Cardiovascular system: heart, blood vessels and transport

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Cardiovascular System

Function = Transport materials TO and FROM the body's cells!

Blood is MAJOR CARRIER of materials

Nutrients (from DIGESTIVE SYSTEM)

Oxygen (from RESPIRATORY SYSTEM)

Hormones (insulin) = secreted by GLANDS and NERVE CELLS

Immune cells/products - FIGHT INFECTIONS

Materials carried away from the body include:

Waste products (eventually excreted as URINE)

Carbon Dioxide (eventually EXHALED)

Excess salts/other materials (often RETAINED by body)

Circulatory System's 3 parts:

The HEART

The BLOOD

The BLOOD VESSELS

Lymphatic System = network of CAPILLARIES/VEINS carrying INTERSTITIAL FLUIDS/WASTES through lymph fluid

Blood Vessels: Arteries vs. Veins

Arteries = Thick-walled vessels that CARRY OXYGENATED BLOOD AWAY from the heart

Branch into smaller vessels (ARTERIOLES) and then into even smaller vessels (CAPS.)

Veins = Thinner-walled vessels that CARRY DEOXYGENATED BLOOD from body cells BACK TO HEART

Blood diffuses into the LUNGS into tiny caps.

Returns through VENULES that merge

Creating LARGER VEINS

As blood moves through the system from larger tubules through smaller ones = rate slows down

Blood Pressure

Blood Pressure = Fluid pressure generated by the CARDIAC CYCLE

ARTERIAL blood pressure = transports OXYGEN POOR blood into the LUNGS and OXY RICH blood to BODY TISSUES

Arteries branch into SMALLER ARTERIOLES which contract and expand based on signals from the body

Arterioles = where adjustments are made in BLOOD DELIVERY to specific areas based on COMPLEX COMMUNICATION from body systems

Capillary Beds = DIFFUSION sites for exchanges between BLOOD and INTERSTITIAL FLUID

Caps merge into VENULES which in turn merge with LARGER DIAMETER tubules (VEINS)

Caps have the THINNEST walls of any blood vessel consisting of a layer of ENDOTHELIAL cells (allows for oxygen to exchange)​​​​​​

Veins transport BLOOD FROM BODY TISSUES back to the heart

Valves inside veins FACILITATE transport

Walls in veins are THIN and contain SMOOTH MUSCLE (and also function as BV reserves!)

The Heart

The Heart = muscular pump providing necessary pressure to keep blood flowing

The Human heart has FOUR CHAMBERS:

Top

Left Atrium

Right Atrium

Bottom

Left Ventricle

Blood pressure is the HIGHEST

Larger muscle to pump blood systematically

Right Ventricle

Valves: keep blood moving in a SINGLE DIRECTION and prevent any backwash into the chambers!

Tricuspid Valve

Pulmonary Valve