Blood & Heart Flashcards

Appendicular Muscles

• Muscles that move:
  • Hip joint/thigh (posterior compartment)
  • Knee joint/leg
  • Leg & foot

Surface Anatomy

• Head
• Neck
• Trunk
• Shoulder & upper limb
• Lower limb

Review

• Quiz 3 was a review.

Important Dates

• Quiz 4 is on 6/11
• Last day to withdraw from course with a W grade is 6/12
• Exam 2 & practical 2 are on 6/16
  • Study guide for exam 2 posted on 6/8.

Topics Covered

• Blood intro
• Composition & function of blood
• Formed elements in blood:
  • Erythrocytes
  • Leukocytes
  • Platelets
• Hematopoiesis
• Blood disorders
• Cardiovascular system & heart
• Heart anatomy:
  • Pericardium
  • Heart wall

Blood Function

• Transports substances throughout the body.
• Carries molecular evidence of body activities.
• Essential for clinical assessment.
• Used to screen for:
  • Disease
  • Substance abuse
  • Nutritional status
  • Pregnancy

Blood Properties

• Fluid connective tissue.
• Viscosity is 4 times that of water.
• Runs hotter than body temperature by about 1°C.
• Blood volume:
  • Females: 4-5 liters
  • Males: 5-6 liters

Composition of Whole Blood

• Plasma:
  • Yellowish liquid.
  • Upper layer.
  • Approximately 55% of blood sample.
• Buffy coat:
  • Thin, gray-white layer.
  • Contains leukocytes and platelets.
  • Less than 1% of blood sample.
• Erythrocytes (red blood cells):
  • Lower layer.
  • Approximately 44% of blood sample.

Blood Sample Processing

1. Withdraw blood and place in tube.
2. Centrifuge blood sample to separate components.

• Plasma: 55% of whole blood, least dense component.
• Buffy coat: Leukocytes & platelets, less than 1% of whole blood.
• Erythrocytes: 45% of whole blood, most dense component.

Functions of Blood

• Transportation:
  • Respiratory gases (O2 & CO2)
  • Nutrients
  • Waste products of cells & organs
  • Hormones
• Regulation:
  • Temperature
  • pH
  • Fluid levels
• Protection:
  • Leukocytes & immune response
  • Antibodies
  • Clotting (platelets & plasma proteins)

Composition of Blood Plasma

• Approximately 92% water.
• Contains over 100 solutes:
  • Proteins (~7% of plasma):
  • Albumin
  • Globulins
  • Clotting proteins (fibrinogen)
  • Serum = plasma – clotting proteins
  • Regulatory proteins
  • Nonprotein nitrogenous wastes: lactic acid, urea, creatinine
  • Organic nutrients: glucose/carbohydrates, amino acids, fats
  • Electrolytes (ions): sodium, potassium, calcium, chloride, bicarbonate
  • Respiratory gases: O2 & CO2

Formed Elements in the Blood

• Erythrocytes (99%; transport O2 & CO2)
• Leukocytes (0.01%; immune response)
• Platelets (1%; clotting)

Hematocrit

• Percentage of volume of all formed elements in blood.
• Varies with sex and age.
  • Newborns: 42-68%
  • Males: 42-56%
  • Females: 38-46%
• Affected by altitude.

Production and Characteristics

• Produced in bone marrow.
  • Erythrocytes & platelets are not true cells.
  • RBCs lack nuclei & organelles, & platelets are cell fragments.
  • Cannot divide.
  • Survive in bloodstream for a short time (few hours to months) before being replaced or broken down & recycled.
• Staining of blood cells (Wright’s stain):
  • Acidic dye – eosin; stains pink.
  • Basic dye – methylene blue; stains blue & purple.

Types of Formed Elements

• Platelets
• Erythrocytes
• Monocyte
• Neutrophils
• Lymphocyte

Erythrocytes

• RBCs are manufactured continuously in bone marrow of pelvis, skull, ribs, vertebrae, & ends of long bones.
• Before release from bone marrow, RBCs lose their nucleus & synthesize hemoglobin.
• Contain plasma membrane protein spectrin.
  • Give erythrocytes their flexibility.
  • Allow them to change shape.
• Life span is ~120 days.

Erythrocyte Characteristics

• Oxygen-transporting cells.
• Most numerous formed element.
  • Females: 4.3-5.2 million cells/cubic millimeter.
  • Males: 5.2-5.8 million cells/cubic millimeter.
• No organelles or nuclei.
• Ideal measuring tool for estimating sizes of nearby structures.

Hemoglobin

• Dedicated to respiratory gas transport.
• Cytoplasm packed with hemoglobin.
• Hemoglobin reversibly binds with oxygen.
• Composed of 4 polypeptide chains called globins.
  • 2 alpha & 2 beta chains.
  • Each chain contains a heme group.
• Heme group has iron atom which binds to 1 oxygen molecule.
• Hemoglobin can transport 4 molecules of oxygen.
• Oxidation of iron on hemoglobin gives blood its red color.

Hemoglobin Structure

• (a) Hemoglobin - showing polypeptide chains.
• (b) Iron-containing heme group.

Function of Erythrocytes

• Pick up O2 at lung capillaries & distribute O2 throughout body.
• Release O2 across other tissue capillaries.
• Structural characteristics contribute to respiratory function:
  • Biconcave shape → 30% more surface area.
  • 97% hemoglobin.
  • Lack mitochondria.
  • Do not consume O2; they pick it up.

Leukocytes

• Far less numerous than RBCs: 4,500–11,000/cubic millimeter.
• Complete cells, with organelles & nuclei.
• Protect body from infectious microorganisms; fight infections.
• Function outside bloodstream in loose connective tissue.
• Chemotaxis: Chemicals attract circulating WBCs to infection sites.

Diapedesis

• Leave capillaries/vessels by squeezing between endothelial cells.
• Once in loose connective tissue, they move by amoeboid motion.

Origin and Function

• Originate in bone marrow & are released continuously into the blood.
• Bone marrow also stores WBCs & releases them in mass during a serious infection.
• WBC count – marker for infectious disease.
  • A count exceeding 11,000 per cubic mm indicates infection or inflammation – leukocytosis.

Types of Leukocytes

• White blood cells are usually larger than red blood cells (contain a nucleus).
• Appear translucent/white without staining.
• 5 types divided into 2 classes:
  • Granular leukocytes – contain granules in cytoplasm & have a lobed nucleus:
  • Neutrophils
  • Eosinophils
  • Basophils
  • Agranular leukocytes – lack granules & have a circular or indented nucleus:
  • Monocytes
  • Lymphocytes

Granular Leukocytes

• Neutrophils, eosinophils, & basophils.
  • Contain cytoplasmic granules that stain specifically (acidic, basic, or both) with Wright’s stain.
  • Are larger & usually shorter-lived than RBCs.
  • Have lobed nuclei.
  • Are all phagocytic cells.
  • Make up 1% of total blood volume.

Neutrophils

• Have 2 types of granules that:
  • Take up both acidic & basic dyes.
  • Give cytoplasm a lilac color.
  • Contain peroxidases, hydrolytic enzymes, & defensins (antibiotic-like proteins).
• Neutrophils are body’s bacteria slayers.
• Account for ~50-70% of WBCs.

Eosinophils

• Account for 1–4% of WBCs.
  • Have red-staining, bilobed nuclei connected via a broad band of nuclear material.
  • Have reddish or pink-orange (acidophilic) large, coarse, lysosome-like granules.
  • Lead body’s counterattack against parasitic worms.
  • Lessen severity of allergies by phagocytizing immune complexes.

Basophils

• Account for 0.5-1.0% of WBCs &:
  • Have U- or S-shaped nuclei; usually bilobed.
  • Are functionally like mast cells.
  • Have large, blue-violet (basophilic) granules that contain histamine.
    Histamine – inflammatory chemical that acts as a vasodilator & attracts other WBCs (antihistamines counter this effect).

Agranular Leukocytes

• Lymphocytes & monocytes:
  • Lack visible cytoplasmic granules.
  • Are similar structurally, but are functionally distinct & unrelated cell types.
  • Have spherical (lymphocytes) or kidney-shaped (monocytes) nuclei.

Monocytes

• Account for ~2–8% of leukocytes.
  • Are the largest leukocytes.
  • Have abundant pale-blue cytoplasm.
  • Have purple-staining, C- or folded kidney-shaped nuclei.

Monocyte Differentiation

• After ~3 days in circulation, monocytes leave blood vessels, enter tissue, & differentiate into macrophages.
  • Are highly mobile & actively phagocytic.
  • Activate lymphocytes to mount an immune response.

Lymphocytes

• Account for 20-40% of WBCs &:
  • Have large, dark-purple, circular nuclei with a thin rim of blue cytoplasm.
  • Are found mostly enmeshed in lymphoid tissue (some circulate in blood).
• There are 2 types of lymphocytes: T cells & B cells.
  • T cells function in immune response.
  • B cells give rise to plasma cells, which produce antibodies.