Medical Terminology Simplified

5–110 An aneurysm is an abnormal dilation of the vessel wall due to a weakness that

causes the vessel to balloon and potentially rupture. There are three types of aneurysms:

fusiform, with a dilation of the entire circumference of the artery; saccular,with bulging

on only one side of the artery wall; and dissecting, with an inner layer tear (dissection)

that causes a cavity to form and fill with blood with each heartbeat. (See Fig. 5–9.)

A ballooning out of the wall of the aorta is called an aort/ic

____________________.

5–111 If a cerebr/al aneurysm ruptures, the hem/o/rrhage occurs in the cere-

brum or brain. If an aort/ic aneurysm ruptures, the hem/o/rrhage occurs in the

____________________.

5–112 Identify the words in Frame 5–111 that mean

pertaining to the aorta:__________ / __________

bursting forth (of) blood:__________ / _____ / ____________________

pertaining to the cerebrum:____________________ / __________

dilation of a vessel caused by weakness:____________________

LYMPHATIC SYSTEM

The lymphatic system consists of lymph, lymph vessels, lymph nodes, and three organs: the tonsils, thymus, and spleen.
The lymphatic system has three main functions:

1. It drains excess interstitial fluid from tissue spaces and returns it to circulating blood.


2. It protects the body by defending against foreign or harmful agents, such as bacteria, viruses, and
   cancerous cells.


3. It absorbs and transports digested fats to venous circulation. These fats are provided by aggregations of
   lymphatic tissue known as Peyer patches that are present in the lining of the ileum (small intestine).
   The fluid (lymph) circulating through the lymphatic system comes from the blood. It contains white blood cells
   (leukocytes) responsible for immunity, as well as monocytes and lymphocytes. As certain constituents of blood plasma
   filtrate through tiny capillaries into the spaces between cells, they become interstitial fluid. Most interstitial fluid is
   absorbed from the interstitial (or intercellular) spaces by thin-walled vessels called lymph capillaries. At this point of
   absorption, interstitial fluid becomes lymph and is passed through lymphatic tissue called lymph nodes. The nodes
   are found in clusters in such areas as the neck (cervic/al lymph nodes), under the arm (axill/ary lymph nodes), the
   pelvis (ili/ac lymph nodes), and the groin (inguin/al lymph nodes). The nodes act as filters against foreign materials.
   Eventually, lymph reaches large lymph vessels in the upper chest and reenters the bloodstream. (See Fig. 5–1.)

Frame 5–101to Frame 5–112

Lymphatic System • CHAPTER 5 181

aort/ic

ā-ŎR-tĭk

hem/o/rrhage

HĔM-ĕ-rĭj

cerebr/al

SĔR-ĕ-brăl

aneurysm

ĂN-ū-rĭzm

aorta

ā-ŎR-tă

aneurysm

ĂN-ū-rĭzm

Fusiform Saccular Dissecting

Figure 5-9Aneurysms. (A)Fusiform. (B)Saccular. (C)Dissecting.

AB C