BIO 222 Lecture1.Blood

BIO 222 Anatomy & Physiology 2

Distribution of body fluids in average adult Total body mass (female)

45% Solids.

55% Fluids.

Distribution of body fluids in average adult Total body mass (male)

40% Solids.

60% Fluids.

Total body fluid

Intracellular fluid (ICF).

Extracellular fluids (ECF).

Extracellular fluid

Interstitial fluid.

Blood plasma.

Interstitial fluid also includes

• Lymph.

• CSF.

• Synovial fluid.

• Aqueous and vitreous humor (eye).

• Pleural.

• Peritoneal.

• Pericardial fluids.

Water continuously exchanges between

Fluid compartments to help maintain osmotic balance between them.

General Properties of Blood

• ~38^oC.

• pH = 7.35-7.45.

• Bright to dark red (depending on oxygen content).

• ~5-6 L in average male/~4-5 in average female.

General Functions of Blood

• Transportation.

• Regulation.

• Protection.

Transportation

Transports gases like O2 and CO2, nutrients, regulatory substances (ex: hormones), waste, proteins, etc.

Regulation

Helps maintain homeostasis (pH, temperature, water content).

Protection

• Blood clotting.

• WBCs.

• Blood proteins (immunoglobulins, interferons [response to viruses], etc.).

BODY WEIGHT

Whole blood 8%.

Other fluids and tissues 92%.

VOLUME

BLOOD PLASMA 55%. A water extracellular matrix.

FORMED ELEMENTS 45%.

BLOOD PLASMA (weight)

Proteins 7%.

Water 91.5%.

Other solutes 1.5%.

FORMED ELEMENTS (number per uL).

PLATELETS 150,000-400,000.

WHITE BLOOD CELLS 5,000-10,000.

RED BLOOD CELLS 4.8-5.4 MILLION 99%.

SOLUTES

Proteins.

Albumins 54%.

Globulins 38%.

Fibrinogen 7%.

All others 1%.

Other solutes.

Electrolytes.

Nutrients.

Gases.

Regulatory substances.

Waste products.

WHITE BLOOD CELLS

Neutrophils 60-70%.

Lymphocytes 20-25%.

Monocytes 3-8%.

Eosinophils 2-4%.

Basophils 0.5-1.0%.

Substances in Blood Plasma

• Water (91.5%).

• Plasma proteins (7%).

• Albumins.

• Globulins.

• Fibrinogen.

• Other Solutes (1.5%).

• Electrolytes.

• Nutrients.

• Gases.

• Regulatory substances.

• Waste products.

Water (91.5%) Description

Liquid portion of blood.

Water (91.5%) Function

Solvent and suspending medium. Absorbs, transports, and releases heat.

Plasma proteins (7%) Description

Most produced by liver.

Plasma proteins (7%) Function

Responsible for colloid osmotic pressure. Major contributors to blood viscosity. Transport hormones (steroid), fatty acids, and calcium. Help regulate blood pH.

Albumins Description

Smallest and most numerous plasma proteins.

Albumins Function

Help maintain osmotic pressure, an important factor in the exchange of fluids across blood capillary walls.

Globulins Alpha

Transport.

Globulins Beta

Transport.

Globulins Gamma

Antibodies.

Globulins Description

Large proteins (plasma cells produce immunoglobulins). Other globulins [alpha, beta] made in liver.

Globulins Function

Immunoglobulins help attack viruses and bacteria. Alpha and beta globulins transport iron, lipids, and fat-soluble vitamins.

Fibrinogen Description

Large protein.

Fibrinogen Function

Plays essential role in blood clotting.

Other solutes (1.5%). Electrolytes Description

Inorganic salts; positively charged (cations) Na⁺ , K⁺ , Ca²⁺ , Mg²⁺ ; negatively charged (anions) Cl^- , HPO₄^2- , SO₄^2- , HCO₃^- .

Other solutes (1.5%). Electrolytes Function

Help maintain osmotic pressure and play esstionial roles in cell functions.

Other solutes (1.5%). Nutrients Description

Products of digestion, such as amino acids, glucose, fatty acids, glycerol, vitamins, and minerals.

Other solutes (1.5%). Nutrients Function

Essential roles in cell functions, growth, and development.

Other solutes (1.5%). Gases Description

Oxygen (O₂).

Carbon dioxide (CO₂).

Nitrogen (N₂).

Other solutes (1.5%). Gases Oxygen (O₂) Function

Important in many cellular functions.

Other solutes (1.5%). Carbon dioxide (CO₂) Function

Involved in the regulation of blood pH.

Regulatory substances Description

Enzymes.

Hormones.

Vitamins.

Regulatory substances Enzymes Function

Catalyze chemical reactions.

Regulatory substances Hormones Function

Regulate metabolism, growth, and development.

Regulatory substances Vitamins Function

Cofactors for enzymatic reactions.

Waste products Description

Urea, uric acid, creatine, creatinine, bilirubin, ammonia.

Waste products Function

Most are breakdown products of protein metabolism that are carried by the blood to organs of excretion.

Formed Elements in Blood - RBCs

• aka erythrocytes.

• Structure is designed for oxygen transport function.

Structure is designed for oxygen transport function

• Biconcave disc.

• Lack a nucleus & other organelles (including mitochondria).

• Strong, flexible membrane that allows them to squeeze through capillaries.

• Cytosol contains Hemoglobin (Hb) [1 cell = ~280 million].

Lack a nucleus & other organelles (including mitochondria)

Can’t reproduce or carry out major metabolic reactions.

Hb Key role

Transports oxygen (oxyhemoglobin).

Hb also has ability to bind

Carbon dioxide (carbaminohemoglobin).

More on RBCs – Erythropoiesis

• Production of RBCs in the red bone marrow with a cell called a proerythroblast.

• Proerythroblasts →reticulocytes (no nucleus; some mitochondria & other organelles)→ enter blood stream.

• Reticulocytes become mature RBCS (1-2 days after entering blood stream).

• Typically, rates of RBC destruction & erythropoiesis are relatively equal.

Production of RBCs in the red bone marrow with a cell called a

Proerythroblast.

Reticulocytes become

Mature RBCS (1-2 days after entering blood stream).

More on RBCs – the Life Cycle

• Only live ~120 days (remember no nucleus/organelles).

• Old RBCs broken down and parts are recycled.

Hemoglobin develops in cells in the bone marrow that become red blood cells. When red cells die, hemoglobin is broken up:

Iron is salvaged, transported to the bone marrow by proteins called transferrins, and used again in the production of new red blood cells; the remainder of the hemoglobin forms the basis of bilirubin, a chemical that is excreted into the bile and gives the feces their characteristic yellow-brown color.

Hematocrit

Percentage of blood volume that is occupied by RBCs.

Hematocrit

• Females = 38-46% (average 42).

• Males = 40-54% (average 47).

Males = 40-54% (average 47).

• Testosterone = hormone that stimulates erythropoietin production.

• Erythropoietin = hormone that triggers RBC production.

Testosterone

Hormone that stimulates erythropoietin production.

Erythropoietin

Hormone that triggers RBC production.

Anemia

Lower than normal level of RBCs.

Anemia Multiple causes

• Iron deficiency.

• Vitamin B12 deficiency.

• Blood loss, etc.

Polycythemia

Abnormally high levels of RBCs (>64%).

Induced polycythemia

Blood doping by athletes.

How the body responds when oxygen delivery to tissues decreases

Cellular oxygen deficiency = HYPOXIA (usually because of high altitudes, anemia (low RBC levels), or circulatory problems.

STIMULUS.

CONTROLLED CONIDITON.

RECEPTORS.

Input.

CONTROL CENTER.

Output.

EFFECTORS.

RESPONSE.

Return.

STIMULUS.

CONTROLLED CONIDITON.

RECEPTROS.

Input.

CONTROL CENTER.

Output.

EFFECTORS.

RESPONSE.

Return.

STIMULUS

Disrupts homeostasis by decreasing.

CONTROLLED CONDITION

Oxygen delivery to kidneys (and other tissues).

RECEPTORS

Kidney cells.

Input

Detect low oxygen levels, increasing erythropoietin secretion into blood (a hormone).

CONTROL CENTER

Proerythroblasts in red bone marrow mature more quickly into reticulocytes.

Output

More reticulocytes enter circulating blood.

EFFECTORS

Larger number of red blood cells in circulation.

RESPONSE

Increased oxygen delivery to tissues.

Return

To homeostasis when oxygen delivery to kidneys increases to normal.

Cellular oxygen deficiency

HYPOXIA

Sickle Cell Disease

• The RBCS have an abnormal Hb called HB-S.

• HB-S causes the RBC to bend into a sickle shape.

• These sickle cells lyse at a rate far greater than erythropoiesis (the cells die within 10-20 days).

• Symptoms = shortness of breath, paleness, fatigue

Sickle Cell Disease Symptoms

Shortness of breath.

Paleness.

Fatigue.

Formed Elements in Blood - WBCs

• aka leukocytes.

• Have nuclei and organelles.

• NO Hb (bc their role is not to transport oxygen).

• Function: Combat inflammation and infection (immune response).

• Can live for hours or days – & some for years (lymphocytes).

• Generally classified as GRANULAR or AGRANULAR.

Granular

• Neutrophils.

• Eosinophils.

• Basophils.

Agranular

• Lymphocytes.

• Monocytes.

Granular Leukocyte

• Neutrophil (aka polymorphonuclear leukocytes or PMNs) (aka segs [because of segmented nucleus]).

• Eosinophil.

• Basophil (least numerous of the WBCs).

Granule Neutrophil

• Smallest.
• Evenly distributed.
• 3 types of granules (involved in defense).
• Stain lilac color.

Granule Eosinophil

• Larger than neutrophil.

• Stain Reddish-orange.

Granule Basophil

• Largest.
• Stain dark blue/purple.

Nucleus Neutrophil

• 2-5 lobed (some texts say 3-5 lobes).
• (number increases as cell ages).

Nucleus Eosinophil

2-3 lobes.

Nucleus Basophil

2 lobes (usually obscured by the granules).

General function Neutrophil

• Typically first cell to respond.

• Defend against bacteria, fungi, foreign substances, etc.

• Phagocytosis.

General function Eosinophil

• Connected to allergic reactions.

• Connected to parasitic infections (attach to parasite & use enzymes to kill it).

• Phagocytosis.

General function Basophil

Connected to allergic reactions- release histamine.

Agranular Leukocyte Lymphocyte

• Most common agranular!

• T cells, B cells, natural killer cells.

• Have unique surface markers that help define their functions

Agranular Leukocyte Monocyte

• Migrate into tissues & mature into macrophages.

• Macrophages become “fixed” or “wandering”.

Nucleus Lymphocyte

Slightly indented

Nucleus Monocyte

Larger indention (kidney or horseshoe shaped).

Function Lymphocyte

• Described as “main functional cell of the immune system”.

• B cell = differentiate to form plasma cells = produce antibodies [aka immunoglobulins]= (humoral immunity).

• T cell = helper Ts & cytotoxic.

• Helper = activate other immune cells.

• Cytotoxic = involved in cell-mediated immunity.

• Natural Killer = involved in innate immunity (recognizes any non-self cells); destroy foreign cells.

B cell

Differentiate to form plasma cells = produce antibodies [aka immunoglobulins]= (humoral immunity).

T cell

Helper Ts & cytotoxic.

Helper

Activate other immune cells.

Cytotoxic

Directly attacks infected cells.

Natural Killer

Involved in innate immunity (recognizes any non-self cells); destroy foreign cells.