Cadriovascular system

Question 1

Cardiac fibrous skeleton

Answer 1

4 fibrous rings surrounding Valve orifices

2 fibrous trogones connecting the rings and the membranous part of the interventricular septum

Question 2

Valves

Answer 2

Atrioventricular (tricuspid, bicupsid)
Semilunar (Aorta, pulmonary)

layers:
dense CT (Valve leaflet)
subendothelial CT
Endothelium

Question 3

Three layers of heart wall

Answer 3

Endocardium
Myocardium
Epicardium

Question 4

Endocardium

Answer 4

thicker in atrium than in ventricle

Layers:
1. Endothelium - simple suqamous
2- Subendothelial loose CT
3. Myoelastic layer - CT and smooth muscle cells
4. Subendocardial layer: loose CT and Purkinje cells

Question 5

Myocardium

Answer 5

thicker in ventricles than in atria

Question 6

Epicardium

Answer 6

2 layers:

1. Mesothelium (simple squamous) (außen)
2. Underling loose CT and adipose tissue (innen)

Question 7

Cardiac conducting system

Answer 7

Sinoatrial node (SA): specialized cells near Junction of sup. vena Cava and right atrium
--> initiates Impulse along internidal tracts

Atrioventricular node (AV): carried across ventricles by bundle of His

Bundle of his: divides into left and right and then into purkinje fibers

Question 8

Purkinje cells

Answer 8

• in subendocardial layer
• elongates cells with large nuclei
• glycogen and mitochondria
• propagate impuls and stimulate cardiac muscle

Question 9

Classification of blood vessels

Answer 9

ARTERIES
- elastic
- musclular
ARTERIOLES
CAPILLARIES AND AV SHUNTS
VENULES
VEINS
- small
- middle sized
- large

Question 10

Organization of blood vessel wall

Answer 10

von innen nach außen

1. tunica intima
2. tunica media
3. tunica adventitia

Question 11

Tunica intima

Answer 11

Endothelium
Subendothelial loose CT
Internal elastic membrane (in arteries)

Structures have longitudinal orientation

Question 12

Endothelial cells

Answer 12

• connected by tight junctions
• vesicles for Transport across Endothelium
• actin and Myosin fibers in cytoplasm
• Variety of Surface adhesion molecules and receptors

Question 13

Functions of Endothelium (6)

Answer 13

• selective permeability barrier
• nonthrombogenic barrier
• Regeneration and growth
• Modulation of blood flow
• immune Responses
• hormonal Synthesis

Question 14

Tunica media

Answer 14

• smooth muscle and CT
• External elascic membrane (in arteries)
• structues have circular orientation

Question 15

Tunica adventitia

Answer 15

loose CT

structures have longitudinal orientation
- thickest layer of veins

Question 16

Vasa vasorum

Answer 16

• tunica Adventitia and media of arteries
• all layers of veins

System of vessels that supply wall of vessels themselves

Question 17

Nervi vasculares

Answer 17

• autonomic nerves that Control contraction and Dilation of smooth muscle in vascular walls

Question 18

Elastic arteries

Answer 18

Aorta, brachiocephalic, subclavian, common carotid…

t. intima:
- Endothelium
- subendothelial loose CT with myocytes
- internal elastic membrane (non conspicuous)

t. media:
- 40-70 concentric lamellae
- external elastic membrane (non conspicuous)

t. Adventitia
- loose CT with fibroblasts, Collagen and elastic fibers

Question 19

Muscular arteries

Answer 19

t. intima:
- Endothelium
- subendothelial loose CT
- internal elastic membrane (sheet of Elastin)

t. media:
- smooth muscle
- external elastic membrane

t. adventitia
- loose CT with Collagen and elastic fibers

Question 20

Sectors of microvascular bed

Answer 20

Arterioles
Capillaries or Arteriovenous shunts
Venules

Question 21

Arteriole

Answer 21

t. intima:
Endothelium

t. media:
- 1-3 smooth mscule cells arranged radially

t. adventitia:
- loose CT (thin)!

Question 22

Capillary wall

Answer 22

Endothelial cells
Basement membrane
+ occasional pericytes

Question 23

Types of capillaries

Answer 23

Continuous
Fenestrated
Sinusoidal (discontinuous)

Question 24

Continuous capillary

Answer 24

• continuous Endothelium
• continuous b.m.
• in tissues where gases and small molecules are exchanged
• CNS, msucles, nerves, lungs

Question 25

Fenestrated capillary

Answer 25

- Endothelium with fenestrations - contiuous b.m. Most fenestrations have membranous diaphragms - for large volumes of fluid, electrolytes, AA

Question 26

Sinusoidal (discontinuous) capillary

Answer 26

``` - discontinuous Endothelium: >pores and holes >Fenestrations without diaphragms >Gaps between cells - dicontinuous b.m. ``` in liver, Spleen, bone marrow

Question 27

Pericytes

Answer 27

capillaries, postcapillary venules contract structural support stem cells to repair damage

Question 28

Classification of Arteriovenous shunts

Answer 28

- preferential thoroughfare channels - arteriovenous anastomoses (AVA) >>> simple AVA >>> specialized AVA

Question 29

Preferential thoroughfare channle

Answer 29

- allows blood to pass from arteriole to venule - proximal Segment --> metarteriole - metarteriole has precapillary sphinters - common in mesentery

Question 30

Simple AVA

Answer 30

- between arteriole and venule - straight or coiled - thick smooth muscle layer - Skin, noes, lips, erectile tissues

Question 31

Specialized AVA

Answer 31

- simple AVA with additional structures - branches of afferent arteriole that roll into a ball (glomera AVA ) - additional longitudinal and circular muscular cells (epithelioid AVA)

Question 32

Postcapillary venule

Answer 32

t. intima: - Endothelium on b.m. t. media: - pericytes (not smooth muscle!) t. Adventitia - loose CT

Question 33

Vein

Answer 33

t. intima: - Endothelium - subendothelial CT - smooth muscle cells in large veins - valves in middle-sized veins t. media: - thin/absent: muscle cells, Collagen fibers, elastic fibers t. Adventitia: - loose CT (thick) with longitudinally oriented smooth mscules bundles in large veins

Question 34

Lymph vascular system

Answer 34

- vessels drain excess fluid from the tissue - begin as blind lymphatic capillaries that take up excess fluid - lymph flows from peripheral tissue through collectinc lymphatic vessels - lymph is filtered in lmyph nodes

Question 35

Lymphatic capillaries

Answer 35

- Continusou Endothelium (without tight junctions!!), cell borders are overlapping - Discontinuous b.m.