Circulatory System Flashcards
1
Q
CIRCULATORY SYSTEM:
2 Components
A
Blood vascular system (cardiovascular system)
Lymphatic vascular system
2
Q
Serves as the transportation system for various metabolites and nutrients in the body
A
CARDIOVASCULAR SYSTEM
3
Q
CARDIOVASCULAR SYSTEM
components (4)
A
- Heart
- Arteries
- Capillaries
- Veins
4
Q
Muscular organ that pumps blood into two separated circuits
A
Heart
5
Q
Two circuits of the Heart and their function
A
Pulmonary circuit – to the lungs
Systemic circuit – to the tissues
6
Q
Contracts to force blood to move through the system
A
Heart
7
Q
Carry blood away from the heart to the capillaries
A
Arteries
8
Q
Sites of exchange of materials between the vascular bed and the surrounding tissues
A
Capillaries
9
Q
Returns the blood from the capillary bed to the heart
A
Veins
10
Q
is the Four-chambered pump of the cardiovascular system. what are its chambers and function?
A
HEART
2 atria (receive blood)
2 ventricles (discharge blood)
11
Q
LAYERS OF THE HEART WALL (4)
A
Epicardium
Myocardium
Endocardium
Pericardium
12
Q
Outermost layer of the heart wall
Composed of a ______ _______ mesothelium (epithelium) and subepicardial layer of connective tissue
A
Epicardium
simple squamous
12
Q
visceral layer of pericardium
A
Epicardium
13
Q
Middle muscular layer (cardiac muscle fibers)
Thickest layer of the heart wall
A
Myocardium
14
Q
Innermost layer of heart
______ _______ endothelium and subendothelial layer composed of ____ ____ ___
A
Endocardium
Simple squamous
dense irregular CT
15
Q
Surrounds the heart like a sac
A
Pericardium
16
Q
2 layers of Pericardium
A
outer
inner
17
Q
Outer layer of pericardium consists of (2)
A
Fibrous pericardium
Parietal pericardium
18
Q
inner layer of pericardium
A
visceral pericardium (epicardium)
19
Q
Space between parietal and visceral pericardium
A
Pericardial cavity
20
Q
Composed of dense irregular connective tissue
A
CARDIAC SKELETON
21
Q
Functions of Cardiac skeleton (3)
A
Surround and support the bases of all heart valves
Providing firm points of insertion for cardiac muscle in the atria and ventricles
Help coordinate the heartbeat by acting as electrical insulation between atria and ventricles
22
Q
CARDIAC SKELETON
Main components (3)
A
Annuli fibrosi
Trigona fibrosa cordis
Septum membranaceum
23
Q
Surrounds ______ valves and the
atrioventricular valve
Composed of intermingling bundles
of collagen and a few elastic fibers
A
Annuli fibrosi
semilunar
24
Fill the spaces between the atrioventricular openings and the base of the aorta
Small areas of connective tissue
Trigona fibrosa cordis
25
Trigona fibrosa cordis of pigs, cats, and rabbits is....
predominantly dense, irregular
connective tissue
26
Trigona fibrosa cordis of dogs is...
fibrocartilage
27
Trigona fibrosa cordis of horses is...
hyaline cartilage
28
Trigona fibrosa cordis of large ruminant is...
bone
29
Fibrous portion of interventricular
septum
Consists of collagen fiber bundles
Septum membranaceum
30
Specialized to regulate the sequence of atrial
and ventricular contractions
CARDIAC CONDUCTION SYSTEM
31
CARDIAC CONDUCTION SYSTEM
Modified cardiac muscle cells
Purkinje fibers
32
CARDIAC CONDUCTION SYSTEM is consists of (3)
Sinoatrial node (SA node)
Atrioventricular node (AV node)
Atrioventricular bundle (Bundle of His)
33
GENERAL STRUCTURE OF BLOOD VESSELS (7)
VESSEL TUNICS
BLOOD VESSELS
ARTERIES
CAPILLARIES
ARTERIOVENOUS ANASTOMOSIS
VEINS
ATYPICAL BLOOD VESSELS
34
BLOOD VESSELS 3 layers (vessel tunics)
Tunica intima (interna)
Innermost
Tunica media
Middle
Tunica adventitia (externa)
Outermost
35
Tunica intima layers (3)
a. Endothelium
b. Subendothelial layer
c. Internal elastic lamina
36
A layer of tunica intima which consists of
Simple squamous epithelium
Common and consistent feature
of all blood vessels and heart
Rests on a basal lamina
Tunica intima Endothelium
37
A layer of tunica intima which consists of
Thin layer of loose CT
Sometimes contains smooth muscle
cells
Tunica intima Subendothelial layer
38
A layer of tunica intima which consists of
Composed of elastin
Separates the tunica intima from the
tunica media
Especially well developed in
muscular arteries
Tunica intima Internal elastic lamina
39
Usually the thickest layer
Concentric cell layers: helically arranged smooth muscle cells
Interspersed with varying amounts of elastic
fibers, reticular fibers, proteoglycans, collagen
fibers
Tunica media
40
Present in tunica media of large vessels (2)
Nervi vasorum (nerve supply)
vasa vasorum (blood supply)
41
tunica media layer (1)
External elastic lamina
42
A layer of tunica media that is
Similar in structure to the internal elastic
membrane
Separates tunica media from tunica adventitia
Clearly distinguishable in the largest muscular arteries
External elastic lamina
43
Outermost covering
Connective tissue – principally of
__________ and ________
Generally difficult to distinguish the
end of this tunic
Continuous with the connective
tissue elements
- Nervi and vasa vasorum are present
in this tunic
Tunica adventitia
type I collagen
elastic fibers
44
Only the endothelium is constantly present in tunics: true or false?
true
45
BLOOD VESSELS 3 types
Arteries
Capillaries
Veins
46
Carry blood away from the heart to the capillary beds
ARTERIES
47
ARTERIES classifications (4)
Elastic (conducting) arteries
Muscular (distributing) arteries
Arterioles
Metarterioles
48
aka:
Conducting arteries
Large arteries
Elastic arteries
49
Examples of arteries (3)
aorta
pulmonary trunk
their largest branches
50
Transition from elastic to muscular arteries may be either gradual or abrupt
TRUE OR FALSE
true
51
Layers of Elastic artery (3)
Tunica intima
Tunica media
Tunica adventitia
52
well-developed in this elastic artery layer
(+) internal elastic lamina
Tunica intima
53
Most prominent feature in this layer of elastic artery
Concentric layers of elastic membranes
alternating with smooth muscle fibers
(+) external elastic lamina
Tunica media
54
Thinner than t. media in this elastic artery layer
Tunica adventitia
55
aka:
Distributing arteries
Medium arteries
Muscular arteries
56
Examples of muscular arteries
Most vessels arising from the aorta
except for the major trunks
originating from the arch of aorta
and the terminal bifurcation of the
abdominal aorta
57
thinner
(+) internal elastic lamina: more prominent
Occasionally duplicated (bifid internal elastic lamina)
T. intima muscular artery
58
Thick and mostly of many layers of smooth muscle cells
Less elastic membranes than elastic arteries
(+) external elastic lamina
T. media of muscular artery
59
Relatively thicker than in elastic arteries
T. adventitia of muscular artery
60
aka:
Resistance vessels
Small arteries
Control blood flow to capillary
networks
Arterioles
61
(+) thin subendothelial layers and elastic fibers
(+) internal elastic lamina
T. intima of arterioles
62
1 – 3 layers of smooth muscle cells
May also contain collagen fibers
(-) external elastic lamina
t. media of arterioles
63
Thin sheath of loose connective tissue
T. adventitia of arterioles
64
Narrow vessel surrounded by large,
isolated bundles of smooth muscle
Initial portion is surrounded by
additional smooth muscle cells, which
form a _____ ______
Metarterioles
precapillary sphincter
65
aka exchange vessels
Smallest blood vessels
Single layer of _______ (endothelial)
cells surrounded by a basal lamina
and occasional _____
CAPILLARIES
squamous
pericytes
66
CAPILLARIES
central channels (2)
Proximal end – metarterioles
Distal end – thoroughfare channel
67
CLASSIFICATION OF CAPILLARIES (3)
Continuous capillaries
Fenestrated capillaries
Sinusoidal (discontinuous) capillaries
68
Most common type of capillary
Individual endothelial cells are held together
by ______ ______
_____ _____ may be found either
numerous or few in number
Continuous capillaries
tight junctions
Transcytotic vesicles
69
capillaries
Found in areas such as:
Peripheral nerve fibers, skeletal muscle,
lungs, thymus
Continuous capillaries
70
Have a sieve-like structure
Endothelial cells have portions with numerous small circular openings (_____)
_______are closed by monolayered
diaphragms that are thinner than the cell
membrane
Fenestrated capillaries
fenestrae
71
capillaries
Found in areas such as:
Endocrine glands, pancreas, and lamina propria of the intestines, renal glomeruli*
Fenestrated capillaries
72
Larger than other capillaries
Larger in diameter and more irregularly-shaped
Large _____ ______ and pores through the endothelial cells
Sinusoidal (discontinuous) capillaries
intercellular openings
73
Found in:
Liver, spleen, lymph nodes, bone marrow, suprarenal cortex
Sinusoidal (discontinuous) capillaries
74
Direct connections between arterioles and
venules
Short, usually nonbranched, and often coiled vessels
Possess a thick smooth muscle layer in the
subendothelium that receives a dense vasomotor nerve supply
ARTERIOVENOUS ANASTOMOSIS
75
Function of ARTERIOVENOUS ANASTOMOSIS (3)
Regulation of blood pressure and blood
flow into capillary beds
Thermoregulation
Erection
76
Return blood to the heart
Capacitance or reservoir vessels
VEINS
77
3 classifications of Veins
Venules
Small and Medium veins
Large veins
78
3 Types of Venules
Postcapillary venules
Pericytic venules or collecting venules
Muscular venules
79
Similar in structure to capillaries but larger in diameter
_______ venules found in most lymphoid tissues: aka high endothelial
venules
Postcapillary venules
80
Pericytes form a continuous layer
Pericytic venules or collecting venules
81
Located distal to the postcapillary venules
Pericytes are gradually replaced by circularly arranged smooth muscle cells
Muscular venules
82
T. intima of Venule
Endothelium
83
T. media of venule
(+) in muscular venules
84
T. adventitia of venule
A thin layer may be present in
muscular venules
85
Most veins are classified as small or medium veins
May contain _____
Usually located close and parallel to corresponding muscular arteries
Small and Medium Veins
valves
86
Continuation of muscular venules
Small veins
87
Valves are characteristic features
Most numerous in the inferior portion of the body
Medium veins
88
usually thin
Endothelium with subendothelial layer
IEL: thin layer may be present in larger vessels
T. intima of small and medium veins
89
what can be found in t. media of small veins
2 – 3 layers of smooth muscle
90
what can be found in t. media of medium veins
3 – 5 layers of smooth muscle
91
: thicker than its t. media
Medium v: longitudinal smooth muscle may be present
Medium v: with collagen and elastic fibers
t. adventitia
92
Return venous blood directly to the heart
May have prominent valves
Large Veins
93
Examples:
Superior and inferior vena cava and hepatic portal vein
Renal, internal jugular, iliac, azygos vein
Large Veins
94
Tunica intima
Endothelium with subendothelial layer
IEL: May be present
Large Veins
95
Tunica media: relatively thin
> 5 layers of smooth muscle; only few have well-developed smooth muscle layer
Large Veins
96
thickest layer
Also with bundled longitudinal smooth muscle
_____ _____:
(+) in t. adventitia of superior and inferior vena cava, pulmonary trunk
Large Veins
Myocardial sleeves
97
Prevent backflow of blood
Especially abundant in lower extremities
VALVES OF THE VEINS
98
ATYPICAL BLOOD VESSELS (4)
Coronary arteries
Dural venous sinuses
Great saphenous vein
Central adrenomedullary vein
99
Considered muscular arteries
Walls are usually thicker than those of comparable arteries in the upper or lower limb
Coronary arteries
100
Represent venous channels in the cranial cavity
Broad spaces within the dura mater that are lined with endothelial cells; devoid of
smooth muscles
Dural venous sinuses
101
Often described as muscular vein due to unusual amount of smooth muscle
Great saphenous vein
102
Has unique eccentric arrangement of smooth muscle bundles
Resulting in irregularity in the thickness of the vascular wall
Contraction of the longitudinally arranged smooth muscles in the tunica media enhances the efflux of hormones from the adrenal medulla into the circulation
Central adrenomedullary vein
103
Unidirectional
Collect excess extracellular fluid (lymph) from the interstitial tissue spaces
LYMPHATIC VASCULAR SYSTEM
104
Begin as “blind-ended” tubes
Lined by endothelium with incomplete basal lamina
Usually thin and larger in diameter than blood capillaries and variable in shape
Lymphatic capillaries
105
sequence of lymph drainage to cardiovascular system
Lymphatic capillaries → lymphatic vessels → lymphatic ducts → cardiovascular system
106
LYMPHATIC DUCTS types (2)
Right lymphatic duct
Thoracic ducts
107
Shorter
Empties its contents into the venous system at the junction of the right internal
jugular and subclavian veins
Right lymphatic duct
108
Larger
Begins in the abdomen as the ___ _____
Ascends through the thorax and neck to empty its contents at the junction of the
left internal jugular and subclavian veins.
Thoracic ducts
cisterna chyli
