Blood

Chapter 12

Introduction

Essential for transport of substances between body cells and external environment

More than just a liquid Blood cells Carbohydrates Proteins Lipids

Blood

General facts Adult males have 6 qts of blood (1.5 gal) Adult females have closer to 3.5 qts (.8

gal) Helps maintain homeostasis

Ion and water transport throughout the bodyHeat distributionMovement of food

Parts of Blood

Plasma Approx. 55% by volume Mostly water Also find proteins, carbs, hormones,

vitamins, and cellular waste here

Parts of Blood

Formed elements AKA: Hematocrit The other 45% of blood volume The cellular parts of blood

Red Blood CellsWhite Blood CellsPlatelets

*All three are formed in red bone marrow

Blood Cells

Red Blood Cells

Blood Cells

Red Blood Cells AKA: Erythrocytes Shape = biconcave discs

Increases surface area for better O2 uptakeHelps RBCs squeeze through small vessels

When mature, RBCs lack a nucleus Live about 120 days

Blood Cells

Red Blood Cells Why Red???

Contain hemoglobin proteinHemoglobin has iron in itHemoglobin has a high affinity for oxygenWhen iron and oxygen combine you get a red

color

Blood Cells

The color of blood Healthy individuals = pink Individuals with breathing problem = blue

When you don’t get enough O2 to your tissues = hypoxiaHypo - belowOx - oxygen

The blue color is called cyanotic

Blood Cells

Red Blood Cell Count The number of RBCs in a mm3 of blood Primary function of RBCs = carrying

oxygen from the lungs to the body Red blood cell count is tied closely with

blood’s oxygen-carrying capacity Too few RBCs or too little iron for the

hemoglobin in RBCs = anemia

Blood Cells

Red Blood Cell Production Happens in the red bone marrow Controlled through a Negative feedback

mechanismReceptor = Liver sensing a lack of oxygenEffector = Liver producing hormone

erythropoietinEffect = Bone marrow responds by producing

more RBCs

Blood Cells

Red Blood Cells Sickle-Cell Anemia

Genetic disorderHemoglobin is misshapenRBCs are stiff and don’t

pass through vessels easily.

Blood Cells

White Blood Cells AKA: Leukocytes Major part of immune system Two major groups

Granulocytes - have granules in cytoplasm Neutrophils - eat bacteria Eosinophils - kill parasites Basophils - control blood flow to infected area

Agranulocytes - no grains in cytoplasm Monocytes - eat bacteria Lymphocytes - produce antibodies (proteins) that

attach to and destroy foreign bodies

Granulocyte

Blood Cells

Platelets AKA: Thrombocytes Not complete cells; fragments Life span of about 10 days Major component of blood clotting

Blood Cells

Leukemia Cancer affecting leukocytes Excessive number of WBCs are produced

WBCs are immatureCan’t fight infection

Extra WBCs crowd out platelets and RBCsLeukemia patients often bruise easilySome suffer from anemia

Treatments include chemotherapy, radiation, or even bone marrow transplant

Plasma

92% waterPlasma Proteins

Globulins - help transport lipids and fat-soluble vitamins

Fibrinogen - used in clot formation (discussed later)

Albumins - help hold water in the vessels

Plasma

Carries Nutrients Glucose

Absorbed by intestinesTransported to cells for energy……or to liver for storage as glycogenRemember homeostatic mechanism from Ch1

Amino acidsTaken to liver for storage or breakdown into

energy-rendering molecules

Plasma

Carries Nutrients Lipids

Excellent source of energyHydrophobic (problem???)Must combine with globulins to be transported

Form a complex called a lipoprotein

Plasma

Carries Nutrients Cholesterol levels

Dieticians recognize different types of lipids in the blood

Low-density lipids (LDL) Primarily cholesterol with little protein “Bad” cholesterol

High-density lipids (HDL) Little cholesterol with large protein molecule “Good” cholesterol

Plasma

Carries Nutrients Waste

Urea (primary component of urine) and carbon dioxide dissolve in plasma

ElectrolytesA term that refers to any salt (ion) dissolved in

plasmaIncludes sodium, calcium, phosphate,

potassium, etc…

When you get cut

Hemostasis is the stoppage of bleedingThree steps

Blood vessel spasms Platelet plug formation Coagulation

Hemostasis

Blood vessel spasm Small vessels contract when damaged Platelets release serotonin, contracting

smooth muscles Short term fix. Waiting for a platelet plug to

form…Platelet Plug

Platelets stick to rough surface at break All that is needed in small cuts

Hemostasis

Coagulation End result = a full blood clot (scab) Clotting factors in blood

Some promote coagulationOthers inhibit it (these dominate when no cut)

Two factors you need to know (and their function)Fibrinogen / FibrinProthrombin / Thrombin

Blood Clot Flow Chart (pg 316)

Hemostasis

Coagulation Normally, blood doesn’t clot in healthy

vesselsMoving to fast to form clot

An abnormal blood clot in a healthy vessel is called a thrombus

If a thrombus dislodges and moves through vessels = embolus

Hemophilia Genetic condition in which one or more of

the clotting agents are damaged.

Blood Types

There are four different blood groups in the human population Type A Type B Type AB Type O

Different based on antigens found on RBCs.

Blood Types

Type A blood = A antigens on RBCsType B blood = B antigens on RBCsAB = ?O = ?

Agglutination

Agglutination is the clumping of RBCs following an improper blood transfusion Results in major complications Can be fatal

Caused by response by immune system

Agglutination

When you are born, lymphocytes produce antibodies that recognize foreign invaders

Individuals with Type A blood have antibodies that recognize (and clot) Tyep B blood Anit-B antibodies

Type B blood have anti-A antibodiesLock and Key recognition

Blood Types

Rh Types

Named after the rhesus monkey, in which it was discovered

Humans are either Rh+ or Rh-Individuals who are Rh+ have antigens

on their RBCs. You DO NOT make antibodies for this

antigen at birth Must be exposed to the antigen…then

make the antibody

Rh Type & Pregnancy