Transcript Lecture Chapter 45

Chapter 45
Skeletal, Muscular, and
Integumentary Systems
Table of Contents
Section 1 The Human Body Plan
Section 2 Skeletal System
Section 3 Muscular System
Section 4 Integumentary System
Chapter 45
Section 1 The Human Body Plan
Objectives
• Describe four types of tissues that make up the
human body.
• Explain how tissues, organs, and organ systems are
organized.
• Summarize the functions of the primary organ
systems in the human body.
• Identify the five human body cavities and the organs
that each contains.
Chapter 45
Section 1 The Human Body Plan
Body Tissues
• All tissues are a collection
of cells that have a similar
structure and that work
together to perform a
particular function.
• Muscle Tissue
– Muscle tissue is
composed of cells
that can contract in a
coordinated fashion.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Muscle Tissue, continued
– The human body has three types of muscle tissue:
skeletal, smooth, and cardiac.
• Skeletal muscle moves the bones in your trunk,
limbs, and face.
• Smooth muscle handles body functions that you
cannot control consciously.
• Cardiac muscle, found in your heart, pumps
blood through your body.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Nervous Tissue
– Nervous tissue
contains cells,
or neurons, that
receive and
transmit messages
in the form of
electrical impulses.
– Neurons are nerve cells that are specialized to
receive and send electrical impulses.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Nervous Tissue, continued
– Nervous tissue can be found throughout the
human body and has various functions.
• For example, nervous tissue can be found
in the brain and sensory organs and is used
to interpret sensory information.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Epithelial Tissue
– Epithelial tissue is tissue that is composed of a
sheet of cells and that covers a body surface
or lines a body cavity.
– Epithelial tissue is found in various
thicknesses and arrangements, depending on
where it is located.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Epithelial Tissue, continued
– Each epithelial layer
is formed from cells
that are tightly bound
together, often
providing a protective
barrier for these
surfaces.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Connective Tissue
– Connective tissue is
a tissue that has a
lot of intracellular
substance and that
connects and
supports other
tissues.
Chapter 45
Section 1 The Human Body Plan
Body Tissues, continued
• Connective Tissue, continued
– Connective tissues are the most abundant
and diverse of the four types of tissue and
contain a substance called matrix.
– Matrix is an intracellular substance that gives
connective tissue its strength and flexibility
and can be solid, semisolid, or liquid.
Chapter 45
Human Body
Tissues
Section 1 The Human Body Plan
Chapter 45
Section 1 The Human Body Plan
Body Tissues
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 1 The Human Body Plan
Organs and Organ Systems
• An organ consists of various tissues that work
together to carry out a specific function.
• Groups of organs interact in an organ system.
• Organ systems work together to function in an
efficient, integrated manner.
Chapter 45
Major Organ
Systems of
the Human
Body
Section 1 The Human Body Plan
Chapter 45
Section 1 The Human Body Plan
Organs and Organ Systems, continued
• Integration of Organ Systems
– An even higher level of organization is the
integration of organ systems.
– The integration of organ systems can be
described as each organ system having
organs associated with it according to that
organ’s primary function. This is so the organ
system can work more efficiently.
Chapter 45
Section 1 The Human Body Plan
Overview of Organ Systems
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 1 The Human Body Plan
Body Cavities
• Many organs and organ systems in the human
body are housed in compartments called body
cavities.
• These cavities protect internal organs from injuries
and permit organs to function while remaining
securely supported.
• Each human cavity can contains one or more
organs.
Chapter 45
Section 1 The Human Body Plan
Body Cavities, continued
– The human body has five main body cavities,
including the cranial cavity, the spinal cavity,
the thoracic cavity, the abdominal cavity, and
the pelvic cavity.
– The cranial cavity is the cavity that contains,
supports, and protects the brain.
– The spinal cavity is the cavity that contains,
supports, and protects the spinal cord.
Chapter 45
Section 1 The Human Body Plan
Body Cavities, continued
• The thoracic cavity is the cavity that contains,
supports, and protects the heart, esophagus, and
the organs of the respiratory system.
• The abdominal cavity is the cavity that contains,
supports, and protects the digestive system.
• The pelvic cavity is the cavity that contains,
supports, and protects the organs of the
reproductive and excretory systems.
Chapter 45
Cavities of the
Human Body
Section 1 The Human Body Plan
Chapter 45
Section 1 The Human Body Plan
Human Body Cavities
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 2 Skeletal System
Objectives
• Distinguish between the axial skeleton and the
appendicular skeleton.
• Explain the function and structure of bones.
• Summarize how bones develop and elongate.
• List three types of joints and give an example of each.
• Describe a common disorder that affects the skeleton.
Chapter 45
Section 2 Skeletal System
The Skeleton
• A skeleton is the bones of a human or animal
body that form the framework of the body,
support the muscles and organs, and protect the
inner organs.
• The variation in size and shape among the bones
that make up the skeleton reflects their different
roles in the body.
Chapter 45
Human Skeleton
Section 2 Skeletal System
Chapter 45
Section 2 Skeletal System
The Skeleton, continued
• The human skeleton is composed of two parts—
the axial skeleton and the appendicular skeleton.
• The bones of the arms and legs, along with the
scapula, clavicle, and pelvis, make up the
appendicular skeleton.
• The bones of the skull, ribs, spine, and sternum
form the axial skeleton.
Chapter 45
Section 2 Skeletal System
Anatomy of a Human Skeletal System
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 2 Skeletal System
Bone Function and Structure
• The bones that make up the skeleton function in a
variety of ways, such as supporting the muscles,
protecting internal organs, helping movement,
and playing vital roles in important metabolic
processes.
• Bones do not make up most of a body’s mass.
Chapter 45
Section 2 Skeletal System
Bone Function and Structure, continued
• Long Bone Structure
– A long bone’s surface is covered by a tough
membrane called the periosteum.
– Periosteum is a white, double layered
membrane that covers the entire surface of
bone except for the joint surfaces and is richly
supplied with nerve fibers and blood vessels.
Chapter 45
Section 2 Skeletal System
Bone Function and Structure, continued
• Long Bone Structure, continued
– Under the periosteum is a hard material called
compact bone, and this part of the bone gives
all bones their strength and rigidity.
– Compact bone is composed of cylinders made
of mineral crystals and protein fibers called
lamellae.
Chapter 45
Section 2 Skeletal System
Bone Function and Structure, continued
• Long Bone Structure, continued
– Each lamellae is made up of a narrow channel
called a Haversian canal, which contains the
blood vessels in compact bone.
– Surrounding each Haversian canal are protein
fibers and osteocytes.
• Osteocytes are a specific type of bone
cell.
Chapter 45
Section 2 Skeletal System
Bone Function and Structure, continued
• Long Bone Structure, continued
– Beneath some compact bone is a network of
connective tissue called spongy bone.
– Spongy bone is less dense bone tissue that
has many open spaces.
Chapter 45
Section 2 Skeletal System
Structure of Bone
Chapter 45
Section 2 Skeletal System
Bone Function and Structure, continued
• Bone Marrow
– Bone marrow is a soft tissue inside some
bones that can be either red or yellow.
– The type of bone marrow present determines
both its composition and function.
Chapter 45
Section 2 Skeletal System
Parts of a Human Bone - 1 & 2
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 2 Skeletal System
Bone Function and Structure, continued
• Injury and Repair
– Despite their strength, bones will crack or even
break if they are subjected to certain situations
or are overused.
– A crack or break is referred to as a fracture.
• A fracture is an injury in which the tissue of
a bone is broken.
Chapter 45
Section 2 Skeletal System
Bone Development
• During fetal development, some bones that were
originally cartilage will slowly be replaced by
actual bone. This process is called ossification.
Chapter 45
Section 2 Skeletal System
Bone Development, continued
• Bone Elongation
– Bones continue to grow after a person’s birth.
– Bone elongation and growth take place near
the ends of long bones in an area known as
the epiphyseal plate.
• The epiphyseal plate is found at the joint
ends of long bones and is composed of
cartilage. This area of bone will eventually
become mature bone.
Chapter 45
Section 2 Skeletal System
Human Bone Growth
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 2 Skeletal System
Joints
• The place where two bones meet is known as a
joint.
• Three major kinds of joints are found in the
human body—fixed, semimovable, and movable.
• Fixed Joints
– A fixed joint is a joint at which no movement
occurs.
Chapter 45
Section 2 Skeletal System
Joints, continued
• Semimovable Joints
– A semimovable joint is one that will permit
limited movement.
– Cartilage can be involved to help these joints
move.
Chapter 45
Section 2 Skeletal System
Joints, continued
• Movable Joints
– A movable joint is a joint at which a wide range
of motion occurs.
– There are different types of movable joints,
including hinge, ball-and-socket, pivot, saddle,
and gliding.
– A hinge joint allows limited movement in only
one plane.
Chapter 45
Section 2 Skeletal System
Joints, continued
• Movable Joints, continued
– A ball-and-socket joint is another type of moveable joint
and allows 360 degree movement in 2 planes.
– A pivot joint allows 180 degree movement in only one
plane.
– A saddle joint will allow 360 degree movement in only
one plane.
– A gliding joint allows bones to slide over one another.
Chapter 45
Section 2 Skeletal System
Joints, continued
• Joint Structure
– Joint structure helps movable joints deal with
the pressure and stress of everyday life.
– Joints are covered with cartilage and secrete
synovial fluid to reduce friction. Joints are also
connected with ligaments to aid in joint
movement.
– Even with all this protection a joint can still be
injured.
Chapter 45
Section 2 Skeletal System
Joints, continued
• Joint Structure, continued
– The term arthritis is used to describe disorders that
cause painful, swollen joints.
• Rheumatoid arthritis develops when the immune
system begins to attack body tissues, and joints
become stiff and deformed.
• Osteoarthritis is a degenerative joint disease in
which the cartilage covering the surface of bone
becomes thinner and rougher.
Chapter 45
Types of Joints
Section 2 Skeletal System
Chapter 45
Section 2 Skeletal System
Types of Joints
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 3 Muscular System
Objectives
• Distinguish between the three types of muscle
tissues.
• Describe the structure of skeletal muscle fibers.
• Explain how skeletal muscles contract.
• Describe how muscles move bones.
• Explain the process in which a muscle becomes
fatigued.
Chapter 45
Section 3 Muscular System
Muscle Types
• A muscle is an organ that can contract in a
coordinated fashion and includes muscle tissue,
blood vessels, nerves, and connective tissue.
• Their ability to contract and relax not only enables
the body to move, but also provides the force that
pushes substances, such as blood and food,
through the body.
• The human body has three types of muscle
tissues: skeletal, smooth, and cardiac.
Chapter 45
Section 3 Muscular System
Muscle Types, continued
• Skeletal muscles consciously control the moving
parts of the body and are often referred to as
voluntary muscles.
• Skeletal muscles are made up of muscle fibers.
– Muscle fibers consist of multinucleated
elongated cells with light and dark stripes.
These stripes are called striations.
Chapter 45
Section 3 Muscular System
Muscle Types, continued
• Muscle fibers are grouped into bundles called
fascicles.
• Groups of fascicles are bound together by
connective tissue to form a muscle.
• The connective tissue in skeletal muscle cells
can unite to form tendons.
Chapter 45
Section 3 Muscular System
Muscle Types, continued
• Smooth muscles are spindle-shaped, have a single
nucleus, and interlace to form sheets.
• Smooth muscle lacks striations, and the connective
tissue that surrounds it cannot form tendons.
• Smooth muscle forms the walls of the stomach,
intestines, blood vessels, and other internal organs.
Because most of its movements cannot be
consciously controlled, smooth muscle is
referred to as involuntary muscle.
Chapter 45
Section 3 Muscular System
Muscle Types, continued
• Cardiac muscle makes up the walls of the heart.
• Cardiac muscle shares some characteristics with
both skeletal muscle and smooth muscle.
– As with skeletal muscle, cardiac muscle tissue
is striated; as with smooth muscle, it is
involuntary and each cell has one nucleus.
Chapter 45
Three Types
of Muscle
Tissue
Section 3 Muscular System
Chapter 45
Section 3 Muscular System
Anatomy of the Human Muscular System
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 3 Muscular System
Muscle Structure
• A skeletal muscle fiber is a single, multinucleated
muscle cell.
• Although muscle fibers make up most muscle
tissue, a large amount of connective tissue, blood
vessels, and nerves are also present.
• Connective tissue covers and supports each
muscle fiber and reinforces the muscle as a whole.
Chapter 45
Section 3 Muscular System
Muscle Structure, continued
• Each skeletal muscle fiber has a nerve ending that
controls its activity.
• Muscles produce large amounts of metabolic waste
that must be removed through veins.
• A skeletal muscle fiber contains bundles of structures
called myofibrils.
– A myofibril is a threadlike structure that contains
two types of protein.
Chapter 45
Section 3 Muscular System
Muscle Structure, continued
• Each myofibril is made up of two types of protein
filaments—thick ones and thin ones.
• The thick filaments are mostly made of the
protein myosin, which is also the most abundant
protein in muscle tissue.
• The thin filaments are made of the protein actin,
which is the protein that functions in the
contraction and relaxation of muscles.
Chapter 45
Section 3 Muscular System
Muscle Structure, continued
• Since actin filaments are the main protein in
contraction and relaxation, actin filaments are
anchored at their endpoints and create a
structure called the Z line.
• The region from one Z line to the next is called a
sarcomere. This unit is the basic unit of
contraction for skeletal and cardiac muscle.
Chapter 45
Skeletal Muscle
Section 3 Muscular System
Chapter 45
Section 3 Muscular System
Muscular Contraction
• When a nerve impulse stimulates a muscle to
contract, the myosin filaments’ heads attach to
points on the actin filaments.
• The myosin heads then bend inward, pulling the
actin with them.
• The myosin heads then let the actin go, bend
back into their original position, attach to a new
point on the actin filament, and pull again.
Chapter 45
Section 3 Muscular System
Muscular Contraction, continued
• The action just described shortens the sarcomere, and
when all the sarcomeres of a muscle fiber are
shortened, the muscle fibers (and thus the muscle)
contract.
• Muscle contraction requires energy, which is supplied
by ATP.
• Because myosin heads must attach and detach a
number of times during a single muscle contraction,
muscle cells must have a continuous supply of
ATP.
Chapter 45
Contraction of
a Muscle
Section 3 Muscular System
Chapter 45
Section 3 Muscular System
Muscle Contraction
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 3 Muscular System
Muscular Contraction, continued
• Muscle contraction is an all-or-none response—
either the fibers contract or they remain relaxed.
• The force of a muscle contraction is determined by
the number of muscle fibers that are stimulated.
– As more fibers are activated, the force of the
contraction increases.
Chapter 45
Section 3 Muscular System
Muscular Movement of Bones
• Muscles are attached to the outer membrane of
bone, the periosteum, either directly or by a
tough fibrous cord of connective tissue called a
tendon.
• The point where the muscle attaches to the
stationary bone is called the origin.
• The point where the muscle attaches to the
moving bone is called the insertion.
Chapter 45
Section 3 Muscular System
Muscular Movement of Bones, continued
• Most skeletal muscles are arranged in opposing
pairs, and muscles move bones by pulling them.
• The muscle that bends a joint is known as a flexor.
• A muscle that straightens a joint is known as an
extensor.
• In order for smooth movement, one muscle in a pair
must contract while the opposing muscle relaxes.
Chapter 45
Section 3 Muscular System
Opposing Muscles in the Arm
Chapter 45
Section 3 Muscular System
Muscular Movement and Bones
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 3 Muscular System
Muscle Fatigue
• Muscle cells store glycogen, which provides
muscles with energy.
• During prolonged and vigorous exertion and when
glucose has been used up, fat molecules are
utilized for energy.
• When energy availability fails to keep pace with its
use, muscle fatigue sets in. Muscle fatigue is the
physiological inability of a muscle to contract,
and is a result of a relative depletion of ATP.
Chapter 45
Section 3 Muscular System
Muscle Fatigue, continued
• Oxygen Debt
– When the level of oxygen coming into the body
is not enough to meet the demands of energy
production, an oxygen debt is established.
• Oxygen debt is the extra amount of oxygen
that must be taken in by the body to replenish
the muscles’ oxygen reserves and to allow
for the breakdown of lactic acid within the
muscles.
Chapter 45
Section 4 Integumentary System
Objectives
• Describe the functions of the skin.
• Distinguish between the two layers that form skin.
• Identify two types of glands found in the skin, and
describe their functions.
• Describe the structure of nails.
• Describe the structure of hair.
Chapter 45
Section 4 Integumentary System
Skin
• Skin is composed of two layers the epidermis and
the dermis.
• Epidermis
– The epidermis is the outer layer of skin and is
composed of flattened epithelial cells.
– The cells of the epidermis are filled with a protein
called keratin, which gives skin its rough,
leathery texture and its waterproof quality.
Chapter 45
Section 4 Integumentary System
Skin, continued
• Epidermis, continued
– The color of skin is mainly determined by a
brown pigment called melanin, which is
produced by cells in the lower layers of the
epidermis.
• The amount of melanin produced in skin
depends on two factors: heredity and the
length of time the skin is exposed to
ultraviolet radiation.
Chapter 45
Section 4 Integumentary System
Skin, continued
• Dermis
– The dermis is the inner layer of skin and is
composed of living cells and other specialized
structures.
– These specialized cells help the skin protect
the body as much as possible.
Chapter 45
Section 4 Integumentary System
Skin, continued
• Glands
– The skin contains exocrine glands, which are
glands that release secretions through ducts.
The main exocrine glands present in the skin
are sweat glands and oil glands.
– Sweat glands are distributed throughout the
body and release excess water salts and urea.
Sweat glands also help regulate the bodies
temperature.
Chapter 45
Section 4 Integumentary System
Skin, continued
• Glands, continued
– Oil glands are excretory glands that secret a substance
called sebum. Oil glands are also called sebaceous
glands.
– Sebum is an oily secretion that prevents excess water
loss, softens hair and skin, and protects the body by
being mildly toxic to some bacteria.
• Acne occurs when the ducts of oil glands become
clogged with excessive amounts of sebum, dead
cells, and bacteria.
Chapter 45
Section 4 Integumentary System
Structure of Skin
Section 4 Integumentary System
Chapter 45
Parts of the Skin
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 4 Integumentary System
Nails
• Nails help protect the fingers and toes by forming
nail roots under skin folds at the base and sides
of the nail.
• Nails are also made primarily of keratin and rest
on a bed of tissue filled with blood vessels.
• Nails can be an indicator of some kinds of
diseases due to their composition and location.
Chapter 45
Section 4 Integumentary System
Cross Section of Fingernail
Click below to watch the Visual Concept.
Visual Concept
Chapter 45
Section 4 Integumentary System
Hair
• Hair protects and insulates the body and is
produced by hair follicles, which are clusters of
cells at the base of deep dermal pits.
• Hair is composed of keratin and is kept soft by
the oil glands associated with the hair follicle.
• Hair color is the result of the presence of the
pigment melanin in the hair shaft.