Transcript Human Circulatory System

The Human Body
=
HOMEOSTASIS
(maintaining a constant condition)
Human Circulatory System:
• Also known as the
cardio-vascular system
• Cardio refers to the
heart
• Vascular refers to the
blood vessels
• It is a closed system,
which means that blood
is confined within vessels
Function of the heart:
• Every cell in your
body needs oxygen
(O2) in order to live
and function.
• The purpose of the
heart is to deliver
the oxygen-rich
blood to every cell in
the body
The
Atria:
• Top two chambers of
the heart
• They have thin walls
• The function of the
atria are to collect
blood returning to the
heart from the body
• The atria then send the
blood directly to the
ventricles through the
atrio-ventricular valves
The Ventricles
• Bottom two chambers
• They have much thicker walls
• More powerful than the atria,
especially the left ventricle
• The left ventricle pumps
blood to the rest of the body
and is therefore the strongest
chamber
• The right ventricle pumps
blood only to the lungs to pick
up oxygen (O2)
There are 3 main types
of blood vessels:
•Arteries
•Veins
•Capillaries
Arteries
• Carry oxygen-rich blood AWAY from the
heart to the body (exception___?)
• The Aorta is the main artery leaving the
heart
• Arterioles (little arteries) connect larger
arteries with capillaries
• Small arterioles
branch into
collections of capillaries
known as capillary beds
Balloon Angioplasty
Veins
• Carry oxygen-poor blood
from capillaries back to
the heart (exception __?)
• Blood pressure in veins is
low, so veins depend on
nearby muscle
contractions to move
blood along
• Veins are sandwiched in
between skeletal muscles
and whenever we move
these muscles they pinch
the veins and squeeze
blood through
Capillaries
• Thin-walled blood vessels in
which gases, nutrients,
wastes, and hormones are
exchanged
• Only one cell layer thick and
microscopic in size
• Blood leaving the capillary
beds flow into a gradually
larger series of Venules
which join to form Veins.
• Capillaries therefore connect
arteries and veins.
Something to think about…
• How many times does your heart beat in one hour?
(assuming 80 bpm)
• 80 x 60 = 4,800 bph
• One day?
• 4800 x 24 = 115,200 bpd
• One week?
• 115,200 x 7 = 806,400 bpw
• One month?
• 806,400 x 4 = 3,225,600 bpm
• One year?
• 3,225,600 x 12 = 38,707,200 bpy
• In your lifetime?
• 38,707,200 x your age (25) = 967,680,000
There are 3 different types of
Circulation throughout your
body:
1. Coronary (to the heart)
2. Pulmonary (to the lungs)
3. Systemic (to the body)
Coronary Circulation
• Refers to the movement of
blood through the
chambers of the heart
• Two small coronary
arteries branch off the
aorta and spread over the
surface of the heart
• These coronary arteries
supply oxygen and
nutrients to specific regions
of heart muscle
Pulmonary Circulation
• The movement of blood from the heart to
the lungs and back to the heart again
• Blood flows to the lungs to pick up oxygen
and release CO2
Systemic Circulation
• The movement of nutrient-rich blood to
all of the tissue located throughout your
body
Stroke
• Results from a
blockage of an
artery (Carotid
artery) in the head
• As a result,
nervous tissue in
the brain dies
• Can be fatal
High Blood
Pressure:
• Also known as
hypertension
• Result of reduced
elasticity of artery walls
which makes the heart
work harder to force
blood through
• Can also result from a
narrowing of arteries
• Caused by poor diet,
stress, heredity, obesity,
and cigarette smoking
Heart
Attack
• A heart attack is
when part of the
heart muscle is
damaged or dies
because it isn't
receiving oxygen.
• Oxygen is carried to
the heart by the
arteries
There are 2 types of Respiration
going on in your body…
1. Cellular Respiration – gases
entering your individual cells
2. Body (Systemic) Respiration –
gases (O2) entering your lungs
(breathing)
So, how does Oxygen get
to the Lungs?
• Gases are transported
through the nostrils into
the nasal cavity
• Here the air is warmed
and filtered by mucous
and cilia
• The air then travels
down the trachea (wind
pipe) into your lungs.
Cilia
• The trachea & nose are lined
with cilia.
• Cilia sweep with a wavy
motion. They move the mucus
around to attract dirt and
germs.
• The cilia sweep the dirty
mucus up toward your mouth.
• Cigarette smoke slows down
that motion and then stops the
action of cilia, thereby
allowing foreign substances to
enter your lungs.
Alveoli
• Bronchi divide further into
bronchioles which are very thin
and made of muscle and nerve
endings
• Bronchioles lead to alveoli
which are the functional unit of
the lung.
• Alveoli are air sacs surrounded
by capillaries and look like
little bunches of grapes
• Exchange of gases occurs at the
alveoli.
• There are ~ 1 Billion alveoli in
the linings of your lungs!
Lungs
• Each lung contains 1
bronchi, many
bronchioles, and
millions of alveoli
• They are highly elastic
(stretchy) but have no
muscle for moving air.
• Instead, they respond
to the action of the
diaphragm muscle.
The Diaphragm
• The Diaphragm is a sheet of
muscle that separates the
chest cavity from the
abdominal cavity.
• The brain and spinal cord
control the movement of the
diaphragm and the muscles
which move the ribs.
• These 2 sets of muscles
control inhalation and
exhalation.
Negative Feedback
• The Medulla in the lower brain
continuously monitors blood pH
• As CO2 concentration in the blood
increases, blood pH decreases
(becomes more acidic).
• When blood pH drops, the medulla
will stimulate the diaphragm and
rib muscles to contract so you can
take in more O2 and release more
CO2.
• This process is an example of
negative feedback and operates to
maintain homeostasis.
Problems of the Respiratory
System are…
1. Asthma
2. Lung Cancer
What is Asthma?
• Asthma is a disease
that causes swelling
and blockage of the
airways that bring
air from the nose and
mouth to the lungs.
• We do not know
what causes asthma
but it tends to run in
families that also
have hay fever and
eczema.
Asthma Triggers…
• Asthma triggers are
commonly related to
some kind of allergic
reaction, for example,
to pollen or dust mites.
• Other common triggers
include inhalation of
pollution, tobacco
smoke, emotional
upset, aspirin, exercise
and breathing cold air.
What is Lung Cancer?
• An uncontrollable growth of tumors
in your lungs
• Lung cancer is the number one
cause of cancer deaths among men
and women in the United States.
• Approximately 85 to 87 % of all
cases are caused by tobacco use,
making lung cancer one of the most
preventable cancers.
• However, it is one of the most
difficult to detect early, which makes
treatment drastic when it is detected.
The
Human
Digestive
System
What is Digestion?
• The process of breaking
down large food molecules
into smaller molecules that
the body can use
• There are 2 types of
digestion:
– Mechanical (physical)
– Chemical (by
enzymes)
The Mouth
• Food enters the mouth and
both mechanical and
chemical digestion begins.
• Teeth – (mechanical
digestions) - cut, tear, grind,
and crush large pieces of
food into smaller pieces.
• Tongue – a muscle that
helps move food around and
helps mix food with saliva.
• Saliva – (chemical digestion)
– enzymes break down
starches.
Chemical Digestion
• Your Saliva contains enzymes which
break down food.
• Ex: Complex Carbs (grains, potatoes,
veggies) are broken down into simple
sugars by the enzyme amylase.
• Proteins are broken down into amino
acids by the enzyme protease.
• And fats are broken down into fatty
acids and glycerol by the enzyme
lipase.
• Each enzyme has it’s own job that
breaks down only 1 specific kind of
food molecule.
The Esophagus
• A short tube (~ 25
cm long) between
the mouth and the
stomach
• Lined with mucus
which helps food
move easily
through tube
How does Food get to the
stomach?
2 WAYS!!!
1. Gravity – helps food
move down
2. Peristalsis – muscle
contractions help
move food down the
esophagus
• Peristalsis can push
against gravity, so that
you can swallow even
when you are standing
on your head!
The Stomach
“Churn and Burn”
The stomach performing both
mechanical and chemical
digestion
• The “burn” part refers to
Chemical digestion –
- Glands in the stomach
release a combination of
enzymes to further break
down food particles.
• The “churn” part refers to
Mechanical digestion–
– 3 layers of muscles
contract in different
directions twisting and
churning the stomach
contents.
•As your stomach “churns” the
muscles twist the stomach in
three (3) different directions.
1. Circular
2. Diagonal
3. Longitudinal
What does my meal look
like after digestion?
• By the time the stomach is
done burning and churning
the food for five hours, it is no
longer recognizable.
• The offensive line of the
digestive team does such a
good job on the food that it is
only a white creamy, liquid
known as chyme.
• Chyme consists of water,
starch (broken down carbs),
fats and partially broken
down proteins
Small Intestine (S.I.)
• A narrow muscular
tube about 20 feet long
and 2.5 cm wide
• Food moves through
by peristalsis (remember
this from the esophagus???)
• Chemical digestion of
starches, proteins, and
fats is completed in
the S.I by digestive
juices secreted from
the liver, pancreas,
and the SI itself
Villi
• Absorption of the broken down food takes place in
the wall of the SI
• The inner lining is folded and has millions of tiny
fingerlike projections called VILLI
• These villi help food pass into the bloodstream
The Large Intestine (LI) is
made up of 3 parts:
1.The Cecum
2.The Colon
3.The Rectum
The Colon
• Like the small
intestine, the colon
section of the LI is
twisted around the
abdomen .
• The food in the colon
is now considered to
be waste, and is
waiting to be kicked
out.
• The function of the
colon is to absorb
water to maintain
the consistency of
the feces.
The Rectum
• The first part of the rectum is
called the rectal cavity, its
other parts are the sphincter
and the anus.
• Waste or feces that are
expelled from the large
intestine have no nutritional
value.
• The body has already taken
everything out of the food that
it can use.
• And is now waiting to be
expelled from the body
completely.
Ulcer
• When stomach acids
eat away at the lining
of the stomach and
create a hole or sore
• Ulcers are generally
caused by an
imbalance between
pepsin (enzyme) and
stomach acid
• Can be caused by an
infection of the
bacteria Helicobacter
Pylori which changes
the stomachs mucus
layer causing an ulcer.
Appendicitis
• Inflammation of the
appendix
• The appendix is located
where the SI and the LI
join
• It occurs when food gets
trapped in the appendix
and becomes infected
with bacteria
What metabolic wastes is
the body excreting?
• H20
• CO2
• Heat
• Salts
• Urea (ammonia) – produced when
amino acids are broken down
Organs of Excretion:
•SKIN
•LUNGS
•LIVER
•KIDNEYS
The Skin
• Largest organ of the body
• Consists of 2 layers:
– Thin epidermis
– Thicker dermis (inner layer)
Sweat
• Through special glands
the skin can remove
wastes from the body
such as water, oils, urea
or salt.
• Sweating is a good
example of how many of
these wastes are
removed.
• The excretory system
and the skin work
together to rid the body
of various wastes
through specialized
glands.
The Lungs
• The lungs
excrete CO2
and H20
during
exhalation
What are Kidneys?
• The kidneys are
bean-shaped
organs about the
size of your fist
• They are found
along the back
wall of your
abdomen
What do the kidneys do?
• The kidneys act like strainers, filtering
the waste and excess fluid from the
blood.
• Blood passes through the kidneys and
is cleaned before returning to the heart.
What do the
Kidneys do?
• First blood enters the
kidneys via the renal
arteries.
• Then, inside the kidneys,
millions of mini-filtering
systems called nephrons
filter the blood.
• Certain substances the
body needs are
reabsorbed and the waste
products and extra fluid
that the body doesn't
need are removed in the
form of urine.
The Flow of Urine…
• The urine is carried
from the kidneys to
the bladder by tubes
called ureters.
• The bladder stores
the urine until it is
full, when the urine
passes out of the
body via the urethra.
How does the kidney function in
homeostasis? • The kidney continuously
regulates the chemical
composition of the blood within
narrow limits.
• When excess water, salt, calcium
ions, etc. are present, the excess
quickly passes out of the urine.
• On the other hand, the kidneys
also help to reclaim these
substances when they are present
in the blood in less-than normal
amounts, thereby maintaining
homeostasis.
HOMEOSTASIS
• How does circulation maintain
homeostasis?
• How does the excretory system maintain
homeostasis?
• How does the respiratory system
maintain homeostasis?