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Human A&P BIO 304 · American River College ← Week 6 pre-work hub

BIO 304 · Human Anatomy & Physiology

Blood Composition & Hemopoiesis

Blood · Module 10

A reference for the Blood Composition video. Blood is the only fluid connective tissue: cells suspended in plasma. Plasma carries dissolved everything; the formed elements transport gases, fight infection, and stop bleeding.

How to use this sheet Toggle the toolbar above. Notes prints the full reference for review. Study prints as a fill-in-the-blank worksheet , print it, then write each definition while you watch the video or read your book. Quiz me is on-screen typing practice; type the term, click Reveal to check yourself.

Open spaced recall
By the end
  1. Identify the components of plasma and the three categories of formed elements.
  2. Distinguish the five types of leukocytes by appearance and function.
  3. Describe hemopoiesis from hematopoietic stem cell to mature blood cell.
Anterior view of the body and face labeled with upper-body regions: cranial, frontal, orbital, nasal, buccal, oris, mental, cervical, acromial, deltoid, axillary, brachial, antecubital, antebrachial, carpal, digital, mammary, sternal, abdominal, umbilical.
Anterior · upper body & face
Anterior view of the body labeled with lower-body regions: pelvic, inguinal, pubic, coxal, pollex, femoral, patellar, fibular, crural, tarsal, plantar, digital toes, and hallux.
Anterior · lower body
Posterior view labeled occipital, cervical, scapular, vertebral, lumbar, sacral, glu#0B1530, femoral, popli#0B1530, sural, tarsal, calcaneal; lateral head view labeled otic, buccal, occipital, cervical.
Posterior & lateral head

Click any image to enlarge.

Plasma & Formed Elements

Plasma (~55% of blood)

  • Water (~92%)solvent for everything else
  • Albuminmost abundant plasma protein; sets oncotic pressure; carries hormones, drugs
  • Globulinsalpha/beta carriers + gamma (antibodies)
  • Fibrinogenclotting precursor; becomes fibrin in clots
  • ElectrolytesNa+, K+, Cl-, HCO3-, Ca²⁺
  • Nutrients, wastes, gases, hormonesdissolved transit cargo

Formed elements (~45%)

  • Erythrocytes (RBC)4-6 million/µL; biconcave disc; no nucleus; carries O₂ via hemoglobin
  • Leukocytes (WBC)4,500-11,000/µL; nucleated; immune defense
  • Platelets (thrombocytes)150,000-400,000/µL; cell fragments; clotting

Erythrocyte details

  • Hemoglobinfour globin chains + four heme groups; each binds one O
  • Lifespan~120 days; recycled in spleen
  • Biconcave discincreases surface area; flexible for capillaries
  • Bilirubinbreakdown product of heme; excreted in bile

WBCs & Hemopoiesis

Granulocytes

  • Neutrophilmost numerous WBC (50-70%); multi-lobed nucleus; first responder; bacterial phagocyte
  • Eosinophil1-4%; bilobed nucleus; pink granules; parasites + allergies
  • Basophil<1%; deep blue granules; releases histamine + heparin; allergic response

Agranulocytes

  • Lymphocyte20-40%; large round nucleus, little cytoplasm; T cells, B cells, NK cells
  • Monocyte2-8%; largest WBC; kidney-shaped nucleus; becomes tissue macrophage

Mnemonic

  • Never Let Monkeys Eat Bananasorder of WBC abundance: Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils

Hemopoiesis

  • Site (adult)red bone marrow of axial skeleton + proximal limb bones
  • Hematopoietic stem cell (HSC)pluripotent; gives rise to all blood cells
  • Myeloid lineageRBCs, platelets, granulocytes, monocytes
  • Lymphoid lineageT cells, B cells, NK cells
  • Erythropoietin (EPO)kidney hormone; drives RBC production in response to low O₂
  • Thrombopoietinliver/kidney; drives platelet production
Dr. Sharilyn Rennie BIO 304 · Module 10 · Blood Composition