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.

1Compilation: Lisa Radmall

Vessels: Layers of Vessel Wall

2

• 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

3Fig. 23.1

Vessels: System Comparison

4Fig. 23.3

Vessels: Histology

5Fig. 23.2

Vessels: Histology

6

Vessels: Identification on Cadavers

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• Arteries• Round shape

• Collapse when ‘pinched’ (hollow lumen)

• Rebounds to round shape

• Veins• Flat shape

• Usually collapsed

• Often dark in color

• Nerves• Round shape

• Does not collapse when ‘pinched’ (contains nerve fibers)

Circulation: Overview

8

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

9

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

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Left

Rightpulmonaryveins

Rightpulmonary artery

Left pulmonary artery

Left pulmonarycapillaries

Rightpulmonarycapillaries

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(A) A

scen

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Aorta

Systemic Circulation: Arterial Flow Away From Heart

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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)

Aortic Arch

(B) Brachiocephalic trunk

(C) Left Common Carotid Artery

(S) Left Subclavian Artery

Systemic Circulation: Venous Return to Heart

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• 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

13Fig. 22.5b

Circulation: Head and Neck – Arterial Supply

14Fig. 23.10a

Circulation: Head and Neck – Arterial Supply

15Fig. 23.11a

Circulation: Head and Neck – Venous Drainage

16Fig. 23.11b

Circulation: Head and Neck – Venous Drainage

17Fig. 23.10b

Circulation: Ventral Cavity – Arterial Supply

18Fig. 23.12

Circulation: Ventral Cavity – Celiac Trunk

19Fig. 23.15a

Circulation: Ventral Cavity – Mesenteric Arteries

20Fig. 23.15b

Circulation: Ventral Cavity – Venous Drainage

21Fig. 23.13

Circulation: Hepatic Portal System

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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

23Fig. 23.16

Circulation: Hepatic Portal System Mnemonic

24Table 23.3

Visual Mnemonic: The location of the main veins of the hepatic portal system seem to form a visual “chair” when isolated.

Circulation: Arterial Supply to Upper Limb

25Fig. 23.19a

**All vessels are paired**(right and left sides)

Circulation: Venous Return to Upper Limb

26Fig. 23.19b

**All vessels are paired**(right and left sides)

Circulation: Arterial Supply to Lower Limb

27Fig. 23.20a

**All vessels are paired**(right and left sides)

Circulation: Venous Return to Lower Limb

28Fig. 23.20b

**All vessels are paired**(right and left sides)

Circulatory System - Summary

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Circulatory System – Plastinated Vessels

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Image References

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