BLOOD

CARDIOVASCULAR SYSTEMPART 1

FUNCTIONS of BLOOD

transports substances & maintains homeostasis in the body

Hemo = blood

hemophobia: fear of blood hemostasis: bleeding is under control hematocyte: blood cell hematemesis: vomiting blood hematuria: bloody urine hematopoiesis: formation of blood

cells

Blood

is a type of CT made up of scattered cells & a liquid matrix

What’s in blood?

1. Cells (45%) RBCs WBCs Platelets (plts)

2. Plasma (55%) water, a.a., proteins, carbohydrates,

lipids, vitamins, hormones, electrolytes, cellular waste

Hematocrit

vol of blood cells in a sample of blood blood centrifuged then % cells

figured normal levels:

Newborns: 55-68% 10 yr olds: 36-40% Women: 38-46% Men: 42-54%

RBCs erythrocytes, hematocytes, corpuscles

formed in bone marrow shape: biconcave disc

allows for optimal surface area for diffusion of O2 & CO2

5 million/mm3 no nucleus

so no cell division live about 120 days

then phagocytosed in liver & spleen

RBCs Functions

1. transport O2 thru out body (lungs cells)

hemoglobin: (hgb) large protein that O2 attaches to inside RBC

2. transports CO2 thru out body (cells lungs)

Hemoglobin

Hemoglobin

oxyhemoglobin: plenty of oxygen being carried in RBCs, blood is bright red

deoxyhemoglobin: not carrying much oxygen, blood is burgundy-red

Iron critical element needed to make hgb

& normal RBCs most of body’s Fe is in RBCs

in heme portion

Erythropoietin hormone secreted by kidneys

stimulates formation of more RBCs by bone marrow

requires: vit B12 & Folic Acid

White Blood Cells (WBCs)

leukocytes general function: defend the body

against pathogens

White Blood CellsType Name Function Picture

Granulocytes

Neutrophils aka

PMNspolymorpho-neutrophils

very active in phagocyting

bacteria & are present in large #s in pus of wounds,

most common of all types, normal= 60% of WBCs

(granular cytoplasm)

Eosinophils attack parasites, control allergic

reactions2% of WBC count

White Blood Cellstype Name Function Picture

Granulocytes continued

Basophils produces heparin (prevents blood

clots) & histamines (inflammatory

reaction)1% of WBC

Agranulaocytes (lacking granular cytoplasm)

Monocytes precursors of macrophages;

6% of WBC

Lymphocytes main cell of immune system

30% of WBC

Platelets (plts) thrombocytes cell fragments formed from

megakaryocyte, live ~4 days help initiate formation of blood clots

release clotting factors

Plasma

92% water Functions:

transport nutrients, gases, vitamins, hormones

maintain fluid & electrolyte balance maintains normal pH

Plasma Proteins1. Albumins

made in liver maintain osmotic pressure & blood vol.

2. Globulins α & β, from liver transport lipids & fat-soluble vitamins

3. Fibrinogen from liver, largest of plasma proteins in blood clotting fibrin

Hemostasis process of stopping bleeding1. blood vessel spasm

damaged vessel smooth muscle to contract slows or stops blood loss

plts release serotonin (vasoconstrictor)

2. plt plug forms plts become sticky forming plug over

damaged area

3. Coagulation forms hematoma/fibrinogen fibrin

Coagulation

when tissue damaged damaged cells release prothrombin activator (with Ca++)

prothrombin thrombin thrombin acts as enzyme to cause

fibrinogen fibrin fibrin traps plts & RBCs to form

hematoma (blood clot w/in vessel)

Coagulation Pathway

Clotting Animation

http://www.youtube.com/watch?v=--bZUeb83uU