Circulatory System 1 Flashcards
1
Q
What does “cardiovascular” refer to?
A
The heart (“cardio”) and blood vessels (“vascular”).
2
Q
What is the main function of the heart in the circulatory system?
A
The heart pushes blood through the circulatory system via its constant pumping action.
3
Q
What are some functions of blood as it travels through the body?
Answer:
A
Carrying substances to cells (e.g., O2, nutrients, hormones)
Carrying substances away from cells (e.g., CO2, wastes).
Regulating the acid-base balance in the body through the use of buffers.
Regulating body temperature by absorbing heat internally and releasing it peripherally (i.e., in the skin).
Helping defend against disease (e.g., WBCs, antibodies).
C.C.R.R.H
4
Q
What are the three basic layers of most blood vessels?
A
Tunica externa - composed of connective tissue.
Tunica media - consists of smooth muscle and elastic connective tissue.
Tunica interna - made up of epithelial tissue.
5
Q
Tunica externa
A
composed of connective tissue.
6
Q
Tunica media
A
consists of smooth muscle and elastic connective tissue.
7
Q
Tunica interna
A
made up of epithelial tissue.
8
Q
How do slight differences in the composition and thickness of these layers affect blood vessels?
A
Slight differences in the composition and thickness of these layers account for the functional differences between the different types of blood vessels.
9
Q
What is the primary difference between different types of blood vessels?
A
In general, the thickness and composition of the tunica media are the primary differences between different types of blood vessels.
10
Q
How are contractions of smooth muscle within the tunica media used?
A
Contractions of the smooth muscle within the tunica media are used to regulate the diameter of the blood vessels and therefore the distribution of blood to different regions and tissues in the body.
11
Q
Define vasoconstriction and vasodilation.
A
Vasoconstriction: Refers to a decreased blood vessel diameter resulting from smooth muscle contraction.
Vasodilation: Refers to an increased blood vessel diameter resulting from smooth muscle relaxation.
12
Q
Elastic connective tissue within blood vessel:
A
allows the blood vessel to stretch and recoil as the pressure within it fluctuates
13
Q
What types of vessels usually contain oxygenated blood?
A
Arteries and arterioles usually contain oxygenated blood.
14
Q
What types of vessels usually contain deoxygenated blood?
A
Venules and veins usually contain deoxygenated blood.
15
Q
What is the composition of blood in capillaries?
A
Capillaries contain a mixture of oxygenated and deoxygenated blood.
16
Q
purpose of arteries:
A
Carry blood away from the heart
17
Q
arteries have relatively ___ ___ (compared to veins).
A
Have relatively thick walls (compared to veins)
18
Q
What is the primary reason for the thick walls of arteries?
A
The thick walls of arteries are primarily due to their thick tunica media, which allows for an increased ability to stretch with each heartbeat.
19
Q
What is the composition of the tunica media in large arteries close to the heart?
A
The tunica media of large arteries close to the heart contains an abundance of elastic tissue.
20
Q
How does the composition of the tunica media in large arteries affect blood pressure?
A
The elastic tissue in the tunica media of large arteries allows these vessels to expand and recoil with each heartbeat, thereby increasing the pressure of the blood being propelled away from the heart.
21
Q
What is the composition of the tunica media in medium-sized arteries branching off from large arteries?
A
The tunica media of medium-sized arteries branching off from large arteries contains an abundance of smooth muscle.
22
Q
What are elastic arteries?
A
Elastic arteries are the larger arteries of the body, such as the aorta and its major branches, the pulmonary trunk.
23
Q
What is the predominant tissue in the tunica media of elastic arteries?
A
The tunica media of elastic arteries is predominantly elastic connective tissue.
24
Q
How do elastic fibers in elastic arteries contribute to blood flow?
A
The recoil of elastic fibers in elastic arteries helps propel blood away from the heart.
25
What are muscular arteries?
Muscular arteries are medium-sized arteries.
26
What is the predominant tissue in the tunica media of muscular arteries?
The tunica media of muscular arteries is predominantly smooth muscle.
27
What advantage does the abundance of smooth muscle in muscular arteries provide?
The abundance of smooth muscle in muscular arteries allows for more control of blood flow.
28
What are arterioles?
Arterioles are small blood vessels that connect arteries to capillaries.
29
What is the primary function of the smooth muscle in the tunica media of arterioles?
The smooth muscle in the tunica media of arterioles is used to tightly regulate the amount of blood entering capillaries.
30
what do arteries give rise to?
arterioles
31
Describe the scenario depicted in the left image. (slide 10)
In the left image, all precapillary smooth muscle sphincters are relaxed, allowing blood to distribute fully through the entire capillary bed.
32
Describe the scenario depicted in the right image. (slide 10)
In the right image, some of the precapillary sphincters are contracted, preventing blood from being distributed to certain portions of the capillary bed.
33
What are capillaries?
Capillaries are very small, highly-branched blood vessels that form networks among the individual cells of the body.
34
What is unique about the structure of capillaries compared to other blood vessels?
Capillaries do not contain a tunica externa or tunica media. Their walls are so thin that they allow the exchange of substances between the blood and surrounding cells.
35
What are venules?
Venules are small veins that collect deoxygenated blood from capillary beds and start transporting it back to the heart.
36
What is the primary function of veins?
Veins carry blood to the heart.
37
How do the walls of veins compare to those of arteries?
Veins have relatively thin walls compared to arteries.
38
What prevents veins from collapsing?
Veins would essentially collapse if they were not filled with blood.
39
What are the mechanisms that assist the flow of blood through veins?
1. Pumping action of the heart.
2. Valves projecting into the interior that prevent the backflow of blood.
3. "Skeletal muscle pump" – contraction of skeletal muscles compresses the veins of the upper and lower limbs.
4. "Respiratory pump" – fluctuations in abdominal cavity pressure during respiration compress abdominal veins.
"Pumping, Valves, Skeletal muscles, Respiratory Pump."
40
What can happen if valves in veins fail?
If valves in veins fail, it can allow blood to pool in certain regions, such as the lower limbs, leading to distension and twisting of veins, a condition known as varicose veins.
41
What is Deep Vein Thrombosis (DVT)?
DVT is when a clot (thrombus) forms in a deep vein, most commonly in the lower limbs.
42
What are some risk factors for DVT?
Risk factors for DVT include trauma, long periods of immobilization (e.g., flights, casts), and certain drugs (e.g., HRT, oral contraceptives).
43
What are the symptoms of DVT?
Symptoms of DVT (if present) include swelling/warmth, local pain/tenderness, and distension of superficial veins.
44
What is Pulmonary Embolism (PE)?
PE occurs when a clot (embolus) detaches and gets trapped within blood vessels, such as the pulmonary artery.
45
What are some symptoms of PE?
Symptoms of PE include chest pain, shortness of breath, and cyanosis.
46
What are the potential consequences of severe cases of PE?
Severe cases of PE can affect both the right side (increased pressure) and left side (decreased ejection) of the heart, potentially leading to cardiac arrest and death.
47
Why is the amount of blood contained within the systemic veins greater than the blood contained within all other types of blood vessels in the body?
The amount of blood contained within the systemic veins is greater due to the sheer number of systemic veins compared to other types of blood vessels in the body.
48
what is the distribution of blood?
9% pulmonary vessels
7% heart
13% systemic arteries and arterioles
7% systemic capillaries
64% systemic veins and venules (blood reservoirs)
49
What is Blood Pressure (BP)?
Blood Pressure (BP) is the pressure exerted on blood vessel walls by the blood.
50
What does Systolic BP represent?
Systolic BP represents the pressure on arterial walls during ventricular contraction.
51
What does Diastolic BP represent?
Diastolic BP represents the pressure on arterial walls during ventricular relaxation
52
How does blood pressure change through the circulatory system?
Blood pressure progressively decreases through the circulatory system as the distance from the left ventricle increases.
53
120/80 mmHg
Systolic BP = 120 mmHg
Diastolic BP = 80 mmHg
54
“mmHg”
The pressure exerted by 1mm of mercury
55
What regulates cardiovascular function?
Various feedback systems, including neural and endocrine mechanisms.
56
Where is the cardiovascular (CV) center located?
The cardiovascular (CV) center is located in the medulla oblongata of the brainstem.
57
How does the CV center regulate cardiovascular function?
The CV center receives input from various sources and relays output signals to the heart and blood vessels via the autonomic nervous system (ANS).
58
What are some sources of input to the cardiovascular center?
Input to the cardiovascular center comes from various sources, including barrel receptors in the blood vessel walls and higher brain centers.
59
How does the cardiovascular center provide parasympathetic output?
The cardiovascular center provides parasympathetic output via connections with the vagus nerve.
60
How does the cardiovascular center provide sympathetic output?
The cardiovascular center provides sympathetic output via connections with the thoracolumbar spinal cord segments.
61
What are the targets of the outputs from the cardiovascular center?
The targets of these outputs are the cardiac muscle within the heart walls and the smooth muscle within the walls of blood vessels.
62
What is the Baroreceptor Reflex?
a neural negative feedback system.
63
What serves as the input for the Baroreceptor Reflex?
Baroreceptors in the arch of the aorta and carotid arteries send sensory signals to the cardiovascular (CV) center via Cranial Nerve IX (carotids) and Cranial Nerve X (aorta).
64
What serves as the output for the Baroreceptor Reflex?
The CV center sends autonomic motor signals to the heart via sympathetic nerves or Cranial Nerve X (parasympathetic).
65
What is the baroreceptor reflex initiated by?
The baroreceptor reflex is initiated by input from blood pressure receptors in the carotid arteries and arch of the aorta.
66
How are visceral sensations from the carotid arteries and arch of the aorta transmitted to the brain?
(provide specific name for these vessels)
Visceral sensations from these receptors are transmitted to the brain via the glossopharyngeal nerve and vagus nerve.
67
How does the cardiovascular center respond if blood pressure is too low?
If blood pressure is too low, the cardiovascular center can increase its input to the thoracolumbar spinal cord segments and/or decrease its input to the vagus nerve, causing the heart rate and force of contraction to increase, thereby raising blood pressure.
68
How does the cardiovascular center respond if blood pressure is too high?
If blood pressure is too high, the cardiovascular center can decrease its input to the thoracolumbar spinal cord segments and/or increase its input to the vagus nerve, causing the heart rate and force of contraction to decrease, thereby lowering blood pressure.
69
How can the effect of the baroreceptor reflex be clinically induced?
The effect of the baroreceptor reflex can be clinically induced in specific situations by massaging the carotid arteries, which essentially tricks the center into thinking that the blood pressure is too high.
70
What is carotid sinus syncope?
Carotid sinus syncope refers to fainting induced by pressure on particularly sensitive carotid sinus receptors.
71
What are the two main circuits of the circulatory system?
The two main circuits of the circulatory system are systemic circulation and pulmonary circulation.
72
Describe systemic circulation.
Systemic circulation is the system of blood vessels that carry oxygenated blood from the heart to the majority of the body and return deoxygenated blood to the heart. Therefore, blood loses oxygen in this circuit.
73
Describe pulmonary circulation.
Pulmonary circulation is the system of blood vessels that carry deoxygenated blood from the heart to the lungs and return oxygenated blood to the heart. Therefore, blood gains oxygen in this circuit.
74
What is the largest artery in the body?
The largest artery in the body is the AORTA.
75
How is the aorta divided?
The aorta is divided into four sections.
76
What are the branches of the ascending aorta?
The branches of the ascending aorta supply blood to the heart.
77
What regions are supplied by the branches of the arch of the aorta?
The branches of the arch of the aorta supply blood to the head, neck, and upper limbs.
78
What regions are supplied by the branches of the thoracic aorta?
The branches of the thoracic aorta supply the organs and tissues within the thoracic cavity.
79
What regions are supplied by the branches of the abdominal aorta?
The branches of the abdominal aorta supply the organs and tissues within the abdominal cavity, as well as the organs of the pelvic cavity and lower limbs.
80
What are the branches of the ascending aorta?
The branches of the ascending aorta are the coronary arteries, which supply blood to the heart.
81
How many branches does the arch of the aorta have?
The arch of the aorta has three branches.
82
What is the first branch of the arch of the aorta?
The first branch of the arch of the aorta is the brachiocephalic trunk.
83
What does the brachiocephalic trunk supply?
The brachiocephalic trunk supplies blood to the upper limb and head.
84
What are the branches of the brachiocephalic trunk?
The branches of the brachiocephalic trunk are the right common carotid artery and the right subclavian artery.
85
What is the branch that supplies blood to the right side of the neck and head?
The branch that supplies blood to the right side of the neck and head is the right common carotid artery.
86
What is the branch that supplies blood to the right upper limb?
The branch that supplies blood to the right upper limb is the right subclavian artery.
87
How do the left common carotid artery and left subclavian artery branch off?
The left common carotid artery and left subclavian artery branch off directly from the arch of the aorta.
88
What branches off the common carotid artery in the neck?
About halfway up the neck, each common carotid artery branches into an external carotid artery and an internal carotid artery.
89
What does the external carotid artery supply?
The external carotid artery supplies blood to structures outside the skull.
90
What does the internal carotid artery supply?
The internal carotid artery passes into the cranial cavity via the carotid foramen and supplies blood to the brain.
91
What branches off the subclavian artery?
Branching off each subclavian artery is a vertebral artery.
92
What is the pathway of the vertebral artery?
The vertebral artery passes up the neck through the transverse foramina of the cervical vertebrae and into the cranial cavity via the foramen magnum to help supply blood to the brain.
93
What forms the basilar artery?
The vertebral arteries join inside the cranium to form the basilar artery.
94
What arteries join with the basilar artery?
The basilar artery has branches that join with the internal carotid arteries.
95
What is the cerebral arterial circle also known as?
The cerebral arterial circle is also known as the "circle of Willis."
96
ring of communicating arteries is called the ___ ___ ___ ("_ _ _")
cerebral arterial circle (“circle of Willis”)
97
What happens to the subclavian artery after passing under the clavicle?
After passing under the clavicle, each subclavian artery enters the shoulder region, at which point its name changes to the axillary artery.
98
What artery does the axillary artery continue into?
The axillary artery continues into the anterior arm, at which point its name changes to the brachial artery.
99
What arteries do the brachial artery branch into near the elbow?
Near the elbow, the brachial artery branches into a radial artery and ulnar artery.
100
What regions do the radial artery and ulnar artery pass into?
Each passes into one of the two forearm compartments.
101
What types of branches does the thoracic aorta have?
The thoracic aorta has both visceral branches that supply blood to the viscera inside the thoracic cavity and parietal branches that supply the structures that make up the thoracic cage.
102
How is blood supplied to the heart?
Blood to the heart is supplied by the coronary arteries, which are branches of the ascending aorta, not branches of the thoracic aorta.
103
What is the function of the pulmonary arteries?
The pulmonary arteries carry deoxygenated blood to the lungs, where it gains more oxygen.
104
What is the function of the pulmonary veins?
The pulmonary veins carry oxygenated blood back to the heart.
105
How is lung tissue itself primarily supplied with oxygenated blood?
Lung tissue itself is primarily supplied with oxygenated blood by the bronchial arteries, which are visceral branches of the thoracic aorta.
106
NOURISHMENT/WASTE REMOVAL
Bronchial arteries/veins
107
GAS EXCHANGE (O2, CO2)
Pulmonary arteries/veins
108
What types of branches does the abdominal aorta have?
The abdominal aorta has both visceral branches that supply the viscera inside the abdominal cavity and parietal branches that supply structures that make up the abdominal wall.
109
How many unpaired visceral arteries branch off the anterior surface of the abdominal aorta?
Three unpaired visceral arteries branch off the anterior surface of the abdominal aorta.
110
What is the most superior unpaired visceral artery of the abdominal aorta?
The most superior unpaired visceral artery of the abdominal aorta is the celiac trunk.
111
What organs does the celiac trunk supply blood to?
The celiac trunk has branches that supply blood to the organs located in the upper third of the abdominal cavity.
112
After the celiac trunk, what is the next unpaired visceral artery of the abdominal aorta?
The next unpaired visceral artery of the abdominal aorta is the superior mesenteric artery.
113
What portions of the intestines does the superior mesenteric artery supply blood to?
The superior mesenteric artery has branches that supply blood to the portions of the small and large intestines located within the middle third of the abdominal cavity.
114
What is the final unpaired visceral artery of the abdominal aorta?
The final unpaired visceral artery of the abdominal aorta is the inferior mesenteric artery.
115
What portion of the large intestine does the inferior mesenteric artery supply blood to?
The inferior mesenteric artery has branches that supply blood to the portion of the large intestine located within the lower third of the abdominal cavity.
116
What are the three paired visceral arteries that branch off the abdominal aorta?
The three paired visceral arteries that branch off the abdominal aorta are the suprarenal, renal, and gonadal arteries.
117
What structures do the suprarenal arteries supply blood to?
The suprarenal arteries supply blood to the adrenal glands.
118
What structures do the renal arteries supply blood to?
The renal arteries supply blood to the kidneys.
119
What structures do the gonadal arteries supply blood to?
The gonadal arteries supply blood to the gonads (testes in males, ovaries in females).
120
What are the branches of the abdominal aorta around the level of the L4 vertebra?
Around the level of the L4 vertebra, the abdominal aorta branches into left and right common iliac arteries.
121
What arteries do the common iliac arteries branch into?
Each common iliac artery branches into an internal iliac artery and an external iliac artery.
122
What structures does the internal iliac artery supply blood to?
The internal iliac artery has branches that supply blood to the organs of the pelvic cavity and external genitals.
123
What happens to the external iliac artery?
The external iliac artery passes into the lower limb deep to the inguinal ligament.
124
What happens to each external iliac artery after passing under the inguinal ligament?
After passing under the inguinal ligament, each external iliac artery enters the anterior thigh, at which point its name changes to the femoral artery.
125
What is the name of the artery in the anterior thigh?
The artery in the anterior thigh is called the femoral artery.
126
What happens to the femoral artery as it enters the posterior thigh?
The femoral artery passes through an opening in the adductor Magnus to enter the posterior thigh.
127
What is the name of the artery in the posterior thigh?
The artery in the posterior thigh is called the popliteal artery.
128
What arteries does the popliteal artery branch into just distal to the knee?
Just distal to the knee, the popliteal artery branches into an anterior tibial artery, posterior tibial artery, and fibular artery.
129
What structures do the anterior tibial artery, posterior tibial artery, and fibular artery supply blood to?
Each of these arteries passes through one of the three leg compartments.
