Chapter 6
The Human Body
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6-1
Objectives
6-2
Introduction
• Anatomy
– The study of the structure of an organism,
such as the human body
• Physiology
– The study of the normal functions of an
organism, such as the human body
6-3
Structural Organization
6-4
Cell Function
6-5
Body Organization
• Cells
• Tissues
• Organs
– Vital organs
• Organ systems
6-6
10 Major Organ Systems
1.
2.
3.
4.
5.
Circulatory
Digestive
Endocrine
Integumentary
Muscular
6. Nervous
7. Reproductive
8. Respiratory
9. Skeletal
10.Urinary
6-7
Homeostasis
• Organ systems work together to maintain
a constant internal environment
(homeostasis).
• Cell metabolism
– Aerobic metabolism
– Anaerobic metabolism
6-8
Homeostasis
• Body fluids
– Two main compartments
– Intracellular fluid (ICF)
• Fluid within the walls of body cells
• Accounts for about two-thirds of body water
– Extracellular fluid (ECF)
• Fluid within the blood vessels
• Fluid within the tissues
6-9
Body Cavities
6-10
Abdominal Quadrants
6-11
Body Planes
6-12
Musculoskeletal System
6-13
Musculoskeletal System
• Gives the body its shape
• Allows the body to move
• Protects major organs
of the body
6-14
Skeletal System
• Consists of 206 bones of
varying types
• Bones
– Store minerals
– Many bones contain bone
marrow.
• Bone marrow produces
blood cells.
6-15
Skeletal System
6-16
Skeletal System
6-17
• Bones are classified by shape and size.
6-18
Bones of the Skull
6-19
Vertebral (Spinal) Column
6-20
Vertebral Discs
6-21
Spinal Cord and Spinal Nerves
6-22
The Chest (Thorax)
6-23
Upper Extremity
6-24
Lower Extremity
6-25
The Muscular System
• Gives the body shape
• Protects internal organs
• Provides for movement of the body
• Maintains posture
• Helps stabilize joints
• Produces body heat
6-26
The Muscular System
• Muscles are classified according to their
structure and function.
– Skeletal (voluntary) muscle
– Smooth (involuntary) muscle
– Cardiac muscle
6-27
• Skeletal muscles and bones work together as
levers.
6-28
Smooth Muscle
• Involuntary
• Strong, slow contractions
• Found in
– Walls of GI tract and urinary system
– Blood vessels
– Eye
– Bronchi
6-29
Cardiac Muscle
• Found only in the heart
• Produces heart’s contraction and pumps
blood
• Has its own blood supply through the
coronary arteries
• Normal contractions are strong and rhythmic.
• Involuntary
6-30
Comparison of Muscle Types
Skeletal
Smooth
Location
Attached to bone
by tendons
Function
Moves the
Moves food through
skeleton
the digestive
Produces heat that
tract
helps maintain Adjusts the size of
a constant
blood vessels to
body
control blood
temperature
flow
Maintains posture
Contracts and
relaxes the
heart
Moves blood
through the
body
Voluntary
Involuntary
Type of
Control
Walls of the
esophagus,
stomach,
intestines,
bronchi, uterus,
blood vessels,
glands
Cardiac
Involuntary
Walls of the
heart
6-31
Respiratory System
6-32
Respiratory System
6-33
Respiratory System
6-34
Swallowing
6-35
Respiratory System
6-36
Respiratory System
6-37
Respiratory System
6-38
Ventilation
• Breathing (pulmonary ventilation)
– Process of moving air into and out of the
lungs
• Inspiration (inhalation)
– Process of breathing in and moving air
into the lungs
• Expiration (exhalation)
– Process of breathing out and moving air
out of the lungs
6-39
Respiratory System
• Respiration
• Tidal volume
• Anatomic dead space
• Minute volume
6-40
Mechanics of Breathing
• Chemoreceptors
– Central
• Medulla oblongata in the brain
• Monitor carbon dioxide level
– Peripheral
• Carotid arteries
• Arch of the aorta
• Monitor oxygen and carbon dioxide levels
6-41
Mechanics of Breathing
6-42
Structures that Support Ventilation
• Chest wall
• Pleurae
• Diaphragm
• Intercostal muscles
• Phrenic nerves
• Pulmonary capillaries
6-43
Respiration
• Respiration
– Exchange of gases
between a living
organism and its
environment
• Internal respiration
• External respiration
6-44
Respiration
• Alveolar/capillary gas
exchange
• Cell/capillary gas
exchange
6-45
Circulatory System
6-46
Circulatory System
• Cardiovascular
system
– Pump (heart)
– Fluid (blood)
– Container (blood
vessels)
• Lymphatic system
– Lymph
– Lymph nodes
– Lymph vessels
– Tonsils
– Spleen
– Thymus gland
6-47
Circulatory System
•
Functions
– Delivers oxygen-rich blood and
nutrients to body tissues
– Helps maintain body temperature
– Protects the body against infection
– Controls bleeding
– Removes waste and by-products of
metabolism from body tissues
– Transports hormones and other
chemical messengers to targeted
tissues of the body
6-48
The Heart
6-49
Blood Flow through the Heart
6-50
Blood Flow through the Heart
6-51
Blood
• Transport system
• Works with lymphatic system to protect the
body against infection
6-52
Blood Components
6-53
Blood Vessels
Arteries → arterioles → capillaries → venules → veins
6-54
Veins Contain One-Way Valves
6-55
Major Arteries
6-56
Major Veins
6-57
Physiology of Circulation
• Pulse
– Central
– Peripheral
• Blood pressure
– Systolic
– Diastolic
6-58
Nervous System
6-59
Nervous System
6-60
• The brain is housed in the cranium.
6-61
Areas of the Brain
6-62
Spinal Cord
• Relays electrical
signals to and from
the brain and
peripheral nerves
6-63
Peripheral Nervous System (PNS)
6-64
Autonomic Nervous System
• Sympathetic division
– Mobilizes energy, particularly in stressful
situations
– “Fight-or- flight” response
– Effects are widespread throughout the
body
• Parasympathetic division
– Conserves and restores energy
– Effects are localized in the body
6-65
Integumentary System
6-66
Integumentary System
6-67
Digestive System
6-68
Digestive System
• Functions
– Ingestion
– Digestion
– Absorption
– Defecation
6-69
Digestive System Components
6-70
Digestive System
• Peristalsis
• Process of digestion
6-71
Endocrine System
6-72
Endocrine System
• Functions
– Secretes chemicals (hormones) directly
into the circulatory system
– Influences body activities and functions
– Works closely with nervous system to
maintain homeostasis
6-73
Endocrine System Components
6-74
Reproductive System
6-75
Reproductive System
• Function
– Makes cells (sperm, eggs) that allow
continuation of the human species
6-76
Male Reproductive System
6-77
Female Reproductive System
6-78
Urinary System
6-79
Urinary System
• Functions
– Removes body wastes
– Assists in regulating blood pressure
– Helps control the amount and composition
of water and other substances in the body
6-80
Urinary System
• Components
– Kidneys
– Ureters
– Bladder
– Urethra
6-81
Questions?
6-82