Chapter 19 Flashcards
7 ways blood helps maintain homeostasis
1) transport gases, nutrients, and waste products
2) transport of processed molecules
ex. Vitamin D produced in skin, transported to liver by blood
3) transport of regulatory molecules (enzymes&hormones)
4) regulation of pH & osmosis
5) reg of temp
6) protect against foreign substances
7) clot formation
Normal pH range in body
7.35-7.45
Define blood
Connective tissue consisting of liquid matrix containing cells and fragments
Facts about blood
Female adult has 4-5 L
Male adult has 5-6 L
Blood makes up 8% body weight
% of plasma and formed elements in blood
55% plasma, 45% formed elements
Plasma composition
Mostly water, 7% protein
Where is formed elements originated from
Red bone marrow
Formed elements
Red blood cells, white blood cells, platelets
Colloid
Liquid containing suspended substances that do not settle
3 major proteins in plasma
Albumin, globulins, fibrinogen
Albumin
Regulates water movement between tissues and blood, maintains blood colloid osmotic pressure
Globulins
Transport many substances, ex is antibodies
Fibrinogen
Forms blood clots
Serum
Plasma without clotting factor
Formed elements derived from
Hemocytoblasts
Hemocytoblasts give rise to 2 stem cells
Myeloid and lymphoid
Myeloid stem cells give rise to
RBC platelets and WBC
Lymphoid stem cells give rise to
Lymphocytes
Erythropoiesis
Production of red blood cells
- kidneys produce erythropoietin to stimulate*
- takes about 4 says*
Red blood cells contain
Hemoglobin and anhydrase
Hemoglobin molecule contains
4 heme and 4 globin molecules
- heme transport O2
- globin transport CO2
Iron required for O2 transport
Carbonic anhydrase involved w CO2 transport
Describe erythropoiesis production
1) stem cells in red bone marrow create erythroblasts
2) erythroblasts loose nuclei and are released into blood as reticulocytes
3) loss of ER produces RBC
Function WBC
Protect against microorganisms and remove dead cells/debris
5 types of WBC
1) Neutrophils
2) Eosinophils reduce inflammation
3) Basophils release histamine&involved w/increasing inflammation response
4) lymphocytes, produce antibodies
5) monocytes leave blood, enter tissue and become macrophages
Platelets
(Thrombocytes) cell fragments pinched off from megakaryocytes in red bone marrow
Platelet plug formation
- platelet adhesion: platelets bind to collagen in damaged tissue
- platelet release action: chem for more platelets
- platelet aggregation: form plug by binding
Steps of coagulation
1) extrinsic or intrinsic pathways produce activated factor C
* extrinsic: damaged tissue releases thromboplastin
* intrinsic: activate factor XII
2) factor X/ factor V/ phospholipids/ Ca2+ form prothrombinase
3) prothrombinase converts prothrombin into thrombin
4) thrombin converts fibrinogen into fibrin (fibrin forms clots)
What inhibits thrombin?
Heparin and antithrombin
What counteracts effects of thrombin
Prostacyclin
Clot retraction
Platelets pulls edges of damaged tissue together
3 characteristics of WBC
Ameboid movement: WBC more directed movement instead of only w flow of blood
Diapedesis: thin&elongated&slip through cell walls, can leave blood&enter tissue
Chemotaxis: attracted to dead cells&phagocytize, pus is dead WBC&bacteria
Hemolysis
When RBCs rupture, takes 110-120 days
hemoglobin in plasma broken down by macrophages
