Lecture 16 - The Cardiovascular System Flashcards
3 Main Components
- Heart - Muscular pump
- Blood Vessels - Conduits for blood to flow
- Blood - Fluid that circulates through the body and carries materials between cells
Cardiovascular Disease Examples
- Heart Attack
- Stroke
- Heart Failure
- Hypertensions
- Coronary artery disease
- Peripheral Artery Disease
- Myocarditis
Arteries
- Thick muscular walls
- Designed to handle the high pressures in arterial blood
Arterioles
- A bit less muscle
- Lots of innervation to control smooth muscle contraction
Capillaries
- No muscle so there is no control over diameter or connective tissue
- can’t withstand high pressure
- high permeability ( for movement of fluid)
Veinules
Main site of lymphocytes crossing from blood to lymph nodes
Veins
Thin walled, fairly muscular, for easy expansion and recoiling
Blood Vessles Differ by Velocity and Area
High velocity + small surface area = direct, rapid conductance of blood
Large surface area + Low Velocity = optimal exchange
Capillary
Nutrient, waste, fluid exchange at local level
Cardiac output
Most amount of blood pumped by the heart per minute (heart rate x stroke volume)
Resting blood flow cardiac output
5 L/min
Exercise Blood Flow Cardiac Output
25.0 L/min (mostly in skeletal muscle)
Blood Movement for Veins
Against gravity - toward the heart
- Facilitated by the expansion of the thoracic cavity, contracting skeletal muscles and valves
Varicose Veins
- One way valves malfunction
- Allows backwards flow of blood and pooling
- Often in thigh and calf veins (Saphenous vein)
Heart Muscle
Myocardium - Involuntary and Autonomic
