Transcript 1285174151_463952

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Chapter 1
The Human Body
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Introduction
• Anatomy: the study of the structure of the
body
• Physiology: the study of the function of the
body parts
• Pathology: the study of the disease of the
body
• Basic reference systems
– Directions, planes, cavities, structural units
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Terms of Direction
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Terms of Direction (cont’d.)
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Planes
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Planes (cont’d.)
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Cavities
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Cavities (cont’d.)
• Dorsal
– Cranial, spinal
• Ventral
– Thoracic, abdominopelvic
• Parietal: walls of a cavity
• Visceral: covering on an organ
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Cavities (cont’d.)
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Structural Units
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Structural Units (cont’d.)
• Cells
– Smallest units of life
– Perform all activities necessary to maintain
life
• Metabolism, assimilation, digestion, excretion,
reproduction
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Structural Units (cont’d.)
• Tissues
– Made up of different types of cells
– Epithelial: covers and protects
– Connective: binds and supports other tissues
– Muscle: movement
– Nervous: connects sensory structures to
motor structures
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Structural Units (cont’d.)
• Organs
– Cells integrated into tissues
– Serve a common function
– Examples
• Liver
• Stomach
• System is a group of organs
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Structural Units (cont’d.)
• Integumentary system
– Organs
• Skin, hair, nails, sweat glands, sebaceous glands
– Functions
• Protection, insulation, regulation of water and
temperature
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Structural Units (cont’d.)
• Skeletal system
– Organs
• Bones, cartilage, membranous structures
– Functions
• Movement, blood production, fat and mineral
storage, protection
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Structural Units (cont’d.)
• Muscular system
– Organs
• Muscles, fasciae, tendon sheaths, and bursae
– Functions
• Movement, pushing food and blood, contracting
heart
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Structural Units (cont’d.)
• Nervous system
– Organs
• Brain, spinal cord, cranial and peripheral nerves,
sensory and motor structures
– Function
• Control and regulation, interpreting stimuli
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Structural Units (cont’d.)
• Endocrine system
– Organs
• Endocrine glands
– Function
• Works with nervous system to regulate chemical
aspects of the body
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Structural Units (cont’d.)
• Cardiovascular system
– Organs
• Heart, arteries, veins, capillaries
– Function
• Transport substances to and from cells
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Structural Units (cont’d.)
• Lymphatic/immune system
– Organs
• Lymph nodes, lymph vessels, thymus gland,
spleen
– Functions
• Drains tissues of excess fluids, transports fats,
develops immunities
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Structural Units (cont’d.)
• Respiratory system
– Organs
• Nasal cavities, pharynx, larynx, trachea, bronchi,
lungs
– Function
• O2 > CO2 exchange in the blood
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Structural Units (cont’d.)
• Digestive system
– Organs
• Alimentary canal: mouth, esophagus, stomach,
small and large intestines, rectum and anus
• Associated glands: salivary, liver, pancreas
– Functions
• Convert food into absorbable substances,
eliminates wastes
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Structural Units (cont’d.)
• Urinary system
– Organs
• Kidneys, ureters, bladder, urethra
– Functions
• Chemical regulation of blood
• Formation and elimination of urine
• Maintenance of homeostasis
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Structural Units (cont’d.)
• Reproductive system
– Organs
• Women: ovaries, uterine tubes, uterus, vagina
• Men: testes, seminal vesicles, prostate gland,
penis, urethra
– Functions
• Maintains sexual characteristics and perpetuates
the species
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Homeostasis
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Homeostasis (cont’d.)
• Maintenance of the body’s internal
environment
– Within varying narrow limits
• Negative feedback loop
• Examples
– Blood sugar levels
– Body temperature
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Homeostasis (cont’d.)
• Blood glucose
– Levels rise dramatically after meal
– Cells take in glucose
– Pancreas secretes insulin
• Moves glucose into liver for storage as glycogen
– Between meals, pancreas secretes glucagon
• Turns glycogen into glucose and returns it to blood
– Thus, glucose levels remain nearly constant
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Homeostasis (cont’d.)
• Body temperature
– Hypothalamus detects increase in body
temperature
– Causes sweating
• Water evaporates and body is cooled
– Blood vessels dilate to bring blood near body
surface
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Homeostasis (cont’d.)
• Body monitors deviations in homeostasis
– Negative feedback loop
• Responses that revise disturbances to body’s
condition
– Positive feedback
• Increase in function in response to stimulus
• Uterine contractions during labor
• Organ systems help control internal
environment
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Summary
• Discussed the four basic reference
systems of body organization (directions,
planes, cavities, and structural units)
• Discussed organization of the body into
different structural levels (cells, tissues,
organs, systems, human organism)
• Discussed homeostasis and mechanisms
for maintaining it
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