Transcript organization of the human body axial portion

GENERAL ANATOMY &
PHYSIOLOGY—Introduction to
the Human Body
Dr. V.P.C.Rajakaruna
MBBS (COLOMBO)
Objectives
• Introduction to anatomy and
physiology
• Life
• Levels of Organization
• Organ Systems
• Body divisions and cavities
• Homeostasis
Anatomy--the study of the structure of
the human body.
Physiology—the study of the function of
the human body.
Life
Characteristics of Life
• Movement
– Change in position of organism or parts of
organism
• Responsiveness
– Reaction to change (inside or outside of body)
• Growth
– Increase in size without change in shape
• Respiration
– Use of oxygen
• Digestion
– Breakdown of food substances into
simpler forms
Characteristics of Life
• Absorption
– Passage of substances through membranes
and into body fluids.
• Circulation
– Movement of substances throughout body
• Assimilation
– Changing absorbed substances into
chemically different forms
• Excretion
– Removal of waste products
Levels of Organization
The body is organized according to levels of
complexity. The lowest level of complexity
is the atom. The highest level of
complexity is the organism.
Levels of Organization
Here are the levels from lowest to highest
complexity:
Organism
Atom
System
Molecule
Macromolecule
Organelle
Cell
Organ
Tissue
Organ Systems
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Integumentary
Skeletal
Muscular
Nervous
Endocrine
Lymphatic
Digestive
Respiratory
Cardiovascular
Urinary
Reproductive
Organ Systems
The integumentary system consists of the
hair, skin, nails, sweat glands, and
sebaceous glands. Its function is
protection, regulation of body temperature.
The integumentary system also supports
sensory receptors that send information to
the nervous system.
Organ Systems
The skeletal system consists of the bones,
ligaments, and cartilage. It provides
protection and support and produces red
blood cells. It also stores chemical salts.
Organ Systems
The muscular system produces movement,
helps to maintain posture and produces
heat.
Organ Systems
The nervous system consists of the brain,
spinal cord, and receptors. It receive
sensory information detects changes and
in response, stimulates muscles and
glands.
Organ Systems
The endocrine system is a series of glands that
secrete hormones. The endocrine system
contains many feedback systems to help
maintain homeostasis. The glands include:
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Pituitary
Thyroid
Parathyroid
Adrenal
Pancreas
Ovaries
Testes
Pineal gland
Thymus
Hypothalamus
Organ Systems
The cardiovascular system includes the
heart, arteries, capillaries and veins. The
function of the cardiovascular system is to
transport blood.
Organ Systems
The lymphatic system includes the lymph
vessels, lymph nodes, thymus and spleen.
Organ Systems
The function of the lymphatic system is to
return tissue to blood as well as transport
some absorbed food molecules and
defend against infection.
Organ Systems
The respiratory consists of the nasal cavity,
lungs, pharynx, larynx, trachea, and
bronchi.
Function include gas exchange between the
external environment and an organism's
circulatory system
Organ Systems
The digestive system includes:
– Mouth
– Tongue
– Teeth
– Salivary glands
– Pharynx
– Esophagus
– Liver
– Gallbladder
– Pancreas
– Intestines
Organ Systems
The function of the digestive system is to
receive, break-down, and absorb food. It
also eliminates wastes.
Organ Systems
The urinary system includes the:
– Kidneys
– Ureters
– Urinary bladder
– Urethra
Organ Systems
The function of the urinary system is to
remove wastes, maintain water and
electrolyte balance, and store and
transport urine.
Organ Systems
The male reproductive system includes:
• Scrotum
• Testes
• Epididymes
• Vasa deferentia
• Seminal vesicles
• Prostate
• Bulbourethral glands
• Urethra
• Penis
Organ Systems
The female reproductive system includes:
• Ovaries
• Uterine tubes
• Uterus
• Vagina
• Clitoris
• Vulva
• The chief function of the reproductive
system is to ensure survival of the species
BODY DIVISIONS AND
CAVITIES
ORGANIZATION OF THE HUMAN BODY
AXIAL PORTION
• Head
• Neck
• Trunk
APPENDICULAR
PORTION
• Arms
• Legs
Body Cavities
• There are 2 main cavities in the body that
are divided into sub cavities.
• The ventral cavity is subdivided into the
thoracic and abdominopelvic cavities.
• The dorsal cavity is subdivided into the
cranial cavity and the spinal canal.
• The thoracic and abdominopelvic cavities
are separated by the diaphragm.
• The cranial cavity contains the brain.
• The spinal canal contains the spinal cord.
Body Cavities
• Axial
– Dorsal cavity
• Cranial cavity (brain)
• Vertebral canal (spinal cord)
– Ventral cavity
• Thoracic (lungs and mediastinum)
– Mediastinum (area separating right and left containing heart,
esophagus, trachea, thymus gland)
• Abdominopelvic
– Stomach, liver, spleen, urinary bladder, intestines (abdominal
portion)
– Large intestine, urinary bladder, reproductive organs.
• Besides the large cavities, there are some
smaller cavities in the body.
• Smaller Body Cavities
• Oral (teeth, tongue)
• Nasal (sinuses)
• Orbital (eyes and associated muscles,
nerves)
• Middle ear (middle ear bones)
Homeostasis
What is Homeostasis ?
• Maintain the relative constancy of the internal
environment of the cell as well as the human
body despite external environmental changes
• Body cells work best if they have the correct
– Temperature
– Water levels
– Glucose concentration
• Your body has mechanisms to keep the cells in
a constant environment
Examples of Homeostasis
• Body Temperature
• Water Balance
• Chemistry Balance of Blood
• Homeostasis is continually being disrupted by
– External stimuli
• heat, cold, lack of oxygen, pathogens, toxins
– Internal stimuli
• Body temperature
• Blood pressure
• Concentration of water, glucose, salts, oxygen,
etc.
• Physical and psychological distresses
• Disruptions can be mild to severe
• If homeostasis is not maintained, death may
result
To maintain the homeostasis our
body has feed back systems
Feedback System
• A feedback system must have 3 parts:
1. Something to sense the environment—a
sensor or the receptor
2. Analyzes the input, determines the
appropriate response – a control center /
integrator
3. A response mechanism that responds to
the control center – a effector
• The pathway carrying information from the
receptor to the control center named as
afferent pathway
• The pathway which carrying the command
of response from the control center to the
effector named as efferent pathway
• The feedback system can produce 2 types
of responses:
• It can have an opposite response to the
stimulus.
• OR
• It can have the same kind of response as
the stimulus.
• The 2 types of responses are known as:
1. Negative feedback
2. Positive feedback
Negative Feedback
• Negative feedback is when the response
is opposite to the stimulus and original
stimulus is reversed
• Most feed back systems in the body are
negative feed back systems
• Eg: Controlling of body temperature
Positive Feedback
• Positive feedback is where the response is
the same as the stimulus.
• In positive feedback the response can be
magnified.
• Eg: Pain during child birth
Main systems involve in
maintenance of Homeostasis
• Nervous system
– Controls and coordinates bodily activities that
require rapid responses
– Detects and initiates reactions to changes in
external environment
• Endocrine system
– Secreting glands of endocrine regulate
activities that require duration rather than
speed
– Controls concentration of nutrients and, by
adjusting kidney function, controls internal
environment’s volume and electrolyte
composition
Activity
• Group activity – Presentation on Control of
human body temperature