The layer of the walls of arteries and veins that is smooth to prevent abnormal clotting is the:

• middle layer, made of smooth muscle

• lining, made of smooth muscle

• lining, made of simple squamous epithelium

• outer layer, made of simple squamous epithelium

The layer of the walls of arteries that helps maintain diastolic blood pressure is made of:

• fibrous connective tissue and elastic connective tissue

• smooth muscle and fibrous connective tissue

• smooth muscle and elastic connective tissue

• fibrous connective tissue and simple squamous epithelium

Backflow of blood within veins is prevented by:

• Smooth muscle

• Valves

• Precapillary sphincters

• The middle layer

In capillaries, nutrients are transported from the blood to tissue by the process of:

• osmosis

• diffusion

• active transport

• filtration

In capillaries, O2 and CO2 are exchanged between the blood and tissue fluid by the process of:

• Osmosis

• Filtration

• Active Transport

• Diffusion

A systematic blood pressure reading always consists of two numbers, which are called:

• systemic/systolic

• systolic/diastolic

• diastolic/systolic

• diastolic/systemic

Pulmonary blood pressure is always low and thereby prevents:

• osmosis of tissue fluid into pulmonary capillaries

• filtration of tissue fluid into the alveoli

• filtration of tissue fluid into pulmonary capillaries

• osmosis of blood plasma into alveoli

Systemic circulation begins at the:

• right atrium

• right ventricle

• left ventricle

• left foot

In hepatic portal circulation, blood from the digestive organs and spleen circulates through the _____ before returning to the ______

• brain/liver

• liver/heart

• liver/brain

• heart/liver

Venous return in veins that pass through the thoracic cavity is increased by the:

• skeletal muscle pump

• pumping of the right ventricle

• pumping of the left ventricle

• respiratory pump