1D - Biol 165 - The Skeletal System (Muscles, Cardiovascular Circuits, Lymphatic system)

Skeletal Muscle

A muscle that is attached to the bones of the skeleton and provides the force that moves the bones, these movements are voluntary and are controlled.

*moves skeleton

Cardiac muscle

Involuntary muscle tissue found only in the heart.

*moves blood

Smooth muscle

Involuntary muscle found inside many internal organs of the body

*moves blood, food

Muscle Cells

Shorten to cause movement of the body. They are organized into tissues and move the skeleton, heart, and internal organs. These muscle cells are called fibers because they are long and narrow when relaxed.

Epimysium

a sheath of fibrous elastic tissue surrounding a muscle.

Perimysium

Connective tissue surrounding a fascicle. Fascicles are small compartments of muscle fibers.

Endomysium

Connective tissue surrounding a muscle fiber.

Myofibrils

protein structures that make up muscle fibers.

pulmonary circulation

The passage of venous blood from the right atrium of the heart through the right ventricle and pulmonary arteries to the lungs where it is oxygenated and its return via the pulmonary veins to enter the left atrium and participate in systemic circulation.

* Artery's are more thicker than veins because they have more components. They have an elastic membrane and smooth muscles.

* difference: since veins don't have smooth muscles they have a valve cusps that helps pump the blood back to the heart.

Layers of Arteries and Veins

Top layer is the Adventitia, Middle layer is the MEdia containing smooth muscle, the internal layer is the Intema. the lumen is in the middle and is where the blood flows.

Lymphatic system

(overflow system) The network of vessels through which lymph drains from the tissues into the blood. The drained liquid includes fluid that is not reabsorbed by the capillaries and the plasma proteins that leak into the extracellular spaces. Also removes debris from cellular decomp and infection.

* the lymphatic system also works as a defense mechanism for the body that can respond to foreign proteins from an infected area and create antibodies.

* The reason why lymph nodes are enlarged when someone has an infection.

Lymphatic Plexuses

Network of lymphatic capillaries, originating in the extracellular spaces. Permeable to tissue fluid, plasma proteins, bacteria, cellular debris, and whole cells (especially lymphocytes)

Lymphatic Vessels

large vessels with valves, which collect and carry lymph to lymph nodes from the Lymphatic capillaries.

Lymphatic Trunks

Large lymphatic vessels that drain lymph from different parts of the body.

Lymph

The watery fluid in the lymph vessels collected from the tissue spaces.

* similar to blood plasma

Lymph nodes

Bean-shaped filters that cluster along the lymphatic vessels of the body. They function as a cleanser of lymph.

Lymphocyte

Cells apart of the immune system that react against foreign materials.

Lymphoid Organs

parts of the body that produce lymphocytes.

Primary Lymphoid Organs

red bone marrow and thymus

Secondary Lymphoid Organs

Spleen, lymph nodes and tonsils.

Superficial & Deep Lymphatic vessels

drain lymph from arteries and internal organs.

Left Lymphatic trunk

drains lymphatic fluid from the left part of the body and drains fluid from both lungs.

Right Lymphatic trunk

drains right upper quadrant only.

Right lymphatic duct

Receives lymph from the right upper part of the body

Thoracic duct

receives lymph from the left side of the head, neck, chest, abdomen, left arm, and lower extremities