Study guide for exam 5 human anatomy & physiology

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arteries, arterioles, capillaries, venules & veins

What are the 5 types of blood vessels?

arteries

these vessels carry blood away from the heart & toward the tissues; the heart's ventricles pump blood into these

arterioles

these vessels are small subdivisions of the arteries; they carry blood into the capillaries

capillaries

these are tiny, thin-walled vessels that allow for exchanges between systems; exchanges occur between the blood & body cells/ between the blood & air in the lung; these connect arterioles & venules

venules

these are small vessels that receive blood from capillaries & begin its transport back toward the heart

veins

these are vessels formed by the merger of venules; they continue blood's transport until it is returned to the heart

pulmonary & systemic circuits

what are are the 2 different blood circuits?

pulmonary circuit

this circuit delivers blood to the lungs, where some carbon dioxide is eliminated & oxygen is replenished

1. the pulmonary trunk & its arterial branches, carry blood low in oxygen from the right ventricle to the lungs
2. the capillaries in the lungs, through which gases, nutrients, & wastes are exchanged
3. the pulmonary veins carry freshly oxgenated blood back to the left atrium

what does the pulmonary circuit do?

pulmonary arteries carry blood that is low in oxygen content, & pulmonary veins carry blood that is high in oxygen content; in contrast the systemic arteries carry highly oxygenated blood, & the systemic veins carry blood that is low in oxygen

what is the difference of the vessels in the systemic & pulmonary circuit?

systemic circuit

this circuit serves the rest of body; these vessels supply nutrients & oxygen to all tissues & carry waste materials away from the tissues for disposal

1. the aorta receives freshly oxgenated blood from the left ventricle & then branches into the systemic arteries carrying blood to the tissues
2. the systemic capillaries are the blood vessels through which materials are exchanged
3. the systemic veins carry blood in oxygen back toward the heart; the venous blood flows into the right atrium of the heart through the superior vena cava & inferior vena cava

What does the systemic circuit do?

endothelium- inner tunic, smooth muscle- middle tunic & connective tissue- outer tunic

what are the 3 layers of the artery?

thick walls, strong enough to receive blood pumped under pressure from heart's ventricle; elastic tissue between layers of arterial wall allows these vessels to stretch when receiving blood & then return to their original size

what is the vessel structure of arteries?

endothelium- inner tunic

inner most membrane; forms a smooth surface over which the blood flows easily; simple flat epithelial cells

smooth muscle- middle tunic

thickest layer under the control of the ANS

connective tissue- outer tunic

this layer is supportive connective tissue

vasoconstriction

narrows, decrease in the diameter of blood vessels (when muscle contracts)

vasodilation

widens, dilation of blood vessels (especially the arteries) (when muscle relaxes)

arterioles

these have thinner walls than arteries, little elastic connective tissue, but relatively more smooth muscle

capillaries

these connect arterioles & venules; these have the thinnest walls of any vessels: one cell layer; transparent walls that are a continuation of smooth endothelium that lines the arteries

allows for exchange between the blood & body cells & between the lung tissue & outside air

why are the capillary walls so thin?

capillary boundaries

what on the capillary is the most important center of activity for the entire circulation system?

venules

these are the smallest veins; formed by the union of capillaries; their walls are only slightly thicker than those of capillaries; as these merge to form veins, the smooth muscle in the vessel walls become thicker & these begin to aquire the additional layers found in larger vessels

veins

this vessel has the same 3 layers as arteries- endothelium- inner tunic, smooth muscle- middle tunic & connective tissue- outer tunic

the veins & arteries have the same 3 layers; however the middle smooth muscle tunic is relatively thin in veins; the vein wall is much thinner than the wall of artery; veins have less elastic tissue between the layers, so they can expand easily & carry blood under much lower pressure; because of their thinner walls, veins collapse easily; most veins have one-way valves that permit blood to flow in only 1 direction: toward the heart, capillaries don't have valves

what is the difference in vessel structure of veins & arteries?

pulmonary circuit- carries blood from the heart to the lungs to pick up oxygen & then back to the heart; the systemic circuit carries blood to & from all remaining tissues in the body

what are the 2 blood circuits & what areas does each serve?

smooth muscle makes the middle tunic; it is involuntary muscle controlled by autonomic nervous system

what type of tissue makes up the middle tunic of arteries & veins, & how is this tissue controlled?

single layer of squamous epithelium

how many cell layers make up the wall of a capillary?

the aorta, the largest artery

where do the systemic arteries begin?

aorta

this vessel receives blood from the left ventricle, ascends from the heart, & then arches back to travel downward through the body, branching to all organs

1. ascending aorta
2. aortic arch
3. thoractic aorta
4. abdominal aorta

what are the 4 parts of the aorta?

ascending aorta

this part of aorta is near the heart & inside the pericardial sac

aortic arch

this part of the aorta curves from the right to the left & also extends posteriorly

thoracic aorta

this part of aorta lies just anterior to the vertebral column posterior to the heart in the mediastinium

abdominal aorta

this part of aorta is the longest section of the aorta, beginning at the diaphragm & spanning the abdominal cavity

descending aorta

the thoracic & abdominal aorta together make up

1. brachiocephalic artery, divides into right subclavian artery & right common carotid artery
2. the left common carotid artery
3. left subclavian artery

what are the branches of the ascending aorta& arch?

brachiocephalic artery

this is a short vessel that supplies the arm & head on the right side (unpaired)

right subclavian artery

after extending upward about 5 cm, the brachiocephalic divides into this, which extends under the right clavicle (collar bone) supplies the right upper (arm)

right common carotid artery

supplies the right side of the neck, head, & brain

left common carotid artery

this extends upward from the highest part of the aortic arch; supplies the left side of the neck & head

left subclavian artery

this extends under the left clavicle & supplies the left upper extremity; this is the aortic arch's last branch

1. celiac trunk, subdivides into 3 branches: left gastric artery, splenic artery, & hepatic artery
2. superior mesenteric artery
3. inferior mesenteric artery

what are the unpaired branches of the descending aorta?

1. superior & inferior phrenic arteries
2. renal arteries
3. suprarenal arteries
3. gonadal arteries (ovarian & testicular arteries)
4. 4 pair of lumbar arteries

what are the paired lateral branches of the descending aorta?

celiac trunk

this is a short artery, about 1.25 cm long, that subdivides into 3 branches: left gastric artery, splenic artery & hepatic artery

left gastric artery

this artery goes to the stomach

splenic artery

this artery goes to the spleen

hepatic artery

this artery goes to the liver

superior mesenteric artery

this is the largest of the these branches, carries blood to most of the small intestine & to the 1st half of large intestine

inferior mesenteric artery

this is located below the superior mesenteric artery & near the end of the abdominal aorta, supplies the 2nd half of the large intestine

superior & inferior phrenic arteries

these arteries supply the diaphragm

renal arteries

the largest in this group of abdominal aorta paired lateral branches, carry blood to the kidneys

suprarenal arteries

these arteries supply the adrenal glands

gonadal arteries

the ovarian arteries in females & testicular arteries in males- supply the sex glands

4 pair of lumbar arteries

these arteries extend into the musculature of the abdominal wall

the abdominal aorta divides into 2 common iliac arteries, each subdivides into internal & external iliac artery; branches in the thigh & then becomes popliteal artery, which subdivides into anterior & posterior tibial arteries, the anterior tibial artery terminates as the dorsalis pedis at the foot; posterior tibial artery gives rise to fibular artery in leg

what are the iliac arteries & their subdivisions?

common iliac artery

these vessels are 5 cm long, extend into the pelvis, where each subdivides into an internal & external iliac artery

internal iliac artery

these vessels send branches to the pelvic organs, includng the urinary bladder, the rectum & reproductive organs other than the gonads (reproductive organs)

external iliac artery

each of these vessels continues into the thigh as femoral artery, this vessel gives rise to branches in the thigh & then becomes the popliteal artery subdivides below the knee, subdivisions include posterior & anterior tibial arteries & dorsalispedis which supply leg & foot

popliteal artery

this artery branches off the femoral artery; subdivides below the knee into the anterior & posterior tibial arteries

tibial arteries

artery supplying the leg & foot

anterior tibial artery

what artery terminates as the dorsalis pedis?

fibular artery

the posterior tibial artery gives rise to this artery in the leg

external & internal carotid arteries, subclavian artery, vertebral artery, axillary artery, brachial artery, radial artery & ulnar artery

what are the arteries that branch to the arm & head?

external & internal carotid arteries

each common carotid artery travels along the trachea enclosed in a sheath with the internal jugular vein & vagus nerve; just anterior to the angle of the mandible (lower jaw) it branches into these

internal carotid artery

this artery travels into the head & branches to supply the eye, the anterior portion of the brain, the other structures in the cranium

external carotid artery

this artery branches to the thyroid gland & to other structures in the head & upper part of the neck

subclavian artery

this artery supplies blood to the arm & hand; this changes names as it travels through the arm & branches to the forearm & hand; it 1st becomes axillary artery, then brachial artery, then radial artery, then ulnar artery

vertebral artery

the 1st branch of subclavian artery, which passes through the transverse processes of the 1st cervical vertebrae & supplies blood to the posterior brain

axillary artery

the 1st name change in the subclavian artery; this artery is in the axilla (armpit)

brachial artery

the 2nd name change of subclavian artery, the longest part of the vessel, is in the arm proper; this subdivides into branches near the elbow: radial & ulnar arteries

radial artery

this artery branches off the brachial artery; continues down the thumb side of the forearm & wrist

ulnar artery

this artery branches off the brachial artery; extends along the medial or little finger side into the hand

anastomosis

a communication between 2 vessels, by means of these, blood reaches vital organs by more than 1 route

circle of Willis (cerebral arterial circle), superficial palmar arch, mesenteric arches, & deep plantar arch

what are the 4 different types of anastomoses?

circle of Willis (cerebral arterial circle)

this receives blood from the 2 internal carotid arteries & from the basilar artery, which is formed by the union of 2 vertebral arteries; this arterial circle lies just under the brain's center & sends branches to the cerebrum & other parts of brain

superficial palmar arch

this arch is formed by the union of the radial & ulnar arteries in the hand; it sends branches to the hand & fingers

mesenteric arches

this arch is made up of communications between branches of the vessels that supply blood to the intestinal tract

plantar arch

this arch is formed by the union of the lateral plantar artery, which travels across the bases of the metatarsal bones, & the dorsalis pedis

ascending aorta, aortic arch, thoracic aorta, & abdominal; the thoracic & abdominal make up the descending aorta

what are the subdivisions of the aorta, the largest artery?

brachiocephalic, left common carotid & left subclavian

what are the 3 branches of the aortic arch?

arm & head on right side

what areas are supplied by the brachiocephalic artery?

communication between 2 vessels

what is an anastomosis?

veins in the back of the hand & front of the elbow: cephalic vein, basilic vein, median cubital veins & saphenous veins

where are the superficial veins?

for drawing blood for testing purposes (venipunture) & (IV) intravenous injections

the veins at the elbow: cephalic, basilic & median cubital veins are used for what purpose?

saphenous veins

what are the body's longest veins

saphenous veins

veins of lower extremities, which are the body's longest veins; begins in the foot & extends up the medial side of leg, the knee, & thigh; it finally empties into the femoral vein near the groin

deep veins

what veins tend to parallel arteries & usually have the same names as corresponding arteries?

the veins of the head, neck, upper extremities, & chest

what veins drain into the superior vena cava?

by the union of the right & left brachio cephalic veins

how is the (SVC) superior vena cava formed?

the SVC is formed by the union of the right & left brachiocephalic veins, which drain the head, neck, & upper extremities; the unpaired azygos vein drains the veins of the chest wall & empties into the superior vena cava

what are the tributaries of the superior vena cava?

the inferior vena cava

this is much longer than the superior vena cava, returns blood from the areas below the diaphragm; drainage in this is more complicated , divided into 2 parts

1. unpaired veins that drain the spleen & parts of the digestive tract empty into hepatic portal veins (enables blood to circulate through the liver before returning to the heart)
2. iliac, lumbar, ovarian & testicular, renal & suprarenal, & hepatic veins (from the liver) these vessels empty into IVC

what are the 2 groups of veins that empty in the IVC?

sinus

"space" or "hollow"

venous sinus

this is a large channel that drains blood low in oxygen, but does not have a vein's usual tubular structure

coronary sinus

this is an example of a venous sinus that receives most of the blood from the heart wall; it lies between the left atrium & left ventricle on heart's posterior surface & empties directly into the right atrium, along with the 2 venae cavae

a portal system

blood circulates through a 2nd capillary bed, usually in a 2nd organ, before it returns to the heart; it's kinda like a detour pathway of venous return that transport materials directly from 1 organ to another

hepatic portal system

this system carries blood from the abdominal organs to the liver to be processed before it returns to the heart; it includes the veins that drain blood from capillaries in the spleen, stomach, pancreas, & intestine; instead of emptying blood directly in IVC its delivered thru the hepatic portal vein to the liver; the portal vein's largest tributary is the superior mesenteric vein which drains blood from the proximal portion of the intestine

is to transport blood from the digestive organs & spleen to liver sinusoids so that the liver cells can carry their functions (when food is digested most of end products are absorbed from sm intestine into blood stream & transported to the liver by portal system; in the liver these nutrients are processed, stored, & released as needed into general circulation)

what is the purpose of the hepatic portal system?

superficial veins are near the surface; deep veins are closer to the interior & generally parallel the arteries

what is the difference between superficial & deep veins?

the superior vena cava & inferior vena cava drain the systemic circuit & empty into right atrium

What 2 large veins drain the systemic blood vessels & empty into the right atrium?

a large channel that drains blood low in oxygen

What is a venous sinus?

to the liver

the hepatic portal system takes blood from the abdominal organs to which organ?

interstitial fluid or tissue fluid

all living cells are immersed in this slightly salty liquid; this fluid serves as "middleman" between the capillary membrane & neighboring cells

diffusion

this is the main process by which substances move between the cells & the capillary blood; the movement of a substance from an area where it is in higher concentration to an area where it is in lower concentration; does not require transporters or cellular energy

blood pressure

this is the force that filters or pushes water & dissolved materials out of the capillary into the tissue fluid

osmotic pressure

fluid is drawn back into the capillary by this pressure, the "pulling force" of substances dissolved & suspended in the blood; this pressure is maintained by plasma proteins (mainly albumin), which are too large in molecular size to go through the capillary wall

this allows time for exchanges to occur

why is movement of blood thru the capillaries slow?

by changing the size of the blood vessels supplying that organ: vasodilation- allows more blood to area & vasoconsriction- decrease in blood flow

how can the volume of blood flowing to a particular organ be regulated?

vasomotor activities

these activities result from the contraction or relaxation of smooth muscle in the walls of blood vessels, mainly the arterioles

vasodilation- widening & vasoconstriction- narrowing

name 2 types of vasomotor changes?

in the medulla of the brain

where is the vasomotor center, which regulates vasomotor activities, sending its messages through the autonomic nervous system?

precapillary sphinter

this is smooth muscle that encircles the entrance to the capillary & regulates blood flow, widens to allow more blood to enter when tissues need more oxygen

contraction of skeletal muscles- they compress the veins & squeeze blood forward, valves in the veins- prevent back flow & keep blood flowing toward the heart, & breathing- pressures changes in the abdominal & thoracic cavities help with bloods return to the heart

what mechanisms help to get blood returned to the heart, in the venous system?

blood pressure

what force helps to push materials out of a capillary?

blood osmotic pressure

what force helps to draw materials into a capillary?

pulse

the rhythmic contraction and expansion of the arteries with each beat of the heart

1.size of person- pulse is somewhat faster in small people than in large & in women than in men
2. age of person- in a newborn infant may be 120 to 140 beats/min as child grows the rate becomes slower
3. muscular activity influences pulse rate- during sleep pulse may slow down to 60 beats/ min- during strenuous exercise the rate may go up to over 100 beats/min
4. emotional disturbances- may increase the pulse rate
5. temperature- pulse rate increases with increased temperature as in infection
6. thyroid hormone- excessive secretion of thyroid hormone may cause a rapid pulse

what are 6 factors that influence the pulse rate?

blood pressure

this is the force exerted by the blood against the walls of the vessels

total blood volume, cardiac output, resistance to blood flow, & blood vessel compliance & elasticity

what factors affect blood pressure?

total blood volume

this refers to the total amount of blood that is in the vascular system at a given time; loss of bld volume by hemorrhage will lower bld pressure; increase in bld volume will increase pressure within the vessels thereby increase CO by increasing venous return

cardiac output (CO)

the volume of blood pumped out of each ventricle in 1 minute; is the product of 2 factors- heart rate & stroke volume

heart rate

the number of times the heart beats each minute (basic heart rate is set by SA node but can be infleunced by autonomic nervous system, hormones, & other substances circulating in the blood)

stroke volume

the volume of blood ejected from the ventricle with each beat; sympathetic nervous system can stimulate more forceful heart contractions to increase blood ejection

blood vessel diameter: a narrow vessel offers more resistance to blood flow than a wider vessel, blood viscosity or thickness: increased blood thickness will increase blood pressure, & blood vessel length: a longer vessel offers more resistance to blood than a shorter vessel

what factors affects the resistance to blood flow?

baroreceptors

the carotid arteries & the aorta have these in their walls to detect changes in blood pressure

compliance

the ease with which arteries expand to receive blood

elasticity

the ability of blood vessels to return to their original size after being stretched

systolic pressure & diastolic pressure

what 2 variables are measured when taking blood pressure?

systolic pressure

the maximum pressure that develops in the arteries after heart muscle contraction ( normal = 120)

diastolic pressure

the lowest pressure measured in the arteries after relaxation of heart muscle (normal= 80)

pulse pressure

the difference between the systolic & diastolic pressure

sphygmomanometer (blood pressure cuff or blood pressure apparatus)

the instrument used to measure blood pressure

as systolic pressure 1st, then diastolic pressure, separated by a slash, such as 120/80

how is blood pressure recorded?

hypotension

lower-than-normal blood pressure

hypertension

high blood pressure

essential hypertension

hypertension that has no apparent medical cause

renin

this enzyme produced in the kidney, appears to play a role in the severity of essential hypertension

1. weaken vessels & lead to saclike bulges (aneurysms) in vessel walls that are likely to rupture
2. stress the heart by causing it to work harder to pump blood into arterial system; in response to this greater effort, the heart enlarges, but eventually weakens & becomes less efficient
3. stress the kidneys & damage renal vessels
4. damage the lining of vessels predisposing to atherosclerosis

hypertension can cause these 4 things

1. diuretic drugs that promote water loss through the kidneys
2. drugs that limit production of renin or block its action
3. drugs that relax blood vessels, including adrenergic blockers & calcium channel blockers

treatment of hypertension

arteriosclerosis

hardening of the arteries

atherosclerosis

what is the most common form of arteriosclerosis?

atherosclerosis

this begins with microscopic damage to the arterial endothelium caused by direct contact with LDL (the
"bad" cholestrol), oxidizing chemicals; streaky areas of yellow, fatlike material (plaque) appear in vessel, it accumulates, separates the wall's muscle & elastic tissue layers; arterial wall bulges into vessel's lumen & interferes with blood flow. Platelets can aggregate at the site of plaque formation, leading to development of blood clot (thrombus) & partial or complete obstruction of the vessel

atherosclerosis

this accounts for 40% of all deaths in the United States

1.leg cramps, pain, & sudden lameness while walking caused by insufficient blood supply to lower extremities resulting from arterial damage
2. headaches, dizziness & mental disorders may be result of cerebral artery sclerosis
3. hypertension may result from a decrease in lumen size within many arteries throughout body
4. palpitations, dyspnea (difficulty breathing), paleness, & weakness
5. an increase in amount of urine with appearance of albumin
6. ulceration & tissue necrosis (death)

signs & symptoms of arterial degeneration

albumin

this is a normal plasma protein usually found in urine only if there is kidney damage

stents & endarterectomy

treatment for arterial degeneration

stents

small tubes inserted to keep vessels open

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