physiology exam 4

The presence of endothelins causes

• vasoconstriction

• vasodilation

• bronchodilation

• bronchoconstriction

Nitric oxide induces vasodilation, and can be found in which of the following?

• Viagra

• Nitroglycerin

• Epinephrine

• Endothelial tissue

A tissue is noticed to have increased hydrogen presence. What is the most likely arteriole response directly upstream of the tissue?

• vasoconstrict

• vasodilate

• None of the above

• Depends on nitric oxide presence

Tags

NGSS.HS-LS1-3

Blood pressure is dependent on

• peripheral resistance

• cardiac output

• venous return rate

• end systolic volume

Tags

NGSS.HS-LS1-3

Smooth muscle is found in walls of most hollow organs, including the heart.

• True

• False

Answer explanation

Excluding the heart

Peristalsis is the alternating contractions of smooth muscle layers that mix and squeeze substances through the lumen of hollow organs.

• True

• False

Single-unit (visceral) smooth muscle is innervated by varicosities of the

• central nervous system

• autonomic nervous system

• peripheral nervous system

• Smooth muscle is only controlled by chemical stimuli, not nerves.

Choose the option that is true about smooth muscle.

• There is no troponin complex, rather, protein calmodulin binds to calcium.

• Myofilaments are arranged perpendicularly.

• Smooth muscle units contract more quickly than skeletal muscle units.

• Only responds to neural, not chemical, stimuli.

Choose the option that is FALSE regarding smooth muscle contraction.

• Responds to stretch only briefly, then adapts to new length.

• Retains ability to contract on demand.

• Enables organs such as stomach and bladder to temporarily store contents.

• Lines the entire GI tract, except the esophagus.

Arteries are vessels that are leaving the heart, and only carry oxygenated blood.

• True

• False

Answer explanation

All arteries leave the heart, but the pulmonary artery carries deoxygenated blood.