module 8 - cardiovascular system

functions of blood

• transporting elements throughout the body

• regulating bodily functions

• protecting the body from immune repsonses

physical characteristics

viscosity - thickness of a fluid

• 4x more thick than water

temp - 38 degrees

ph levels - 7.35-7.45

volume - avg. 5L

2 components of blood

• plasma

• formed elements

  • erythrocytes

  • thrombocytes

  • leukocytes

plasma

• 55% of total volume of blood

  • 92% water

  • 8% solutes

    • plasma proteins - 7%

    • calcium, sodium and potassium - 1%

erythrocytes

• red blood cells

• hemoglobin transports oxygen and carbon dioxide

• lack of nuclei - non true cells

• 8 diameter and 2 thicks

• life span in 120 days

thrombocytes

• platelets

• smallest formed elements

• hemostasis - stops bleeding

• lack nuclei

• round/spindle discs

• 2-4 diameter

• originate from red bone marrow - megakaryocytes

leukocytes and 2 types

• white blood cells

• no hemoglobin

• has a nucleus

1. granulocytes

2. agranulocytes

granulocytes and 3 types

• granules in cytoplasm

• segmented nucleus

1. neutrophils

2. eosinophils

3. basophils

neutrophils

• mosts abundant - 60-70% of all WBCs

• first against bacterial invasion

• phagocytic - engulfs bacteria

• nucleus is 2-6 lobes - usually 3

• small neutral coloured granules

  • lysomal enzymes

  • bactericidal compounds

eosinophils

• 2-4% of all WBCs

• defends body against allergic reactions or parasitic infections

• nucleus is bilobed

• granules are stained pinkish red

• cytoplasm is filled with spherical large granules

• enzymes that control the spread of inflamation

basophils

• least common - less than 1% of WBCS

• heparin and histamine are released during inflammatory reactions

• nucleus has 2-3 irregular lobes

• obscured by dark granules

agranulocytes and 2 types

• lack of granules in the cytoplasm

• nucleus is round and indented

1. lymphocytes

2. monocytes

lymphocytes

• 20-30% of WBCs

• similar size to RBCs

• involved in the branch of the immune system

  • attacks pathogens and abnormal cells

• nucleus in large and dark

• cytoplasm is narrow

• pale / light blue

monocytes

• 3-8% of WBCs

• large - 16-20 in diameter

• can move outside of blood cells into tissue

• change into large phagocytic cells

  • called macrophages

  • act as a part of the immune system

• nucleus is large and oval

• cytoplasm is pale blue

structure of blood vessels

outside layer - tunica externa

• composed of connective tissue

• collagen and elastic fibres

middle layer - tunica media

• composed of smooth muscles and elastic fibres

inner lining - tunica intima

• composed of simple squamous epithelium

• known as endothelium

venous system

veins

• large lumen

• less muscle in tunica media

• one way valves

• prevents blood from flowing backwards

venule

• give rise to viens

• small venules resemble capillaries in structure

• one tunic

• tunica are thick

arterial system

elastic artery

• near heart

• aorta - major blood vessels branching off the heart

• large lumen

• tunica media has more elastic fibres than smooth muscle

• exhibit stretching and recoil

muscular artery

• deliver blood

• thick tunica media

• lots of smooth muscle

• exhibits contractile characteristics

arteriole

• from muscular arteries

• creates smaller arteries

• tunica media has a few layers of smooth muscles

• small arterioles have single layer of smooth muscle around tunica intima

capillary

• smallest blood vessels

• between venous and arterial systems

• only tunica intima

• “basement membrane”

distribution of cardia output

• heart - major part

• pumps blood throughout the body

• refers to the amnt of blood in the arterial and venous system

• 30-35% blood volume in arterial system

• 65-70% in venous system

pulmonary circulation

• carries deoxygenated blood from heart to lungs

• after gas exchange oxygenated blood returns back to heart

systemic circulation

• carries oxygenated blood from heart to other organs and tissues

  • except to lungs

• then deoxygenated blood returns to the heart

anatomical location of heart

• resides in the mediastinum

  • between lungs in the thorax

• shape resembles an inverted pear

• most inferior and lateral portion on the left in the apex

coverings of the heart - 3 layers

1. fibrous pericardium

• most external

• protective covering

2. parietal pericardium

3. visceral pericardium

• pericardial space is filled with pericardial fluid

• it decreases friction between layers during heart beats

chambers of the heart

• right and left atrium

• right and left ventricle

atria of the heart - 4 parts

• receives blood from the body and lungs

• before blood enters the ventricles

1. interatrial septum

2. sossa ovalis

3. auricles

4. atrioventricular groove

interatrial septum

• wall between left and right atria

• where fossa ovalis are

sossa ovalis

• depression in the interatrial septum

• embryological remnant of fetal foramen ovale

  • opening from left to right atrium during fetal life

auricles

• extensions above left and right atria

• increases capacity of each atrium

atrioventricular groove

• depression between atria and ventricles - coronary sulcus

• grooves separates atria from ventricles externally

• houses coronary vessels

ventricles of the heart - 4 parts

• right pumps blood to lungs to become oxygenated

• left pumps oxygenated blood to the rest of the body

1. interventricular sulcus

2. interventricular septum

3. trabeculae carneae

4. papillary muscle

interventricular sulcus

• groove on the external surface of heart

• separates right and left ventricle

• sits above interventricular septum

interventricular septum

wall between left and right ventricle

trabeculae carneae

• irregular muscular ridges on internal walls of each ventricle

• formed by large ventricular muscles

papillary muscle

• small muscular projections on internal walls

• attach to valves of heart

valves of the heart - 4 valves

• controls one way flow of blood

1. tricuspid valve

2. bicuspid valve

3. aortic semilunar valve

4. pulmonary semilunar valve

tricuspid valve

• controls blood flow from right atrium and right ventricle

• “right atrioventricular valve”

• chordae tendineae

  • thin strands of collagen fibres that attach to papillary muscles

bicuspid valve

• controls blood flow from left atrium to left ventricle

• “left atrioventricular/mitral valve”

• has chordae tendineae that anchors it to left ventricle

aortic semilunar valve

located and controls blood flow from left ventricle into aorta

pulmonary semilunar valve

located and control blood flow from right ventricle to pulmonary trunk

vessels into the heart - 4 parts

pulmonary veins - right and left

• drains oxygenated blood from lungs to left atrium

superior vena cava

• drains deoxygenated blood from upper body to right atrium

coronary sinus

• drains deoxygenated blood from coronary circulation to the right atrium

inferior vena cava

• drains deoxygenated blood from lower body to right atrium

vessels away from the heart - 3 parts

ascending aorta

• oxygenated blood from left ventricle to the body

pulmonary trunk

• oxygenated blood from right ventricle to pulmonary arteries

pulmonary arteries - left and right

• deoxygenated blood from trunk to lungs

arterial supply of the heart

right and left coronary artery branches

coronary circulation

how the heart supplies itself with blood

venous drainage

• tributaries of the venous drainage of the heart

• returns deoxygenated blood to right atrium