Download Human Body Systems PP

HUMAN BODY SYSTEMS
A little about how our bodies work
The systems we will study…
Body Organization
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Cells  Tissue  Organ  Organ System
ALL major body systems must work together to maintain
homeostasis
What are the four types of tissue? Let’s look at the
stomach
1.
2.
3.
4.
Epithelial – covers and protects underlying tissue, cells form a
continuous sheet, Ex – stomach lining
Nervous – sends electrical signals through body, found in
brain, nerves, and sense organs, Ex – controls acids, “full”
feeling
Connective – joins, supports, protects, insulates, nourishes and
cushions organs, literally keeps them from falling apart, Ex –
collagen in walls
Muscle – made of cells that contract and relax to produce
movement, Ex – layered so they help break-up food
Think it through…

Tanya went to a restaurant and
ate a slice of pizza. Describe
how Tanya used five organ
systems to eat and digest her
pizza.

Answer: The nervous system
sends messages to Tanya’s
muscular system to bite the pizza.
Her jaws, which are part of the
skeletal system, help grind the
food. The food moves into
Tanya’s stomach, which is part of
the digestive system. The
digestive system breaks down the
food, and the circulatory system
picks up nutrients and delivers
them throughout the body.

Predict what would happen if the
human body did not have
specialized cells, tissues, organs
and organ systems to maintain
homeostasis.

Answer: The body would be
unable to maintain homeostasis
because the cells of the body
would have too many jobs to do.
The cells likely would not be able
to do all of these jobs.
Digestive System


Major Organs – Mouth
(teeth, salivary glands),
esophagus, stomach, liver,
gallbladder, pancreas,
small intestine, large
intestine, rectum, anus
Functions
 Breaking
down food so that
the individual nutrients may
be readily used by the cell’s
of the body
Organs of the Digestive System

Mouth
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Esophagus
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Teeth – MD, grind food down into bits
Saliva – CD, released from salivary glands,
enzymes that breaks a carbohydrate into simple
sugars
The long straight tube connecting the pharynx
and stomach
Peristalsis – rhythmic muscle contractions that
squeeze food
Stomach


Muscular sac-like organ, attached between the
esophagus and small intestine
Breaks down food into a liquid (chyme) by the
actions of muscles (MD), enzymes and acids (CD)
Further down the digestive tract…

Liver
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Gallbladder
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Sac-shaped organ that stores bile
Pancreas
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The large, reddish brown organ that makes
bile to break up fat (CD)
Stores nutrients like glycogen (sugars)
Filters blood and breaks down toxins
Organ that lies behind the stomach and makes digestive enzymes and hormones
that regulate sugar levels (insulin), involved in CD
Juices flow out of pancreas into the small intestine, these juices (bicarbonate)
help to neutralize stomach acids in the chyme
Small Intestine


Organ between the stomach and large intestine, is a muscular tube 2.5 cm in
diameter and about 6 meters long, food is MD and CD here
Villi – Finger-like projections, where nutrients are absorbed and whisked into the
circulatory system
The end of the line…


See the villi 
Large Intestine

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
AKA colon
A wider and shorter portion
of the intestines
Water is absorbed here so
that solid waste materials can
be discarded by the body
Rectum – the last part of the
large intestine, stores feces
until they can be expelled
Anus- the opening through
which feces passes to the
outside of the body
For each organ…
1. Label the
organ
2. List the type
of digestion
(MD, CD)
3. Describe the
function
verbally
Think about it…

How would the
inability to make
saliva affect digestion?

Without saliva, swallowing
would be more difficult
and the chemical digestion
of carbohydrates would
not begin until the food
reached the stomach.

How does the structure
of the small intestine
help achieve its
functions?

The long length, folds and
villi increase the surface
area that comes in contact
with the food that is being
digested in the small
intestine , allowing more
nutrients to be absorbed.
Respiratory System



AKA cardiovascular
system
Major Organs – Nose,
Pharynx, Larynx,
Trachea, Bronchi,
Alveoli, Lung,
Diaphragm
Functions
Respiration – breathing
and cellular respiration
 Exchange of O2 and
CO2

Organs of the Respiratory System
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Pharynx – the passage from the mouth
to the larynx and esophagus, throat
Larynx – area of the throat that
contains the voice box
Trachea – wind pipe, connects the
larynx to the lungs
Bronchus – one of the two tubes
connecting the trachea with the lungs
Alveoli – Tiny air sacs of the lungs
where O2 and CO2 are exchanged,
covered in capillaries
Diaphragm – A dome-shaped muscle
beneath the lungs, inhale – moves down,
exhale – moves up
More on respiration
Breathing

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Inhaling and exhaling air
The diaphragm causes you to
breathe not your lungs, the
lungs are for gas exchange
When the diaphragm
contracts it moves down, the
rib cage opens up, and air
flows into the lungs
Exhaling is when the
diaphragm relaxes, lifts
upward and air is forced out
of the lungs
Cellular Respiration

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When oxygen is used by cells
to release energy stored in
glucose
Occurs in the mitochondria of
individual cells
RBC temporarily bind with
and carry O2 in the
bloodstream through the body
to all cells via hemoglobin
O2 and sugars are broken
down into CO2 and water
during this process, while
energy (ATP) is released
Label the respiratory organs…
Think about it…

If a respiratory disorder
causes lungs to fill with fluid,
how might this affect a
person’s health?

The alveoli in the lungs are
made for the exchange of
gases, not liquids. Fluids in the
lungs would prevent a person
from getting all of the oxygen
needed to maintain regular
activity. The person might feel
weak or tired. Also, the
person could not get rid of
the carbon dioxide from the
cells, which might cause a
problem, too.

Are breathing and respiration
the same thing?

No, breathing is only one part
of respiration. Respiration
also includes cellular
respiration.
Excretory System
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
AKA urinary system
Major Organs – Kidneys
(2), ureters, bladder,
urethra
Functions
 Removing
waste from the
blood in the form of urine,
storing the urine, and
eliminating the urine so that
the body is not poisoned.
Organs of the Excretory System

Nephrons
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Kidneys – a pair of organs responsible for
cleansing the blood. Filter about 2000 L of
blood per day in other words your blood
cycles through your kidneys 350 times per
day
 Nephrons – Inside kidneys these are
microscopic filters that remove waste
and/or harmful substances from the
blood. Urea is one waste product that is
removed. Urea is created when cells use
protein for energy, high in nitrogen.
Ureter – tube that whisks the urine from the
kidney to the bladder
Bladder – a muscle that collects/stores urine
Urethra – tube used to expel urine from the
bladder and body
Kidneys as filtering agents
Renal artery/Aorta
Renal vein/Vena cava
Think about it…

When people have one
kidney removed, their
other kidney can often
keep their blood clean.
But the remaining kidney
often changes, Predict how
the remaining kidney may
change to do the work of
two kidneys?

The remaining kidney
enlarges. By enlarging, the
remaining kidney is able to
clean much more blood.

Which of the following
contains more water: the
blood going into the
kidney or the blood
leaving it?

The blood going into the
kidney contains more
water. Though the kidney
returns most of the water
back to the blood vessels,
some of the water leaves
the bloodstream when the
kidneys produce urine.
Circulatory System
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AKA cardiovascular system
Major Organs – Heart, blood
vessels (arteries, veins,
capillaries), blood
Functions
 Transport
of gases, nutrients,
waste, hormones, toxins and
excess molecules
 Protects the body for immune
response and prevents leaks
Circulatory System Functions

Transport
Moves H2O and nutrients from the intestine
to the cells or to a storage site
 Moves O2 from the respiratory organ to the
cells and CO2 from the cells back to the
respiratory organ
 Moves hormones from endocrine glands
 Moves toxic or waste molecules to the
excretory organ

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Protection
of the organism from foreign invaders
(immune system)
 of itself from loss of blood (clotting
mechanism)

Organs of the Circulatory System

Heart –
A pump the size of a fist with two atria (upper part)
and two ventricles (lower part), valves separate the
parts of this organ
 Made of cardiac muscle that contracts and relaxes
 Bottom of heart is tipped to the left side of the body,
heart beat strongest
 Beats 60-80 times per minute
The heart is actually two hearts side-by-side. The right side
of our heart pumps blood to the lungs and the left side
collects the blood from the heart and pumps the
oxygenated blood to the entire body.
Lub-dub of sound of heart beat – “Lub” comes from
contracting ventricles, “Dub” comes from aortic valve closing
sharply
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More on the heart…
***The freshly oxygenated blood is sent
first to the coronary arteries that supply
the heart and to the aorta which branches
into many arteries which in turn supply
blood to all the organs and tissues. The
carotid artery to the brain also branches
off the aorta near its origin.
1. Our hearts have a thin walled right atrium
which collects deoxygenated blood from the
body.
2. Blood is then sent to the right ventricle.
3. After that blood flows on to the lungs via
the pulmonary arteries (with deoxygenated
blood).
4. The blood then flows through the capillaries
surrounding the alveoli in the lung where
CO2 is released and O2 is picked up.
5. The capillaries then lead to the pulmonary
vein (with oxygenated blood) which leads
back to the left atrium.
6. The blood then flows to the thicker walled
left ventricle which pumps the blood under
pressure to the body.
Blood flow through the heart…
Other Organs of the Circulatory System
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Arteries –
 Lead oxygenated blood AWAY from the heart, blood looks
RED
 Have thick, elastic walls containing smooth muscle, muscle
contractions propel blood away from heart
Capillaries  Arteries branch and become narrower until they meet a
capillary bed
 Found in ALL body tissues, help to control amount of heat lost
from body
 Are where the action is! These vessels are only one cell thick
and are where gases, nutrients, hormones, toxic molecules,
water, etc. can freely flow in and out or be exchanged
(simple diffusion, no ATP needed)
Veins –
 Have thin walls and valves to prevent backflow of blood
 Contains waster from cells, low in oxygen so blood looks
dark red or BLUE
More on circulation
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Two types of circulation 
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Blood pressure –
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Pulmonary circulation – the flow of blood from the heart to the lungs and back
to the heart through pulmonary arteries, capillaries and veins
Systemic circulation – the flow of blood from the heart to all parts of the body
and back to the heart
Average BP is 120/80, BP varies from person to person, drops when asleep and
increases when excited
Affected by: amount of blood, clogged blood vessels, rate of heart beat
Cardiovascular problems –
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High blood pressure
Artherosclerosis – high cholesterol and clogged arteries
Heart attacks – muscle tissue dies, damaged, lack of O2
Heart failure – heart can’t pump enough blood to meet body’s needs
When a person has a "coronary" we mean s/he has a block (usually an
atherosclerotic plaque) in the coronary arteries that supply the heart with
fresh oxygen. When this happens, some of the heart tissue is deprived of
oxygen and dies (an MI or myocardial infarction).
Blood
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Blood is complex tissue containing 
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Functions –
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O2 from lungs to cells, CO2 from cells to lungs
Circulates nutrients from intestines to cells
Removes waste and excess substances (toxins) via kidney
Location of immune and hormonal responses
Blood cells –
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Plasma, RBC, WBC, and cell fragments called platelets (help create
clots)
RBC – live 120 days, 2.4 million destroyed every second and created in
bone marrow at equal rate, contain hemoglobin
WBC – lifespan varies as needed, help fight infection, created in
marrow, lymph nodes/glands
Blood types –
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A, B, AB (universal receiver), O (universal donor)
Rh factor – protein found in blood, inherited
Think about it…

How is the structure of
capillaries related to
their function?
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Capillaries are very small
and have thin walls, which
lets them be near every
cell to allow oxygen,
nutrients in and carbon
dioxide, and wastes out of
cells into the bloodstream.

How does the body
use the circulatory
system to help
maintain proper body
temperature?

As blood circulates in the
body, it picks up heat from
the cells and carries it
through blood vessels close
to the skin’s surface, the
heat leaves the blood and
goes into one’s
surroundings.
Skeletal System
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
Major Organs – Bones and
connective tissues (tendons,
ligaments, and cartilage)
Functions
 Protection
 Storage
 Blood
Cell Formation
 Movement & Support
Bone functions revealed
Protection
Storage
Blood Cell
Formation
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Movement
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Ribs protect heart and lungs, the skull protects the brain,
vertebrae protect the spinal cord
Bones store minerals that help the nerves and muscles function
properly
The marrow in bones is responsible for making blood cells
Bones have muscles attached to them that contract and relax to
make movement
Without bone you would not be able to stand, crawl, walk or
even sit
Bones provide support for your body’s structure against gravity,
Tendons are tough inelastic bands that attach muscle to bone,
ligaments are strong elastic bands cover the ends of bones and
connect bones at a joint
Your skeleton is strong but light
More on bones
Structure of a
Bone
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Injuries and
Diseases
Keeping
Bones Healthy
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The outer layer of bone is hard or compact and very strong, dense
and tough
The inside layer of bone is spongy, like honeycomb, lighter and
slightly flexible
The middle portion of a bone is jelly-like bone marrow, where new
blood cells are constantly being produced
Broken bones are known as fractures
When broken, bones produce new cells to rebuild themselves, these
cells cover both ends of the broken part and close the break

Sprains, osteoporosis, arthritis
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Bones need regular exercise to stay as strong as possible

Strengthen your skeleton by consuming calcium, which helps bones
harden and become strong
Joints
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Joints are places where two or more bones meet
Ligaments hold joints together
Three types of joints:
 Gliding
– bones glide over each other to allow for
flexibility, Ex – Wrist, ankle
 Ball and socket – allows the appendage to move
freely in ALL directions, Ex – Shoulder, hip
 Hinge – enables bones to flex and extend, Ex – Knee,
elbow
Think it through…

Human bones and bird bones
are quite different. Compare
the bones of these two
animals and assess why birds
have hollow bones.

Answer: Human bones are
dense and filled with marrow
which adds weight to bones.
Most birds fly so additional
weight would hinder them;
therefore, they have hollow
bones.

Red bone marrow produces
blood cells. Children have red
bone marrow in their long
bones, while adults have
yellow bone marrow, which
stores fat. Why might adults
and children have different
bone marrow?

Answer: Children are still
growing, so they need more
blood cells as their bodies get
bigger. After children
become adults, they don’t
need as many new blood
cells, so long bones store fat
instead.
Muscular System
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Major Organs – 3 types
of muscles
Functions
 To
move things in and
through the body
 To allow for body
movement
Types of Muscle



Skeletal muscle – allows bones to move, protects inner organs
Smooth muscle – moves food through the digestive system, makes walls of
blood vessels
Cardiac muscle – makes the heart, pumps blood around the body
Movement

Muscles attach to bones via
tendons
 Ex
– where the bicep muscle
attaches to the shoulder and
forearm

Skeletal muscles work in pairs:
 Flexors
– muscle that bends
part of the body, Ex - biceps
 Extensors – muscle that
straightens part of the body, Ex
– triceps
Exercise & Injury

Exercise
 Use
it or lose it, muscle atrophy
 Aerobic vs anaerobic exercise

Injury
 Strain
– muscle torn or stretched too far
 Tendinitis – inflammation of a tendon
Think it through…

Describe some of the
muscle action needed to
pick up a book. Include
the terms flexor and
extensor in your
description.

Answer: An extensor in the
back of my arm straightens
out my arm as I reach for
the book. Flexors in my
hand allow me to close my
fingers on the book, and a
flexor in my arm bends my
arm as I pick up the book.

If aerobic exercise
improves heart strength,
what likely happens to
heart rate as the heart
gets stronger?

Answer: As the heart gets
stronger it will pump more
blood with each beat. The
heart will not need to work
as hard to pump the same
amount of blood, so heart
rate decreases.
Nervous System
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The nervous system acts like a telephone
system. Information is transmitted from and
to the brain, the brain receiving information
from the sensory nerves, and from the motor
nerves. Information about our environment is
received by the sensory nerves, then sent to
our brain. At the same time, information
about our bodies (Ex. We are hungry) is
received by the motor nerves, and it too is
sent to the brain.
Major Organs – Brain, spinal cord, nerves,
neurons
Functions


Gathers and interprets information
inside/outside the body
Responds to stimuli from inside/outside the
body
The Nervous System
The nervous system can be broken into two (2) parts, the central nervous system (CNS) and
the peripheral nervous system (PNS). Further more, the brain and the spinal cord makes up
the CNS, while the sensory nerves and the motor nerves makes up the PNS. The PNS is
composed of the sense organs (e.g. the eye, the ear, touches nerve cells, taste buds, and
olfactory nerve cells). The somatic nervous system and the autonomic nervous system are the
parts of the motor nerves.
Peripheral Nervous System

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PNS covers a large portion of
the body, see pink in picture…
Involuntary movement, such the
beating of our hearts, does not
need our brain to work. But we
when we run, our bodies need
more oxygen, so our brain tells
the autonomic nervous system
that controls our heart to beat
faster. One very easy difference
to see between the two nervous
system's is that the autonomic
nervous system act much faster.
PNS continued…


A nerve cell, or neuron acts exactly like a phone line or
a computer cable. It conducts electrons, just like wires
and electricity. For these electrons to be able to move
from one cell to another, they must pass through across
a gap or space lying between two nerve cells called a
synapse. But electrons cannot move across a gap. So a
neurotransmitter carries these electrons across the
synapse, in the form of Na+ and K+. As the
neurotransmitter move across the synapse, they are
caught by a receptor protein on the next nerve cell.
Nerve cells never touch each other, or other cells. If
they did, the nervous system would short out like an
unprotected wire. So nerve cells are coated by a
myelin sheath, which insulates it from other cells in our
body, exactly like the plastic coating on an electrical
wire, or computer cable. This myelin sheath prevents the
nerve cells from shorten out, and keeps our bodies
working properly.
Central Nervous System
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Brain is the main control center
Brain has three parts:
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Cerebrum – largest part, looks like a mushroom cap, has hemispheres,
where memories are stored
Cerebellum – second largest part, processes sensory info from body such
as skeletal muscles and joints relaying info about balance
Medulla – smallest, can’t live w/out it, controls involuntary processes like
heart rate and body temperature
Our brain controls how our body acts. Voluntary movement is
initiated by our brain, and sent to the somatic nervous system,
which controls our biceps, triceps and other voluntary muscles.
Spinal cord is made of bundles of neurons and axons that
relay impulses from the brain
Nerve fibers in the spinal cord allow the brain to
send/receive messages from neurons all over the body
Humans have sensory and motor neurons
Think it through…

Some medications slow a person’s
nervous system. These drugs are
often labeled “May cause
drowsiness.” Explain why a
person needs to know about this
side effect.

Answer: A drug that causes
drowsiness may affect the way
that impulses travel in neurons.
Affecting the impulses may
increase the time it takes a
message to get to the brain or
the time it takes a message to
get from the brain to muscles. It is
important to be aware of this
side effect so that activities that
requires a fast reaction time, such
as driving, can be avoided.

Explain how your life would
change if your autonomic nervous
system suddenly stopped
working.

Answer: If my autonomic nervous
system suddenly stopped
working, I would not be able to
digest food, my eyes would not
adjust to light or darkness, my
heart rate and blood pressure
couldn’t change as they need to,
and my lungs wouldn’t work
properly.
Integumentary System

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The integumentary system covers your
body and helps you maintain
homeostasis. It is composed the dermis
(inside) and epidermis (outermost
layer).
Major Organs – Skin
Functions

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Protects you by keeping water in your
body and foreign particles out.
Keeps you in “touch” with the outside
world. Nerve endings (sensory
neurons) let you feel things around
you.
Skin helps you regulate body
temperature. You sweat to help cool
your body
Skin also releases small amounts of
liquid waste.
Think about it…

When and why do dogs
pant? How is this related
to the function of skin?

Answer: Dogs pant on hot
days or after they have
had physical activity. Dogs
do not sweat to cool down
the way humans do. As a
result, dogs pant to
regulate their body
temperature.

The epidermis on the
palms of your hands and
soles of your feet is thicker
than anywhere else on
your body. Why might this
skin need to be thicker?

Answer: The epidermis
forms a protective covering
of dead cells. The hands
and feet are areas of the
body that are often used,
so the epidermis in these
areas needs to be thicker
for better protection.