Ch. 12 Circulatory System pt 2

the circulation of the blood in the smallest blood vessels!

Microcirculation

What is a network of tiny blood vessels that connect arteries & veins and allow for exchange of oxygen, nutrients, waste. Between blood & surrounding tissue

Capillary beds

The types of capillaries that are all your tissues and organs

Systemic capillary beds

Functions of microcirculation:

• Regulates and supports cell metabolism

• Equalize & distribute pressure fluctuations

• Influences heat distribution

are little rings of smooth muscle restricting the entrance to the capillary beds.

Precapillary sphincters

can bypass some regions like capillary bed. Provide direct connection b/w arterioles and venules 

Shunts

what are shunts needed for?

• Thermoregulation (shunt will open to disperse the heat throughout the body and if too cold, they close)

• Blood flow regulation (Open when you need blood flow in body

Pattern in which blood passes only once through the heart during each complete circuit. Most fishes have this!

Single circulation

Which right chamber of heart receives deoxygenated blood that the superior (cranial) & inferior (caudal) vena cava delivers

Right atrium

Which right heart chamber pumps blood from right atrium to lungs via pulmonary artery for oxygen?

Right ventricle

Blood passes through the heart twice during each circuit, traveling from the heart to the lungs, back to the heart, out to the systemic tissues, and back to the heart a second time. Amniotes

Double circulation

creation of negative pressure that sucks blood into the heart.

Aspiration

heart rate increases significantly (~100 beats/minute)

Tachycardia

heart rate decreases significantly (~60 beats/minute)

Bradycardia

The heart lies within the ___________ lined by a thin epithelial membrane, the _________.

Pericardial cavity; pericardium