Post on 14-Dec-2015
Chapter 1The Human Body: An
Orientation
Anatomy vs. Physiology
Anatomy- studies the structure of the body parts and their relationships to one another (seen, felt, examined)
• Physiology- concerns the function of the body’s structural machinery (how parts work and carry out life sustaining activities)
Gross Anatomy- study of large body structures visible to the naked eye
• Regional- One region studied in detail
• Systemic- Study system by system
• Surface- How organs relate to the skin
Microscopic Anatomy- parts of the body too small to see with the naked eye (EX: thin slices of tissue)
• Cytology- study of cells
• Histology- study of tissue
Developmental anatomy- changes that occur throughout life
Embryology- changes that occur before birth (look at birth defects)
Tools to Study anatomy Observation
• Manipulation
• Palpation (feeling organ with hands)
• Auscultation- (listening to the organ sounds)
Working Together* What a structure can do
depends on its specific form – Principle of Complementarity of Structure and Function
Levels of Structural Organization
Chemical (atoms form molecules)
Cells (smallest unit of living things)
Tissue (group of cells with common function)
Organ
Organ Systems (organs working together with
common purpose)
Organ Systems 1. Cardiovascular 2. Integumentary 3. Skeletal 4. Muscular 5. Nervous 6. Endocrine
Organ Systems (Cont.) 7. Respiratory 8. Digestive 9. Lymphatic 10. Urinary 11. Reproductive
Maintaining LifeNo organ system works in
isolation they work cooperatively to promote well-being of entire body.
1. Boundaries Single Celled Organisms- outer
membrane to hold in all contents and restrict foreign objects from entering
** All Cells of our body are surrounded by a selectively permeable membrane
Boundaries (Cont) Whole body protected by Integumentary
System or Skin
Protection From: ? Drying out Bacteria Heat Sun Chemicals in the Environment
2. Movement Muscular System allows for the
movements we make while the skeletal system provides the framework for muscles to pull on and create work
• Also have movement of items through internal organs such as food, blood, urine by contracting or shortening of muscle cells
3. Responsiveness
Nervous System – sends electric pulses to stimuli from the environment
4. Digestion Break food into simple molecules that
can be absorbed by blood
Transported through the body cells by the cardiovascular system
5. Metabolism All Chemical Reactions that occur within
the body cells
Systems Working Together: Metabolism depends on Digestive & Respiratory Systems to make nutrients and oxygen available to the blood and Cardiovascular to distribute through the body- regulated largely by hormones secreted by the Endocrine System
6. Excretion Removing Waste from the body
o Digestive System- rids indigestible food
o Urinary- rids of nitrogen containing waste- urine
o Respiratory- rid of Carbon Dioxide
7. Reproduction Can be cellular or organismal level
• Cellular- original cell divides into daughter cells
• Organismal- sperm unites with egg to form an embryo
• Reproductive responsible for offspring but function regulated by Hormones of Endocrine System
8. Growth Increase in size of body part or organism
Can have increase in the number of cells or increase in the individual cell size
Constructive activities must occur faster than destructive activities to have growth
SURVIVAL NEEDS Body Systems goal is to maintain life
but there are other factors that must be present to do so
Including:
NutrientsOxygenWaterAppropriate TemperatureAtmospheric Pressure
1. Nutrients Energy/ Cell Building Carbohydrates- major fuel for cells Proteins- essential for building cell
structures Fats- cushion body organs, insulate,
and provide energy- rich fuel reserve Select Minerals and Vitamins-
chemical reactions that go on in cells for oxygen transport
2. Oxygen Human cells can only survive a few
minutes without oxygen
Approximately 20 % of air we breathe is oxygen
3. Water 60 to 80 % of body weight Single most abundant chemical
substance in the body
• Provides a base for chemical reactions and body secretions and excretions
• Obtain mostly from foods we eat
• Lost by evaporation from lungs, skin, and body excretions
4. Normal Body Temperature Muscular System produces most body heat
As temperature drops below 98 F metabolic reactions become slower until they eventually stop
If temperature is too high chemical reactions occur at a frantic pace and cause proteins to lose their shape and stop functioning
5. Atmospheric Pressure Force air exerts on surface of the body Breathing and gas exchange in the
lungs depends on appropriate atmospheric pressure
High altitudes cause atmospheric pressure to be lower and the air to be thin- gas exchange may be inadequate for cellular metabolism
BALANCE IS IMPORTANT It is very important to have each of
the needs in the appropriate amount Too much oxygen- toxic to body Too much/ little food- obesity/ starvation
Homeostasis The body’s ability to maintain relatively
stable internal conditions even though the outside world changes continuously
* Communication Is KEY- Nervous and Endocrine systems very important for this state of balance
Negative Feedback System shuts off original stimulus or reduces it Change in direction Controls the everyday (moment to moment
changes in Homeostasis of body)
“ Like your Thermostat at Home”
Your thermostat is known as the hypothalamus located in your brain
Positive Feedback Enhances original stimulus
Proceeds in the same direction
Usually control infrequent events such as blood clotting, or enhancing labor contractions during child birth
Homeostatic Imbalance Diseases As we age body is less efficient at
fighting illness
Could also come from negative feedback mechanisms being overwhelmed and destructive positive feedback mechanisms taking over- Example= HEART FAILURE
Language of Anatomy Anatomical Position- standing straight,
feet slightly apart, palms facing forwards “standing at attention”
“right” and “left” on the person not from observers viewpoint
Regional Terms Axial- main axis (head, neck, trunk)
Appendicular- appendages or limbs
Body Planes Sagittal- Vertical/ divided into left and
right
Frontal- Vertical/ Anterior and Posterior
Transverse- Horizontal/ Superior and Inferior “Cross Section”
Organ Systems Do you remember how many organ
systems there were?
11 Organ Systems
Integumentary System Function:
Protects deeper tissue from injury Pain/ Pressure receptors Sweat/ Oil Glands
• Major Organs
• Hair• Skin• Nails
Skeletal System Function:
Protects and Supports body organs Framework for muscles to Pull on Stores Minerals
• Major Organs
• Bones• Joints
Muscular System Function:
Allows manipulation of environment Locomotion, facial expressions, maintain
posture Produce Heat
• Major Organs
• Muscles
Nervous System Function:
Control System Responds by activating appropriate
muscles and glands
• Major Organs
• Brain• Nerves• Spinal Cord
Endocrine System Function:
Glands secrete hormones that regulate growth, reproduction, and nutrient use
• Major Organs
• Thyroid gland• Thymus• Pancreas• ovary
• Testis• Adrenal Gland• Pineal Gland• Pituitary Gland
Cardiovascular System Function:
Blood Vessels transport blood Carries oxygen, Carbon dioxide, nutrients,
and wastes Heart pumps the blood
• Major Organs
• Blood Vessels• Heart
Lymphatic (Immune) Function:
Picks up fluid leaked from the blood vessels and returns it to the blood
Houses White Blood Cells that are involved in immunity (fighting diseases and sickness)
• Major Organs
• Red Bone Marrow• Thymus• Lymphatic Vessels
• Spleen• Thoracic duct• Lymph Nodes
Urinary System Function:
Eliminates nitrogenous waste Regulates Water Electrolyte and acid-base balance of blood
• Major Organs
• Kidney• Ureter• Urinary Bladder• Urethra
Respiratory System Function:
Keeps the blood supplied with oxygen and removes carbon dioxide
Gas exchange for the lungs
• Major Organs• Nasal Cavity• Pharynx• Larynx• Trachea • Lung • Bronchus
Digestive System Function:
Breaks down food into absorbable units Indigestible food is eliminated out of body
• Major Organs• Oral Cavity • Esophagus• Liver• Stomach
• Small Intestine• Rectum• Anus• Large Intestine
Reproductive System Function:
Production of Offspring Testes- Produce sperm and male sex
hormones Ovaries- produce eggs and female sex
hormones
Major Organs – MALE Prostate Gland Penis Testes Scrotum Ductus deferens
Major Organ- Female Mammary Glands Ovary Uterus Vagina Uterine tube
Dorsal Body Cavity Protects the fragile nervous system
organs There are 2 subdivisions
Cranial- encases the brain Vertebral- encloses the spinal cord
Ventral Body Cavity More anterior and larger body cavity
Also has 2 subdivisions Thoracic- (superior) surrounded by ribs
and muscles Abdominopelvic- (inferior)
Thoracic Pleural Cavity- each houses a lung
Mediastinum- contains the pericardial cavity – encloses the heart
and surrounds the thoracic organs such as esophagus, trachea, and others
AbdominopelvicAbdominal Cavity- stomach,
intestines, spleen, liver and other organs
Pelvic Cavity- bladder, some reproductive organs, and rectum