a&p chapters 18-21 Flashcards

the heart and blood vessels

arteries, capillaries, and veins

carry blood away from the heart

continues with the endocardium, blood flows easily here

thickest layer, composed of elastic tissue and smooth muscle.

made up of elastic tissue and smooth muscle, capable of stretching in response to the pumping of blood by the heart

composed of tough connective tissue, function is to support and protect.

the smallest artery, numerous and branch out

smallest and most numerous of all blood vessels

close to every cell, numerous, provide the cells with oxygen and nutrients

smallest of the arteries

• composed of smooth muscle that contact and relax
• have the thinnest walls of all blood vessels

• blood vessels that carry blood back to the heart
• smallest veins are called venules
• the largest veins empty the blood into the right atrium of the heart

converge from capillaries

wall of venule is slightly thicker than capillary wall

• largest of all arteries
• average diameter of a garden hose

1. ascending aorta
2. arch of the aorta
3. descending aorta

1. thoracic aorta
2. abdominal aorta

extends upward from the highest point of the aortic arch and supplies the left side of the head and neck

supply blood to the shoulders and upper arms

located superficially and can be seen

located more deeply and usually run parallel to the arteries

veins draining blood from the head, the shoulders, and the upper extremities empty into the SVC

main brain to drain the brain

a large vein that carries blood from the organs of digestion to the liver

• the largest organ In the body
• essential for keeping the body functioning properly

• removes poisons from the blood
• produces immune agents to control infection
• removes germs and bacteria in the blood

blood flow to the stomach, spleen, pancreas, intestines and liver

1. acts as a delivery system
2. regulate blood pressure
3. redistribute blood in response to changing body needs
4. help regulate body temperature

• pain. diminished oxygen supply stimulates pain receptors
• pulselessness. the blocked artery decreases the flow of blood to the extremity; the pulse distal to the occlusion is diminished or absent
• pallor. due to lack of blood the extremity is pale, especially when elevated
• paresthesia. diminished blood flow decreases the supply of oxygen to the nerves of the leg, causing numbness and tingling.
• paralysis. persistent oxygen deficit causes permanent nerve damage and paralysis (late sign)

1. skeletal muscle action
2. respiratory movements
3. constriction of ht veins

large veins in the legs are surrounded by skeletal muscles

• sympathetic nerve activity
• various hormones
• pharmacologic agents

• lymph nodes
• tonsils
• thymus gland
• spleen

small pea-shaped patches of lymphatic tissue strategically located so as to filter the lymph as it flows through the lymphatic vessels

located in the axillary or armpit. drain and cleanse lymph coming from the upper extremities, shoulder, and breast area

located in the groin region. drain and cleanse lymph from the lower extremities and external genetalia

partially encapsulated lymph nodes in the throat area

located near the opening of the nasal cavity in the upper pharynx

located at the back of the tongue

located in the upper mediastinum in thoracic cavity

hormone secreted by the thymus gland

largest lymphoid organ in the body

• filters blood rather than lymph

defense system

• protect the body from pathogens
• protect the body from foreign agents

protects the body against different types of foreign agents

intact skin and mucous membrane. pathogens cannot cross these structures to enter the body

secretions of the skin and mucous membranes

• phagocytes
• inflammation
• fever
• protective proteins
• natural killer cells

WBC'S ingest and destroy pathogens and other foreign substances

responses the body makes when confronted by an irritant

if an irritation is caused by a pathogen, the inflammation is called an infection

big eaters