UNIT 4 ANATOMY

Heart

Arteries

Capillaries

Veins

Lungs

Functions of blood

transportation, protection, and regulation

Function of blood: transportation

gases, hormones, nutrients and waste products

Function of blood: protection

immune response (WBCs and antibodies), clotting (platelets and proteins)

Function of blood: regulation

pH, fluid lvls, temperature by flow to skin

Blood

consists of plasma and formed elements (RBC, WBC, platelets)

Plasma

fluid matrix of blood (no cells), 55%, mostly water

Interstitial fluid

fluid that leaks out of capillaries (derived from plasma), no WBC and RBC

Lymph

interstitial fluid that has entered the lymph vessels, no WBC and RBC

Serum

the clear, straw-colored liquid component of blood that remains after blood has clotted and all cells and clotting factors (such as fibrinogen) have been removed

Formed elements

blood cells, 45%

Hematocrit

percentage of volume of all formed element, 45%

Buffy coat

<1%, leukocytes (WBCs) and platelets

Plasma solutes

8%, proteins and electrolytes

Erythrocytes (RBCs)

biconcave discs, no nucleus and no organelles, plasma membrane is very flexible

Erythrocytes (RBCs) Function

Gas transport: filled with hemoglobin that binds to gases (O2)

Erythrocytes (RBCs) ATP generation

ATP generated anaerobically so no O2 use in erythrocytes

Hemoglobin

280 million molecules of hemoglobin/RBC, red-pigmented protein with 4 heme groups, each heme has a Fe2+

Oxyhemoglobin

hemoglobin bound to oxygen (at iron ions), oxygen loading occurs in lungs, bright red when O2 blood

Deoxyhemoglobin

the form of hemoglobin that does not have oxygen bound to it

Total WBC count

45000-11000 WBC/mm3

Neutrophils

granulocytes, 50-70% of WBC, nucleus segemnted and varied, 2-5 lobes, granules appear light purple

Neutrophils function

phagocytize infectious pathogens, particularly bacteria

Eosinophils

granulolytes, 1-4% WBC count, bi-lobed nucleus, granules stain reddish-pink

Eosinophils function

attack parasite worms, phagocytize antigen-antibody phagocytize allergens (allergic0reaction causing antigens)

Basophils

granylulytes, 0.5-1% WBC count, bi-lobed nuclei, granules stain blue-violet,

Basophils function

release histamine and heparin during inflammatory or allergic reactions

Lymphocytes

agranulolytes, 20-40% of WBC, as it gets active it becomes larger with more cytoplasm

Lymphocytes function

act as the primary engines of your immune system, defending your body against infections, viruses, toxins, and abnormal or cancerous cells

Monocytes

agranulocytes, 2-8% of WBC count, largest leukocyte, kidney-shaped or c-shaped nucleus

Monocytes function

exit blood vessles after 3 days and enter tissues, becoming macrophages

Platelets

150000-400000/mm3, small, irregular, membrane enclosed cellular fragments, produced by megakaryocytes in red bone marrow

Platelet function

involved in blood clotting, help form temporary plug that seals blood vessels

Hemostasis

stopping flow of blood

List the steps required to form circulating platelets

1. stem cell differentiation

2. endomitiosis and maturation

3. proplatelet extension

4. fragmentation and release

5. circulation and storage

Diagnostic blood test

laboratory examination of blood can asses an individuals health state, various diseases can be identified by WBC type and number

Where are blood cells made until about the 7th month of pregnancy?

Takes place in the fetal yolk sac to then the liver

Where are the blood cells made after the 7 month of pregnancy?

red bone marrow is primary hematopoietic area

Hematopoiesis

process of making blood cells

RBC synthesis is called

erythroesis

WBC synthesis is called

leukopoiesis

Erythrocyte stem cell

hemocytoblasts, myeloid stem cell: proerthroblasts

Platelets stem cell

Hemocytoblasts, myeloid stem cell: megakarcoctyes

Neutrophil, basophil, and eosinophil stem cell

myeloblasts

Monocyte stem cell

monoblasts

Lymphocyte stem cell

lymphoblasts→ b-lymphocytes and T-lymphocytes

Apex

the lowermost, pointed tip of the heart, formed primarily by the inferolateral region of the left ventricle

Base

basis cordis or posterior surface) is the upper, posterior part of the heart opposite the apex

Fibrous pericardium

outer layer of sac, attached to diaphragm inferiorly and major vessels superiorly

Serous pericardium

lines inside of fibrous pericardium continuous with visceral layer at level of major vessles

Pericardial cavity with pericardial fluid

serous fluid between parietal and visceral layers

Epicardium v(isceral serous pericardium)

serous membrane and areolar and adipose CT, outer layer

Myocardium

cardiac muscle, middle layer

Intercalated disks

specialized end-to-end cell junctions that connect adjacent cardiac muscle cells (cardiomyocytes) in the hear

Endocardium

simple squamous epithelium (endothelium) areolar CT, lines heart, covers valves, inner most

Atria

receiving chambers of the heart

Right atrium

one of the four main chambers of the human heart, located in the upper right portion, receives deoxygenated blood

Left atrium

one of the four main chambers of the heart, located in the upper left portion of the organ, situated posteriorly (behind) the aortic root and above the left ventricle, receives oxygenated blood

Auricle

a small, ear-shaped muscular pouch that extends from each of the two upper chambers (atria) of the heart

Pectinate muscles

on inner walls

Fossa ovalis

depression that is remanent from fetal heart circulation

Ventricles

discharging chambers of heart

Left ventricle

pumps blood to rest of the body, oxygenated blood, myocardium is thicker on this side

Right ventricle

pumps blood to the lungs, deoxygenated blood

Tricuspid valve

right atrioventricular valve, prevents back flow of blood

Bicuspid valve

left atrioventricular valve or mitral valve, prevents back flow of blood in the heart

Atrioventricular valves

bicuspid and tricuspid valve

Semilunar valves

pulmonary-semilunar and aortic semilunar valve

Aortic semilunar valve

prevent back-flow from aorta

Pulmonary semilunar valve

prevent back-flow of blood from pulmonary trunk

Chordae tendinae

connects ends of atrioventricular valves to papillary muscles

Papillary muscles

to prevent the atrioventricular (AV) valves from inverting or prolapsing into the atria during ventricular contraction (systole)

Superior and inferior vena cava

transports blood from upper body and lower body to right atrium, deoxygenated blood

Right and left pulmonary veins

From lungs to left atrium, oxygenated blood

Pulmonary trunk

From right ventricle to R and L pulmonary arteries, deoxygenated blood

Ascending aorta

blood from left ventricle to rest of the body, oxygenated blood

Anterior coronary arteries

anterior heart supplied by right marginal artery, anterior inter ventricular artery

Anterior cardiac veins

transport blood from the upper anterior myocardium of the right ventricle to the right atrium, carrying deoxygenated blood

Posterior coronary arteries

transports blood from the aorta to the PDA and LDx, oxygenated blood

Posterior cardiac veins

transports blood from the inferior and later walls of left ventricle to coronary sinus, deoxygenated blood

Pulmonary circulation

Arteries carry deoxygenated blood away from the right side of the heart to

the lungs and veins return oxygenated blood back to the left side of the

heart

Systemic circulation

Arteries carry oxygenated blood away from the left side of the heart out to

the body’s tissues and veins return deoxygenated blood back to the right

side of the heart

Coronary circulation

L heart→ aorta→coronary arteries→heart tissue→ cardiac veins→coronary sinus→R heart→

Where are the auto-rhythmic cells of the heart located?

Autorhythmic cells (pacemaker cells) of the heart are located within the cardiac conduction system

What make them different than the other myofibers of the heart?

the heart contains specialized pacing and conducting myofibers (such as Purkinje fibers and nodal cells) that differ fundamentally from the standard contractile myofibers making up 99% of the heart muscle

Cardiac muscle excitation

sinoatrial node (pacemaker), spreads to atrioventricular nod→atrioventricular bundle→inter ventricular septum→purKinje fibers

Systole

contraction of a heart chamber

Diastole

he relaxed phase of the cardiac cycle when the heart muscle decompresses and the chambers refill with blood

Cardiac cycle

1. Artia systole

2. Early ventricular systole

3. Later ventricular systole

4. Early ventricular diastole

5. Late ventricular diastole

Which primary germ cell layer was the heart derived from?

mesoderm

Summarize the differences between circulation in the adult as compared to fetal circulation

Fetal circulation relies on the placenta for oxygen and nutrients, whereas adult circulation uses the lungs and digestive system. Because the fetus's lungs are collapsed and non-functional, the cardiovascular system uses specialized shunts to bypass

Arteries

thickest layer is tunic media; narrower lumen; tunic externa is more elastic, carries blood away from the heart

Arterioles

smallest, regulated blood flow into capillaries by vasoconstriction or vasodilation

Capillaries

functional unit of cardiovascular system-site of diffusion between blood and tissues, only has tunica intima

Venules

smallest veins, larger venules have all 3 tunics

Veins

thickest layer is tunic externa; wider lumen; more prone to collapse, carries blood to the heart