Term
The walls of all blood vessels, except the very small one, are composed of __ layers (_____)
______ – inner most. In contact with blood, composed of simple squamous epithelium
______ – middle layer. Sheets of smooth muscle
Contraction – _______
Relaxation – _______
_____ – composed of connective tissue - collagen and elastic fibers.
Protects the vessels and strengthens its wall.
Anchors the vessel to surrounding structures
____ – central blood-filled space of a vessel |
|
Definition
The walls of all blood vessels, except the very small one, are composed of three layers (tunics)
Tunica intima – inner most. In contact with blood, composed of simple squamous epithelium
Tunica media – middle layer. Sheets of smooth muscle
Contraction – vasoconstriction
Relaxation – vasodilation
Tunica externa – composed of connective tissue - collagen and elastic fibers.
Protects the vessels and strengthens its wall.
Anchors the vessel to surrounding structures
Lumen – central blood-filled space of a vessel |
|
|
Term
Passage of blood through arteries proceeds from:
____ arteries to
_____ arteries to
______ |
|
Definition
Passage of blood through arteries from
Elastic arteries
Muscular arteries
Arterioles |
|
|
Term
Elastic arteries – the largest arteries -near the heart
Diameters range from 2.5 cm to 1 cm
____ lumen
Low resistance passage for conducting blood from the heart to _____ arteries
Includes the ___ and its major branches.
Sometimes called _____ arteries
High _____ content dampens surge of blood pressure |
|
Definition
Elastic arteries – the largest arteries -near the heart
Diameters range from 2.5 cm to 1 cm
Large lumen
Low resistance passage for conducting blood from the heart to medium-size muscular arteries
Includes the aorta and its major branches
Sometimes called conducting arteries
High elastin content dampens surge of blood pressure |
|
|
Term
Muscular (distributing) arteries
Lie ___ to elastic arteries
Diameters range from 1 cm to 0.3 mm
Includes most of the named arteries
Supply groups of ___, individual ___ and parts of ___
Tunica media is ___
Called muscular because tunica media is ____ relative to the size of the lumen than in any other vessels
Unique features
Internal and external ____ laminae |
|
Definition
Muscular (distributing) arteries
Lie distal to elastic arteries
Diameters range from 1 cm to 0.3 mm
Includes most of the named arteries
Supply groups of organs, individual organs and parts of organs
Tunica media is thick
Called muscular because tunica media is thicker relative to the size of the lumen than in any other vessels
Unique features
Internal and external elastic laminae |
|
|
Term
Arterioles
Smallest arteries
Diameters range from 0.3 mm to 10 µm
Tunica media has only _ or _ layers of ____ muscles
Larger arterioles possess ___ tunics
Diameter of arterioles controlled by:
Local factors in the tissues signaling the smooth muscles to contract or relax (blood flow amount into capillary beds regulation)
______ nervous system adjusts diameter of arterioles through the body therefore regulates systemic blood ___ |
|
Definition
Arterioles
Smallest arteries
Diameters range from 0.3 mm to 10 µm
Tunica media has only 1 or 2 layers of smooth
muscles
Larger arterioles possess all three tunics
Diameter of arterioles controlled by:
Local factors in the tissues signaling the smooth muscles to contract or relax (blood flow amount into capillary beds regulation)
Sympathetic nervous system adjusts diameter of arterioles through the body therefore regulates systemic blood pressure |
|
|
Term
Capillaries
Smallest blood vessels
Diameter from 8–10 µm
Red blood cells pass through in single file
Body’s most important blood vessels because they renew surrounding tissue fluid
Site-specific functions of capillaries
In the __ – oxygen enters blood, carbon dioxide leaves
In the _____ – receive digested nutrients
In ___ glands – pick up hormones
In the _____ – removal of nitrogenous wastes |
|
Definition
Capillaries
Smallest blood vessels
Diameter from 8–10 µm
Red blood cells pass through in single file
Body’s most important blood vessels because they renew surrounding tissue fluid
Site-specific functions of capillaries
In the lungs – oxygen enters blood, carbon dioxide leaves
In the small intestines – receive digested nutrients
In endocrine glands – pick up hormones
In the kidneys – removal of nitrogenous wastes |
|
|
Term
Capillary Beds
Network of capillaries running through most tissues
_____ - smooth muscles
Regulate the flow of blood to tissues
Wrap around the root of each capillary where it leaves the ______.
_____ - intermediate vessel between arteriole and capillary
Tendons and ligaments – ____ vascularized
Epithelia and cartilage – ______
Receive nutrients from nearby connective tissues |
|
Definition
Capillary Beds
Network of capillaries running through most tissues
Precapillary sphincters - smooth muscles
Regulate the flow of blood to tissues
Wrap around the root of each capillary where it leaves the metarteriole
Metarteriole - intermediate vessel between arteriole and capillary
Tendons and ligaments – poorly vascularized
Epithelia and cartilage – avascular
Receive nutrients from nearby connective tissues |
|
|
Term
Precapillary sphincters - smooth muscles
Regulate the _____ to tissues according tissue’s need in ____ and _____
When tissue is functionally active, sphincters ____, blood flows through wide-open capillaries. Supplies surrounding tissue cells
When tissue has lower requirements in oxygen and nutrient, sphincter ___, closes capillaries, forcing blood flow straight from the metarteriole into the ____ channel and ___. |
|
Definition
Precapillary sphincters - smooth muscles
Regulate the flow of blood to tissues according tissue’s need in oxygen and nutrients
When tissue is functionally active, sphincters relax, blood flows through wide-open capillaries
Supplies surrounding tissue cells
When tissue has lower requirements in oxygen and nutrient, sphincter contract, closes capillaries, forcing blood flow straight from the metarteriole into the thoroughfare channel and venule. |
|
|
Term
| Capillary is a tube of a thin ___ layer surrounded by a ____ membrane |
|
Definition
| Capillary is a tube of a thin endothelial layer surrounded by a basement membrane |
|
|
Term
Endothelial cells – held together by ___ junctions and ______
Intercellular ___ – gaps of unjoined membrane
Small molecules can enter and exit
Two types of capillary
_____ – most common no pores
_____ – have pores spanning the endothelial cells |
|
Definition
Endothelial cells – held together by tight junctions and desmosomes
Intercellular clefts – gaps of unjoined membrane
Small molecules can enter and exit
Two types of capillary
Continuous – most common no pores
Fenestrated – have pores spanning the endothelial cells |
|
|
Term
Capillary Permeabillity
Continuous
Occur in (4)
Fenestrated
Occur only when exceptional high rates of exchange of small molecules between blood and surrounding tissue fluid
(3) |
|
Definition
Capillary Permeabillity
Continuous
Occur in most organs - skeletal muscles, skin, CNS
Fenestrated
Occur only when exceptional high rates of exchange of small molecules between blood and surrounding tissue fluid
Small intestine, kidneys, joint of synovial membranes |
|
|
Term
Capillary Permeability Routes
Four routes into and out of capillaries for molecules
Direct _____
Through intercellular ___
Through ____ vesicles
Through ______
Most exchange of small molecules through fenestrations
CO2/O2 direct _____ |
|
Definition
Capillary Permeability Routes
Four routes into and out of capillaries for molecules
Direct diffusion
Through intercellular clefts
Through cytoplasmic vesicles
Through fenestrations
Most exchange of small molecules through fenestrations
CO2/O2 direct diffusion |
|
|
Term
Blood-brain barrier
Capillaries have complete _____
No intercellular __ are present
Vital molecules pass through
Highly selective transport mechanisms
Not a barrier against
(3) |
|
Definition
Blood-brain barrier
Capillaries have complete tight junctions
No intercellular clefts are present
Vital molecules pass through
Highly selective transport mechanisms
Not a barrier against
Oxygen, carbon dioxide, and some anesthetics |
|
|
Term
________:
Wide, leaky capillaries found in some organs
Usually fenestrated
Intercellular ____ are wide open
____ occur wherever there is an extensive exchange of large molecules such as proteins or cells between blood and surrounding tissue
Occur in ____, ____ and ____
_____ have a large diameter
Large diameter and twisted course help blood to flow slowly, allowing many exchange across their walls |
|
Definition
Sinusoids
Wide, leaky capillaries found in some organs
Usually fenestrated
Intercellular clefts are wide open
Sinusoids occur wherever there is an extensive exchange of large molecules such as proteins or cells between blood and surrounding tissue
Occur in bone marrow, liver and spleen
Sinusoids have a large diameter
Large diameter and twisted course help blood to flow slowly, allowing many exchange across their walls |
|
|
Term
Veins
Conduct blood from _____ toward the heart
Blood pressure is much ___ than in arteries
Smallest veins – called _____
Diameters from 8–100 µm
Smallest venules – called _____ venules
Venules join to form veins
Lumen of veins ___ than arteries
At any given time, veins hold __% of the body‘s blood
Tunica ____ is the thickest tunic in veins (opposite to the arteries) |
|
Definition
Veins
Conduct blood from capillaries toward the heart
Blood pressure is much lower than in arteries
Smallest veins – called venules
Diameters from 8–100 µm
Smallest venules – called postcapillary venules
Venules join to form veins
Lumen of veins larger than arteries
At any given time, veins hold 65% of the body‘s blood
Tunica externa is the thickest tunic in veins (opposite to the arteries) |
|
|
Term
Mechanisms to Counteract Low Venous Pressure
Valves in some veins
Particularly in ___
Prevent ___ of blood away from the heart
____ muscle pump
Muscles press against thin-walled veins |
|
Definition
Mechanisms to Counteract Low Venous Pressure
Valves in some veins
Particularly in limbs
Prevent backflow of blood away from the heart
Skeletal muscle pump
Muscles press against thin-walled veins |
|
|
Term
Vessels interconnect or unit to form ________
Organs receive blood from more than one arterial source |
|
Definition
Vascular Anastomoses
Vessels interconnect or unit to form vascular anastomoses
Organs receive blood from more than one arterial source |
|
|
Term
Arterial anastomoses provide alternative pathways or _____ for blood to reach a given region
If one arterial branch is blocked or cut, the _____ provide this regions with adequate blood supply
Around joints, abdominal organs, brain, heart |
|
Definition
Arterial anastomoses provide alternative pathways or collateral channels for blood to reach a given region
If one arterial branch is blocked or cut, the collateral channels provide this regions with adequate blood supply
Around joints, abdominal organs, brain, heart |
|
|
Term
Veins anastomoses ___ frequently than arteries
Because of ___ anastomoses, occlusion of a vein ____ blocks blood flow or leads to death |
|
Definition
Veins anastomoses more frequently than arteries
Because of abundant anastomoses, occlusion of a vein rarely blocks blood flow or leads to death |
|
|
Term
Tunica _____ of large vessels have:
Tiny arteries, capillaries, and veins
________:
Nourish ___ region of large vessels |
|
Definition
Tunica externa of large vessels have:
Tiny arteries, capillaries, and veins
Vasa Vasorum
Nourish outer region of large vessels |
|
|
Term
Blood Distribution
~ __% of blood volume at rest is in systemic veins and venules
function as blood _____
veins of skin & abdominalorgans (liver and spleen)
blood is diverted from it in times of need
increased muscular activity produces ______
hemorrhage causes
_____ to help
maintain blood pressure
~ __% of blood volume in arteries & arterioles |
|
Definition
Blood Distribution
~ 64% of blood volume at rest is in systemic veins and venules
function as blood reservoir
veins of skin & abdominalorgans (liver and spleen)
blood is diverted from it intimes of need
increased muscular activityproduces venoconstriction
hemorrhage causes
venoconstriction to help
maintain blood pressure
~ 15% of blood volume in arteries & arterioles |
|
|
Term
Pulmonary Circulation
Pulmonary trunk leaves the ____ventricle
Divides into right and left ______
____ and ___ pulmonary veins
Carry oxygenated blood into the ___ atrium |
|
Definition
Pulmonary Circulation
Pulmonary trunk leaves the right ventricle
Divides into right and left pulmonary arteries
Superior and inferior pulmonary veins
Carry oxygenated blood into the left atrium |
|
|
Term
The Aorta
Ascending aorta – arises from the ____ ventricle
Aortic arch – lies ____ to the manubrium
Branches (3) |
|
Definition
The Aorta
Ascending aorta – arises from the left ventricle
Branches – coronary arteries
Aortic arch – lies posterior to the manubrium
Branches
Brachiocephalic trunk
Left common carotid
Left subclavian arteries |
|
|
Term
Descending aorta – continues from the aortic arch
Thoracic aorta – in the region of T_-T_
Abdominal aorta – ends at L_
Divides into right and left common ____ arteries |
|
Definition
Descending aorta – continues from the aortic arch
Thoracic aorta – in the region of T5-T12
Abdominal aorta – ends at L4
Divides into right and left common iliac arteries |
|
|
Term
| Inferior phrenic arteries |
|
Definition
| paired, branch from abdominal aorta at T12 supply inferior surface of diaphragm |
|
|
Term
|
Definition
| supplies viscera in superior abdomen stomach gallbladder pancreas spleen and duodenum. emerges from aorta at T12 and branches in to left gastric, splenic, and common hepatic arteries |
|
|
Term
| Superior mesenteric artery |
|
Definition
| serves most of the intestine off aorta at L1 |
|
|
Term
|
Definition
| paired, emerge from aorta at L1. supply adrenal glands on superior poles of kidneys |
|
|
Term
|
Definition
| paired, supply kidneys. stem from aorta at L1-L2 (kidneys remove nitrogenous waste from blood) |
|
|
Term
| Gonadal (testicular or ovarian) arteries |
|
Definition
| paired, testicular arteries and ovarian arteries, branch from aorta at L2 |
|
|
Term
| Inferior mesenteric artery |
|
Definition
| final branch of abdominal aorta (L3) serves distal half of large intestine branches:left colic, sigmoidal, superior rectal arteries |
|
|
Term
|
Definition
| aorta splits at L4, supplies inferior part of anterior abdominal wall as well as pelvic organs and lower limbs |
|
|
Term
|
Definition
| supplies pelvic walls, pelvic viscera, bottocks, medial thigh, perineum |
|
|
Term
|
Definition
| paired, carry blood to lower limbs |
|
|
Term
|
Definition
| descends vertically through the thigh medial to the femur and along the anterior surface of the adductor muscles. emerges to distal femur as popliteal artery |
|
|
Term
|
Definition
| continuation of femoral artery gives rise to genicular arteries that circle the knee. splits into anterior and posterior tibial artery |
|
|
Term
|
Definition
| runs through anterior muscle compartment lateral to tibia at ankle becomes dorsalis pedis artery |
|
|
Term
|
Definition
| descends through the posterior part of leg deep to soleus. |
|
|
Term
| Three major veins enter the right atrium |
|
Definition
| Superior and Inferior Vena Cava + Coronary Sinus |
|
|
Term
|
Definition
| veins of the brain drain into dural sinuses (lie between layers of cranial dura matter) |
|
|
Term
|
Definition
| s shaped sigmoid sinus becomes internal jugular vein and leaves the scull through the jugular foramen. facial and superfacial temporal veins join it before it joins with the subclavian vein to form the brachiocephalic vein. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A superficial vein that descends on the surface if the sternocleidomastoid muscle. tributaries drain posterior and lateral scalp and some of the face. empties into subclavian vein. |
|
|
Term
|
Definition
| drain cervical vertebra, cervical spinal cord, and small muscles in the superior neck. |
|
|
Term
Deep Veins
Follow the paths of companion ____
Have the same names as the companion _____ |
|
Definition
Deep Veins
Follow the paths of companion arteries
Have the same names as the companion arteries |
|
|
Term
superficial veins of the upper limb are larger than deep veins. form anastomoses. Begin with dorsal venous network on dorsum of hand. the cephalic vein starts on the lateral side of this network
Superficial veins of the forearm
(4) |
|
Definition
cephalic vein: starts at lateral side of venous dorsal network bends around distal radius to enter anterior forearm and ascends the anteriolateral limb and joins the axillary vein.
basilic vein arises from medial aspect of dorsal venous network ascends posteriormedial forearm and anteriomedial arm. joins brachial vein in the axilla.
median cubital vein connects basilic and cephalic veins
medain vein of the forearm -ascends center of forearm termination at elbow- joins basilic vein |
|
|
Term
Veins of the Thorax
Azygos vein
Hemiazygos vein
Accessory hemiazygos vein |
|
Definition
veins from intercostal spaces and some of the thoracic viscera drains into the azygos. these veins flank the vertebral column and empty into the superior vena cava.
Azygos - receives from the right posterior intercostal veins
Hemiazygos - left side of vertebral column corresponds to inferior half of azygos. receives the 9th to 11th posterior intercostal veins.
accessory hemiazygos vein _- superior half of hemiazygos plus it courses to the right to join the azygos |
|
|
Term
|
Definition
| right and left hepatic veins exit liver superiorly and empty into inferior vena cava. carry all blood drained from digestive organs of abdominopelvic cavity. |
|
|
Term
|
Definition
| drain posterior wall of abdomin |
|
|
Term
| Gonadal (testicular or ovarian) veins |
|
Definition
| paired, ascend posterior abdominal wall with gonadal arteries. right drains into inferior vena cava, left drains into left renal vein. |
|
|
Term
|
Definition
right drains into inferior vena cava. left into left renal vein
(Adrenal glands) |
|
|
Term
|
Definition
|
|
Term
The Hepatic Portal System
A specialized part of the vascular circuit
Picks up digested _____
Delivers ____ to the ___ for processing |
|
Definition
The Hepatic Portal System
A specialized part of the vascular circuit
Picks up digested nutrients from stomach and intestines and
Delivers nutrients to the liver for processing |
|
|
Term
|
Definition
| Share the name of the accompanying artery |
|
|
Term
|
Definition
Great saphenous vein empties into the femoral vein
Small saphenous vein empties into the popliteal vein |
|
|
