Arteries (5/8/2024 & 5/15/2024)

What makes up the circulatory system?

What makes up the circulatory system?

lymphatic system and cardiovascular system

What does the lymphatic system do

transports lymph fluid which contains WBCs that eliminate toxins and waste throughout the body

What does the cardiovascular system do?

provides tissues with oxygen and nutrients (both pulmonary and systemic circulation)

blood, vessels, and heart

What are the 3 main components of the cardiovascular system?

blood, vessels, and the heart

What is the circulatory system?

a vast network of organs and vessels that are responsible for the flow of blood, nutrients, oxygen, gases, and hormones to and from cells

In the average human, ___ gallons of blood travels through the body daily

2,000

What are the 6 main functions of the cardiovascular system?

• HOMEOSTASIS

• transports O₂ and CO₂

• transports nutrients and waste

• protects against disease

• transports hormones

• regulates temperature

Explain how the cardiovascular system transports O₂ and CO₂ (as one of the main functions of the cardiovascular system)

• every cell requires a constant supply of O₂

• inhale O₂, exhale CO₂

• 3 essential processes

  • ventilation

  • diffusion

  • perfusion

Explain how the cardiovascular system transports nutrients and waste (as one of the main functions of the cardiovascular system)

• respiratory

  • O₂ and CO₂ exchange

• digestive

  • intestinal capillaries

  • nutrients to body tissues

• urinary

  • waste materials filtered by kidneys

Explain how the cardiovascular system protects against disease (as one of the main functions of the cardiovascular system)

• transports disease fighting cells to all parts of the body

• fights disease

  • blood transports WBCs, antibodies, and proteins that defend the body against infectious diseases

• fights blood loss

  • clotting mechanisms are also presents the protect the body from blood loss after injuries

Explain how the cardiovascular system transports hormones (as one of the main functions of the cardiovascular system)

• endocrine system

  • glands that regulate an organs activity

  • control many important functions in the body

    • growth, development, reproduction, sleep

• hormones released into the blood stream

  • ex: pancreas

Explain how the cardiovascular system regulates body temp (as one of the main functions of the cardiovascular system)

• too high

  • vessels close to the skin dilate

  • larger surface area = more heat loss

• too low

  • vessels close to the skin constrict

  • smaller surface area = less heat loss

Explain blood

a body fluid in the circulatory system that delivers necessary substances such as nutrients and oxygen to the cells, AND transports metabolic waste product away from those cells

What are the 4 main components of blood?

• RBCs

  • hemoglobin

  • 44%

• WBCs

  • 1%

• plasma

  • liquid portion

  • 55%

• platelets

  • 1%

Explain the heart

• a muscular organ the size of a fist

• the “pump” that moves blood through arteries, capillaries, and veins

What do arteries do?

transport oxygenated blood away from the heart to the cells in the body

named by location or organ it supplies

What do veins do?

transport deoxygenated blood back to the heart

What are the 2 types of veins?

superficial and deep

What do capillaries do?

facilitate the movement of blood from arteries to veins

Explain the chain of exchange from the heart, through the body, back to the heart

heart → arteries → arterioles → capillaries → venules → veins → heart

Exchange of O₂ and CO₂ takes place at the level of the ___

capillaries

List and describe the 3 layers of arteries

1. tunica intima

   1. endothelial cells

   2. elastic tissue

2. tunica media (muscle layer)

   1. elastic connective tissue

3. tunica adventitia/externa

What are the 2 layers of arterioles and venules?

intima and media

List and explain the 3 layers of veins

1. tunica intima

   1. endothelial cells only

2. tunica media

   1. elastic connective tissue

3. tunica adventitia/externa

Explain valves

• only in the intima of veins

• permit blood flow in 1 direction

• BP is lower in veins, which can allow for pooling of veins

  • varicose veins

  • most common in lower extremities

Which vessel has the thinnest walls?

capillaries

Explain the walls of capillaries

• transparent

• a single intima layer

  • allows for easy diffusion of nutrients and gas

• carry blood from arterioles to venules

Explain the function of pulmonary circulation

• carry deoxygenated blood from the heart to the lungs to get oxygenated

• returns blood to heart to be transported through body

What are the trunk vessels of pulmonary circulation?

pulmonary veins and pulmonary arteries

Explain pulmonary arteries

• carry deoxygenated blood from heart

• begins at right side of heart

• divides at T5 into right and left

Explain pulmonary veins

• carry oxygenated blood from the lungs to the heart

• ends at the left side of the heart

• right and left veins

Explain the function of systemic circulation

• supplies oxygenated blood from the heart to the rest of the body

• returns deoxygenated blood back to the heart

What are the trunk vessels of systemic circulation?

aorta, inferior vena cava, superior vena cava

Explain the aorta (including origin and parts)

• the largest artery

• originates from left ventricle of the heart

• contains artery branches that supply oxygenated blood to body tissues

• parts:

  • ascending

  • arch

  • descending (thoracic and abdominal)

Explain the ascending aorta

• segment that merges from the top of the left ventricle

• left ventricle to T4

• aortic root

• 2” in length

What are the first branches off of the aorta?

right and left coronary arteries (supply blood to the heart)

Explain myocardial infarct

(heart attack)

acute thrombus in the coronary arteries

What is CAD?

• coronary artery disease (plaque buildup that decreases lumen size of coronary arteries)

• can cause angina pectoris

Explain angioplasty

procedure done to widen a narrowed or blocked artery to increase blood flow (balloon insertion with stent placement)

Explain the location and branches of the aortic arch

• begins at sternal angle

  • curves posteriorly and to the left

• branches

  • right brachiocephalic artery

  • left common carotid artery

  • left subclavian artery

What is the first branch off of the aortic arch?

brachiocephalic artery

Explain the brachiocephalic artery

divides into the right common carotid artery (supplies right side of head) and right subclavian artery (supplies right shoulder and arm)

Explain the left common carotid artery

• 2nd branch off the aortic arch

• supplies blood to the left side of the head

Explain the left subclavian artery

• 3rd branch off the aortic arch

• supplies blood to the left arm and shoulder

Explain vertebral arteries

• branches off of subclavian arteries

• through transverse foramen of cervical vertebrae

• merge to form one of the major cerebral arteries of the brain

Explain the thoracic portion of the descending aorta

• descends along the left borders of the thoracic vertebrae

• extends from T4-T12

• ends at diaphragm

• supplies mediastinal structures

• branches:

  • esophageal

  • pericardial

  • intercostals

  • superior phrenic

  • bronchial

  • inferior phrenic

Explain the path of the blood through the circulatory system

right atrium → right ventricle → pulmonary arteries → pulmonary circulation → pulmonary veins → left atrium → left ventricle → aorta → systemic circulation

Explain aortic aneurysms

• a weakening in a portion of the arteries wall

  • arteriosclerosis/atherosclerosis (plaque build up)

• most common is abdominal level just below kidneys

Explain saccular aneurysms

• involves only one side of the arterial wall

• common in cerebral arteries

Explain fusiform aneurysm

• involves both sides of arterial wall

• common in distal abdominal aorta

Explain dissecting aneurysm

• most deadly

• inner layer (intima) tears and allows blood flow in the vessel

Explain old and new repair options for aneurysms

• old

  • synthetic graft

  • very invasive

  • removal of expanded portion

  • graft is surgically sewn into place

• new

  • endovascular graft

  • minimally invasive (go in through the femoral artery)

  • done in IR

Where is the abdominal descending aorta located?

extends from T12-L4

begins at aortic hiatus and ends in a bifurcation

Are branches of the abdominal descending aorta paired or unpaired?

lateral branches are paired, anterior branches are unpaired

What are the paired branches of the abdominal aorta?

• inferior phrenic

• suprarenal (produce hormones to regulate metabolism, immune system, blood pressure, and stress response)

• renal

• gonadal

• lumbar

List and explain the 3 unpaired branches of the abdominal aorta

celiac trunk/axis

• supplies upper abdominal organs

• liver, stomach, esophagus, spleen, ½ of duodenum and pancreas

superior mesenteric

• largest single branch

• at level of L1

• supplies lower abdominal organs

• small intestine and proximal ½ of colon

inferior mesenteric

• at level of L3

• supplies lower abdominal organs

• distal ½ of colon, sigmoid, and rectum

What are the 3 main branches of the celiac trunk?

• left gastric artery

  • stomach and distal esophagus

• splenic artery

  • spleen

• common hepatic artery

  • liver, duodenum, and pancreas

Explain the bifurcations of the terminal abdominal aorta

• bifurcates into right and left common iliac artery at L4

  • middle sacral artery is in between the 2

• bifurcates into internal and external iliac arteries at level of pelvic inlet

  • internal supplies genital organs

  • external supplies lower extremities

List the main arteries of the lower extremity in order from proximal to distal

• internal iliac

• external iliac

  • common femoral artery

• popliteal

• tibial

• fibular

List the main arteries of the upper extremity in order from proximal to distal

• subclavian

  • right - brachiocephalic

  • left - 3rd branch

• axillary

  • once it passes the clavicle

• brachial

  • continuation of axillary artery

  • artery that is compressed when taking BP

• antebrachium

  • radial artery (pulse)

  • ulnar artery

• dorsal and palmar arches

What are the 2 main arterial sources of cerebral circulation?

• right and left internal carotids

  • supplies anterior and middle part of brain (80%)

  • enters through carotid foramen/canal

• right and left vertebral arteries

  • supplies posterior part of brain (20%)

  • enters through foramen magnum

The internal carotids branch into:

• anterior cerebral artery

  • smaller branch

  • supplies anterior and superior

• middle cerebral artery

  • larger branch

  • supplies lateral

The vertebral artery is a branch of the ___

subclavian artery

Explain the location and function of the right and left vertebral arteries

• through the transverse foramen of C-spine to foramen magnum and sits at the basilar portion of skull

• join together to create the basilar artery

  • posterior cerebral arteries originate at the bifurcation of the basilar artery at midbrain and supplies the posterior part of the brain

List and explain the 2 communicating arteries

• anterior communicating artery

  • unites cerebral arteries

• posterior communicating artery

  • unites posterior cerebral arteries with the internal carotids

Explain the function and location of the circle of willis

• the circle made up by the communicating arteries

• at the inferior aspect of the brain

• safeguards the brain

  • provides a collateral blood flow

  • in case of blockage in any of the major vessels (internal carotid and vertebral)

• basilar artery occlusion has a high mortality rate

List and explain the 2 types of strokes

• ischemic

  • most common

  • blockage of blood flow (thrombotic or embolic)

• hemorrhagic

  • cerebral aneurysm

  • rupture of an aneurysm (damages cells and increases pressure)

diagnosed through CT

Explain treatment for a hemorrhagic stroke

aneurysm clipping

• usually saccular

• surgical procedure

• remains for life

Explain treatment for ischemic stroke

medication (Tissue Plasminogen Activator) or stent placement

List the 4 types of brain hematomas

• epidural

• subdural

• subarachnoid

• intracerebral

Explain epidural brain hematomas

• arterial blood leaks between the dura mater and skull to form a blood mass that presses on brain tissue

• the most common cause is trauma

Explain subdural brain hematomas

• venous blood vessels burst between the dura mater and arachnoid mater

• leaking blood forms a hematoma that presses on the brain tissue

• gets bigger and can cause gradual loss of consciousness and death

Explain subarachnoid brain hematomas

• bleeding ON the brain

• arterial bleeding in the space around the brain

• usually happens when an irregular bulge in a blood vessel (aneurysm) bursts in the brain

Explain intracerebral brain hematomas

• bleeding IN the brain

• occurs when arterial blood pools in the tissue of the brain

• causes include trauma, aneurysm, poorly connected veins and arteries (from birth), high BP, tumors