Activity #10: Vessels and Circulation Chapter 23 – McKinley et al., Human Anatomy, 4e. Objectives: Observe and sketch histology slide of an artery and a vein and identify structures on each. Identify structures and vessels involved in pulmonary circulation on cadavers and classroom models. Identify structures and vessels involved in systemic circulation (by region) on cadavers and classroom models. Compilation: Lisa Radmall

Vessels: Layers of Vessel Wall Tunica intima Thin, innermost layer of vessel wall. Endothelium and thin layer of areolar connective tissue. Tunica media Middle layer of vessel wall, thickest layer in arteries. Smooth muscle cells, circular arrangement for vasoconstriction when contracted and vasodilation when relaxed. Tunica externa Outermost layer of vessel wall, thickest layer in veins. Areolar connective tissue, helps to anchor vessels to other structures.

Vessels: Layers of Vessel Wall Fig. 23.1

Vessels: System Comparison Fig. 23.3

Vessels: Histology Fig. 23.2

Vessels: Histology

Vessels: Identification on Cadavers Arteries Round shape Collapse when ‘pinched’ (hollow lumen) Rebounds to round shape Veins Flat shape Usually collapsed Often dark in color Nerves Does not collapse when ‘pinched’ (contains nerve fibers)

Circulation: Overview Pulmonary Circulation carries deoxygenated blood from right ventricle through pulmonary trunk and ultimately to capillary beds of the lungs, then carries oxygenated blood back through the pulmonary veins to the left atrium.

Circulation: Overview Systemic circulation carries oxygenated blood from the left ventricle of the heart through the aorta, ultimately to the capillary beds of systemic body organs, then carries deoxygenated blood back to the right atrium Note: Coronary arterial and venous circulation is also part of systemic circulation and was covered in the previous laboratory activity.

Pulmonary Circulation Left pulmonary artery Right pulmonary artery Left Pulmonary trunk Right pulmonary veins Left pulmonary capillaries Right pulmonary capillaries

Systemic Circulation: Arterial Flow Away From Heart Aorta – Carries oxygenated blood from the left ventricle to body organs and tissues. Ascending aorta Left & right coronary arteries. Supplies heart muscle. (A) Aortic arch - ABCs (B) Brachiocephalic trunk (C) Left common carotid artery (S) Left subclavian artery Descending Aorta Descending thoracic aorta (above diaphragm) Descending abdominal aorta (below diaphragm) (C) Left Common Carotid Artery Pulmonary trunk (A) Ascending Aorta (B) Brachiocephalic trunk (S) Left Subclavian Artery Aortic Arch

Systemic Circulation: Venous Return to Heart Superior vena cava Returns deoxygenated blood from head, neck, thorax, and upper limbs to right atrium. Inferior vena cava Returns deoxygenated blood from the lower limbs, abdomen, and perineum to right atrium. Coronary sinus Returns deoxygenated blood from heart muscle to right atrium.

Systemic Circulation: Blood Flow to/from Heart Fig. 22.5b

Circulation: Head and Neck – Arterial Supply Fig. 23.10a

Circulation: Head and Neck – Arterial Supply Fig. 23.11a

Circulation: Head and Neck – Venous Drainage Fig. 23.11b

Circulation: Head and Neck – Venous Drainage Fig. 23.10b

Circulation: Ventral Cavity – Arterial Supply Fig. 23.12

Circulation: Ventral Cavity – Celiac Trunk Fig. 23.15a

Circulation: Ventral Cavity – Mesenteric Arteries Fig. 23.15b

Circulation: Ventral Cavity – Venous Drainage Fig. 23.13

Circulation: Hepatic Portal System A portal system consists of two capillary beds in a series connected by a portal vein. The hepatic portal system is a venous network that drains the GI tract and shunts blood to the liver for absorption and processing of transported materials. (p.703) Blood drained from the abdominal organs is processed in the liver’s wide sinusoid capillaries before returning to systemic venous circulation. (1st capillary beds) (2nd capillary bed)

Circulation: Hepatic Portal System Fig. 23.16

Circulation: Hepatic Portal System Mnemonic Visual Mnemonic: The location of the main veins of the hepatic portal system seem to form a visual “chair” when isolated. Table 23.3

Circulation: Arterial Supply to Upper Limb **All vessels are paired** (right and left sides) Fig. 23.19a

Circulation: Venous Return to Upper Limb **All vessels are paired** (right and left sides) Fig. 23.19b

Circulation: Arterial Supply to Lower Limb **All vessels are paired** (right and left sides) Fig. 23.20a

Circulation: Venous Return to Lower Limb **All vessels are paired** (right and left sides) Fig. 23.20b

Circulatory System - Summary

Circulatory System – Plastinated Vessels

Image References Pulmonary Circulation: https://healthconspiracyblog.files.wordpress.com/2015/01/heart.jpg, www.ck12.org