Biology. A Guide to the Natural World. Chapter 30 Lecture Outline Transport and Exchange 1: Blood and Breath. Fifth Edition.

Transcription

1 Biology A Guide to the Natural World Chapter 30 Lecture Outline Transport and Exchange 1: Blood and Breath Fifth Edition David Krogh

2 30.1 The Cardiovascular System

3 The Cardiovascular System The human cardiovascular system is a fluid transport system that consists of the heart, all the body s blood vessels, the blood, and the bone marrow tissue in which red blood cells are formed.

4 The Cardiovascular System This system transports substances both to and from the body s cells. Such substances include oxygen, carbon dioxide, nutrients, vitamins, hormones, waste products, and immune system cells and proteins.

5 Respiratory system moves O 2 into, and CO 2 out of, the body. Cardiovascular system transports materials to and from all other systems. Digestive system transforms food into a form that can be transported throughout the body. Urinary system filters bodily fluids, removes waste while conserving water and other materials. Figure 30.1

6 30.2 The Composition of Blood

7 The Composition of Blood Blood has two primary components: formed elements and blood plasma. Formed elements are blood cells and cell fragments. Blood plasma is the fluid portion of blood in which the formed elements are suspended.

8 The Composition of Blood There are three kinds of formed elements: red blood cells white blood cells platelets

9 blood sample 55% plasma formed elements 45% Formed elements Red blood cells 99.9% White blood cells Platelets 0.1% Plasma Water 92% Plasma proteins 7% Other solutes 1% Red blood cells White blood cells Platelets Figure 30.2

10 The Composition of Blood Red blood cells carry oxygen to, and carbon dioxide from, every part of the body. White blood cells are central to the immune system. Platelets are small fragments of cells that are important in the blood-clotting process.

11 Formed Elements Figure 30.3

12 Plasma Blood plasma is 92 percent water, but it also contains other materials, including proteins, nutrients, and hormones.

13 Plasma There are three primary classes of plasma proteins: Albumins, which transport hormones and fatty acids. Fibrinogen, which aids in blood clotting. Globulins, which aid the immune system and serve as transport proteins.

14 Transport Proteins Two transport proteins are important in the health of the heart. Low-density lipoproteins (LDLs) carry lipids to bodily tissues from the liver and small intestines. High-density lipoproteins (HDLs) carry lipids from these tissues to the liver.

15 30.3 Blood Vessels

16 Blood Vessels Blood vessels carrying blood away from the heart are arteries; blood vessels returning blood to the heart are veins.

17 Blood Vessels The smallest blood vessels, the capillaries, connect the arteries with the veins.

18 Blood Vessels connective tissue muscle epithelium connective tissue muscle epithelium vein artery capillary Figure 30.4

19 Blood Vessels Arteries and veins include an inner layer of epithelial cells, a middle layer of smooth muscle that allows arteries and veins to widen or constrict in diameter, and an outer layer of connective tissue.

20 Blood Vessels Capillaries, conversely, are composed of only a single layer of cells. This allows the movement of blood-borne materials into and out of them along their length.

21 30.4 The Heart and Blood Circulation

22 The Heart and Blood Circulation Two blood circulation loops exist in the body. Pulmonary circulation Blood circulates between the heart and the lungs (with the result that blood is oxygenated). Systemic circulation Blood circulates between the heart and the rest of the body (with the result that needed materials are transported to and from all parts of the body).

23 The Heart and Blood Circulation (a) The pulmonary and systemic circulation networks (b) The circulation of blood through the heart The right side of the heart pumps deoxygenated blood to the lungs. The left side of the heart pumps oxygenated blood to the entire body. superior vena cava 7. From the aorta, blood is distributed to the rest of the body. 3. Blood is delivered to the lungs via the pulmonary arteries. pulmonary circulation (to lungs) pulmonary arteries pulmonary veins 1. Deoxygenated blood enters the right atrium through the superior and inferior vena cavae. 4. Oxygenated blood returns from the lungs through the pulmonary veins. 5. Blood then moves into the left atrium which pumps it into the left ventricle. systemic veins systemic arteries 6. Powerful contractions of the left ventricle force blood into the aorta. systemic circulation (to all tissues) inferior vena cava 2. The right atrium pumps blood into the right ventricle, which contracts, pumping blood to the lungs. Figure 30.5

24 The Heart and Blood Circulation The human heart contains four muscular chambers: Two for pulmonary circulation (the right atrium and right ventricle). Two for systemic circulation (the left atrium and left ventricle).

25 The Heart and Blood Circulation A series of valves that open and close ensures that blood flows only one way through the heart.

26 The Heart and Blood Circulation The pace at which the human heart beats is controlled by a specialized set of muscle cells that are located within the heart itself. These cells, which form the heart s sinoatrial node, generate electrical signals that prompt heart muscles to contract.

27 30.5 What Is a Heart Attack?

28 Heart Attacks Nearly 20 percent of all deaths in the United States today are caused by the blockage of one or more of the coronary arteries that supply heart tissue with blood.

29 Heart Attacks Such blockages generally are caused by a buildup of plaque in the wall of a coronary artery, followed by a movement of plaque into the bloodstream, and then formation of a blood clot.

30 Heart Attacks A heart attack occurs when this process results in the complete blockage of a coronary artery, which cuts off the blood supply to groups of cells within the heart, thus killing them.

31 Critical Vessels LDL molecules superior vena cava right coronary artery aorta pulmonary artery left main coronary artery left anterior decending coronary artery: blocked blood clot damaged heart muscle 1. LDL molecules infiltrate the wall of the artery; immune cells follow. 2. An inflammatory reaction follows; a growing number of cells and cellular debris form a plaque. 3. Plaque cap ruptures, sending plaque material into bloodstream; a blood clot forms that blocks blood flow. Figure 30.7

32 30.6 Distributing the Goods: The Capillary Beds

33 The Capillary Beds Arteries near the heart branch into smaller arterioles, which feed into the delivery vehicles of the cardiovascular system, the capillary beds.

34 Capillary Beds The capillary beds then feed back into the body s system of veins that returns blood to the heart.

35 (a) artery vein capillary bed arteriole venule (b) interstitial fluid O 2 glucose epithelial cells of capillary wall CO 2 wastes tissue cells (c) Figure 30.8

36 Capillary Beds Materials needed by the body s tissues move out of the capillaries and into the interstitial fluid that surrounds both the capillaries and nearby cells after which the materials move into cells. Meanwhile, carbon dioxide and wastes move from cells into the capillaries.

37 Capillary Beds The movement of all these substances is aided by their concentration gradients.

38 Capillary Beds Blood pressure is at low levels by the time blood has moved through the capillaries. Blood returns to the heart through the contraction of skeletal muscles, which squeeze the veins in a way that moves the venous blood toward the heart.

39 Valves allow blood to go forward but not backward valve open muscles contracted valve closed muscles relaxed valve closed valve open Figure 30.9

40 30.7 The Respiratory System

41 The Respiratory System The central function of the respiratory system is to capture oxygen and to dispose of carbon dioxide. It also aids in controlling ph balance in the bloodstream and in producing sounds for speaking.

42 The Respiratory System Respiration can be defined as the exchange of gases between the atmosphere outside the body and the cells within it.

43 The Respiratory System The respiratory system includes: the lungs, the nose, nasal cavity, and sinuses the pharynx (upper throat) the larynx (voice box) the trachea (windpipe) the conducting passageways, called bronchi and bronchioles, that lead to the lungs

44 The Respiratory System The lungs themselves are largely composed of the tiny hollow sacs, called alveoli. Alveoli lie at the end of each bronchiole and they are the air exchange chambers of the body.

45 (a) Anatomy of the respiratory system The Respiratory System (b) The structure of alveoli sinuses pharynx nasal cavity larynx trachea vein artery Elastic fibers alveoli left lung esophagus left bronchus right lung bronchioles capillary network (c) A bronchiole and its alveoli diaphragm Figure 30.10

46 The Respiratory System The enormous surface area of the alveoli and their associated capillaries is used for the exchange of oxygen and carbon dioxide.

47 30.8 Steps in Respiration

48 Steps in Respiration The first step in respiration is breathing or ventilation, meaning the physical movement of air into and out of the lungs.

49 Ventilation inhalation Elevation of rib cage and contraction of diaphragm decrease pressure in the lungs, causing air to flow in. respiratory cycle ribs lungs diaphragm exhalation Depression of rib cage and elevation of diaphragm increase pressure in lungs causing air to flow out. Figure 30.11

50 Steps in Respiration Once in the lungs, oxygen diffuses across the thin wall of an alveolus into an adjacent capillary and binds with hemoglobin protein in red blood cells.

51 Steps in Respiration Oxygen then moves with the blood cells to the heart. The heart pumps the blood to body tissues, where the oxygen diffuses into the interstitial fluid and then into nearby cells.

52 Steps in Respiration The carbon dioxide produced in the body s cells moves into nearby capillaries, to be carried to the lungs.

53 air out air in alveoli in lung O 2 CO 2 capillary CO 2 O 2 tissue cell Figure 30.12

54 Steps in Respiration All the oxygen loaded into red blood cells binds initially with the hemoglobin in them. Carbon dioxide is transported both within red blood cells and in blood plasma. Hemoglobin has a great capacity to bind to carbon monoxide as well as to oxygen.

55 The Respiratory System Animation 29.2: The Respiratory System