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Human organ systems
• The human body is composed of 11 organ systems.
• We have covered 7 in this course.
- Circulatory
- Respiratory
- Musculoskeletal
- Urinary
- Reproductive
- Lymphatic
- Immune
- Digestive
- Nervous
- Endocrine
- Integumentary
THE ENDOCRINE SYSTEM
• The endocrine system is made up of glands that produce and
secrete hormones (chemical substances produced in the
body that regulate the activity of cells or organs – “chemical
messengers”). These hormones regulate the body's growth,
metabolism, and sexual development and function. The
hormones are released into the bloodstream and may affect
one or several organs throughout the body (i.e. the
difference between target and non-target hormones).
• Hormones transfer information from one set of cells to
another to coordinate the functions of different parts of the
body.
• The major glands of the endocrine system are the
hypothalamus, pituitary, thyroid, parathyroids, adrenals,
pineal, and the reproductive organs (ovaries and testes). The
pancreas is also a part of this system; it has a role in
hormone production as well as in digestion.
Major
endocrine
glands
Function of the Endocrine Glands
• Pituitary Gland:
"master gland"
because of its great
influence on the other
body organs. Its
function is complex
and important for
overall well-being.
Function of the Endocrine Glands
• Hypothalamus:
releases
hormones that
start and stop
the release of
pituitary
hormones.
Function of the Endocrine Glands
• Thymus is a gland
needed early in life
for normal immune
function. Secretes
hormones which
help develop the
immune system.
Function of the Endocrine Glands
• Pineal Gland:
produces
melatonin, which
controls sleep
patterns.
Function of the Endocrine Glands
• Testes: only in males,
produce the hormone
testosterone.
Testosterone helps a
boy develop and then
maintain his sexual
traits.
Function of the Endocrine Glands
• Ovaries: only in females,
produce estrogen and
progesterone. These
hormones are
responsible for
developing and
maintaining female
sexual traits, as well as
maintaining a
pregnancy.
Function of the Endocrine Glands
• Thyroid: secretes
hormones that
control metabolism.
Function of the Endocrine Glands
• Adrenal Glands:
secretes hormones that
help the body respond
to stressors
• produces some sex
hormones (for some
secondary sex
characteristics in both
men and women).
Function of the Endocrine Glands
• Parathyroid Glands:
make hormones
that help control
calcium and
phosphorous levels
in the body
(important for bone
growth).
Example Hormones
• Antidiurectic hormone (ADH)
– from the Pituitary gland.
Increases water absorption in
the body (kidneys).
Example Hormones
• Oxytocin – from the
Pituitary gland.
Controls labour and
milk production for
nursing mothers.
Example Hormones
• Adrenaline – Produced in
the adrenal glands.
Adrenaline works with
noradrenaline to produce
the "fight or flight"
response by increasing the
supply of oxygen to the
brain and muscles, dilating
the pupils, and suppressing
bodily functions not useful
in an emergency situation
(such as digestion).
Example Hormones
• Growth Hormone (GH) –
from the pituitary gland.
GH stimulates growth
during childhood and
also stimulates cell
reproduction, which
helps adults maintain
muscle and bone mass.
LOCATION
IMPORTANT HORMONE
PITUITARY
Growth hormone (body growth)
PINEAL
Melatonin (control sleep patterns)
THYROID
Thyroxin (control metabolism – how fast you burn fuel)
ADRENAL
Adrenaline (prepares body for stressful situations)
PANCREAS
Insulin (controls blood glucose levels)
TESTES
Testosterone (secondary sex traits, growth)
OVARIES
Estrogen, progesterone (sex traits, reproduction)
Endocrine disorders
• Diabetes – low levels of insulin
• Goiter – swelling of the neck caused by
enlargement of the thyroid gland
• Hyperthyroidism – overactive thyroid gland;
sweating, nervous behaviour, weight loss
• Gigantism – high levels of growth hormone
• Dwarfism – low levels of growth hormone
• Sleep disorders / anxiety / depression – low
levels of melatonin
THE CIRCULATORY SYSTEM
• The circulatory system
transports gases and
nutrients throughout the
body and carries away
wastes.
• The system is made up
of blood,
the heart, and blood
vessels.
Function of The Circulatory System
-
-
Moves oxygen from the lungs to all the
body cells
Moves carbon dioxide from the body cells
to the lungs
Moves nutrients from the small intestine
to the body cells
Moves waste materials from the body cells
to the kidneys and skin to be removed
The Blood
• Blood is a type of connective
tissue that circulates through
your body, it consists of 4
components:
– Red Blood Cells (RBC)
– White Blood Cells (WBC)
– Platelets
– Plasma
Did you know…
- It takes about
20 seconds for
a RBC to
circulate the
entire body
Components of Blood
Red Blood Cells
-make up approx. 45% of blood volume
-contain hemoglobin (protein that carries O2)
-have no nucleus (when mature)
White Blood
Cells
-make up less than 1% of blood volume
-function is to fight infection
-have a nucleus
Platelets
-are actually just fragments of cells
-make up less than 1% of blood volume
-function is to clot blood
Plasma
-liquid that suspends the other 3 components
-makes up approx. 55% of blood volume
-contains dissolved materials (i.e. protein)
Blood Vessels
1) Arteries: blood vessels that carry blood away from the heart
• heart pumps blood with force so arterial blood pressure is higher than
venous blood pressure
• due to higher pressure, artery walls are thicker than those of veins
2) Veins: blood vessels that carry blood toward the heart
• contents are under low pressure so walls are thinner than those of
arteries
3) Capillaries: tiny blood vessels with very thin walls to allow substances to
diffuse between the blood and the body fluids and tissues
• are the blood vessels that link arteries and veins
• oxygen and nutrients diffuse from the blood into the surrounding tissues
• carbon dioxide and other wastes diffuse from tissues into the blood
The Heart (a pump):
●
Made of 3 types of tissue:
- Cardiac Muscle Tissue
- Nerve Tissue
- Connective Tissue
●
Consists of four chambers:
- 2 Atria (left and right atrium)
- 2 Ventricles (left and right ventricles)
Let’s explore the flow through the heart….
(from body)
(to body)
(to lungs)
(from lungs)
(from body)
Circulatory System Diseases and
Disorders
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Coronary artery disease
Heart attack – blocked coronary vessel
Heart murmurs
Irregular heart beat
Anemia – low hemoglobin or low iron
Leukemia
Hemophilia – inherited blood clotting disorder
THE RESPIRATORY SYSTEM
Review the following diagram to locate the system’s components:
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•
•
•
•
•
•
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nasal cavity
mouth
pharynx
larynx (vocal cords)
trachea
bronchi
bronchioles
alveoli
lungs
diaphragm
•
Air travels through the trachea to the lungs. The trachea contains many
epithelial cells that have hairlike projections called cilia. Cilia help filter out and
remove foreign materials (such as dust) that might otherwise enter the
bronchial tubes and lungs.
•
The main purpose of the respiratory system is to exchange gases. Breathing
brings air into and out of the lungs, so that gas exchange can occur.
•
Oxygen enters the bloodstream in the lungs by diffusion, and carbon dioxide
leaves in the same way. This gas exchange specifically takes place in the
alveoli, which are surrounded by capillary networks containing blood.
•
When the blood arrives at the cells, the oxygen diffuses from the blood into the
cells. At the same time, carbon dioxide diffuses from the cell into the blood.
The Epiglottis
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•
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The function of the epiglottis is to allow the air
inhaled while breathing to pass freely to the lungs.
It covers the larynx to prevent the solids and liquids
we consume from entering the windpipe (trachea).
While swallowing, the tongue pushes the larynx
downwards. This makes the epiglottis block the
entrance to the windpipe. Once the swallowing is
done, the epiglottis opens up for the air to pass
through the windpipe again.
If the epiglottis is absent or fails to function
correctly, a person will not be able to swallow
anything comfortably. He would cough and choke,
as anything he would swallow would enter the
windpipe. This is why it is said that a person should
not talk or laugh while eating.
Breathing
• Involves the diaphragm
(a large sheet of muscle
underneath the lungs)
and the muscles between
the ribs.
• Is an involuntary process
that we can override
while talking but only
temporarily.
• It is controlled by a part
of the human brain that
detects the concentration
of CO2 in our blood
Non-smoker vs smoker LUNGS
Respiratory System Diseases
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Tuberculosis (bacterial)
Cancers
Emphysema
Asthma
THE NERVOUS SYSTEM
What is the Nervous System?
• The control system that enables animals to
detect a stimulus and coordinate a response
– Stimulus: changes in the body that are detected by
your body
– Response: your body’s reaction to this stimulus
•
The nervous system is made up of the brain, spinal cord, and peripheral
nerves. It senses the environment and coordinates an appropriate
response.
•
The core of the nervous system is the brain and the spinal cord.
This is called the central nervous system.
•
The central nervous system is protected from injury by bones and by
cerebrospinal fluid.
•
The peripheral nervous system consists of the nerves that carry the
signals between the central nervous system and the body. It also relays
instructions from the brain to other parts of the body to control many of the
body’s functions and responses.
•
Reflexes are actions that do not require the involvement of the brain: they
occur without conscious thought. The spinal cord acts as a short cut for
reflexes.
Types of Nerve cells (Neurons)
• Sensory neurons
– carry impulses from sensory receptors (eye, ear, nose, skin,
tongue) to the brain
• Motor neurons
– carry impulses from the brain or spinal cord to muscles for
movement or to glands for hormone secretion
• Interneurons
– link the sensory and motor neurons in the brain and spinal cord
How Does Communication Occur?
• Nerve cells are called neurons
• Neurons use electrical signals
called impulses to communicate
with other cells
• Nerve
– Connective tissue and
bundles of neurons
Nerve Cell
(receives message)
(sends message)
Nervous System Disorders
• Multiple sclerosis – degeneration of myelin
sheath; scar tissue builds
• Concussions – jars or shakes brain inside skull
• Damaged / severed spinal cords
• Parkinson’s disease
• Alzheimer’s disease