Cardiovascular System Flashcards
Cardiovascular System
- Circulatory System
- Capillaries
- Structure of large vessels
- Structure of Arteries
- Structure of Veins
- The heart
- Lymphatic
Vascular Systems
- Circulatory System
- Lymphoid System
- *Oxygen content of arteries and veins is REVERSED in systemic and pulmonary systems.
(PIC)
Capillaries
Capillaries and postcapillary venules are the exchange vessels for the tissues
Structure of Capillaries
- Endothelial Cells
- Basal Lamina
- Pericytes (help maintain viability of endothelial cells)
Types of Capillaries: Continous Capillary Found in
Muscle, Skin, lung, brain
Types of Capillaries: Fenestrated Capillary Found in
Intestines, Endocrine, kidneys (fenestrated sinusoids with wider diameter)
Types of Capillaries: Sinusoidal (discontinuous) Capillary Found in
Liver, Spleen, Bone Marrow, Endocrine
Capillary Exchange Mechanisms
- Open pores/gap
- diffusion
- filtration
- Vesicular transport (Transcytosis)
- Transendothelial Channels
Vascular Transport
-System of pinocytotic pits and vesicles which move large molecules across the endothelium
Transendothelial Channels
Vesicles are so numerous sometimes that they form a channel in which fuild/larger molecules transport more rapidly
Secretory and Metabolic Functions of Endothelial Cells
- Adhesion molecules (diapedesis-process when eosinophils can squeeze)
- Produce vasoactive compounds Anti-thrombogenic factors
- Metabolic conversions (angiotensin I to II)-vasoconstriction
Structure of Arteries and Veins
Tunica Intima, Tunica Media, Tunica Adventitia
Tunica Intima
Endothelium, connective tissue, Internal Elastic Lamina (IEL)
Tunica Media
Smooth Muscle, elastic fibers, EEL (thicker in arteries, thinner in veins)
Tunnica Adventitia
Connective tissue +vv+ nerves (thinner in arteries, thicker in veins)
Artery VS. Vein
Artery has larger Tunnica Media (PIC)
Characteristics of Venules and Arterioles
LOOOK AT CHARRRTTTT
Aorta: (Elastin Stain)
Elastin first appeared phylogenetically with the evolution of closed high pressure circulatory systems (jawed fish). Unique to gnathostome vertebrates
- Need elasticity of aorta to pump blood through the body
- Elastin fibers are reliant to blood vessels expanding and contraction
Muscular (distributing) Arteries
- Elastic Lamina NOT in veins
- Elastic Lamina usually is not folded but fully plump from blood being full and stretching it
Arteriole have how many layers of smooth muscle?
<5
Types of Microcirculation
- Arteriole-Capillary Bed-venule (MOST COMMON)
- Arteriovenous anastomosis (skin) (SHORT CIRCUIT CIRCULATION)
- Arteriole-capillary-arteriole (kidney)
- Venule-Capillary-venule (liver), Hepatic portal system
Blood pressue varies through vessels starting in ____ to the ____
Arteriole, Venus System
Structure of the Vein
-not all veins have tunica media
-tunica dventisia is thickest
-in cross sections, tunica adventicia budles have a directionality (perpindicular to those of tunica media
-veins have valves bc of low blood pressure
-valves prevent form flowing backwards
PICS
Medium Sized Vein
- Large lumen
- no scalloped relastic lamina
- adventitia
