Organization and Regulation of Body Systems

1
Chapter 4

• Organization and Regulation of Body Systems

2
Points to Ponder

• What is a tissue? Organ? Organ system?
• What are the 4 main types of tissue?
• What do these tissues look like, how do they
  function and where are they found?
• What is the integumentary system?
• How can you prevent skin cancer?
• What is homeostasis and how is it maintained?

3
What is a tissue?
4.1 Types of tissues

• A collection of cells of the same type that
  perform a common function
• There are 4 major tissue types in the body
• Connective
• Muscular
• Nervous
• Epithelial

4
The four tissues of the Body

• Epithelial Tissue covering
• Covers exposed surfaces
• Lines internal passageways
• Forms glands
• Connective Tissue support
• Fills internal spaces
• Provides structure and strength to support other
  tissues
• Transports materials
• Stores energy

5
The four tissues of the Body

• Muscle Tissue movement
• Specialized for contraction
• Skeletal muscle, heart muscle, and walls of
  hollow organs
• Neural Tissue control
• Carries electrical signals from 1 part of the
  body to another

6
1. Connective tissue
4.2 Connective tissue connects and supports

• Binds and supports parts of the body
• All have specialized cells, ground substance and
  protein fibers
• Ground substance is noncellular and ranges from
  solid to fluid
• prevents microbe penetration
• The ground substance and proteins fibers together
  make up the matrix of the tissue
• There are three main types of connective tissue
  A. fibrous , B. supportive and C. fluid

7
1. Connective Tissue

• Protein Fiber types
• 1. Collagen fibers collagen protein
• -resists force
• 2. Reticular fibers collagen protein
• -branchy, forms framework
• -framework of an organ
• 3. Elastic fibers elastin protein
• -wavy, flexible
• - Designed to stretch

Figure 48
8
3 main types of connective tissue
4.2 Connective tissue connects and supports

• A. Fibrous
• B. Supportive
• C. Fluid

9
Categories of Connective Tissue Proper

• Loose connective tissue
• more ground substance, less fibers
• e.g., fat (adipose tissue)
• Dense connective tissue
• more fibers, less ground substance
• e.g., tendons

10
Loose Connective Tissue

• Highly vascularized
• Functions
• Fill space
• Cushion support tissues
• Store fat
• Feed epithelial layers
• Three types
• Areolar CT
• Adipose Tissue
• Reticular Tissue

11
Loose fibrous connective tissue
12
Loose Connective Tissue

• Areolar CT

13
Dense Connective Tissue

• Poorly vascularized
• Mostly fibers, little ground substance
• Only fibroblasts
• Location
• tendons (muscle to bone)
• ligaments (bone to bone)
• muscle coverings
• Function
• - high strength attachment
• - stabilize positions

14
Dense Connective TissueDense Regular CT
15
B. Supportive Connective Tissues

• Strong framework and few cells
• Function support and shape
• Mature cells in lacunae
• Two types
• 1. Cartilage
• gel-type ground substance
• for shock absorption and protection
• 2. Bone
• calcified (made rigid by calcium salts, minerals)
• for weight support

16
B. Supportive connective tissue Cartilage
4.2 Connective tissue connects and supports

• Cells are in chambers called lacunae
• Matrix is solid but flexible
• 3 types are distinguished by types of fibers
• Hyaline cartilage fine collagen fibers
• Location Nose, ends of long bones and fetal
  skeleton
• Elastic cartilage more elastic fibers than
  cartilage fibers
• Location Outer ear
• Fibrocartilage strong collagen fibers
• Location Disks between vertebrae

17
Hyaline Cartilage ?
Elastic ?Cartilage
Fibro Cartilage ?
18
B. Supportive connective tissue Bone

• Highly vascularized
• Little ground substance
• Matrix
• solid and rigid that is made of collagen and
  calcium salts
• Cells Osteocytes
• Located in chambers called lacunae arranged
  around central canals within matrix
• Connected by cytoplasmic extensions that extend
  through canaliculi
• Canaliculi excess blood supply
• Canaliculi necessary for nutrient and waste
  exchange, no diffusion through calcium

19
B. Structures of Bone

• Osteocytes
• Connected by cytoplasmic extensions that extend
  through canaliculi (small channels through
  matrix)
• Canaliculi necessary for nutrient and waste
  exchange

Figure 415
20
B. Supportive connective tissueBone
4.2 Connective tissue connects and supports

• Function
• Support Protection
• Levers for movement
• Storage of minerals
• Compact made of repeating circular units called
  osteons which contain the hard matrix and living
  cells and blood vessels
  Location Shafts of long bone
• Spongy an open, latticework with irregular
  spaces
• Location Ends of long bones

21
What do bone and cartilage look like?
4.2 Connective tissue connects and supports
22
C. Fluid connective tissue Blood
4.2 Connective tissue connects and supports

• Made of a fluid matrix called plasma and cellular
  componentsthat are called formed elements
• Function
• - transport nutrients, wastes and defense cells
  throughout the body
• 3 formed elements
• Red blood cells cellsthat carry oxygen
• White blood cells cells that fight infection
• Platelets pieces ofcells that clot blood

23
Formed Elements of Blood

• Erythrocytes (RBCs) carry oxygen
• Leukocytes (WBCs) defense
• Neutrophils, Eosinophils, Basophils, Lymphocytes
  (B and T cells), Monocytes (Macrophages)
• Platelets carry clotting factors

Figure 412
24
C. Fluid connective tissue Lymph
4.2 Connective tissue connects and supports

• Matrix is a fluid called lymph
• White blood cells congregate in this tissue
• Location
• contained in lymphatic vessels
• Function
• purify and return fluid to blood

25
2. Muscle tissue
4.3 Muscle tissue moves the body

• Allows for movement in the body
• Made of muscle fibers/cells and protein fibers
  called actin and myosin
• There are 3 types of muscle tissue in humans
  
• A. Skeletal
• B. Smooth
• C. Cardiac

26
A. Muscle tissue - Skeletal
4.3 Muscle tissue moves the body

• Appearance
• long, cylindrical cells, multiple nuclei,
  striated fibers
• Location
• attached to bone for movement
• Nature
• voluntary movement

27
B. Muscle tissue Cardiac
4.3 Muscle tissue moves the body

• Appearance
• branched cells with a single nucleus, striations
  with darker striations called intercalated disks
  between cells
• Location heart
• Nature
• involuntary movement

28
C. Muscle tissue - Smooth
4.3 Muscle tissue moves the body

• Appearance
• spindle-shaped cell with one nucleus, lack
  striations
• Location
• walls of hollow organs and vessels
• Nature
• involuntary movement

29
3. Nervous tissue
4.4 Nervous tissue communicates

• Function
• Allows for communication between cells through
  sensory input, integration of data and motor
  output
• Location
• Most in brain and spinal cord Central Nervous
  System
• 2 in Peripheral Nervous System
• Made of 2 major cell types
• A. Neurons
• B. Neuroglia

30
A. Nervous tissue - neurons
4.4 Nervous tissue communicates

• Made of dendrites, a cell body and an axon
• Dendrites carry information toward the cell body
• Axons carry information towards a cell body

31
Cell Parts of a Neuron

• Cell body
• contains the nucleus and nucleolus
• Dendrites
• short branches extending from the cell body
• receive incoming signals
• Axon (nerve fiber)
• long, thin extension of the cell body
• carries outgoing electrical signals to their
  destination

32
A. Nervous tissue - neuroglia
4.4 Nervous tissue communicates

• A collection of cells that support and nourish
  neurons
• Outnumber neurons 91
• Examples are oligodendrocytes, astrocytes and
  microglia

33
4. Epithelial tissue
4.5 Epithelial tissue protects

• A groups of cells that form a tight, continuous
  network
• Lines body cavities, covers body surfaces and
  found in glands
• Cells are anchored by a basement membrane
• on one side and free on the other side
• Named after the appearance of cell layers and the
  shape of the cells
• There is transitional epithelium that changes in
  appearance in response to tension

34
Free Surface and Attached Surface

• 1. Apical Surface exposed to environment, may
  have
• Microvilli absorption or secretion
• Cilla fluid movement
• 2. Basolateral Surface attachment to
  neighboring cells via intercellular connections

Figure 41
35
Classes of Epithelia

• Based on shape and layers
• Shape (all are hexagonal from the top)
• Squamous flat, disc shaped nucleus
• Cuboidal cube or square, center round nucleus
• Columnar tall, basal oval nucleus

Table 41
36
Layers

• Simple epithelium
• single layer of cells
• Function
• absorption, secretion, filtration
• Stratified epithelium
• 2 or more layers of cells
• Function
• Protection
• In stratified, name for apical cell shape

37
How do we name epithelial tissue?
4.5 Epithelial tissue protects

• Number of cell layers
• Simple one layer of cells
• Stratified more than one layer of cells
• Pseudostratified appears to have layers but
  only has one layer
• Shape of cell
• Cuboidal cube-shaped
• Columnar column-shaped
• Squamous flattened

38
Epithelial tissue
39
Epithelial tissue
4.5 Epithelial tissue protects
40
How are cells connected within a tissue?
4.6 Cell junction types

• Tight junctions proteins join and form an
  impermeable barrier between plasma membranes in a
  zipper-like fashion
• Prevents passage of water and solutes
• Adhesion junctions cytoskeletal fibers join
  between cells and have flexibility
• Gap junctions a fusion of adjacent plasma
  membranes with small channels between them that
  allow small molecules to diffuse
• Allow ions to pass
• Coordinated contractions in heart muscle

41
Cell junctions
4.6 Cell junction types
42
Glandular Epithelia

• For secretion, makes up glands
• Endocrine glands internally secreting
• -secrete into interstital fluid ? blood
• -secretions hormones
• -regulate and coordinate activities
• e.g. pancreas andthyroid
• Exocrine glands externally secreting
• -secrete into duct ? epithelial surface
• e.g. digestive enzymes, perspiration,
  tears,
• milk, and mucus

43
Exocrine Types of Secretion

• Serous Glands water enzymes
• - e.g. parotid salivary gland
• Mucus Glands mucin
• (water mucus)
• - e.g. goblet cell
• Mixed exocrine glands
• (serous mucus secretion)
• -e.g. submandibular salivary gland

44
Structure of Multicellular Exocrine Glands

• Structural classes of exocrine glands

Simple Glands undivided
tube shape blind
pockets chamberlike
Figure 47 (1 of 2)
45
Structure of Multicellular Exocrine Glands
Compound Glands Divided
tube shaped blind pockets
chamberlike
Figure 47 (2 of 2)
46
Moving from tissue to organs and organ systems
4.7 Integumentary system

• An organ is 2 or more tissue types working
  towards a particular function
• An organ system is a combination of organs that
  work together to carry out a particular function

47
Body Cavities
4.8 Organ systems
48
Body Cavities

• Function
• protect organs
• permit changes in size and shape of internal
  organs
• Two Cavities
• 1. Dorsal body cavity
• Cranial and Spinal Cavity
• 2. Ventral body cavity
• Thoracic Cavity (heart and lungs)
• Abdominopelvic Cavity (guts- viscera)
• Organs enclosed in a cavity are called viscera

49
The Ventral Body Cavity

• Includes organs of the
• Respiratory, cardiovascular, digestive, urinary,
  and reproductive system
• Divided by the diaphragm into the thoracic cavity
  and the abdominopelvic cavity

Figure 110a
50
Ventral Body Cavity Abdominal Cavity

• Also the peritoneal cavity
• Abdominal Cavity
• liver, stomach, spleen, small intestine, and
  large intestine
• Kidneys and pancreas
• Pelvic Cavity
• Inferior large intestine, inferior urinary
  bladder, and some reproductive organs
• Superior urinary bladder, ovaries, and uterus

51
The Body Membranes lining Cavities
4.8 Organ systems

• Mucous membranes
• lining of the digestive, respiratory, urinary and
  reproductive systems
• Serous membranes
• line lungs, heart, abdominal cavity and covers
  the internal organs named after their location
• Pleura lungs
• Peritoneum abdominal cavity and organs
• Pericardium heart
• Synovial membranes
• lines the cavities of freely movable joints
• Meninges cover the brain and spinal cord

52
Organ Systems

• The body is divided into 11 organ systems
• All organ systems work together
• Many organs work in more than 1 organ system

53
What are the organ systems of the human body?
4.8 Organ systems
54
What are the organ systems of the human body?
4.8 Organ systems
55
Homeostasis
4.9 Homeostasis

• The ability to maintain a relatively constant
  internal environment in the body
• The nervous and endocrine systems are key in
  maintaining homeostasis
• Changes from the normal tolerance limits results
  in illness or even death
• All systems important in maintaining homeostasis

56
4.9 Homeostasis
57
What are the mechanisms for maintaining
homeostasis?
4.9 Homeostasis

• Negative feedback
• Positive feedback

58
Negative feedback
4.9 Homeostasis

• The primary mechanism for maintaining homeostasis
• Has two components
• sensor
• control center
• The output of the system dampens the original
  stimulus

59
Example of negative feedback Body Temperature
60
Positive feedback
4.9 Homeostasis

• A mechanism for increasing the change of the
  internal environment in one direction
• An example is the secretion of oxytocin during
  birth to continually increase uterine
  contractions
• Can be harmful such as when a fever is too high
  and continues to rise

61
Homeostasis

• Requires coordinated efforts of multiple organ
  systems. Any adjustment made by one
  physiological system has direct and indirect
  effects on a variety of other systems.
  Therefore, the use of homeostasis integrates the
  human body to allow for the support of life.

62
Structure of the Integument

• 16 of body mass
• Composed of
• Cutaneous Membrane
• Epidermis Superficial epithelium
• Dermis underlying CT with blood supply
• Accessory Structures originate in dermis
• Hair
• Nails
• Exocrine Glands
• Subcutaneous layer
• under the skin between the dermis and internal
  structures where fat is stored

63
Parts of the Integumentary System
Figure 51
64
Functions of the Integument

• Protects underlying tissues from infection,
  exposure and dehydration
• Excretes salts, water, and organic waste
• Maintains normal body temp
• conserve and radiate heat
• Synthesizes Vitamin D3 for calcium metabolism
• Stores Nutrients and Fat
• Sensory detection
• Allowing awareness of surroundings
• touch, pressure, pain, and temp.
• Is important for maintaining homeostasis

65
Connections

• Circulatory system
• blood vessels in the dermis
• Nervous system
• sensory receptors for pain, touch, and temperature

66
There are two regions of the skin
4.7 Integumentary system

• Epidermis
• Dermis

67
The epidermis
4.7 Integumentary system

• The thin, outermost layer of the skin
• Made of epithelial tissue
• Cells in the uppermost cells are dead and become
  filled with keratin thus acting as a waterproof
  barrier
• Langerhans cells
• a type of white blood cell that help fight
  pathogens
• Melanocytes
• produce melanin that lend to skin color and
  protection for UV light
• Some cells convert cholesterol to vitamin D

68
Skin Color

• Pigment based epidermal pigments and blood
  pigments contribute to the color
• Epidermal Pigmentation
• Dermal Circulation

69
Skin Color

• Epidermal Pigmentation
• A. Carotene yellow-orange, from diet
• - converted into Vitamin A
• - localized to epithelium
• - functions in normal maintenance
• of epithelia and photoreceptors
• - excess accumulates
• B. Melanin Brown, from melanocytes
• - for UV protection

70
1. Epidermal Pigmentation

• Melanocytes in stratum basale
• Packaged in melanosomes
• Transferred to cytoplasm of keratinocytes
• Cluster around top side of nucleus
• Eventually digested by lysosomes
• Everyone has 1000 melanocytes/mm2
• Pale People small melansomes
• Dark People larger, greater number of melansomes

71
1. Epidermal Pigmentation

• Freckles
• Overproduction of melanin form single melanocytes
• UV exposure
• Some needed for Vitamin D3 production
• Excess damage (DNA mutation)
• Fibroblasts ? altered CT structures
• Wrinkles
• Epidermal cells, melanocytes ? cancer
• Squamous cell carcinoma
• Melanoma

72
What you need to know about skin cancer?
4.7 Integumentary system

• 2 of the 3 types that arise in the epidermis
• Basal cell carcinoma is the most common yet least
  deadly form of skin cancer
• Melanoma is the most deadly form of skin cancer
  but is the least common
• What can you do to help prevent this?
• Stay out of the sun between 10am-3pm
• Wear protective clothing (tight weave, treated
  sunglasses, wide-brimmed hat)
• Use sunscreen with an SPF of at least 15 and
  protects from UV-A and UV-B rays
• Dont use tanning beds

73
What might skin cancer look like?
4.7 Integumentary system
74
Skin

• 2. Dermal Circulation hemoglobin pigment
• - Oxygenated blood
• - red color, hemoglobin in RBCs,
• through skin looks pink
• A) Vasodilation ? skin looks more red
• B) Vasoconstriction ? skin looks more pale

75
The Dermis

• Is located between epidermis and subcutaneous
  layer
• Anchors epidermal accessory structures
• hair follicles, sweat glands
• Contains
• All cells of CT proper, accessory organs of
  integument, blood vessels, lymphatic vessels,
  nerves, and sensory receptors
• Has 2 components
• outer papillary layer
• deep reticular layer

76
Dermis

• Papillary layer
• Thin (20)
• Consists
• Areolar CT
• Comprise dermal papillae
• Capillaries, lymphatics, and
• sensory neurons
• Function feed epidermis
• Reticular Layer
• Thick (80)
• Consists
• Dense irregular CT
• Elastic and Collagen fibers
• Function provide strength and flexibility

77
The Hypodermis

• The subcutaneous layer or hypodermis
• lies below the integument
• Not part of cutaneous membrane
• Stabilizes position of skin while permitting
  independent movement of skin and muscles

78
Integumentary Accessory Structures

• Hair and hair follicles
• Sebaceous glands
• Sweat glands
• Nails
• Accessory Structures
• are derived from embryonic epidermis
• are located in dermis
• project through the skin surface

79
Functions of Hair

• Function
• Protects and insulates
• Guards openings against particles and insects
• Is sensitive to very light touch

80
Hair Color

• red iron added
• Range yellow to black due to melanin from
  melanocytes in hair matrix
• Melanin stored in cortex and medulla
• With age, melanin declines, air pockets in
  medulla increase gray or white hair

81
Nails

• Function
• protect tips from mechanical stress, assist in
  gripping
• Consists of dead cells containing hard keratin
• New nail formed at nail root

82
What are the accessory organs of the skin and why
are they important?
4.7 Integumentary system

• Includes nails, hair and glands
• Nails are derived from the epidermis that offer a
  protective covering
• Hair follicles are derived from the dermis but
  hair grows from epidermal cells
• Oil glands are associated with hair and produce
  sebum that lubricates hair and skin as well as
  retards bacterial growth
• Sweat glands are derived from the dermis and
  helps to regulate body temperature