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Levels of Organization
•
•
•
•
•
Chemical
Cellular
Tissue
Organs
System
Level
• Organismic
Chapter 19
Homeostasis & Organization of the
animal body
1-2
4 Primary Tissues
1.
2.
Epithelial Tissue:
– covers surfaces
– lines hollow organs, cavities and ducts
– forms glands (beneath surface)
1. Exocrine glands
2. Endocrine Glands
Connective Tissue: Living cells surrounded by a non-living matrix
–
can be liquid, gel-like, hard
– supports - binds structures together
– stores energy as fat
– provides immunity to disease
– transports things
– Includes: bone, cartilage, blood, tendons, ligaments, fat
4 Primary Tissues
3.
Muscle Tissue:
–
cells shorten in length producing movement
–
produce kinetic energy
3 types:
1. Skeletal: long, striated, muli-nuclei, voluntary
2. Cardiac: single nuclei, striated, branched, involuntary
3. Smooth muscle: no striations, tapered ends, involuntary,
single nuclei
4.
Nerve Tissue:
–
cells that conduct electrical signals
–
detect stimuli inside and outside the body
–
Communication
2 types of nervous tissue cells: glial cells & neurons
- Neuron anatomy!
3-3
3-4
Organ Systems: Two or more organs working
together to do a job
Integumentary system
Skin is an organ that contains
all 4 tissue types
3-5
Skeletal system
Muscular system
Lymphatic system
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Organ Systems
Organ Systems
Circulatory system
Nervous system
Urinary system
Respiratory system
A-7
Digestive system
Male reproductive system
Female reproductive system
Endocrine system
Figure A.11
Figure A.11
A-8
Negative Feedback Control of Blood Pressure
Homeostasis
• Homeostasis – the body’s ability to detect change, activate
mechanisms that oppose it, and thereby maintain relatively stable
internal conditions
Person rises
from bed
Negative Feedback, Set Point
Blood pressure rises
to normal; homeostasis
is restored
Blood drains from
upper body, creating
homeostatic imbalance
75
70
Set point
Cardiac center
accelerates heartbeat
65
Baroreceptors above
heart respond to drop
in blood pressure
60
Time
Baroreceptors send signals
to cardiac center of brainstem
1-9
Positive Feedback
1-10
Circulatory Systems
• Amplifes the change
• Functions of circulatory system
• Transportation of stuff
– leads to greater change in the same direction
– feedback loop is repeated – change produces more change
– Oxygen from lungs or gills to the tissues
– Carbon dioxide from tissues to the lungs or gills
– Nutrients from the digestive system to the tissues
– Hormones
– Waste products and toxic substances to the liver and
the kidney for excretion
• Regulate body temperature
• Protect from viruses & bacteria
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Circulatory Systems
• Open circulatory system
• Circulatory systems have three main
components:
– Blood
– Blood vessels
– Heart
heart
blood
bathes internal
organs
• Animals have two types of circulatory systems:
– Open circulatory system
– Closed circulatory system
blood
vessels
opening
with valves
tubular
hearts
hemocoel
(a) Open circulatory system
• Fish heart
• Closed circulatory system
Fig. 20-1a
gill capillaries
heart
extracellular fluid
ventricle
vessels branch in
each organ
atrium
vessel
hearts
small vessels
(b) Closed circulatory system
Fig. 20-1b
• Amphibian, and most reptiles’ heart
body capillaries
(a) Fish
Fig. 20-2a
• Mammals and birds’ heart
lung capillaries
lung capillaries
atria
atria
ventricle
ventricle
body capillaries
(b) Amphibians, most reptiles
Fig. 20-2b
body capillaries
(c) Mammals, birds
Fig. 20-2c
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• The human heart and its valves and vessels
• The cardiac cycle
pulmonary artery
(to left lung)
aorta
superior
vena cava
Oxygenated blood
is pumped to the
body
Deoxygenated blood is
pumped to the lungs
left atrium
pulmonary artery
(to right lung)
pulmonary veins
(from left lung)
pulmonary veins
(from right lung)
atrioventricular
valve
semilunar valves
Deoxygenated
blood from the
body enters the
right ventricle
right atrium
left ventricle
thicker muscle
of left ventricle
atrioventricular valve
inferior vena cava
Atria contract, forcing
blood into the ventricles
descending aorta
(to lower body)
right ventricle
Oxygenated blood from the
lungs enters the left ventricle
Blood fills the
atria and begins
to flow passively
into the ventricles
Then the ventricles
contract, forcing blood
through the arteries to the
lungs and the rest of the body
The cycle ends
as the heart relaxes
Fig. 20-3
What Is Blood?
• The heart’s pacemaker and its connections
The sinoatrial node
electrical signal starts
the atrial contraction
AV node
• Blood transports dissolved nutrients, gases, hormones, and
wastes through the body.
– It has two major components:
• Fluid, called plasma
• Cellular components—including red blood cells, white
blood cells, and platelets—which are suspended in the
plasma
– The cellular components are produced in bone marrow and
later move into the blood.
Unexcitable tissue
separates the atria
and ventricles
The signal spreads,
causing the atria to
contract
excitable
fibers
The atrioventricular
node transmits the
signal to the ventricles
with a slight delay
Fig. 20-4
The signal travels to
the base of the ventricles
Excitable fibers transmit
the signals to ventricular
cardiac muscle, causing
contraction from the base
upwards
Fig. 20-6
• Blood cells
neutrophil
• Plasma is primarily water and dissolved
substances.
neutrophil
– Plasma is 90% water.
– Dissolved in the plasma are proteins, hormones,
nutrients, salts, and wastes, such as urea.
monocyte
basophil
eosinophil
red blood cells
lymphocyte
(a) Erythrocytes
(b) White blood cells
platelets
megakaryocyte
(c) Megakaryocyte forming platelets
Fig. 20-9
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• Red blood cells carry oxygen from the lungs to
the tissues.
– The most abundant cells in the blood are red blood
cells.
– Red blood cells get their red color from hemoglobin,
an iron-containing protein that can bind up to four
oxygen molecules.
– Hemoglobin picks up oxygen in the lungs, where
oxygen is at high concentration, and releases it in
other tissues of the body, where the oxygen
concentration is low.
• Lymphocytes are responsible for the immune
response against disease.
• White blood cells (Leukocytes) help defend the body against
disease.
– Less than 1% of blood cells
– Play a key role in the body’s resistance to disease.
– There are five types of white blood cells:
• Neutrophils
• Eosinophils
• Basophils
• Lymphocytes
• Monocytes
• Platelets are cell fragments that aid in blood
clotting.
– Neutrophils and monocytes engulf foreign particles.
– Platelets play a key role in blood clotting.
– Blood clotting starts when platelets contact an
irregular surface, such as a damaged blood vessel,
where they partially block the opening.
Fig. 20-10
• The platelets and injured tissue initiate a
complex sequence of reactions among plasma
proteins, which results in a fibrous network,
called fibrin, that traps red blood cells and
closes the wound.
platelets
20.4 What Are The Types And Functions
Of Blood Vessels?
white blood cell
fibrin strands
red blood cell
Fig. 20-11
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• As it leaves the heart,
blood travels from 1)
arteries to 2) arterioles
to 3) capillaries to 4)
venules to 5) veins, and
finally, it returns to the
heart.
jugular vein
carotid artery
aorta
pulmonary
artery
superior
vena cava
20.4 What Are The Types And Functions
Of Blood Vessels?
• Structures and interconnections of blood vessels
lung
capillaries
inferior
vena cava
capillary
network
heart
arteriole
liver
intestine
kidney
smooth
muscle
precapillary
sphincters
venule
femoral vein
femoral artery
cross
section
capillary
valve
smooth muscle
connective tissue
artery
vein
Fig. 20-12
Fig. 20-13
• Red blood cells flow through a capillary.
• Capillaries are microscopic vessels through
which nutrients and wastes are exchanged.
– Diffusion of nutrients and wastes occurs in
capillaries
– Walls are only one cell thick, substances can cross a
capillary cell’s plasma membrane and easily move
into or out of capillaries (diffusion).
Red blood cells must
pass through capillaries
in single file
Capillary walls are thin
and permeable to gases,
nutrients, and cellular
wastes
Fig. 20-14
• Valves direct the flow
of blood in veins.
valve
open
valve
closed
muscle
contraction
compresses
vein
relaxed
muscle
valve
closed
Fig. 20-15
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