Histology

Question 1

Thre major layers of the heart?

Answer 1

1. the inner endocardium of endothelium (and subendothelial connective tissue!)
2. the myocardium of cardiac muscle
3. the epicardium (connective tissue with many adipocytes and covered by mesothelium)

Question 2

What 4 characteristics are found in the epicardium?

Answer 2

1. Mesothelium
2. Connective tissue
3. Autonomic nerve bundles
4. Adipose tissue

Question 3

What is the function of the cardiac conducting system?

What are the 4 parts in order?

Answer 3

Modified cardiac muscle fibers that stimulates rhytmic contraction (heartbeat)

1. Sinoatrial (SA) node (pacemaker)
2. Atrioventricular (AV) node
3. Atrioventricular bundle (of His) (in interventricular septim)
4. Purkinje Fibers

Question 4

How do Purkinje fiber differ from contractile fibers (3)?

Answer 4

1. larger diameter
2. abundant glycogen (therefore pale staining)
3. closer to the endothelium

Question 5

What is the cardiac skeleton?

Three functions of the cardiac skeleton?

Answer 5

The cardiac skeleton is dense fibrous/irregular connective tissue primarily found in the endocardium

1. anchoring and supporting heart valves
2. provides firm points of insertion for cardiac muscle
3. coordinates heartbeat by acting as electrical insulation between atria and ventricles

Question 6

Three layers/tunics of blood vessels?

Answer 6

1. intima
2. media
3. adventitia

Question 7

In an artery, the thickest layer is the _1_ and the lumen is _2_. In a vein, the thickest layer is the _3_ and the lumen is _4_. In a vein, the intima forms _5_ IOT restrict backflow. _6_ contain no tunics and only endothelium.

Answer 7

1. media
2. narrow
3. adventitia
4. large
5. valves
6. capillaries

Question 8

Just as the heart wall is supplied with its own _1_ arteries for nutrients and oxygen, large vessels usually have __ 2 __ (arterioles, capillaries and venules in the _3_ tunic and outer part of the media.

Answer 8

1. coronary
2. vaso vasorum
3. adventitia

Question 9

In arteries and large veins, the intima includes a prominent limiting layer made of elastin. What is the name of this layer?

Answer 9

Internal elastic lamina

Question 10

3 types of microvasculature?

Answer 10

1. Arterioles
2. Capillaires
3. Venules (drain capillaries)

Question 11

What type of blood vessel is this?

1. endothelium present
2. 1-3 layers of smooth muscle
3. Thin connective tissue adventitia

Answer 11

Arterioles

Question 12

What blood vessel type is this?

1. Resists and controls blood flow to capillaries
2. Major determinant of systemic blood pressure

Answer 12

Arterioles

Question 13

What type of blood vessel is this?

1. Endothelium present
2. Pericytes in Media
3. No adventitia

Answer 13

Capillary

Question 14

What type of blood vessel exchanges metabolites by diffusion to and from cells?

Answer 14

Capillaries

Question 15

What type of blood vessel is this?

1. Endothelium present
2. scattered smooth cells in media
3. no adventitia

Answer 15

Venule (no valves present!)

Question 16

What blood vessel drains capillary beds and allows leukocytes to exit vasculature?

Answer 16

Venules

Question 17

Flow of blood through metarterioles (smaller arteriole branches) is regulated by smooth muscle cell bands called what?

Answer 17

Precapillary sphincters

Question 18

What is the purpose of arteriovenous shunts in skin?

Answer 18

They allow (through vasoconstriction) arterioles to bypass the capillary networks and connect directly to venules.

Question 19

Where are venous portal systems found? What is their purpose?

Answer 19

In the **liver **and anterior pituitary gland.

Allows molecules entering the blood at the first set of capillaries to be delivered quickly and at high concentrations to surrounding tissues at the second capillary bed.

Question 20

Where is the arteral portal system found?

Answer 20

In the kidneys.

Question 21

What are the three types of capillaries?

Answer 21

1. Continuous
2. Fenestrated
3. Discontinuous or sinusoids

Question 22

Function of a continuous capillary?

Answer 22

has many tight junctions so all exchange occurs through cells

Question 23

Function of a fenestrated capillary? Where is it usually found?

Answer 23

Has small pores/fenestrations through cells IOT allow for greater exchange across endothelium. Also has a continuous basement membrane.

Commonly found in organs where molecular exchange is important: endocrine organs (hormone uptake), intestinal walls, choroid plexus.

Question 24

Characteristics of a sinusoid? Where are these commonly found?

Answer 24

1. Larger lumen
2. Large spaces between endothelial cells
3. Discontinuous basal lamina

Usually located in organs where exchagne occurs readily between tissue and blood: bone marrow, liver and spleen.

Question 25

Where do white blood cells enter damaged or infected tissues?

Answer 25

Postcapillary venules

Question 26

What are the functions of pericytes?

Answer 26

1. They contract IOT facilitate blood flow. 2. Can produce smooth muscle and connective tissue during microvasculature remodeling or repair.

Question 27

name 5 functions of the cardiovascular system:

Answer 27

1. supply oxygen via RBCs 2. supply/remove metabolic fuels and end products 3. distribute and remove excess heat 4. immune functions (includes lymphatic circulatory system) 5. body fluid regulation (endocrine substances)

Question 28

what are the 5 priorities of the cardiovascular system?

Answer 28

1. maintain homostasis 2. maintain blood pressure 3. deliver adequate cardiac output (keep pumping) 4. supply nutrients to match metabolic demands 5. assure exchange at capillaries

Question 29

the cardiovascular system consists of what to systems?

Answer 29

1. blood vascular system 2. lymphatic vascular system

Question 30

the blood vascular system has two paths called:

Answer 30

1. systemic circulation 2. pulmonary circulation

Question 31

the blood vascular system is lined with what? what is the fancy histological term?

Answer 31

* endothelium * simple squamous epithelium

Question 32

what is the name of the cells in the heart? how do they communicate to each other? where is the nucleus located?

Answer 32

Myocardiocytes, via gap junctions, centrally

Question 33

what are the components of the cardiac skeleton?

Answer 33

the tricuspid, mitral, aortic and pulmonary valves

Question 34

the tricuspid and mitral valves can also be referred to as what?

Answer 34

the atrioventricular valves

Question 35

the atrial and pulmonary valves can also be referred to as what?

Answer 35

the semilunar valves

Question 36

if the heart valves are concave and open away from you, are you looking from the top or bottom?

Answer 36

the top

Question 37

valves are made of what type of tissue? what about arteries?

Answer 37

* dense connective tissue * smooth muscle

Question 38

what is the special functino of a cardiomyocyte?

Answer 38

they have an indvidual ability to beat on their own

Question 39

a muscular artery has 1 layer of \_1\_ \_2\_ lamina while an eleastic artery has many layers of \_1\_ \_2\_ lamina. This feature is located in the tunica \_3\_

Answer 39

1-2. internal elastic 3. media

Question 40

nitric oxide induces (vasodilation/vasoconstrction)?

Answer 40

vasdilation. It relaxes smooth muscle.

Question 41

At any given time, which part of the CV system holds the highest percetage of blood volume?

Answer 41

the venous system