Mod 5- Blood Vessels Flashcards
Three types of blood vessels
1. Arteries
- large blood vessels
- carry blood away from heart to all regions
- walls of arteries have 3 layers making it muscular and elastic
- expand and contract with pimping of heart
Endarterial
- within or inner portion of an artery
Arterial blood
- oxygen rich / bright red
- when cut blood spurts due to pumping action
Largest blood vessel in body
- Aorta
- begins from left ventricle of heart and forms the main trunk of arterial system
CAROTID ARTERY
- major arteries that carry blood upward to head
COMMON CAROTID ARTERY
- located on each side of neck
- divided into the
INTERNAL CAROTID ARTERY - brings oxygen rich blood to the brain
EXTERNAL CAROTID ARTERY
- brings blood to face
Stroke caused by block in blood flow in any of these arteries
ARTERIOLES
- smaller , thinner branches of arteries
- deliver blood to capillaries
2.capillaries
- only one epithelial cell in thickness
- smaller blood vessel in the body
IMPORTANT JOB
- deliver oxygen and nutrients to cells of tissues
- oxygen rich arterial blood is delivered by arteriole ( small artery) to capillaries
- after oxygen has been extracted the oxygen poor blood is returned to circulation as venous blood
- capillaries slow the flow of blood to allow plasma to flow into tissues
- here in the tissues exchange of oxygen, nutrients and waste materials occur within surrounding cells
- after leaving cells 90% of fluids which is oxygen poor enter opposite end of capillary bed through venues
- 10% of fluid left behind in the tissues become lymph
3.veins
- form a low pressure collecting system
- returns oxygen poor blood to the heart
- smallest veins are ‘ venules’
- they join to form larger veins
- walls of veins thinner/less elastic than arteries
- venous blood continues flow in increased speed as it goes back to the heart
- veins have valves that enable blood to flow only toward heart and prevent it from flowing away from heart
SUPERFICIAL VEINS
- located near body surface
DEEP VEIN
- within tissue away from surface
The Venae cavae
- are the two largest veins in the body
- return blood into heart
SUPERIOR VENA CAVA
- transports blood from upper portion of body to heart
INFERIOR VENA CAVA
- transports blood from lower portion of body to heart
Pulse and Blood pressure
Pulse
- rhythmic pressure against walls of artery caused by contraction of the heart
SYSTOLIC PRESSURE
- occurs when ventricles contract
- is the highest pressure against wall of an artery
- systole means ‘ contraction of heart ‘
DIASTOLIC PRESSURE
- occurs when ventricles are relaxed
- is the lowest pressure against walls of an artery
- diastole means ‘ relaxation of the heart ‘
BLOOD PRESSURE
- measurement of the amount of systolic and diastolic pressure against the wall of artery
Blood
- fluid tissue of body
- 55% liquid plasma
2. 45% formed elements ( refer picture )
- PLASMA
- straw colored fluid
- contains nutrients, hormones and waste products
- 91% water
- 9% mainly proteins, including clotting proteins
SERUM
- plasma fluid after blood vessels and clotting proteins are removed
FIBRINOGEN & PROTHROMBIN
- clotting proteins found in plasma
- important role in clot formation
- FORMED ELEMENTS
a. Erythrocytes -erythr-red / cytes- cell
b. Leukocytes
c. Thrombocytes
a. -Erythrocytes also known as ‘ red blood cells ‘
- mature red blood cells produced by red bone marrow
- primary role - transports oxygen to tissues
- transports using ‘ hemoglobin ‘
Hemoglobin - oxygen carrying blood protein pigment of erythrocytes
Hem- means blood
Gloving - means protein
b. Leukocytes
- known as ‘ white blood cells ‘
- primary role - defends body against infective organisms and foreign substance
MAJOR GROUP OF LEUKOCYTES
- NEUTROPHILS
— formed in red bone marrow
—- through phagocytosis , neutrophils play major role in immune system’s defense against pathogens including bacteria, virus and fungi
Phagocytosis- process of destroying pathogens by surrounding and swallowing them
BASOPHILS
- also formed in red bone marrow
- least common type of WBC
- responsible for causing symptoms of allergy
EOSINOPHILS
- formed in red bone marrow
- migrates to tissues throughout the body
- these cells destroy parasitic organisms and play a major role in allergic reaction
LYMPHOCYTES
- formed in red bone marrow , lymph nodes and spleen
- they identify foreign substances and germs in body
- and produce antibodies that specifically target then
MONOCYTES
- formed in red bone marrow , lymph nodes and spleen
- through phagocytosis, monocytes provide immunological defenses against many infections
c. THROMBOCYTES
- also known as ‘ platelets ‘
- smallest formed elements of the blood
- important role - clotting of blood
Thromb = clot
- when blood vessels are damaged , thrombocytes are activated and get sticky
- action causes thrombocytes to clump together to form clot to stop bleeding
Blood types
- classified according to presence or absence of certain antigens
Antigen - anything the body regards as foreign - Blood groups A, AB , B characterized by presence of A and / or B antigens
- O group shows absence of A and B antigens
Rh factor
- defines presence or absence of Rh antigen in red blood cells
- 85% Americans have Rh antigen
- that means Rh positive (Rh +)
- 15% are Rh absent , so Rh negative
- Rh factor important consideration in cross matching flood for transfusions
- Rh factor can cause difficulties when Rh + ve infant is born to Rh -ve mother
Blood gases
- gases that are normally dissolved in the liquid portion of blood
- major gases are
Oxygen , carbon dioxide and nitrogen
