Circulation and Respiration

1
Circulation and Respiration

• Chapter 22

2
The Circulatory System

• Works with other organ systems
• Maintains volume, solute concentration and
  temperature of interstitial fluid
• Interstitial fluid and blood are bodys internal
  environment

3
Blood Circulation

• Blood flows through blood vessels
• Heart generates force to keep blood moving
• Closed system
• Blood is confined to vessels and heart
• Open system
• Blood mingles with fluid in tissues

4
Vertebrate Circulatory Systems
capillary beds of gills
heart
rest of body
a In fishes, a two-chambered heart (atrium,
ventricle) pumps blood in one circuit. Blood
picks up oxygen in gills, delivers it to rest of
body. Oxygen-poor blood flows back to heart.
Fig. 22-2a, p.362
5
Vertebrate Circulatory Systems
lungs
right atrium
left atrium
heart
rest of body
b In amphibians, a heart pumps blood through two
partially separate circuits. Blood flows to
lungs, picks up oxygen, returns to heart. But it
mixes with oxygen-poor blood still in the heart,
flows to rest of body, returns to heart.
Fig. 22-2b, p.362
6
Vertebrate Circulatory Systems
lungs
right atrium
left atrium
right ventricle
left ventricle
rest of body
c In birds and mammals, the heart is fully
partitioned into two halves. Blood circulates in
two circuits from the hearts right half to
lungs and back, then from the hearts left half
to oxygen-requiring tissues and back.
Fig. 22-2c, p.362
7
Functions of Blood

• Transports oxygen and nutrients to cells
• Carries carbon dioxide and wastes away from cells
• Helps stabilize internal pH
• Carries infection-fighting cells
• Helps equalize temperature

8
Components of Blood

• Plasma 55 of total volume
• Water
• Proteins
• Dissolved materials
• Cells
• Red blood cells 45 of total volume
• White blood cells
• Platelets

9
Blood Cell Development

• Stem cells in bone marrow produce blood cells and
  platelets
• Body continually replaces blood cells

10
Erythrocytes (Red Cells)

• Most numerous cells in blood
• Transport oxygen and carbon dioxide
• Colored red by oxygen-binding pigment
  (hemoglobin)
• Have no nucleus when mature

11
Leukocytes (White Cells)

• Function in housekeeping and defense
• Cell types
• Neutrophils
• Lymphocytes
• Monocytes
• Eosinophils
• Basophils

12
Platelets

• Membrane-bound cell fragments
• Derived from megakaryocytes, which arise from
  stem cells
• Release substances that initiate blood clotting

13
Vertebrate Circulatory Systems
lungs
right atrium
left atrium
right ventricle
left ventricle
rest of body
c In birds and mammals, the heart is fully
partitioned into two halves. Blood circulates in
two circuits from the hearts right half to
lungs and back, then from the hearts left half
to oxygen-requiring tissues and back.
Fig. 22-2c, p.362
14
Four Chambers

• Each side has two chambers
• Upper atrium
• Lower ventricle
• Valves between atria and ventricles

15
Heart Anatomy
13. aorta
1. superior vena cava
6. pulmonary arteries
12. left semilunar valve
5. right semilunar valve

• right pulmonary
• veins

8. left pulmonary veins
9. left atrium
2. right atrium
10. left AV valve
3. right AV valve
4. right ventricle
11. left ventricle
1. inferior vena cava

• LUNGS
• 14. Body

16
Conduction and Contraction

• SA node in right atrium is pacemaker
• Electrical signals cause contraction of atria
• Signal flows to AV node and down septum to
  ventricles
• Ventricles contract driving force for
  circulation

SA node
17
Blood Vessels

• Arteries carry blood away from heart
• Arterioles diameter is adjusted to regulate
  blood flow
• Capillaries diffusion occurs across thin walls

18
Blood Pressure

• Highest in arteries
• Usually measured in the brachial artery
• Systolic pressure is peak pressure
• Ventricular contraction (systole)
• Diastolic pressure is the lowest pressure
• Ventricular relaxation (diastole)

19
The Venous System

• Blood flows from capillaries to venules to veins
• Veins are large-diameter vessels with some smooth
  muscle in wall

20
Vein Function
valve closed
blood flow to heart
valve open
valve closed
venous valve
valve closed
Fig. 22-13, p.369
21
Hemostasis

• Processes that stop blood loss and repair vessels
• Blood vessel spasm
• Platelet plug formation
• Blood coagulation
• Clotting

22
Hypertension

• Blood pressure above 140/90
• Tends to be genetic
• May also be influenced by diet
• Contributes to atherosclerosis
• Silent killer, few outward signs

23
Coronary Artery Disease
coronary artery
aorta
coronary artery blockage
location of a shunt made of a section taken from
one of the patients other blood vessels
Fig. 22-16, p.371
24
Respiration

• Respiration
• Physiological process by which oxygen moves into
  an animals internal environment and carbon
  dioxide moves out
• Aerobic respiration
• Cellular process, produces ATP
• Oxygen is used
• Carbon dioxide is produced

25
Pressure Gradients

• Concentration gradients for gases
• Gases diffuse down their pressure gradients
• Gases enter and leave the body by diffusing down
  pressure gradients across respiratory membranes

26
Factors In Gas Exchange

• Surface-to-volume ratio
• Small, flat animals
• Ventilation
• Adaptations enhance exchange rate
• Respiratory pigments
• Hemoglobin and myoglobin

27
Fish Gills

• Usually internal
• Water is drawn in through mouth and passed over
  gills

water flows in through mouth
FISH GILL
water flows over gills, then out
28
NASAL CAVITY
ORAL CAVITY (MOUTH)
PHARYNX (THROAT)
EPIGLOTTIS
LARYNX (VOICE BOX)
TRACHEA (WINDPIPE)
PLEURAL MEMBRANE
LUNG (ONE OF A PAIR)
INTERCOSTAL MUSCLES
BRONCHIAL TREE
DIAPHRAGM
Fig. 22-21a, p.374
29
bronchiole
alveolar sac (sectioned)
alveolar duct
alveoli
Fig. 22-21b, p.374
30
alveolar sac
pulmonary capillary
Fig. 22-21c, p.374
31
Cutaway View of Alveolus
red blood cell
air space inside alveolus
(see next slide)
pore for airflow between alveoli
32
Respiratory Membrane

• Area between an alveolus and a pulmonary
  capillary
• Oxygen and carbon dioxide diffuse across easily

alveolar epithelium
capillary endothelium
fused basement membranes of both epithelial tissue
s
33
Oxygen Transport

• Most oxygen is bound to heme groups in hemoglobin
  in red blood cells
• Hemoglobin has higher affinity for oxygen when it
  is at high partial pressure (in pulmonary
  capillaries) picks up oxygen in lungs
• Lower affinity for oxygen in body tissues, where
  partial pressure is low releases oxygen

34
Carbon Dioxide Transport

• Most carbon dioxide is transported as bicarbonate
• Some binds to hemoglobin
• Small amount dissolves in plasma
• Carbon dioxide picked up from tissues and deliver
  to lungs

CO2 H2O
H2CO3 carbonic acid
HCO3 bicarbonate
H
35
Breathing

• Moves air into and out of lungs
• Occurs in a cyclic pattern called the respiratory
  cycle
• One respiratory cycle consists of inhalation and
  exhalation

36
Inhalation

• Diaphragm flattens
• External intercostal muscles contract
• Volume of thoracic cavity increases
• Lungs expand
• Air flows down pressure gradient into lungs

37
Normal (Passive) Exhalation

• Muscles of inhalation relax
• Thoracic cavity recoils
• Lung volume decreases
• Air flows down pressure gradient and out of lungs
• Active Exhalation
• Abdominal and internal intercostal muscles
  contract

38
Control of Breathing

• Nervous system controls rhythm and magnitude of
  breathing
• Breathing is adjusted as a result of changes in
• Carbon dioxide levels
• Oxygen levels
• Blood acidity

39
Speech Production
vocal cords
glottis (closed)
epiglottis

• Vocal cords stretch across laryngeal opening
• Opening between them is glottis
• Position of cords is varied to create different
  sounds

tongues base
Fig. 22-22a, p.375
40
glottis closed
glottis open
Fig. 22-22b, p.375
41
Bronchitis

• Irritation of the ciliated epithelium that lines
  bronchiole walls
• Caused by air pollutants, smoking, or allergies
• Excess mucus causes coughing, can harbor bacteria
• Chronic bronchitis scars and constricts airways

42
Emphysema

• Irreversible breakdown of lung tissue
• Lungs become inelastic
• May be caused by a genetic defect
• Most often caused by smoking

43
Effects of Smoking

• Shortened life expectancy
• Increased rate of cancers
• Increased rate of heart disease and high blood
  pressure
• Increased risk of stroke and heart attack
• Impaired immune function and healing
• Harmful to fetus