1. Copyright © 2009 Pearson Education, Inc. THE HUMAN CARDIOVASCULAR SYSTEM

2. The Heart  The heart is a muscular organ that pumps blood throughout the body.  The heart functions as two separate pumps. systemic circulation  In systemic circulation the left side of the heart pumps oxygen-rich blood to the rest of the body. pulmonary circulation  In pulmonary circulation the right side pumps oxygen-poor blood from the heart to the lungs.

4. Copyright © 2009 Pearson Education, Inc. 23.4 The heart contracts and relaxes rhythmically  Cardiac output –Amount of blood/minute pumped into systemic circuit  Heart rate –Number of beats/minute

5. Copyright © 2009 Pearson Education, Inc. 23.6 CONNECTION: What is a heart attack?  A heart attack is damage to cardiac muscle –Typically from a blocked coronary artery  Stroke –Death of brain tissue from blocked arteries in the head

6. Blockage Dead muscle tissue Right coronary artery Superior vena cava Pulmonary artery Aorta Left coronary artery

7. Copyright © 2009 Pearson Education, Inc. 23.6 CONNECTION: What is a heart attack?  Atherosclerosis –Plaques develop inside inner walls of blood vessels –Plaques narrow blood vessels –Blood flow is reduced

8. Plaque Epithelium Connective tissue Smooth muscle

10. Copyright © 2009 Pearson Education, Inc. 23.7 The structure of blood vessels fits their functions  Capillaries –Thin walls—a single layer of epithelial cells –Narrow—blood cells flow in a single file –Increase surface area for gas and fluid exchange

11. Nuclei of smooth muscle cells Red blood cell Capillary

12. Diffusion of molecules Capillary Interstitial fluid Tissue cell

13. Connective tissue Capillary Venule Smooth muscle Arteriole ArteryVein Valve Epithelium Basal lamina Epithelium Smooth muscle Epithelium Connective tissue

14. Copyright © 2009 Pearson Education, Inc. 23.8 Blood pressure and velocity reflect the structure and arrangement of blood vessels  Blood pressure –The force blood exerts on vessel walls –Depends on –Cardiac output –Resistance of vessels –Decreases as blood moves away from heart

15. Copyright © 2009 Pearson Education, Inc. 23.8 Blood pressure and velocity reflect the structure and arrangement of blood vessels  Blood pressure is –Highest in arteries –Lowest in veins  Blood pressure is measured as –Systolic pressure—caused by ventricular contraction –Diastolic pressure—low pressure between contractions

16. Copyright © 2009 Pearson Education, Inc. 23.8 Blood pressure and velocity reflect the structure and arrangement of blood vessels  How does blood travel against gravity, up legs? –Pressure from muscle contractions –Between two muscles –Between muscles and bone or skin –Squeezes veins –One-way valves limit blood flow to one direction, towards heart

17. Direction of blood flow in vein Valve (open) Skeletal muscle Valve (closed)

18. Copyright © 2009 Pearson Education, Inc. 23.9 CONNECTION: Measuring blood pressure can reveal cardiovascular problems  Hypertension is a serious cardiovascular problem –Consistent pressures above either –140 systolic –90 diastolic

19. Copyright © 2009 Pearson Education, Inc. 23.9 CONNECTION: Measuring blood pressure can reveal cardiovascular problems  Hypertension causes –Heart to work harder, weakening heart over time –Increased plaque formation from tiny ruptures –Increased risk of blood clot formation  Hypertension can cause –Heart attacks –Strokes –Kidney failure

20. Resistance  For blood flowing through a vessel, resistance is influenced by 4 parameters:  the radius or thickness of the blood vessel  the length of the blood vessel  the viscosity or thickness of the blood  the presence of an obstruction in a vessel  If the tube length increases, resistance increases  If the viscosity increases, resistance increases  If the tube’s radius increases, resistance decreases  If there is any obstructions, resistance increases

21. REPRODUCTIVE SYSTEM

23.  Where is sperm produced?  In a vasectomy, what is cut or blocked? What happens as a result of this?  If the urethra is cut, what happens?  What happens if the testes are damaged?

24. The First Trimester Heart begins to beat Nervous system forms Fetus begins to get nourishment from mother through the placenta via the umbilical cord. Placenta anchors fetus to mother. Fingers and toes form and teeth buds are present.

25. Second Trimester  Teeth form  Eyes open  Bone replaces cartilage  Hair grows  Fetus moves around and kicks

26. Third Trimester  Baby grows rapidly  Lungs mature in preparation for birth

27. Immune System

28. First Line of Defense (Try to keep Pathogens from entering body system) Non-Specific Defense  Skin – keeps pathogens out of the body by forming a barrier.  Mucous, saliva, tears – contain enzymes to kill bacteria and other pathogens.  Stomach acid – kills pathogens that come in with food.

29. Second Line of Defense (Pathogen has entered the body) Non-Specific Defense  Inflammatory Response – wound swells because histamines cause blood vessels to expand and allow phagocytes to come and destroy the invaders.  Interferons – are produced to help keep viruses from replicating.  Fever – caused by release of certain chemicals, serves to speed up immune response and could slow down growth of pathogens.

30. Third Line of Defense Specific Response  Specific Defense (acquired) is a targeted response to one specific pathogen. Includes the use of antibodies, t-cells and macrophages. The specific defense also leads to the creation of memory cells. Pathogens have antigens that identify it as foreign and stimulate the immune system to produce cells that recognize, attack (antibodies), destroy (B-Cells in the blood and T-Cells for infected cells), and “remember” (B-Cells and Memory T-Cells stay in the body) in order to be ready for the next time.

32. Vaccines  Weakened virus or virus parts stimulate the immune system to produce B-Cells and Memory T-Cells. Now the body system is ready to specifically combat that pathogen when it comes again.  Used for treatment of bacterial infections. They are not effective against viruses, parasites or fungal infections.