Transcript 1. Circulation & The Blood

Circulation & The Blood
Functions of the Circulatory System
• Transport oxygen to cells
• Transport nutrients from the
digestive system to body cells
• Transport hormones to body cells
• Transport waste from body cells to
excretory organs
• Distribute body heat
Gastrovascular Cavity of Aurelia
Open Circulatory System
Closed Circulatory System
Ventricle
Atrium
Circulatory Systems in Fish, Amphibian, & Mammal
Electrocardiogram (ECG)
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P = atrial depolarization ~ 0.1 sec atria contracts
QRS = ventricular depolarization ventricles contract
(lub), contraction stimulated by Ca++ uptake
T = ventricular repolarization  ventricles relax (dub)
Vein
Artery
Tunica intima
Valve
Tunica media
Tunica externa
Artery
vein
Arteries
• Carry blood away from the heart.
• Thick-walled to withstand hydrostatic
pressure of the blood during ventricular
systole.
• Blood pressure pushes blood through
arteries.
Veins
• Carry blood to the heart.
• Thinner-walled than arteries.
• Possess one-way valves that prevent backwards
flow of blood.
• Blood flow due to body movements, not from
blood pressure.
One-Way Valves in
Veins
Capillaries
capillary vessel
arteriole
venule
capillaries
arteriole
blood
capillaries
lymphatic
capillaries
venule
lymphatic
vessel
Lymph Transport
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lacks pump for circulation
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relies on activity of skeletal muscles and pulsation of
nearby arteries for movement of fluid
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3L of lymph enters blood stream every 24 hrs
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proteins easily enter lymphatic system
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uptake of large particles such as cell debris, pathogens,
and cancer cells
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lymph nodes where it is cleansed of debris and examined
by cells of the immune system (WBC)
Formation of Lymph
interstitial fluid
blood capillary
lymphatic capillary
tissue cell
Sphygnomamometer
Measuring Blood Pressure
Superficial Pulse Points- arteries, not veins
temporal
60 beats/minute – avg.
facial
carotid
brachial
radial
popliteal
Posterior
tibial
femoral
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Dorsal pedis
Temporal artery
Facial artery
Common carotid artery
Brachial artery
Radial artery
Femoral artery
Popliteal artery
Posterior tibial artery
Dorsal pedis artery
Artery
White blood cells
Platelets
Red blood cells
• Deliver O2
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Remove metabolic wastes
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Maintain temperature, pH, and fluid volume
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Protection from blood loss- platelets
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Prevent infection- antibodies and WBC
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Transport hormones
Plasma-55%
Buffy coat-<1%
Formed
elements-45%
90% Water
8% Solutes:
• Proteins
Albumin (60 %)
Alpha and Beta Globulins
Gamma Globulins
fibrinogens
• Gas
• Electrolytes
• Organic Nutrients
Carbohydrates
Amino Acids
Lipids
Vitamins
• Hormones
• Metabolic waste
CO2
Urea
• Leukocytes
• Platelets
• Erythrocytes (red blood cells)
• Leukocytes (white blood cells)
• Platelets
Erythrocytes
Erythrocyte
7.5m in dia

- (lacks a nucleus)so can't reproduce from
themselves, reproduced in red bone marrow
 Hematopoiesis- production of RBC
 Function- transport respiratory gases
 Hemoglobin- quaternary structure, 2  chains and
2  chains
 Lack mitochondria. Why?
 1 RBC contains 250 million hemoglobin molecules
 Men- 5 million cells/mm3
 Women- 4.5 million cells/mm3
 Life span 100-120 days and then destroyed in
spleen (RBC graveyard)
Types of Leukocytes
4,000-11,000 cells/mm 3
Granulocytes
Neutrophils- 40-70%
Eosinophils- 1-4%
Basophils- <1%
Agranulocytes (lacks ganulocytes)
Monocytes- 4-8%
Lymphocytes- 20-45%
Diapodisis
Leukocyte Squeezing
Through Capillary Wall
Parapodium (functions as gill)
(a) Marine worm
Gills
(b) Crayfish
Coelom
Gills
Tube foot
(c) Sea star
Fluid flow
through
gill filament
Oxygen-poor blood
Anatomy of gills
Oxygen-rich blood
Gill
arch
Lamella
Gill
arch
Gill filament
organization
Blood
vessels
Water
flow
Operculum
Water flow
between
lamellae
Blood flow through
capillaries in lamella
Countercurrent exchange
PO2 (mm Hg) in water
150 120 90 60 30
Gill filaments
Net diffusion of O2
from water
to blood
140 110 80 50 20
PO2 (mm Hg) in blood
Countercurrent exchange system
Tracheal Systems
Air sacs
Tracheae
External
opening
Tracheoles
Mitochondria
Muscle fiber
Body
cell
Air
sac
Tracheole
Trachea
Air
Body wall
2.5 µm
Branch of
pulmonary
vein
(oxygen-rich
blood)
Branch of
pulmonary
artery
(oxygen-poor
blood)
Terminal
bronchiole
Nasal
cavity
Pharynx
Larynx
Alveoli
(Esophagus)
Left
lung
Trachea
Right lung
Bronchus
Bronchiole
Diaphragm
Heart
SEM
50 µm
Colorized
SEM
50 µm
Rib cage
expands as
rib muscles
contract
Air
inhaled
Rib cage gets
smaller as
rib muscles
relax
Air
exhaled
Lung
Diaphragm
INHALATION
Diaphragm contracts
(moves down)
EXHALATION
Diaphragm relaxes
(moves up)
Air
Anterior
air sacs
Posterior
air sacs
Air
Trachea
Lungs
Lungs
Air tubes
(parabronchi)
in lung
INHALATION
Air sacs fill
EXHALATION
Air sacs empty; lungs fill
1 mm
Cerebrospinal
fluid
Pons
Breathing
control
centers
Medulla
oblongata
Carotid
arteries
Aorta
Diaphragm
Rib muscles
Uptake of Oxygen by
Hemoglobin in the Lungs
O2 binds to hemoglobin to form oxyhemoglobin
High Concentration of O2 in Blood Plasma
High pH of the Blood Plasma
Unloading of Oxygen from
Hemoglobin in the Tissues
When O2 is releaseddeoxyhemoglobin
Low Concentration of O2 in Blood Plasma
Lower pH of the Blood Plasma
Carbon Dioxide Chemistry
in the Blood
CO2 + H2O  H2CO3  HCO3- + H+
carbonic
acid
bicarbonate
ion
enzyme = carbonic anhydrase
Transport of Carbon Dioxide
from the Tissues to the Lungs
• 60-70% as bicarbonate dissolved in the
plasma (slow reaction)
• 7-10% dissolved in the plasma as CO2
• 20-30% bound to hemoglobin as HbCO2
CO2 + hemoglobin  HbCO2
Haldane Effect- the amount of CO2 transported in the
blood is markedly affected by the degree of
oxygenation of the blood
The lower the P02 and hemoglobin saturation with O2,
the more CO2 that can be carried by the blood
7. Deep-diving air-breathers stockpile
oxygen and deplete it slowly
Deep Diving Breath-holding
• Adaptations to pressure
- Collapse of lung cavity (ribs)
- Collapse of lungs
7. Deep-diving air-breathers stockpile
oxygen and deplete it slowly
Adaptations to oxygen conservation
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Oxygen stores 2-3 x more than humans
– Humans: 36% of our total O2 in lungs and 51% in our
blood.
– Weddell seal holds 5% of its O2 in its small lungs and
stockpiles 70% in the blood.
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Skeletal muscles and blood as primary storage site
(myoglobin)
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Weddell seal to store about 25% of its O2 in muscle,
13% in humans
Deep-diving air-breathers stockpile
oxygen and deplete it slowly
Adaptations to oxygen conservation
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Reduce heart rate when diving (120 beats/min to 6
b/min)
• Seals and sea lions store oxygenated blood in their
extra-large spleen (which can be 45% of their body
weight)
• Maintain blood flow to brain, heart
Average Dive Times
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Sperm whale: 90 minutes to 2 hrs
Northern elephant seal: 20 to 35 minutes
Harbor seal: 3 to 7 minutes
Walrus: 10 minutes
Bottlenose dolphin: 8 minutes
Killer whale: 10 minutes
Amazon river dolphin: 2 minutes
Loggerhead turtle: 20 minutes