Transcript Human Body Systems

Human Body Systems
Section 35–1
Human Body Systems
Organization of the Body
• List the levels of organization in a
multicellular organism, from
smallest to largest.
– Cells
– Tissues
– Organs
– Organ systems
Nervous system
Coordinates the body’s response to changes in its
internal and external environments
Skeletal system
Stores mineral reserves and provides a site for
blood cell formation
Integumentary
system
Serves as a barrier against infection and injury
Endocrine system
Eliminates wastes and maintains homeostasis
Lymphatic/Immune
systems
Helps protect body from disease.
Muscular system
Helps produce voluntary movement, circulate
blood, and move food
Reproductive
system
Produces reproductive cells
Respiratory system
Provides oxygen and removes carbon dioxide
Excretory system
Eliminates wastes and maintains homeostasis
Circulatory system
Brings materials to cells, fights infection, and helps
to regulate body temperature
Digestive system
Converts food so it can be used by cells
Maintaining Homeostasis
• The process of maintaining a
controlled, stable internal
environment is called
• homeostasis
Maintaining Homeostasis
• What happens if nerve cells sense
that the core body temperature has
dropped below 37°C?
• The hypothalamus produces
chemicals that signal cells
throughout the body to speed up
their activities, which causes a
gradual rise in body temperature.
Maintaining Homeostasis
• What happens if the body
temperature rises too far above
37°C?
• The hypothalamus slows down
cellular activities, minimizing the
production of heat.
Negative Feedback
• when a change in the normal state
occurs a negative feedback mechanism
causes the body to return to the
normal state. Most common way for
the body to return to homeostasis.
Examples:
• You get overheated, so your body
starts to sweat, and you cool back off
What mechanisms are
there to cool the body
down?
1. Sweating
•
•
•
•
•
When your body is hot, sweat glands
are stimulated to release sweat.
The liquid sweat turns into a gas (it
evaporates)
To do this, it needs heat.
It gets that heat from your skin.
As your skin loses heat, it cools down.
Negative Feedback
• Blood pressure gets too high, so your
heart beats slower, and blood pressure
returns to normal.
More examples
• Your glucose (sugar)
levels in your blood
get to high, so the
pancreases secretes
insulin, causing your
body’s cells to store
the glucose, until
levels return to a
normal level.
Digestion
• Processing of food
• Types
– Mechanical (physical)
•
•
•
•
•
Chew
Tear
Grind
Mash
Mix
– Chemical
• Catabolic reactions
• Enzymatic hydrolysis
– Carbohydrate
– Protein
– Lipid
12
Digestion includes both
mechanical and chemical
processes.
• Digestion- the mechanical
and chemical breakdown of
foods for use by the body’s
cells.
• Absorption- the passage of
digested food from the
digestive tract into the
cardiovascular system.
• Elimination- the expulsion of
undigested food or body
wastes.
•The mechanical portion
involves chewing,
mashing, and breaking
food into smaller pieces.
•The chemical process
involves digestive juices
that change food into
simpler substances.
The Nervous and
cardiovascular systems
also play a major role in
the digestion process.
• The nervous system
triggers the digestive
process
• Nutrients are carried
through the body by the
cardiovascular system.
1. Food processing starts with
ingestion (eating).
• Teeth- mechanical digestion by
masticating (chewing) food.
2. Upon entering esophagus,
peristalsis (wave-like
contractions) of smooth
muscle carries the bolus (food
ball) toward the stomach.
3. From the esophagus,
bolus passes through a
sphincter (muscular ring) into
the stomach.
4. In the stomach,
food undergoes
chemical and
mechanical
digestion.
5. Gallbladder contains Bile from
liver that emulsifies (breaks into
small particles) lipids (fats),
which helps mechanical
digestion of fats.
7. Parts of the colon absorb water and
minerals from undigested food and
compact the remaining material into feces.
6. Tiny villi (finger-like projections)
cover walls of small intestine.
This increased surface area
causes more efficient food
absorption
Points of Interaction
Food leaves the digestive system and
enters the circulatory system in the
small intestine at points called villi.
Process called absorption.
Things your Cell needs to
From your respiratory
get daily
From your digestive
system:
Nutrients
Minerals
Lipids
Carbohydrates
Protiens
Water
system:
Oxygen
Enzymes: are
proteins that help
speed up
chemical
reactions and help
your body get
these things.
Then the Cell needs to get
rid of…
C02 using the respiratory system.
Extra water, minerals, and other cellular
waste though the excretory system.
This process is called EXCRETION.
Section 4
The Respiratory System
Breathing
• The Diaphragm Breathing is done by the diaphragm and
rib muscles. The diaphragm is a dome-shaped muscle
beneath the lungs.
Breathing and Cellular Respiration
• Oxygen In cellular respiration, oxygen is used by cells to
release energy stored in molecules of glucose. When you
breathe, you take in oxygen. Oxygen diffuses into red blood
cells and is carried to tissue cells. The cells in turn use the
oxygen to carry on normal life processes. This process is
illustrated on the next slide.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 4
The Respiratory System
Respiration and the Respiratory System
• Nose, Pharynx, and Larynx Your nose is the main
passageway into and out of the respiratory system. From the
nose, air flows into the pharynx, or throat. The larynx is the part
of the throat that contains the vocal chords.
• Trachea The larynx guards the entrance to a large tube called
the trachea, or windpipe.
• Bronchi and Alveoli The trachea splits into two branches
called bronchi. One bronchus connects to each lung. In the
lungs, each bronchiole branches to form thousands of tiny sacs
that are called alveoli. Oxygen enters the blood when CO2
enters the alveoli, completing the exchange with the capillaries.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 4
The Role of Blood in Respiration
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 1
The Cardiovascular System
Your Cardiovascular System
• Main Components of the Cardiovascular System The
cardiovascular system consists of the heart and the three
types of blood vessels that carry blood throughout your
body.
The Heart
• Cardiac Muscle Your heart is an organ made mostly of
cardiac muscle tissue. It is about the size of your fist and is
almost in the center of your chest cavity. The next slide
shows the flow of blood through the heart.
End of Slide
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 1
The Flow of Blood Through the Heart
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Makeup of Heart
• Has two sides(left and right) that are
separated by a thick wall.
• Each side has an upper(Atrium)
chamber and a lower(Ventricle)
chamber.
• The blood enters the Atriums first. The
left atrium receives oxygen-rich blood
from the lungs. The right atrium
receives oxygen-poor blood from the
body.
Makeup Continued
• When the Atria contract they squeeze
blood into the ventricles.
• Blood from the right ventricle goes to
the lungs. Blood from the left ventricle
goes to the body.
The Beating Heart
• On body sides of the heart located
between the Atriums and the Ventricles
are valves.
• These valves open and close to
prevent blood from flowing backwards.
• The opening and closing is what
causes the “beating” of the heart.
Section 1
The Cardiovascular System
Blood Vessels – tubes that blood travels
throughout the body in.
• Arteries A blood vessel that carries blood away from the
heart is an artery. Artery walls are very thick which allows
them to change shape due to blood pressure. As your
heart beats it pumps blood into your arteries. This is what
causes blood pressure.
• Capillaries A capillary is a tiny blood vessel that allows
nutrient, oxygen, carbon dioxide , and waste exchanges
between body cells and blood.
• Veins A vein is a blood vessel that carries blood back to
the heart from the contraction of the skeletal muscles.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 1
The Cardiovascular System
Two Types of Circulation
• Pulmonary Circulation This circulation of blood between
your heart and lungs is called pulmonary circulation.
• Systemic Circulation The circulation of blood between
the heart and the rest of the body is called systemic
circulation. Both systemic and pulmonary circulation are
illustrated on the next slide.
End of Slide
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 1
The Flow of Blood Through the Body
Copyright © by Holt, Rinehart and Winston. All rights reserved.