Ch. 21 Flashcards
Where do the pulmonary vessels carry blood?
transport blood from right ventricle through lungs and back to left atrium
Where to the systemic vessels carry blood to and from?
transport blood from left ventricle through all parts of body and back to right atrium
What are the 5 unique functions of circulatory system?
- Carry blood
- Exchanges nutrients, waste products, and gases with tissues
- Transport substances
- Helps regulate blood pressure
- Directs blood flow to tissues
What are the 3 main types of blood vessels?
arteries, capillaries, veins
What are the layers of blood vessel walls from superifical to deep?
Tunica adventitis
Tunica media
Tunica intima
What are the 4 layers of the tunica intima?
Endothelium
basement membrane
thin layer of connective tissue - lamina propria
internal elastic membrane (separates from next layer)
What is the tunia media made of?
Smooth muscle cells arranged circularly around blood vessel and can be regulated by contraction or relaxation
Also contains elastic and collagen fibers.
External elastic membrane separates tunia media from tunia adventitia
What is vasocontriction? and Vasodialation?
Vasoconstriction is smooth muscle contraction and causes decrease in blood vessel diameter
Vasodialation is smooth muscle relaxation and results in increase in blood vessel diameter
What is the tunia adventitia made of
connective tissue, which varies from dense to to loose
What do arteries do?
What are the 3 classifications of arteries?
Carry blood from the heart
- elastic arteries
- musclular arteries
- arterioles
What is the process of blood flow from ventricles, where does it go?
Ventricles to large elastic arteries that branch for form many smaller arteries. The smaller arteries (muscluar arteries) are made of less elastic and more smooth muscle. The smaller arteries lead to arterioles
What are the charateristics of elastic arteries?
Large diameter
High pressure
When stretched they recoil, can withstand high pressure and low due to diastolic and systoilc activity
Greater amount of elastic, smaller amount of smooth muscle
Tunia intima is thick, tunia media intermeshed with collagen, elastic and smooth muscle, Tunia adventita is thin
What are the charateristics of muscular arteries?
Medium & small arteries
Thick tunia media, 25-40 layers of smooth muscle
disturbing arteries - allowing them to partially regulate blood flow to different body regions by constricting or dialating
What are the charateristics of arterioles?
smallest arteries
Transport blood from small arteries to capillaries
Capable of constriction and dialation
What are the charateristics of capillaries?
most common type of blood vessel
carries blood from arteroiles
Capillary wall consist primarly of a single layer of endothelial cell that rest on basement membrane covered in loose connective tissue
Scattered along length of capillary are pericapillary cells (fibroblasts, macrophages, undifferentiated smooth muscle cells)
Most red blood cells flow single file and are frequently folded
pericapillary cells
fibroblasts, macrophages, undifferentiated smooth muscle cells that are found along the lenght of capillary and found inbetween basement membrane and endothelial cell
What are the 3 ways to classify capillaries?
- continous
- fenestrated
- sinusoidal
What are the charateristics of continous capillaries?
walls exhibit no gaps between endothelial cells
less permeable to large molecules
they are in muscle, nervous and many other locations
What are the charateristics of fenestrated capillaries?
endothelial cells have numerous fenestrae - areas with no cytoplasm or membrane -
highly permeable
found in intestinal villi, ciliary processes of the eyes, chorid plexuses of central nervous system, glomeruli of kidney
What are the charateristics of sinusoidal capillaries?
larger than continous or fenestrated capillaries
basement membrane less prominent or completely absent
fenestrae are larger and gaps can exist between endothelial cells
occur in places where large molecules move into blood. like endocrine glands
What are sinusoids
What are venous sinuses
Sinusoids - large diameter sinusodial capillaries - common in liver and bone marrow
Venous sinuses - even larger in diameter than sinusoids, found primarily in spleen
Where does blood flow from arterioles to capillary networks?
through metaterioles - vessels with isolated smooth muscle cells along their walls
then through thoroughfare channel - a vessle within capillary network that extends in a relatively direct fashion to a venule
How is blood regulated in the capillary branches?
by precapillary sphincters - smooth muscle cells
The ends of capillaries closest to the arterioles are called—–
the ends closest to the venules are called—-
Arterial capillaries
Venous capillaries
Capillary networks are more numerous and more extensive in highly metabolic tissues such as,
what is the major function of capillaries in muscle tissues?
lungs, liver, kidneys, skeletal muscle and cardiac muscle
major function in muscle tissue is nutirent and waste exchange
What is a arteriovenous anastomoses?
specialized vascular connections that allow blood to flow from arterioles to small veins without passing through capillaries
Glomus
an arteriovenous anastomosis that consists of arterioles with abundant smooth muscle in their walls.
What are the 3 classifications of veins?
Venules
Small veins
Medium or large veins
What are the classifications of venules & small veins?
smallest veins
tubes composed of endothelium resting on basement membrane
Small veins are larger than venules and have a smooth muscle cells from a continous layer, also have a tunica adventita composed of collagenous connective tissue
What are the charateristics of medium and large veins?
Medium veins collect blood from small veins and deliver it to large veins which return it to the heart
What are portal veins?
what 3 portal vein systems are found in humans?
what connects one capillary network to another capillary network
Hepatic portal veins - carry blood from capillaries in gastrointestinal tract & spleen to sinusoids in liver
Hypothalamohypophysial portal veins carry blood from hypothalamus to anterior pituitary gland
Renal nephron portal system associated with urine forming structures in kidney
Most blood vessels are innervated by ______ _____ nerve fibers.
Some blood vessles, of penis and clit are innervated by _____ ________ nerve fibers
Unmyelinated sympathetic nerve fibers
parasympathetic nerve fibers
What is arteriosclerosis?
What is atherosclerosis?
Arteriosclerosis is hardening of the arteries - make them less elastic
artherosclerosis is deposition of material in the walls of arteries to from destinct plaques. Mainly in medium and large arteries. Making them less elastic
What 3 parts is the aorta divded into?
What 2 arteries branch from ascending aorta?
Ascending
aortic arch
descending - further divided into thoracic and abdominal
Right and Left coronary artery - which supply blood to cardiac muscle
What 3 major arteries branch from aortic arch?
brachiocephalic artery
left common carotid artery
left subclavian artery
what is an aneurysm?
bulge caused by weakened spot in aortic wall
The brachiocephalic artery forms which arteries and supplys blood to where?
Brachiocephalic branches to form :
right common carotid - supplies blood to right side of head and neck
right subclavian - transports blood to right upper limb
The left common carotid artery supplys blood to where?
ommon carotid artery supplies blood to left side of head and neck
The left subclavian artery supplys blood to where?
The left subclavian artery supplies blood to left upper limb
each common carotid artery extends superiorly and branches to form?
at the point of separation they are dialated slightly to form?
Internal and external carotid arteries
Carotid sinus - important in monitoring blood pressure
The right and left vertebral arteries originate from_______. They enter the cranial cavity via forman magnum and give off arteries to the _______.
The right and left arteries unite to form a single midline _________
Right and left subclavian arteries
Cerebellum
Basilar artery
The basilar artery gives off branches to the —-
Pons and cerebellum
R and L vertebral arteries branch to form ____________ which supply posterior part of cerebrum
Posterior cerebral arteries
Stroke
Sudden neurological disorder often caused by decreased blood supply to part of the brain.
Can results from thrombosis, embolism or hemorrhage
What 2 groups are the thoracic aorta divided into?
- Visceral branches
- Parietal branches
What does the visceral branches supply?
What does the parietal branch supply?
Visceral branches supply portions of thoracic organs - portions of lungs, esophagus and pericardium.
Parietal braches supply portions of thoracic wall
What are the 3 major unpaired branches of the abdominal aorta?
Celiac trunk, superior and inferior mesenteric artery
Deoxygenated blood from the body is returned to the right atrium through what 3 major veins?
Coronary sinus - returning blood from walls of the heart
Superior vena cava - returning blood from head, neck, thorax, and upper limbs
Inferior vena cava - returning blood from abdomen, pelvis, and lower limbs
