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

2. 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

3. 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.

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

5. 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

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

7. Remember: The respiratory system exchanges oxygen and carbon dioxide

8. 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

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

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

11. Unhealthy lungs

12. Lung Recap
What is in your lungs?

13. 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.

14. 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.

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

16. 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

17. What’s going on inside…

18. 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

19. 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.

20. 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

21. 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.

22. 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

23. 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

24. Platelets and different types of blood cells have different functions
The bone marrow manufactures most of the blood components.
Red blood cells make up % 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.

25. Platelets help form clots that control bleeding

26. 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.

27. 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.