Cardiovascular System

Question 1

Circulatory System

Answer 1

• one of two vascular systems in the body

- Circulates blood, uses heart as a pump

Question 2

Lymphoid System

Answer 2

• one of two vascular systems in the body
• Unidirectional
• No pump
• Lymphatic fluid will be drained in the lymph nodes and will make its way into the circulatory system

Question 3

Capillaries

Answer 3

• Lined by single layer of endothelial cells
• Connected by cell junctions
• Has a basal lamina outside around endothelial cell
• Contains pericytes around basal lamina which provide nutrients and maintain viability of endothelial cells

Question 4

Continuous Capillary

Answer 4

• most common

- found in muscle, skin, lung and brain

Question 5

Fenstrated Capillary

Answer 5

• Located in intestines, endocrine system, kidneys
• In the kidneys there is a thick basement membrane and no diaphragm
• have fenstrations spanned by diaphragms

Question 6

Sinusoidal (discontinuous) capillaries

Answer 6

• Located in liver, spleen, bone marrow and endocrine system

- Contain large holes (gaps) where an entire cell can squeeze through

Question 7

Capillary Exchange Mechanisms

Answer 7

• Open pores/gaps
• Diffusion
• Filtration
• Vesicular transport (transcytosis)
• Transendothelial channels- Vesciles join together to form a channel - allows rapid movement of cells

Question 8

Vesicular Transport

Answer 8

• Mechanism of capillary exchange

- System of pinocytotic pits and vesicles which move large molecules across the endothelium

Question 9

Secretory and Metabolic Functions of Endothelial Cells

Answer 9

• Adhesion molecules (diapedesis)
• Produce vasoactive compounds ( NO for vasodilation, endothelin for vasoconstriction
• Anti thrombogenic factors (anti clotting)
• Metabolic conversions (angiotensin I to II, vasoconstriction)

Question 10

Tunica Intima

Answer 10

• Endothelium
• Connective Tissue
• Internal Elastic Lamina (IEL)

Question 11

Tunica Media

Answer 11

• Smooth Muscle
• Elastic Fibers
• External Elastic Lamina (EEL)
• Thicker in arteries, thinner in veins

Question 12

Tunica Adventitia

Answer 12

• Connective Tissue
• vasa vorum
• nerves
• Thinner in arteries, thicker in veins

Question 13

Elastic Arteries (aorta)

Answer 13

• Large Lumen
• Thick tunica interna
• 40+ layers of smooth muscle in tunica media
• Thin Tunica adventitia
• A lot of elastic fibers throughout tunica media
• needs to have elasticity of aorta for it to expand and contract with the pumping of the heart

Question 14

Muscular (Distributing) Arteries

Answer 14

• Thin tunica intima
• up to 40 layers of smooth muscle in tunica media
• thin tunica adventitia
• Internal and external elastic laminas
• elastic lamina’s looked scalloped due to no longer being under pressure

Question 15

Arteriole

Answer 15

• Smaller lumen
• Thin tunica intima
• 2-5 layers of smooth muscle in the tunica media
• Thin tunica adventitia
• may or may not have internal elastic lamina

Question 16

Arteriovenous anastomosis

Answer 16

Seen in skin

- arteriole may short circuit and skip the capillary bed and go straight to venule

Question 17

Arteriole-Capillary-Arteriole

Answer 17

• seen in kidney

- ***

Question 18

Venule- capillary- venule Portal system

Answer 18

• Seen in the liver

- ***

Question 19

Venule (collecting)

Answer 19

• Small lumen
• Thin tunica intima
• no smooth muslce in tunica media
• Thin tunica adventitia
• no elastic lamina

Question 20

Venule (muscular)

Answer 20

• Slightly larger lumen than the collecting venule
• thin tunica intima
• 1-2 layers of smooth muscle in tunica media
• thin tunica adventitia
• no elastic lamina

Question 21

Small to medium Vein

Answer 21

• Larger lumen than venule
• Thin tunica intima (with valves)
• Thin or absent tunica media
• Thick tunica adventitia
• Internal elastic lamina (vague) (almost non existent)

Question 22

Large Veins (vena cava)

Answer 22

• Large Lumen
• Thick tunica intima
• Thin (several layers) of smooth muscle in tunica media (smooth muscle runs planar)
• Thick tunica adventitia with longitudinal smooth muscle bundles (runs perpendicular to the smooth muscle in tunica media)
• Internal elastic lamina
• Contains vasa vasorum which are blood vessels within blood vessels providing nutrients

Question 23

Valves in Veins

Answer 23

• Facilitate unidirectional blood flow in veins

Question 24

Evolution of the Heart

Answer 24

• Fish- mixing of oxy and deoxygenated blood
• Amphibians- separtaion of atria- still some mixing
• Reptiles- partial separation of ventricles and partial separation of oxy and deoxy blood
• Mammals- total separation with 4 chambers

Question 25

Structure of the heart

Answer 25

- built on a cardiac skeleton of high density collagen connective tissue - 3 layers 1) Endocardium (inner lining)- homologous to tunica intima 2) Myocardium- homologous to tunica media 3) Epicardium (outer surface)- homologous to tunica adventitia - Resides in a sac called the pericardium

Question 26

Purkinje Fibers

Answer 26

- In the endocardium | - facilitate the signaling events that regulate the contraction of the heart

Question 27

Signal Transduction through the heart

Answer 27

- Sinoatrial node (SA node)- pacemaker of the heart, continuously releases a wave of depolarization - this is sent to the atrioventricular node (AV node) - It is then sent to the bundle of His - Then to purkinje fibers - Apex of the heart is the first to receive the wave of depolarization

Question 28

Lympatic System Functions

Answer 28

- return excess 10% of interstitial fluid to blood - Transport lipids absorbed from intestines - Immunologic support

Question 29

Lymphokinetic Motion and Pressure Gradient

Answer 29

Blood Capillaries (highest pressure)---> Interstitial fluid---> Lymph capillaries---> Lymph veins---> Lymph ducts---> Large circulatory veins, vena cava (lowest pressure)

Question 30

Lymphatic capillaries

Answer 30

- have unique permeability characteristics, filaments (elastic fibers) - anchor to connective tissue

Question 31

Lymph Nodes

Answer 31

- All lymph gets filtered by at least one lymph node before it re enters the blood