagladin H2
  3. Decreased synthesis of NO or inactivation of NO by the superoxide anion (O2-)
42
Q

How does Endothelial-derived relaxing factor (EDRF) reduce blood pressure?

A

acts via the enzyme endothelial nitric oxide synthatase (enos) to produce nitric oxide (NO) a gas. NO acts on smooth muscle in the tunica media by guanylate cyclase to increase levels cyclic GMP and it will activate protein kinase G (PKG) pathway to produce relaxation of the smooth muscle.

43
Q

How does Prostacyclin (PGI2) reduce blood pressure?

A

binds to receptors on the surface on smooth muscle and acts to increase levels of cAMP which will act in proteins kinase A (PKA) pathway to block phosphorylation of the myosin light chain and deactivation of myosin to produce relaxation of the vascular smooth muscle.

44
Q

How does Endothelium-derived hyperpolarizing factor (EDHF) reduce blood pressure?

A

acts on calcium-dependent potassium channels increasing levels of potassium within smooth msucle cells causing hyperpolarization of smooth muscle cells and their relaxation.

45
Q

Relaxation of the smooth muscle by all these factors results in an __________ in the luminal diameter of the vessel and a __________ in systemic blood pressure.

A

increase; decrease

46
Q

How does Endothelins increase blood pressure?

A

Members of the endothelin family of 21 amino acid peptides (endothelin I, endothelin-2, and endothelin-3) are among the most potent vasoconstrictors in the body and act on vascular smooth muscle to cause constriction of the vessel.

47
Q

What are high levels of endothelins associated with?

A

systemic hypertension, pulmonary hypertension, congestive heart failure, and renal failure. Angiotensin II binding can promote calcium increase by binding of endothelins and contracting smooth muscle

48
Q

How does Thromboxane A2 and prostagladin H2 increase blood pressure?

A

in response to thrombin and angiotensin II binding, acts on receptors on the smooth muscle cell promote calcium increase to cause vasoconstriction.

49
Q

How does Decreased synthesis of NO or inactivation of NO by the superoxide anion (O2-) increase blood pressure?

A

Endothelial cell is producing superoxide anion (O2-), it will diffuse across the membrane and decrease levels of NO in smooth muscle leading to contraction.

50
Q

Vasoconstrictor factos can _________ vascular resistance and blood pressure

A

increase

Histo second semester 23-24 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions