WSU - Bio 315 Lecture Exam 3

Function of blood include

Carrying respiratory gases, nutrients, wastes, and hormones; Helps body regulate temp.

Hematocrit

percentage of blood volume occupied by red blood cells

Males RBC

47% +/- 5%

Females RBC

42% +/- 5%

Serum

plasma without clotting factors

Blood plasma

straw-colored, sticky fluid portion of blood about 55% of whole blood

Blood Plasma Protein: Albumin

most abundant; maintain osmotic pressure

Blood Plasma Protein: Globulins

Alpha and beta globulins: some transport metal ions and some transport lipids; Gamma globulins: immunoglobulins (antibodies)

Blood Plasma Protein: Fibrinogen

converted to fibrin - major component of blood clot

Red blood cells are also called

erythrocytes

Acidic dyes

eosin, stains pink

Basic dyes

hematoxylin or methylene blue - stains blue and purple

Hemoglobin

oxygen-carrying protein

Leukocytes

white blood cells

Diapedesis

circulating leukocytes leave the capillaries by squeezing between endothelial cells

Type of Leukocyte: Granulocytes

contain enzyme filled vesicles in cytoplasm

Type of Leukocyte: Arganulocytes

lack vesicles

Type of Granulocytes: Neutrophils

(appear neutral - both pink and purple) Most numerous leukocyte (60%) phagocytize bacteria and release enzymes

Nucleus is multi-lobed; 2 to 6 lobes

polymorphonucleated granulocytes

Type of Granulocytes: Eosinophils

(appear pink) Turn off allergic reactions and help fight off parasitic infections

Type of Granulocytes: Basophils

(appear purple) secrete histamine

Histamine

Functions in inflammation mediation

Type of Agranulocytes: Lymphocytes

(stains dark purple) the most important cells of the immune system

Lymphocyte: T-Cells

attack foreign cells directly

Lymphocyte: B cells

secrete antibodies and multiply to become plasma cells

Type of Agranulocytes: Monocytes

largest leukocyte that trasnform into macrophages and are phagocytic cells

Platelets

Cell fragments and seal small tears in blood vessels; instrumental in blood clotting

Hematopoiesis

process by which blood cells are formed (all originate in bone marrow)

Red marrow

actively produces blood cells

Location of red marrow

remains in proximal epiphyses, girdles, and all of axial skeleton

Tissue framework for red marrow: Reticular connective tissue

Reticular fibers support developing blood cells

Tissue framework for red marrow: Blood sinusoids

Large capillaries with wide-open intercellular junctions

Yellow marrow

dormant; contains many fat cells; located in long bones of adults

hemopoietic stem cell

most undifferentiated blood stem cell

Lymphoid stem cells

give rise to lymphocytes

Myeloid stem cells

give rise to all other blood cells which then become committed to specific cells

Erythrocytes are formed from

proerythroblasts

Megakaryocytes are formed from

megakaryoblasts (which break apart into platelets)

Granulocytes form from

myeloblasts (one cell line for each type)

Monocytes form from

monoblasts (myeloid line)

Lymphocytes from directly from

lymphoid stem cells

Arteries

carry blood away from the heart; smaller lumen/vessel size ratio

Capillaries

The smallest blood vessels, and the site of exchange molecules between blood and the tissues.

Veins

carry blood to the heart; thicker tunica externa

Structure of blood vessels: Tunica intima

composed of simple squamous epithelium
Subendothelial layer - thin layer of loose connective tissue

Structure of blood vessels: Tunica media

primarily sheets of smooth muscle; also collagen and elastin in larger vessels

Structure of blood vessels: Tunica externa (adventitia)

composed of dense connective tissue

Lumen

central blood-filled space of a vessel

Types of Arteries: Elastic arteries

the largest arteries; high elastin content in tunica media stores energy for continuous flow of blood

Types of Arteries: Muscular (distributing) arteries

internal and external elastic laminae; thick tunica media relative to vessel size

Types of Arteries: Arterioles

smallest arteries, tunica media contains smooth muscle and diameter of lumen can change

Capillaries structure

only tunica intima and has intercellular clefts (gaps of unjoined membrane between tight junctions; overlap)

Pericytes

supporting cells of capillaries

Continuous capillary

most common type of capillary contains very small gaps in the endothelial lining that permit exchange

fenestrated capillaries

have pores in vessel wall; found in kidneys, intestines, and endocrine glands

4 routes of capillary permeability are...

1) Direct diffusion
2) Through intercellular clefts
3) Through fenestrations (pores)
4) Through cytoplasmic vesicles (pinocytosis)

Sinusoids

Wide, leaky capillaries found in
spleen, liver, bone marrow; intercellular clefts are wide open

Capillary beds

network of capillaries running through tissues (Metarteriole and Thoroughfare channels)

precapillary sphincters

regulate blood flow into tissues

What tissues lack or have sparse capillary beds?

Epithelia and cartilage
Cornea and lens of eye
Tendons and ligaments

Venules are the smallest veins, but what are the smallest venules?

postcapillary venules

Mechanisms to Counteract low venous pressure

one way valves and skeletal muscle pump

Vascular Anastomoses

interconnections of blood vessels so that organs can receive blood

"Great Vessels" of Circulation (4 listed)

1) Aorta
2) Pulmonary Trunk/Pulmonary Arteries and veins
3) Inferior vena cava
4) Superior vena cava

Pulmonary Circuit of the heart

takes blood to and from the lungs

Systemic circuit of the heart

vessels transport blood to and from body tissues

Atria of the heart

receiving chambers; blood from the pulmonary and systemic circuits

Ventricles of the heart

the pumping chambers of the heart

Heart Development - Embryo

Blood vessels begin as condensations of lateral plate (splanchnic) mesoderm

Angioblasts

immature endothelial cells

Heart Development - Sinus Venosus

becomes part of right atrium and determines heart rate

Heart Development - Bulbus cordis

becomes great arteries and right ventricle

Pericardium: Fibrous

strong layer of dense connective tissue

Pericardium: Serous

formed from parietal layer and visceral layer with the pericardial cavity between

epicadium

Visceral layer of the serous pericardium

serosal membrane

(epicardium) simple squamous epithelium + thin connective tissue layer

Myocardium

consists of cardiac muscle arranged in circular and spiral patterns

Endocardium

simple squamous epithelium resting on a layer of loose connective tissue (lines internal walls of heart)

Pathway of blood through the heart: Oxygen Poor Blood

in Superior and inferior venae cavae

pulmonary circulation (Deoxygenated blood)

Right atrium, right ventricle, pulmonary trunk. right/left pulmonary arteries, lungs

Returned to heart (systemic Circuit)

left atrium, left ventricle, aorta, distributing arteries to body

Systole

ventricular contraction

Diastole

ventricular relaxation and expansion due to filling with blood

Right Atrioventricular valve

between atria and ventricles and is a tricuspid valve

Left atrioventricular valve

between atria and ventricles and is a mitral (bicuspid) valve

Aortic and pulmonary valves

at junction of ventricles and great arteries and is a semilunar valve (3 crescent shaped leaflets)

What is each valve composed of?

endocardium with connective tissue core

Chordae tendineae

connective tissue strands that connect AV valves to small muscles extending from lower ventricle walls

Papillary muscles

contraction pulls chordae tendineae taut and prevents eversion of AV valves into atria

"lub" sound in heart

AV valves closing

"dup" sound in heart

the semilunar valves closing

2 auto-rhythmic cardiac cells

pacemaker cells and conducting cells

Sinoatrial node

upper right atrium; sets inherent rate of contraction (primary pacemaker)

Atrioventricular node

between atria and ventricles

conducting system of the heart

a series of specialized cardiac muscle cells that conduct action potential throughout heart

Purkinje fibers

through each ventricle wall (between endocardium and myocardium); conduct action potential rapidly, BUT do not contract or contract poorly

Nerves to/from the heart

1) Visceral sensory fibers
2) Parasympathetic branches (of the vagus nerve)
3) Sympathetic Fibers (from cervical ganglia)

Fetal circulation

All major vessels in place by month 3 of development.

Fetus circulation difference

most blood bypasses liver, fetus must supply blood to placenta, very little blood is sent through pulmonary circuit

Paired umbilical arteries

oxygen poor blood to placenta