Blood

Blood is a specialized connective tissue: cells are suspended in liquid

matrix called plasma

• Functions Transport – substances to and from cells in

bodyRegulate – temperature, acids, bases, salts &

waterProtection – vs. disease or loss of fluid via

clotting mechanism

ComponentsPlasma: ~90% water. Contains cells, nutrients, cellular waste, immune factors and proteins.Plasma proteins: albumin, globulins, fibrinogen

Red Blood Cells [erythrocytes]: transports oxygen via hemoglobin

White Blood Cells [leukocytes]: immune function

Platelets[thrombocytes] clotting mechanism

All blood cells are derived from the same stem cells in the bone marrow. Depending on body needs, they will differentiate into specific cells.

Red Blood Cells

• More 600-700x more numerous than WBCs

• 17x more numerous than platelets

• Once mature, lose their nuclei, and interior area is occupied by hemoglobin molecule.

• Hemoglobin contains iron – which binds onto oxygen molecule

Oxygenated hemoglobin = oxyhemoglobin

Deoxygenated hemoglobin = deoxyhemoglobin

White Blood Cells

• Neutrophils• Basophils• Eosinophils• Monocytes• Lymphocytes: B&T

• Develop in bone marrow – mature in spleen and thymus

• Phagocytes: neutrophils, eosinophils, monocytes

Blood Clotting /coagulation

• Injury to tissue causes release of chemicals that initiate clotting mechanism

• Process requires ~30 different proteins called clotting factors

• Calcium is required for this process

Circulatory System: Blood Vessels

Blood Vessels

Arteries – carry blood away from the heart

Veins – carry blood towards the heart –have valves

Capillaries – vessel that allows exchange with tissues

[ 60,000 miles in adult]

Structure of vessels• Outermost layer – tunica externa/adventitia –

dense connective tissue – primarily collagen

• Middle layer – tunica media –muscle layer, also has elastic connective tissue

• Innermost layer - tunica interna – epithelium called endothelium [special name for epithelial tissue of this system]

• Hollow area where blood travels =lumen

Pulses• Carotid• Temporal• Radial• Brachial• Abdominal• Femoral• Popliteal• Dorsalis Pedis• Tibialis

Blood Pressure measures the volume of blood

Read by using a sphygmomanometer [BP cuff] and stethoscope

Record first distinct sound as systolic number [systolic BP] – contraction of heart/how hard the heart is working

Record the last distinct sound as diastolic number [diastolic BP] heart at rest/ the resistance of blood by the vessels – how dilated or constricted they are.

‘Normal’ = <120/<80

Hypertension = high blood pressure 140/90

Hypotension = low blood pressure

2. Make sure patient is comfortable, and limb is supported. Put cuff on limb just above the antecubital crease.

3. Inflate the cuff to approx. 180 mg Hg, and slowly deflate.

4. Listen for first distinct sound – mentally note number, and last distinct sound – noting number.

5. Be sure to completely deflate cuff when done, and remove from arm.

1. Choose a BP cuff that is the proper

size, which depends on the

circumference of the limb

Lowest blood pressure is in the R atrium of heart

Hypertension• Today roughly 65 million Americans have high

blood pressure and another 45 million have pre-hypertension.

• Americans spend more than $15 billion each year on drugs to treat hypertension

• The 2005 Dietary Guidelines for Americans recommends that young adults consume less than 2,300 mg of sodium per day. People with hypertension, African Americans, and middle-aged and elderly people—almost half the population—are advised to consume no more than 1,500 mg per day. Source CSPI