Cardiovascular system Flashcards
The thick tunica media of muscular arteries and decreased quantity of elastic fibres limits what ability?
Their ability to expand
What are collateral arterial branches?
Branches that arise from the side of the main blood vessel
Briefly describe the role of the urinary system in the circulatory system
Delivers 20% of resting circulation to kidneys for filtering, reabsorption of useful products, and seretion of excesses - regulates blood volume and pressure by regulating fluid loss in the form of urine and by releasing the enzyme renin that is essential in the RAAS mechanism
A typical heart is approximately ____cm wide
8cm
Which arteries have a higher percentage of elastic fibres in all three tunics? What is the name for these vessels?
Those closest to the heart - they are known as elastic arteries
The posterior surface of the heart lies near the bodies of the ____.
Vertebrae
What kind of artery are the aortic collateral branches?
Elastic artery
From what does a macrophage develop?
A monocyte that has left circulation
The weight of a female heart is approximately ____ to ____ grams
250 - 300
Where do T lymphocytes mature?
Thymus
Name the single vessel that exits the right ventricle
Pulmonary trunk
Erythrocytes pick up approximately ____% of carbon dioxide waste at the tissues to transport to the lungs for exhalation
24%
Paired vertebral arteries join together to form the large basiliar artery at the base of which structure?
Medulla oblongata
What is the effect of veins having a larger diameter of the lumina?
More blood can flow with less vessel resistance
Do the chemicals released by basophils contribute to or inhibit inflammation?
Contribute, through the release of histamine
Name the two ‘great arteries’
Aorta and pulmonary trunk
What is a product/function of capillaries being extremely narrow in diameter?
It slows the passage of erythrocytes and extends the window of opportunity for gas exchange to occur
What percentage of leukocytes are made up of monocytes?
2 - 8%
Where are continuous capillaries found?
Almost all vascularised tissues
Some therapies are now using infusions of concentrated ____ to stimulate healing.
Platelets
Why are a third of platelets stored in the spleen?
They are released in response to blood vessel rupture
The inferior vena cava parallels the ____ ____.
Abdominal aorta
The diameter of muscular arteries typically ranges from ____mm to ____mm
0.1mm to 10mm
To what do coronary arteries supply blood?
The myocardium and other components of the heart
The left side of the heart is deflected ____.
Posteriorly
How many monocytes are present in 1µL of blood?
455
The space (note: not the cavity) where the heart is situated is known as the ____.
Mediastinum
From what and where do erythrocytes and leukocytes originate?
Haematopoietic stem cells in bone marrow
What is the most common leukocyte?
Neutrophils
Where are sinusoidal capillaries found? There are five possible answers.
Liver, spleen, bone marrow, lymph nodes, and endocrine glands including the pituitary and adrenal/supradrenal glands
The tunica intima is composed of ____ and ____ tissue layers.
Epithelial; connective
What is the primary function of erythrocytes?
To collect inhaled oxygen from the lungs and transpor it to the body’s tissues, and to pick up carbon dioxide waste from the tissues and transport it to the lungs for exhalation
Where do B lymphocytes mature?
Bone marrow
Where is the coronary sinus located?
Posteriorly in the atrioventricular sulcus, where it opens into the right atrium
From where does the inferior mesenteric vein receive blood?
Distal third of the large intestine including the descending colon, sigmoid colon, and rectum
Pulmonary capillaries surround lung strctures known as ____.
Alveoli
Name the large coronary vein that empties into the right atrium
The coronary sinus
The small lumen of arterioles allows them to serve what role in blood flow?
Slowing down/resisting blood flow and so causing a drop in blood pressure
The pulmonary veins conduct blood into the ____ ____.
Left atrium
The hepatic portal vein typically arises in the abdomen as a confluence of which two veins?
Superior mesenteric and splenic veins
After platelets enter circulation, appromately a third migrate to what location for storage?
The spleen
Name the three tissue layers of arteries and veins
Tunica intima (AKA tunica interna), tunica media, tunica externa (AKA tunica adventitia)
Do superficial veins usually have direct arterial counterparts?
No - deep veins usually have corresponding arteries
What is an arteriole?
A very small artery that leads to a capillary
The pericardium sits in its own space called the ____ ____.
Pericardial cavity
Approximately what percentage of leukocytes are lymphocytes?
20-30%
Eosinophils are phagocytic and particularly effective against ____-____ ____.
Antigen-antibody complexes
What is the purpose of the arterial elastic lamina?
To provide structure while allowing the vessel to stretch
How many basophils are present in 1µL of blood?
44
Many veins draining regions share a name with the arteries that supply that region - this is described as a ____ pattern.
Complementary
Do veins have an elastic lamina?
No, only arteries have the distinct layer of elastic fibres
Vessels larger than ____ in diameter are typically elastic arteries.
10mm
Name five subtypes of leukocyte
Neutrophil, eosinophil, basophil, lymphocyte, monocyte
Of neutrophils, eosinophils, and basophils, which has a usually 2-lobed nucleus that can be hard to see?
Basophils
What is the name of the valve leading to the pulmonary trunk?
The pulmonary semilunar valve
Of neutrophils, eosinophils, and basophils, which has granules that typically stain dark blue/purple?
Basophils
Do sinusoidal capillaries in the lymph nodes carry blood or lymph?
Lymph
The number of capillary fenestrations and their degree of permeability varies depending on their ____.
Location
The proper term for a red blood cell is an ____.
Erythrocyte
Why is the pericardial cavity filled with serous fluid?
To reduce friction between the heart and the pericardium
Why doesn’t the right ventricle require the same high pressures to pump blood as the left ventricle?
The pulmonary circuit is much shorter than the systemic circuit and therefore provides less resistance.
The ____ ____ artery terminally branches into internal and external carotid arteries
Common carotid
True or false: on leaving capillaries some leukocytes will assume fixed positions while others will move through tissues and still others will move towards chemical signals
True
Briefly describe the role of the skeletal system in the circulatory system
Provides calcium, posphate, and other materials critical for bone matrix; transports hormones regulating buildup and adbsorption of matric includling growth hormone, thyroid hormone, calcitonins, and parathyroid hormone; erythropoistin stimulates myeloid cell haematopoieses; some level of protection for selet vessels by bony structures
The ____ is continuous throughout the entire vascular system including the lining of the heart
Endothelium
What is the name of the left atrioventricular valve?
The bicuspid/mitral valve
High counts of monocytes are a possible indication of what? There are four possible answers.
Viral/fungal infections, tuberculosis, some forms of leukemia, and other chronic diseases
What is the meaning of the ‘termination’ of a blood vessel?
The point where blood leaves the named blood vessel
What is the appearance of eosinophils in a standard blood smear?
Bright red-orange granules; nucleus is generally two-lobed
What prevents backflow of blood into the left atria during ventricular contraction?
Closing of the bicuspid/mitral valve
Describe the structure of sinusoidal capillaries
Flattened, with extensive intercellular gaps and incomplete basal membranes as well as intercellular clefts and fenestrations
What is the purpose of a macrophage?
To phagocytose debris, foreign pathogens, worn-out erythrocytes, and many other dead/damaged/worn cells
Where does the aortic arch terminate?
Level with the intervertebral disk between the 4th and 5th thoracic vertebrae
Processed blood and systemic blood exit the liver via the ____ veins and flows into the ____ ____ ____.
Hepatic; inferior vena cava
Do erythrocytes move in and out of the blood vessels or do they remain within the vascular network?
Leukocytes typically leave the vessels for defensive functions, but it is abnormal for erythrocytes to do so
What structural features characterise continuous capillaries?
Complete endothelial lining with tight junctions between endothelial cells
Name the three vessels that originate from the aortic arch
Brachiocephalic trunk, left common carotid artery, left subclavian artery
One of the most distinctive characteristics of leukocyte activity is their ____.
Movement
Arteries further from the heart with less elastic fibres and more smooth muscle are described as a ____ artery.
Muscular
The proportions of smooth muscle cells and elastic fibres in the tunica media vary depending on what factor?
Distance from the heart
The external carotid artery supplies blood to which structures?
Numerous structures within the face, lower jaw, neck, oesophagus, and larynx
What is the purpose of the systemic circuit?
To transport oxygenated blood to the tissues of the body and return relatively deoxygenated blood and CO2 to the heart to be sent back into the pulmonary circuit
Which veins are usually the largest entering the inferior vena cava?
Renal veins
Briefly describe the role of the integumentary system in the circulatory system
Carries clotting factors, platelets, and WBC for haemostasis, fight infection, and repairing damage; regulates temperatures by controlling blood flow to the surface where heat can be dissipated; provides some colouration of integument; acts as a blood reservoir
The basal lamina provides ____ while maintaining ____.
Strength; flexibility
What is the general lifespan of eosinophils?
Minutes to days
Larger arteries have what structure at the boundary between tunica intima and tunica media?
A thick distinct layer of elastic fibres known as the internal elastic lamina (or internal elastic membrane)
The left and right sides of the heart each have one ____ and one ____ (chambers).
Atrium; ventricle
How many lymphocytes are present in 1µL of blood?
2185
The inferior mesenteric artery arises approximately ____cm to the common iliac arteries
5cm
What are the smallest arteries called?
Arterioles
Human bodies need blood to deliver ____ and remove ____.
Nutrients; wastes
What is the second most common type of leukocyte?
Lymphocyte
What is the purpose of valves in the cardiovascular system?
To ensure the flow of blood is one-way.
Another way to phrase this answer is ‘to prevent back-flow of blood’
The brachiocephalic trunk is located only on the ____ side of the body
Right
The splenic vein is formed from branches from which sources?
Spleen, pancreas, portions of the stomach, and the inferior mesenteric vein
From what type of cell do monocytes originate?
Myeloid stem cells
What is the purpose of memory cells?
To increase responses to subsequent exposures
The elastic recoil of the vascular wall helps maintain the ____ ____ that drives the blood through the arterial system
Pressure gradient
How do leukocytes migrates from venules or capillaries into tissues?
By squeezing through adjacent endothelial cells to enter tissue fluid
High counts of eosinophils are a possible indication of what? There are three possible answers.
Allergies, parasitic worm infestation, and some autoimmune diseases
Multiple venules join to form ____.
Veins
How do veins typically appear - rounded or flat?
Flattened
The tunica media of arterioles is how many smooth muscle cell layers thick?
One or two
What occurs in the alveoli?
Oxygen and gas exchange
Where does the ascending aorta become the aortic arch?
After moving in a superior direction for ~5cm the ascending aorta turns in an arc to the left and becomes the aortic arch
True or false: arteries generally have thick walls and wide lumens which allow for greater blood volume
False - arteries do have thick walls, but have small lumens which help maintain the pressure in systemic circulation
Why is a biconcave shape beneficial to erythrocytes over a spherical shape?
Relative to cell volume a biconcave shape has a greater surface area for gas exchange than a spherical shape
The common iliac arteries provide blood to which areas of the body?
The pelvic region and lower limbs
The thick tunica media of muscular arteries allows them to play a leading role in ____.
Vasoconstriction
Each gonadal artery supplies blood to the reproductive organs and is known as either an ____ artery or ____ artery depending on the sex of the individual.
Ovarian; testicular
Lymphocytes are primarily involved in ____ immunity
Specific/adaptive immunity
The inferior mesenteric artery supplies blood to which organs?
The distal segment of the large intestine, including the rectum
What component of blood arises from lymphoid stem cells?
Lymphocytes
Which type of cells and muscle fibres predominate in the arterial tunica media?
Smooth muscle cells and elastic fibres
What is the term for the layer of simple squamous epithelium lining the tunica intima?
Endothelium
Name the blood vessels where gas exchange occurs in the lungs
Pulmonary capillaries
What prevents backflow of blood into the right atria during ventricular contraction?
Closing of the tricuspid valve
Which chambers of the heart act as receiving chambers?
The left and right atria
The anterior surface of the heart sits deep to the ____ and ____ ____.
Sternum; costal cartilages
Arterioles are also known as ____ vessels.
Resistance
What is the size range of a venule diameter?
8 to 100µm
A typical heart is approximately ____cm thick
6cm
What is a patent foramen ovale?
A hole between the atria of an adult’s heart that didn’t close after birth to form the fossa ovalis
What is the function of basophils?
Promotes inflammation
Continuous capillaries in the brain are part of what structure?
The blood-brain barrier
Describe the tunica media of veins
Normally thinner than the tunica externa; smooth muscle cells and collagenous fibres predominate; nerves and vasa vasorum present; no external elastic membrane
What is a platelet (structure)?
A fragment of megakaryocyte cytoplasm that is surrounded by a plasma membrane
What is the purpose of the portal system delivering blood to the liver?
The liver processes the blood to remove certain wastes and excess nutrients which are stored for later use
The granules of eosinophils contain ____ which counteracts chemicals produced by basophils and mast cells
Antihistamine
The subclavian vein forms a confluence with the internal jugular vein to form the ____ vein.
Brachiocephalic
Do red blood cells have a nucleus?
No
Where might fenestrated capillaries be found (excluding the small intestine and kidneys)?
Choroid plexus of the brain and many endocrine structures including hypothalamus, pituitary, pineal, and thyroid glands
Each of the major pumping chambers of the heart ejects approximately ____mL blood per contraction in a resting adult
70mL
After gas exchange, oxygenated blood flows from pulmonary capillaries into pulmonary venules that lead to a series of ____ ____.
Pulmonary veins
True or false: the right and left ventricles pump the same volume of blood per contraction.
True. The left ventricle pumps at a high pressure, but the volume is the same.
Which is thicker, the interatrial septum or the interventricular septum? Why?
Interventricular septum, because the ventricles are required to generate greater pressures for contraction
Is the tunica externa of venules thick or thin?
Thin
Which are the primary pumping chambers of the heart?
The right and left ventricles
Name two organs in which fenestrated capillaries are common
Small intestine (primary site of nutrient absorption) and kidneys (blood filtering)
Briefly describe the process of circulation in the systemic capillaries
Oxygen and nutrients exit the systemic capillaries to be used by cells in metabolic processes, and carbon dioxide and waste products enter the blood
Which fibres are present in the arterial tunica externa?
Collagenous and elastic fibres
The descending aorta passes through the ____ diaphragm.
Thoracic
Initial lymphocytes originate in ____ ____.
Bone marrow
The lack of organelles in erythrocytes allows for the presence of ____ molecules
Haemoglobin
Venules go on to form larger ____.
Veins
The common iliac artery branches into the pelvis to form a vessel that passes deep to the inguinal ligament - this artery is known as the ____ artery.
Femoral
Macrophages release ____ and ____ chemicals that attract other leukocytes to the site of an infection.
Antimicrobial; chemotatic
Neutrophils, eosinophils, and basophils are all what category of leukocyte?
Granulocytes
What is the least common capillary subtype?
Sinusoidal capillaries
The right gonadal vein empties directly into the ____ ____ ____.
Inferior vena cava
Which muscle type and fibres are present in the venous tunica externa?
Smooth muscle and collagenous fibres
Is blood flow through sinusoidal capillaries fast or slow?
Very slow
The gonadal arteries arise ____ to the renal arteries and are generally ____ (cavity location)
Inferior; retroperitoneal
The pulmonary trunk leads toward the ____ and bifurcates into which two vessels?
Lungs; left and right pulmonary arteries
Are agranular leukocytes completely deficit of granules?
No - agranulocytes are not completely lacking in granules but they are far fewer and much less obvious.
Of neutrophils, eosinophils, and basophils, which has a nucleus with 2-5 lobes that increase with age?
Neutrophils
When does the abdominal aorta terminate?
When it terminally branches into the two common iliac arteries
From were does the superior mesenteric vein receive blood?
Small intestine, two-thirds of the large intestine, and stomach