An Introduction to the Body Systems

1
An Introduction to the Body Systems

• The Human Body Plan
• Skeletal System
• Muscular System
• Integumentary System

2
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.

3
Levels of Structural Organization

• Chemical atoms combine to form molecules
• Cellular molecules interact to make up cells
• Tissue cells are grouped into tissue
• Organ tissues compose organs
• Organ system organs function together to form
  organ systems
• Organism (individual) made up of the organ
  systems

4
(No Transcript)
5
Body Tissue

• All tissues are a collection of cells that have a
  similar structure and that work together to
  perform a particular function.
• Four types of body tissue
• Muscle tissue
• Nervous Tissue
• Epithelial Tissue
• Connective Tissue

6

• 1. Muscle Tissue
• composed of cells that can contract in a
  coordinated fashion.
• 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.

7
Body Tissues, continued
Chapter 45

• 2. 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

8
Nervous Tissue, continued
Chapter 45

• 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.

9
Body Tissues, continued
Chapter 45

• 3. Epithelial Tissue- 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.

10
Body Tissues, continued
Chapter 45

• Epithelial Tissue, continued
• Each epithelial layer
• is formed from cells
• that are tightly bound
• together, often
• providing a protective
• barrier for these
• surfaces.

11
Body Tissues, continued
Chapter 45

• 4. Connective Tissue
• is a tissue that has a lot of intracellular
  substance and that connects and supports other
  tissues.

12
Body Tissues, continued
Chapter 45

• 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.

13
Human Body Tissues
Chapter 45
14
Organs and Organ Systems
Chapter 45

• 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.

15
(No Transcript)
16
Organs and Organ Systems

• 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 organs primary
  function. This is so the organ system can work
  more efficiently.

17
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.

18
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.

19
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

20
(No Transcript)
21
Objectives Skeletal System

• 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

22
The Skeletal System

• Composed of bone, cartilage, and ligaments
• Protects and supports body organs
• Provides the framework for muscles
• Site of blood cell formation
• Stores minerals

23
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.

24
Subsections of the Human Skeleton

• The purple is the axial skeleton and the yellow
  is the appendicular skeleton.

25
The Skeleton Is Divided Into Two Distinct Parts

• 1. The axial skeleton consists of bones that form
  the axis of the body and support and protect the
  organs of the head, neck, and trunk.

• Click on these links to read about the axial
  parts of the body.
• The skull
• The sternum
• The ribs
• The backbone

26
The Appendicular Skeleton

• 2. The appendicular skeleton is composed of bones
  that anchor the appendages to the axial skeleton.

• Click on these links to read about the
  appendicular parts of the body.
• The lower body
• The upper body
• The shoulders
• The pelvic area

27

• Axial skeleton
• skull (cranium and facial bones)
• hyoid bone (anchors tongue and muscles associated
  with swallowing
• vertebral column (vertebrae and disks)
• thoracic cage (ribs and sternum)
• Appendicular skeleton
• pectoral girdle (clavicles and scapulae)
• upper limbs (arms)
• pelvic girdle (coxal bones, sacrum, coccyx)
• lower limbs (legs)

28
Bone Function and Structure

• The bones that make up the skeleton function in a
  variety of ways
• support muscles
• protect internal organs
• help movement
• play vital roles in important metabolic
  processes.
• Bones do not make up most of a bodys mass.
• Being big boned is no excuse for being
  overweight!

29
Types of Bones

• The bones of the body fall into four general
  categories
• Long bones are longer than they are wide and work
  as levers. The bones of the upper and lower
  extremities are of this type.
• Short bones are short, cube-shaped, and found in
  the wrists and ankles.
• Flat bones have broad surfaces for protection of
  organs and attachment of muscles
• Irregular bones are all others that do not fall
  into the previous categories. They have varied
  shapes, sizes, and surfaces features and include
  the bones of the vertebrae and a few in the
  skull.

30
Bone Function and Structure

• Long Bone Structure
• A long bones 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.

31
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.
• 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.

32
(No Transcript)
33
Bone Function and Structure continued

• 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.

34
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.

35
Bone Development

• During fetal development, some bones that were
  originally cartilage will slowly be replaced by
  actual bone. This process is called ossification.
• Humans are born with over 300 bones, but adults
  have about 206 bones.

36
Where are the 206 Bones?

• 22 bones in skull
• 6 in middle ears
• 1 hyoid bone
• 26 in vertebral column
• 25 in thoracic cage
• 4 in pectoral girdle
• 60 in upper limbs
• 60 in lower limbs
• 2 in pelvic girdle

37
Bone Development

• Bone Elongation
• Bones continue to grow after a persons 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.

38
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
• Movable

39
Types of Joints

• Fixed Joints
• A joint at which no movement occurs
• Semimovable Joints
• A joint that will permit limited movement
• Cartilage can be involved to help these joints
  move.
• Movable joint
• - 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.

40
Movable Joints

• A hinge joint allows limited movement in only one
  plane.
• 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.

41
(No Transcript)
42
(No Transcript)
43
Gliding Joint
44
(No Transcript)
45
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 (hold bone to bone)
  and tendons (hold muscle to bone) to aid in joint
  movement.
• Even with all this protection a joint can still
  be injured.

46
Joints 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.

47
Other Links

• Site of Anatomy Terms
• Listen to audio recordings about the skeletal
  system
• Click on any part of the skeleton and it will
  tell you about that part of the body

48
Objectives Muscular System

• 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.

49
Muscular system

• Composed of muscles and tendons
• Allows manipulation of the environment,
  locomotion, and facial expression
• Maintains posture
• Produces heat

50
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.

51
Skeletal Muscle

• 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.

52
Skeletal Muscle 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.

53
Smooth Muscle

• 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.

54
Cardiac Muscle

• 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.

55
(No Transcript)
56
Muscular Contractions

• Muscle contraction is an all-or-none
  responseeither 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.

57
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.

58
Muscular Movement of Bones

• 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.

59
Opposing Muscles in the Arm
60
ObjectivesIntegumentary System

• 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.

61
Layers of Skin Epidermis and Dermis

• Epidermis
• Outer layer
• From the Greek epi, meaning on or upon and
  derma meaning skin
• Composed of scaly epithelial cells, top layer
  mostly dead
• Cells filled with the protein keratin which gives
  skin a tough, leathery, waterproof quality
• Skin color determined by the amount of melanin in
  the lower layers of the epidermis

62
Layers of Skin Epidermis and Dermis

• Dermis
• The dermis is the inner layer of skin and is
  composed of living cells and other specialized
  structures such as
• Sensory neurons, blood vessels, muscle fibers,
  hair follicles, and glands
• These specialized cells help the skin protect the
  body as much as possible

63
Glands

• Sweat glands are distributed throughout the body
  and release excess water, salts, and urea.
• Oil glands secret a substance called sebum.
• 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.

• 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.
• help regulate the bodies temperature.

64
Cross section of Skin
65
Hair 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.

• 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.