Respiratory, Circulatory and Lymphatic Systems Human Body Systems Respiratory, Circulatory and Lymphatic Systems

Think about it… The respiratory and circulatory systems bring oxygen and nutrients to the cells. The respiratory and circulatory systems work together to maintain homeostasis. The circulatory system transports blood and other materials. brings supplies to cells carries away wastes separates oxygen-poor and oxygen-rich blood

In a nutshell… The respiratory system is where gas exchange occurs. picks up oxygen from inhaled air expels carbon dioxide and water The lungs contain the bronchi, bronchioles, and alveoli. Millions of alveoli give the lungs a huge surface area. The alveoli absorb oxygen from the air you inhale.

Breathing… Breathing involves the diaphragm and muscles of the rib cage. Air flows from areas of high pressure to low pressure.

The circulatory system moves blood to all parts of the body The system includes the heart, arteries, veins, and capillaries. heart pumps blood throughout body arteries move blood away from heart veins move blood back to heart capillaries get blood to and from cells

There are three major functions of the circulatory system transporting blood, gases, nutrients collecting waste materials maintaining body temperature

Remember: The respiratory system exchanges oxygen and carbon dioxide

Gas exchange occurs in the alveoli of the lungs Oxygen and carbon dioxide are carried by the blood to and from the alveoli. oxygen diffuses from alveoli into capillary oxygen binds to hemoglobin in red blood cells carbon dioxide diffuses from capillary into alveoli

How is breathing regulated? Breathing is regulated by the brain stem.

Respiratory diseases interfere with gas exchange Lung diseases reduce airflow and oxygen absorption. Emphysema destroys alveoli. Asthma constricts airways. Cystic fibrosis produces sticky mucus.

Unhealthy lungs

Lung Recap What is in your lungs?

The tissues and structures of the heart make it an efficient pump The heart is a muscular pump that moves the blood through two pathways. Cardiac muscle tissue works continuously without tiring.

Parts of the heart The heart has four chambers: two atria, two ventricles. Valves in each chamber prevent backflow of blood. Muscles squeeze the chambers in a powerful pumping action.

The heartbeat consists of two contractions SA node, or pacemaker, stimulates atria to contract AV node stimulates ventricles to contract

Blood flows through the heart in a specific pathway oxygen-poor blood enters right atrium, then right ventricle right ventricle pumps blood to lungs oxygen-rich blood from lungs enters left atrium, then left ventricle left ventricle pumps blood to body

What’s going on inside…

Pulmonary circulation occurs between the heart and the lungs oxygen-poor blood enters lungs excess carbon dioxide and water expelled blood picks up oxygen oxygen-rich blood returns to heart oxygen-rich blood goes to organs, extremities oxygen-poor blood returns to heart The two pathways help maintain a stable body temperature

The circulatory system transports materials throughout the body Arteries carry blood away from the heart. blood under great pressure thicker, more muscular walls Veins carry blood back to the heart blood under less pressure thinner walls, larger diameter valves prevent backflow Capillaries move blood between veins, arteries, and cells.

Blood pressure is a measure of the force of blood pushing against artery walls systolic pressure: left ventricle contracts diastolic pressure: left ventricle relaxes High blood pressure can precede a heart attack or stroke

Lifestyle plays a key role in circulatory diseases Some choices lead to an increased risk of circulatory diseases. smoking long-term stress excessive weight lack of exercise diet low in fruits and vegetables, high in saturated fats Circulatory diseases affect mainly the heart and the arteries.

Blood is a complex tissue that transports materials Blood is composed mainly of cells, cell fragments, and plasma Whole blood is made up of different materials. plasma red blood cells white blood cells platelets

Plasma is a key factor in maintaining homeostasis molecules diffuse into and out of plasma contains proteins that stabilize blood volume contains clotting factors contains immune proteins

Platelets and different types of blood cells have different functions The bone marrow manufactures most of the blood components. Red blood cells make up 40-45 % of all blood cells. transport oxygen to cells and carry away carbon dioxide have no nuclei and contain hemoglobin White blood cells fight pathogens and destroy foreign matter.

Platelets help form clots that control bleeding

The lymphatic system provides another type of circulation in the body Lymph is collected from tissues and returned to the circulatory system The lymphatic system collects fluid that leaks out of the capillaries. Lymph vessels have valves to prevent backflow. Lymph nodes filter the lymph and destroy foreign matter. Lymph vessels return cleaned fluid to the circulatory system. If lymph vessels or nodes are damaged, lymph collects in an area.

The lymphatic system is a major part of the immune system Structures in the lymphatic system help fight disease. tonsils filter bacteria and viruses thymus develops white blood cells spleen filters lymph, contains immune cells Lymphocytes help destroy pathogens, parasites, and foreign matter.