Biology 2213 Review Sheet for Test #2 Dr. James Adams
Chapter 17: Blood
-- a Connective Tissue
Matrix (plasma): 55% of blood volume (with dissolved fibrous proteins)
Cells (formed elements): 45% of blood volume
I. Distribution -- O2, nutrients, hormones
II. Regulation -- body heat, fluid volume, pH
III. Protection -- Platelets (blood loss), WBC=s, antibodies, complement
Matrix -- Plasma: 90% water, 10% solutes (wide variety, including albumins;
Table 17.1, pg. 633); osmolarity quite constant.
Formed Elements: All come from stem cells (hemocytoblasts)
in red bone marrow
I. Erythrocytes (red blood cells, RBC=s) -- carry O2; lack all organelles, including nucleus;
hemoglobin (Hb) makes up 33% of cell mass; >95% of formed elements (major
contributor to viscosity of blood). Hematocrit.
Production (hematopoiesis): in red blood marrow (where in adults?); mature in 3-5
days (from reticulocytes); production/destruction remarkably constant (±two
million per second turnover)
Hormonal (erythropoietin [from kidney -- WHY?], testosterone) and nutrient
(organics, iron, B-vitamins) requirements for production.
RBC's in turn destroyed in spleen/liver/ bone marrow (100 - 120 day lifespan). Hb
turnover rapid as well -- iron must be stored/transported for reuse; rest of heme
destroyed and eliminated.
RBC disorders: Anemias (know pernicious, sickle-cell), polycythemia (blood doping)
II. Leukocytes (white blood cells, WBC=s) -- major immune system cells; production
(of some) dramatically increases with infection/injury
Types: (Most to least numerous: N, L, M, E, B) -- recognize these for lab practical
1. Neutrophils: active bacterial and fungal phagocytes
2. Basophils (& mast cells): release heparin/histamines
3. Eosinophils: respond to allergic inflammation and macroendoparasites
1. Lymphocytes: T- mature in thymus; attack virus-infected/tumor cells
B- produce antibodies
2. Monocytes (macrophages)
Production (leukopoiesis): in red bone marrow; hormonal control: colony-stimulating
factors (CSF=s) released by several cell types; granulocytes stored in red bone
marrow, short life-spans; agranulocytes in lymphoid tissues, with long life-spans.
Must know myeloid and lymphoid stem cells, and which WBC's come from them.
WBC disorders: Leukemia (cancerous), mononucleosis (viral)
III. Thrombocytes (platelets [not true cells]) -- fragments of megakaryoblasts; form platelet
plug during clotting (to be discussed, below)
Production: thrombopoietin (produced by the liver)
Hemostasis/Maintenance of blood flow (stoppage of blood flow through wound)
1. vascular spasms -- damaged blood vessels constricts, for several reasons
2. platelet plug formation -- platelets stick to damaged tissue edges, release chemicals
(see below), which induce more platelets to stick; also promote a wide variety
of other clot enhancing phenomena, including vascular spasms and coagulation.
3. Coagulation (clotting) -- a cascade of events (see book), many involve Ca+2.
Vitamin K involved in making several clotting proteins in the liver.
Two pathways (intrinsic and extrinsic) -- see Fig. 17.14, pg. 648.
Complete in 3-6 minutes.
Clot Retraction: platelets contract (actin/myosin); pull edges of wound together
Fibrinolysis: clot removal after tissue repair
Chemicals to know involved in clotting/retraction/fibrinolysis: thromboplastin,
(pro-)thrombin, fibrin(-ogen), plasmin(-ogen), thromboxane, ADP, prostacyclin,
antithrombin, heparin, histamine, tissue-plasminogen activator, PDGF, PF, TF
Must be able to identify what cells release these and what they do.
I. Thromboembolytic disorders: persistent clots (thrombus, embolus)
2.. Bleeding disorders: Thrombocytopenia (red. platelet #), liver damage, hemophilia
Transfusions and Blood Groups: A/B Antigens (agglutinogens) and anti-A &
antibodies (agglutinins; unique because they are produced without exposure to antigens)
Blood types; who is universal donor/acceptor, and why?
Rh blood groups
Diagnostic Blood tests: blood is the most frequently tested tissue of the body -- WHY?
Chapter 18: Heart A & P
Heart (the transport system pump); in mediastinum
ANATOMY: See also "Circulatory System Structures -- to know" sheet for lab
Landmarks: Apex/base; ant/post intervent sulci; atriovent sulcus
Covering: visceral (epicardium)/parietal pericardium (serous); fibrous pericardium.
Heart Wall: epicardium/mycardium/endocardium (simple squamous)
Chambers, valves and associated vessels: Know right and left atria and ventricles,
fossa ovalis, interatrial/interventricular septa; trabeculae carneae, papillary muscles,
chordeae tendineae; superior/inferior vena cavae, pulmonary trunk, pulmonary
arteries and veins, aorta; atrioventricular [tricuspid and bicuspid (mitral) valves],
pulmonary and aortic semilunar valves; pectinate muscles
Systemic/pulmonary circuits (know where oxygenated and deoxygenated)
( Simplified diagram of flow ) (will be handed out in class)
Cardiac circulation: right coronary artery, its branches -- marginal artery, posterior
interventricular artery (in posterior interventricular sulcus); left coronary artery, its
branches -- anterior interventricular artery (in anterior interventricular sulcus) and
PHYSIOLOGY: Cells (described under tissues) called fibers, with intercalated disks,
lots of mitochondria. Most of heart a functional syncytium.
Membrane potential (from chap 2); Na+, K+, Cl-, A.A.-; action potential (from chap 11)
Cardiac muscle contraction: ("fast") Na+ channels involved, as is typical for AP, but "slow"
Ca++ channels also involved (Ca++ also enters from extracellular fluids), increases
refractory period; makes tetany virtually impossible. Actual contraction typical of
muscle -- Ca++ release from SR, binds to troponin . . . (as in chap 9)
Nodal conduction system: autorhythmic cells-- use fast Ca++ channels for depolarization
sinoatrial (SA) node (the pacemaker); atrioventricular (AV) node (delays impulse so
atria contract before ventricles).
Fig. 18.15, Page 675 (and handout): Atrioventricular bundle, R & Lbundle branches,
and Subendocardial conducting network (Purkinje fibers) distribute impulse to walls of
ventricles synchronously, with papillary muscles contracting just ahead of rest of
ventricles to tighten chordae tendineae.
Nodal system determines synchronicity of heartbeat
External (ANS, hormonal) stimulation required to accelerate/decelerate
heart rate (H.R.)
Cardiac centers in medulla oblongata -- see Fig. 18.16, page 677.
Sympathetic nervous system (including adrenal gland): release norepinephrine (also
called noradrenalin) -- speeds H.R.
Parasympathetic (mainly vagus nerve): releases acetylcholine -- slows H.R.
Cardiac cycle: systole and diastole, with associated heart sounds (valves);
sequence of events
Cardiac output (C.O.): (stroke volume) x (heart rate)
[S.V. x H.R.]
Frank Starling Law
Regulation of C.O.: autonomic nervous system controls, hormonal controls (thyroxine,
epinephrine), ions, physical factors (age, gender, etc.). All, of course, influence
blood pressure as well.* (see below)
Chapter 19: Vessels
60,000 miles of vessels in the body; arteries/veins just conduits, exchange in caps.
Walls of vessels three-layered:
1. tunica intima (interna) -- endothelium (simp. squam.); slick, continuous with
endocardium; sparse conn. tissue basement membrane
2. tunica media -- circularly arranged smooth muscle, w/vasomotor nerve fibers, and
elastin fibers; partly regulates blood flow/pressure (vasodilation/-constriction);
biggest in big arteries, non-existent in capillaries/small veins
3. tunica adventitia (externa) -- loosely woven collagen with nerves/smaller vessels
(vaso vasorum, branch into tunica media as well)
Arteries: blood away from heart
1. Elastic -- large lumen; closest to heart; withstands large pressure fluctuations, and
act as auxilliary pumps; arterial pulse
2. Muscular -- small to medium-sized; carry blood to specific organs
3. Arterioles -- diameter <.5mm; smaller lose tunica adventitia; fine control of blood
flow here, with precapillary sphincters
Capillaries: tunica intima (endothelium) only
1. Continuous capillaries -- blood-brain barrier; skin; muscles, etc.. Numerous
2. Fenestrated capillaries -- pores increase permeability; mucosa of intestine,
glomerulus in kidney; hypothalamus; many other places.
3. Capillary sinuses -- sluggish flow allows cleaning by special phagocytes
Thoroughfare channels and capillary beds
Veins: Low pressure
1. Venous sinuses -- flattened endothelium only (intracranial [dural sinuses], coronary)
2. Venules -- no tunica media, except in largest; shunt blood to veins
3. Veins -- all layers (tunics), but thinner (particularly media), with larger lumen than
arteries; up to 65% of blood in veins at one time (blood reservoirs)
Because of low pressure, have modifications to aid in blood movement:
one way valves, large lumen (low resistance), respiratory/muscular "pumps"
Vascular Anastomoses -- more common between veins
Physiology of Circulation: blood flow, flow velocity (rate), blood pressure, resistance
Resistance: greatest in small diameter vessels (most friction), especially arterioles
hence, most resistance peripheral (P.R.)
Systemic blood pressure (B.P.): greatest at heart, highest at systole (lower with diastole),
declines further from heart, near zero at vena cavae -- pressure gradient
*Factors affecting B.P.: cardiac output (see
above), blood volume, peripheral resistance
Regulation of B.P.: anything that influences the above factors influence B.P.
1. neural controls: sympathetic/parasympathetic stimulation
2. neural control units: vasomotor center (in medulla)/fibers, presso-(baro-)receptors,
chemoreceptors, higher brain centers (emotional, etc.)
3. chemical controls: O2, CO2, pH, hormones (adrenal, ANF, ADH, NO)
4. renal regulation: involves ANF, ADH, aldosterone, renin/angiotensin
For summary of effects of different factors on smooth muscle in the walls of
blood vessels, see
Fig. 19.15, page 714.
Flow rate (velocity): fastest in large arteries, slowest in capillaries (largest cross-sectional
area), faster again in veins. This is exactly what you would want -- WHY?
Blood Flow to special areas (specific organs); at rest and during exercise
autoregulation: metabolic & myogenic controls; know basics of these mechanisms.
Capillary fluid dynamics: fenestrated capillaries
involves hydrostatic pressure (on plasma) forcing fluid out and osmotic pressure (due
to concentrated plasma solutes [particularly albumins] left behind) pulling fluid back in.
Not all fluid leaving a fenestrated cap bed at arteriole end returns at venule end --
explains need for another fluid "pick up" system -- the Lymphatic system (next test!).
(Circulatory pathways: Pages 721 - 744. You will find out in
lab which specific vessels
you will need to know for lab practical)