Unit 4: Blood Vessels and the Lymphatic System

Blood vessels

The structures that carry blood from the heart to the organs of the body and back to the heart again.

lumen

The space within the blood vessel

3

The walls of all blood vessels (except capillaries) are comprised of how many layers (tunics)?

Tunica Adventitia

The outer tunic made up of collagen fibers and connective tissue that protect the blood vessel and anchor it to surrounding tissues

collagen fibers, connective tissue

Tunica Adventitia is made of ____ and ____

Tunica Media

The middle tunic which consists of smooth muscle and elastic fibers.

smooth muscle, elastic fibers

Tunica Media is made of ____ and ____

thicker, thinner

The tunica media is the ___ layer in arteries and ___ in veins.

Autonomic Nervous System

The smooth muscle of the tunica media is controlled by what? This allows vasoconstriction/vasodilation to regulate circulatory dynamics.

Tunic Intima

The inner-most tunic which is made of connective tissue and flat, tightly bound endothelial cells which create a smooth surface within the lumen of the blood vessel.

connective tissue, fat, and endothelial cells

Tunica Intima is made up of ____, ___, and _____

Capillaries

What lack the tunica media and tunica adventitia layers and only possess the tunica intima which allows gas exchange between the tissues?

Artery

A blood vessel that carries blood away from the heart (regardless of whether it carries oxygenated or deoxygenated blood).

smooth muscle, elastic fibers

Artery walls are composed of ___ ___ and ___ ___ that allow for extension of the vessels and the carrying of a pulse.

Arterioles

Small arteries that arise via branching of larger arteries. Smooth muscle and elastic fibers are also located in the walls of these.

Capillaries

Arterioles branch to form what?

Capillaries

Form connections between arterioles and venules.

capillary

It is at the ___ level where oxygen and nutrients pass from the blood into the tissues and where carbon dioxide and waste materials pass from the tissues into the blood

Venules

Small veins formed by the junction of a number of capillaries.

Veins

Vessels formed by the junction of a number of venules. They are said to be formed by tributaries and carry blood back to the heart.

Veins

What has a thinner wall than the corresponding artery?

valves

Certain veins, especially those that carry blood against gravity, contain ___ that allow for the flow of blood only in one direction, toward the heart.

contraction of surrounding muscles

How does blood move past the valves?

Arteriosclerosis

the thickening of the blood vessels due to increased blood pressure. This occurs gradually over time and is typically observed in older patients.

Atherosclerosis

a specific form of arteriosclerosis and involves the formation of plaques which occur due to excessive cholesterol intake. The plaque narrows the lumen of the blood vessel thus restricting blood flow to the tissues.

exceeds

The fluid filtered out of blood capillaries each day ___ that reabsorbed.

90%

What % of the interstitial fluid is returned directly to the circulatory system; being reabsorbed through the capillaries?

10%

What % of the interstitial fluid remains within the tissues?

lymphatics

The excess interstitial fluid is returned to the blood through what?

Lymph Fluid

What is excess interstitial fluid also called?

Lymphatic capillaries

Capillaries that pick up the Lymph Fluid and differ from blood capillaries in that they are endothelial tubes that begin blindly. They are not open at both ends and conduct the Lymph toward veins.

Afferent Lymphatic Vessel

As the lymphatic capillaries conduct lymph toward veins, a number of them will join to form what?

valves

Lymphatic vessels consists of similar layers that comprise the blood vessels. They contain folds termed ___ which allow for the flow of lymph in one direction, toward the veins.

Lymph Nodes

Afferent lymphatic vessels convey lymph to what things which function in filtering lymph?

Cortex, Medulla

Each node has what 2 things through which lymph will filter?

B and T lymphocytes

Lymph nodes are sits of maturation for what things that are important tissues involved in the body's immune response against foreign material and pathogens?

Efferent Lymphatic Vessels

What leaves the lymph node that also contains valves? These pass filtered lymph to the venous system by forming 2 ducts that drain into the left and right brachiocephalic veins.

Right Lymphatic Duct

Duct that drains the right half of the head, neck, chest, and right upper limb.

Thoracic Duct

Duct that drains the entire rest of the body.

Right Lymphatic Duct

Duct that drains lymph into the Right Brachiocephalic Vein.

Thoracic Duct

Duct that drains lymph into the Left Brachiocephalic Vein.

neck, axilla, inguinal region (groin)

What regions are there prevalent Lymph nodes?