Body Systems
DR NILOFER A R
A S S I S TA N T P R O F E S S O R I N O B G
FA C U LT Y O F M E D I C I N E .
Respiratory System
 The respiratory system is composed of various
structures and organs ensuring that the body is
able to maintain its internal environment
through the exchange of air between the lungs
and the atmosphere.
Respiratory System
 In order to survive the body needs a constant supply
of oxygen, which it obtains from the air.
 The body also needs to dispose of carbon dioxide,
made as a waste product from the process of cell
metabolism.
respiratory system
The ingestion of oxygen and the discarding of carbon
dioxide occurs through the process of respiration or
breathing.
The function of the respiratory system is to supply
oxygen and to remove carbon dioxide from cells.
Oxygen is needed by cells to produce heat and
energy. In using oxygen, the cells produce carbon
dioxide as waste.
respiratory system
 Inhaled air is moistened and warmed as it passes
through the upper respiratory tract - the nose, the
pharynx and the larynx.
 The clean air passes on through the lower
respiratory tract - the trachea and lungs where the
exchange of gases takes place.
respiratory system
 Structure
 The respiratory system is comprised of the:
Upper respiratory system:
 nose
 mouth
 Larynx
Lower respiratory system:
 pharynx
 trachea
 bronchus
 lungs.
respiratory system
Summary:
 The main organ of the respiratory system is the
lungs.
 Our lungs breathe in oxygen and breathe out carbon
dioxide.
 This exchange of gases is vital to life.
respiratory system
 Breathing depends on the diaphragm, a sheet of
muscle slung beneath the lungs inside the ribcage.
 Common problems of the respiratory system include
asthma, bronchitis, emphysema, hay-fever,
influenza, laryngitis and pneumonia.
respiratory system
 Asthma – wheezing and breathlessness caused by
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a narrowing of the airways
Bronchitis – inflammation of the lung’s mucous
lining
Emphysema – disease of the alveoli
Hay-fever – an allergic reaction to pollen, dust or
other irritants
Influenza – caused by viruses
Laryngitis – inflammation of the vocal cords (larynx)
Pneumonia – inflammation of the lung.
Cardiovascular system
 The Heart
The heart is a muscular pumping organ located medial
to the lungs along the body’s midline in the thoracic
region.
 The bottom tip of the heart, known as its apex, is turned
to the left, so that about 2/3 of the heart is located on the
body’s left side with the other 1/3 on right.
 The top of the heart, known as the heart’s base,
connects to the great blood vessels of the body: the
aorta, vena cava, pulmonary trunk, and pulmonary
veins.
Cardiovascular system
 Circulatory Loops
There are 2 primary circulatory loops in the human
body:
 the pulmonary circulation loop
 the systemic circulation loop.
Other loops:
Coronary Circulation
Hepatic Portal Circulation
Cardiovascular system
 Pulmonary circulation transports deoxygenated
blood from the right side of the heart to the lungs,
where the blood picks up oxygen and returns to the
left side of the heart.
 The pumping chambers of the heart that support the
pulmonary circulation loop are the right atrium and
right ventricle.
Cardiovascular system
 Systemic circulation carries highly oxygenated blood
from the left side of the heart to all of the tissues of
the body (with the exception of the heart and lungs).
 Systemic circulation removes wastes from body
tissues and returns deoxygenated blood to the right
side of the heart. The left atrium and left ventricle of
the heart are the pumping chambers for the systemic
circulation loop.
Cardiovascular system
 Blood Vessels :
1- Arteries and Arterioles
2- Capillaries: Capillaries are the smallest and thinnest
of the blood vessels in the body and also the most
common.
3- Veins and Venules: Veins are the large return
vessels of the body and act as the blood return
counterparts of arteries.
Cardiovascular system
 Blood
The average human body contains about 4 to 5 liters
of blood.
 As a liquid connective tissue, it transports many
substances through the body and helps to maintain
homeostasis of nutrients, wastes, and gases.
 Blood is made up of red blood cells, white blood
cells, platelets, and liquid plasma.
Cardiovascular system
1)Red Blood Cells
2) White Blood Cells
a-granular leukocytes--neutrophils, eosinophils, and
basophils
2- a granular leukocytes--lymphocytes and monocytes
3) Platelets
4) Plasma---water, proteins
Cardiovascular system
 Cardiovascular System Physiology:
The cardiovascular system has three major functions:
transportation of materials, protection from
pathogens, and regulation of the body’s
homeostasis.
Cardiovascular system
 Transportation:
The cardiovascular system transports blood to almost
all of the body’s tissues. The blood delivers essential
nutrients and oxygen and removes wastes and
carbon dioxide to be processed or removed from the
body. Hormones are transported throughout the
body via the blood’s liquid plasma.
Cardiovascular system
 Protection:
The cardiovascular system protects the body through
its white blood cells. White blood cells clean up
cellular debris and fight pathogens that have entered
the body. Platelets and red blood cells form scabs to
seal wounds and prevent pathogens from entering
the body and liquids from leaking out. Blood also
carries antibodies that provide specific immunity to
pathogens that the body has previously been
exposed to or has been vaccinated against.
Cardiovascular system
 Regulation:
The cardiovascular system is instrumental in the body’s ability to
maintain homeostatic control of several internal conditions.
Blood vessels help maintain a stable body temperature by
controlling the blood flow to the surface of the skin. Blood
vessels near the skin’s surface open during times of
overheating to allow hot blood to dump its heat into the body’s
surroundings. In the case of hypothermia, these blood vessels
constrict to keep blood flowing only to vital organs in the
body’s core. Blood also helps balance the body’s pH due to
the presence of bicarbonate ions, which act as a buffer
solution. Finally, the albumins in blood plasma help to balance
the osmotic concentration of the body’s cells by maintaining
an isotonic environment.
Skeletal System
 The skeletal system in an adult body is made up of
206 individual bones.
 These bones are arranged into two major divisions:
 the axial skeleton
 the appendicular skeleton.
Skeletal System
 The axial skeleton runs along the body’s midline axis
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and is made up of 80 bones in the following regions:
Skull
Hyoid
Auditory ossicles
Ribs
Sternum
Vertebral column
Skeletal System
 The appendicular skeleton is made up of 126 bones
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in the folowing regions:
Upper limbs
Lower limbs
Pelvic girdle
Pectoral (shoulder) girdle
Skeletal System
 Skeletal System Physiology
Support and Protection:
The skeletal system’s primary function is to form a
solid framework that supports and protects the
body's organs and anchors the skeletal muscles.
The bones of the axial skeleton act as a hard shell to
protect the internal organs—such as the brain and
the heart—from damage caused by external forces.
The bones of the appendicular skeleton provide
support and flexibility at the joints and anchor the
muscles that move the limbs.
Skeletal System
 Movement
The bones of the skeletal system act as attachment
points for the skeletal muscles of the body. Almost
every skeletal muscle works by pulling two or more
bones either closer together or further apart. Joints
act as pivot points for the movement of the bones.
The regions of each bone where muscles attach to
the bone grow larger and stronger to support the
additional force of the muscle. In addition, the overall
mass and thickness of a bone increase when it is
under a lot of stress from lifting weights or supporting
body weight.
Skeletal System
 Hematopoiesis
Red bone marrow produces red and white blood
cells in a process known as hematopoiesis. Red
bone marrow is found in the hollow space inside of
bones known as the medullary cavity. Children
tend to have more red bone marrow compared to
their body size than adults do, due to their body’s
constant growth and development. The amount of
red bone marrow drops off at the end of puberty,
replaced by yellow bone marrow.
Skeletal System
 Storage
The skeletal system stores many different types of
essential substances to facilitate growth and repair of the
body. The skeletal system’s cell matrix acts as our
calcium bank by storing and releasing calcium ions into
the blood as needed. Proper levels of calcium ions in the
blood are essential to the proper function of the nervous
and muscular systems. Bone cells also release
osteocalcin, a hormone that helps regulate blood sugar
and fat deposition. The yellow bone marrow inside of our
hollow long bones is used to store energy in the form of
lipids. Finally, red bone marrow stores some iron in the
form of the molecule ferritin and uses this iron to form
hemoglobin in red blood cells.