CIRCULATORY

Question 1

Blood Vascular System

Answer 1

 Heart
 Blood Vessels
–Arteries
–Blood capillaries
–Veins

Question 2

 Lymphatic capillaries
 Larger lymphatic vessels
 Thoracic duct and right lymphatic
duct

Answer 2

Lymphatic Vascular System

Question 3

Muscular organ that
is rhythmically
contracting
 Middle mediastinum
within the pericardial
cavity

Answer 3

HEART

Question 4

Weight in normal
adult of heart

Answer 4

– Females: 250-300 g
– Males: 300-350 g

Question 5

4 chambers

Answer 5

–Right and left atria
–Right and left ventricles

Question 6

Walls of the heart have 3 layers

Answer 6

– Endocardium
– Myocardium
– Epicardium

Question 7

Lined by
– Underneath is a thin subendothelial
layer ( contains collagen and elastic
fibers and some smooth muscles)

Answer 7

Endocardium

Question 8

–Connects the myocardium to
subendothelial layer
–Contains veins, nerves, branches of
impulse-conducting system

Answer 8

 Subendocardial layer

Question 9

 Central core of dense fibrous tissue
(collagen and elastic fibers)
 Lined on both sides by endothelium
 Bases of valves attached to annuli
fibrosi

Answer 9

Cardiac Valves

Question 10

– Prevent the reflux of blood during
relaxation of heart

Answer 10

Cardiac Valves Function

Question 11

 Middle and thickest layer
 Cardiac muscles arranged in layers
which insert into fibrous skeleton
 Responsible for
– Pumping blood through the circulation
–Conduction of impulses

Answer 11

Myocardium

Question 12

 Outer fibrous layer or fibrous
pericardium
 Inner serous layer or serous
pericardium
– External parietal layer
– Inner visceral layer (epicardium)

Answer 12

Pericardium

Question 13

 Corresponds to the visceral layer of
the pericardium
 Covered by mesothelium
 Subepicardial layer of loose CT
contains veins, nerves, adipose
tissue

Answer 13

Epicardium

Question 14

Formed by visceral and outer parietal
layer of the pericardium
 Has small amount of fluid

Answer 14

Pericardial Cavity

Question 15

Continuous framework of dense
connective tissue (thick collagen
fibers oriented in various directions)
which
– Provide attachment for many cardiac
muscles
–Serves as base of valves

Answer 15

Cardiac Skeleton

Question 16

–Annuli fibrosi
– Trigona fibrosa
–Septum membranosum

Answer 16

Cardiac Skeleton
 Principal components

Question 17

Specialized cardiac muscle fibers for
impulse conduction
–Sinoatrial node (SA)
–Atrioventricular node (AV)
–Atrioventricular bundle (bundle of His)
– Purkinje cells

Answer 17

Conducting System

Question 18

–Vessels more than 0.1 mm in diameter
– Large arterioles, muscular and elastic
arteries, muscular veins

Answer 18

Macrovasculature

Question 19

–Visible only under the microscope
(< 0.5 mm)
–Small arterioles, capillaries,
postcapillary venules
– Important site of exchange between
blood and surrounding tissues

Answer 19

Microvasculature

Question 20

Lined by endothelium supported by
subendothelial layer

Answer 20

Tunica Intima

Question 21

– Forms the boundary between the tunica
intima and tunica media
–Composed of elastin
– Has gaps that allow diffusion of
substances to nourish the deeper layers

Answer 21

internal elastic lamina
(elastica interna)

Question 22

Middle layer of circular smooth
muscles
 Variable amounts of elastic fibers,
reticular fibers, proteoglycans and
glycoproteins

Answer 22

Tunica Media

Question 23

Forms boundary between tunica media
and tunica adventitia

Answer 23

In arteries, has external elastic
lamina (elastica externa)

Question 24

 Outer coat
 Consists principally of collagen and
elastic fibers

Answer 24

Tunica Adventitia

Question 25

 Blood supply to blood vessels  Numerous in the adventitia of large vessels  Supply blood to adventitia and outer part of tunica media  More frequent in veins than arteries

Answer 25

Vasa Vasorum

Question 26

Blood vessels containing smooth muscles are supplied by sympathetic nerve fibers (vasomotor nerve) – Its neurotransmitter is epinephrine

Answer 26

Nerve Supply

Question 27

 Elastic artery  Muscular artery  Small artery and arterioles

Answer 27

Classification of Artery

Question 28

 Large elastic arteries  Thicker intima  Internal elastic lamina not clear

Answer 28

Elastic Artery or Conducting Artery

Question 29

 Numerous elastic fibers in the tunica media  Lumen is larger while wall is thinner  Include the aorta and its large branches

Answer 29

Elastic Artery or Conducting Artery

Question 30

Medium-sized arteries  Intima with very thin subendothelial layer  Prominent internal elastic lamina  Less elastic fibers and more smooth muscles

Answer 30

Muscular or Distributing Artery

Question 31

 Lumen is smaller and wall is thicker  Include branchial, femoral, radial, popliteal arteries and their branches

Answer 31

Muscular or Distributing Artery

Question 32

– 200 u to 400 u in diameter with narrow lumen – Very thin subendothelial layer; internal elastic lamina absent; media with 1 or 2 circular smooth muscles

Answer 32

Arterioles

Question 33

Tunica media more developed with larger lumens

Answer 33

 Small artery

Question 34

 In both, tunica adventitia very thin  Important segment of the circulation – Principal component of the peripheral resistance to flow that regulate blood pressure

Answer 34

Small Artery and Arterioles

Question 35

 Small endothelial tubes that connect arterioles to venules  Average diameter 5-10 u Wall is composed of simple squamous (endothelium) resting on a basal lamina

Answer 35

Blood Capillaries

Question 36

Scattered along the outside are cells called

Answer 36

pericytes

Question 37

– Perivascular contractile cells – Possess long branching processes that extend circumferentially around each capillary – Well developed actin and myosin – Help propel blood through the capillaries

Answer 37

pericytes

Question 38

– Help propel blood through the capillaries –After tissue injury can proliferate and differentiate to form smooth muscles when capillaries are transformed into arterioles or large venules

Answer 38

Pericyte functions

Question 39

 Or tight capillaries  Endothelium forms a thin uninterrupted layer around the capillary  Allows regulated exchange of materials  Found in all types of muscles, CT, exocrine glands, nervous tissue

Answer 39

Continuous Capillaries

Question 40

 Visceral capillaries  Endothelium is interrupted with small circular fenestrae – are obliterated by a diaphragm that is thinner than cell membrane  Basal lamina is continuous  Found in kidneys, small intestine, choroid plexus, endocrine glands

Answer 40

Fenestrated Capillaries

Question 41

 Or tight capillaries  Endothelium forms a thin uninterrupted layer around the capillary  Allows regulated exchange of materials  Found in all types of muscles, CT, exocrine glands, nervous tissue

Answer 41

Continuous Capillaries

Question 42

 Capillaries have wider diameter  Endothelial cells are separated by wide spaces – have large fenestrae without diaphragm  Basal lamina discontinuous  Found in the liver, bone marrow and spleen, some endocrine glands

Answer 42

Sinusoidal Capillaries (Discontinuous)

Question 43

 15-20 u diameter  Endothelium with very pericytes  Loose endothelial junctions  Large diameter and lumen  Converge to form collecting venules, then muscular venules

Answer 43

Postcapillary Venules

Question 44

 Majority of veins are small or medium-sized with < 1 cm diameter Wall has 3 layers – Intima with thin subendothelial layer – Media with small bundles of smooth muscles – Well developed adventitia

Answer 44

Veins

Question 45

 Veins close to the heart Well developed intima  Relatively thin tunica media  Thick tunica adventitia

Answer 45

Large Veins

Question 46

have valves especially numerous in the veins of the legs  Consist of paired semi-lunar folds of tunica intima  Prevent backflow of blood

Answer 46

Large Veins

Question 47

Structural differences with arteries –Veins have lesser smooth muscle fibers and elastic fibers –Boundaries of the layers are not very distinct – Thickest coat in the veins is the tunica adventitia – Presence of valves

Answer 47

Veins

Question 48

 Drain interstitial fluid  Blind-ended terminal branches  Variable diameter between 10-50 u  Single layer of endothelium and incomplete basal lamina  Have openings between endothelial cells with anchoring filaments  Transport clear fluid called lymph

Answer 48

Lymphatic Capillaries

Question 49

Lymphatic vessels are more variable with regards to its shape and caliber  Pericytes are absent  Incomplete basal lamina  End blindly as rounded or swollen ends

Answer 49

Lymphatic Capillaries Differ from Blood Capillaries

Question 50

 Larger lymphatic vessels –Resemble veins more than arteries – 3 layers of coat but are less distinct – Tunica media smooth muscle fibers are more developed –Valves are present  Thoracic duct and right lymphatic duct

Answer 50

Lymphatic Vessels