The Integumentary System: The Skin

1
The Integumentary SystemThe Skin
2
The Integumentary System

• Integument is skin
• Skin and its appendages make up the integumentary
  system
• A fatty layer (hypodermis) lies deep to it
• Two distinct regions
• Epidermis
• Dermis

3
Skin

• Your skin is your largest organ
• It is your first line of defense against disease
  and damage
• It is made of several layers

4
Functions of skin

• Protection
• Cushions and insulates and is waterproof
• Protects from chemicals, heat, cold, bacteria
• Screens UV
• Synthesizes vitamin D with UV
• Regulates body heat
• Prevents unnecessary water loss
• Sensory reception (nerve endings)

5
Layers of Skin

• Epidermis
• Uppermost layer of skin
• Contains dead and living cells
• New cells are replaced daily old ones slough off
  (they shed)
• Dermis-
• Inner thicker layer of skin
• Contains
• Blood vessels
• Nerve receptors
• Hair follicles
• Sebaceous glands
• Sweat glands
• Oil glands
• Wax glands

6
Remember

• Four basic types of tissue
• Epithelium epidermis just discussed
• Connective tissue - dermis
• Muscle tissue
• Nervous tissue

7
Dermis

• Strong, flexible connective tissue your hide
• Rich supply of nerves and vessels
• Critical role in temperature regulation (the
  vessels)
• Two layers (see next slides)
• Papillary includes dermal papillae- makes
  fingerprints
• Reticular reticulum (network) of collagen
  and reticular fibers

8
Skin Layers

• Subcutaneous Layer- lies below the dermis layer,
  not really a skin layer
• Contains
• Fat cells
• Fibers used to attach skin to muscle

9
Dermal papillae
Dermis layers


10
Skin Color

• Skin pigments
• Melanin- dark skin pigment (causes human skin
  colors)
• Where there are darker colors on the skin there
  is a higher concentration of melanin in that area
• Freckles
• Moles
• birthmarks

11
Skin color

• Three skin pigments
• Melanin the most important
• Carotene from carrots and yellow vegies
• Hemoglobin the pink of light skin
• Melanin
• Variations in color
• Protection from UV light by producing vitamin D

12
How does our skin protect us?

• Forming
• callus- a thickened area of epidermis caused by
  rubbing or pressure
• Blisters- area of skin when the layers of skin
  separate due to excessive friction or intense
  heat
• Melanin produces vitamin D- natural sunblock

13
Sweat glands

• Prevent overheating
• 500 cc to 12 Liters/day! (is mostly water)
• Humans most efficient (only mammals have)
• Produced in response to stress as well as heat

14
Fingerprints, palmprints, footprints

• Dermal papillae lie atop dermal ridges
• Elevate the overlying epidermis into epidermal
  ridges
• Are sweat films because of sweat pores
• Genetically determined
• Flexion creases
• Deep dermis, from continual folding
• Fibers
• Collagen strength and resilience
• Elastic fibers stretch-recoil
• Striae stretch marks
• Tension lines (or lines of cleavage)
• The direction the bundles
• of fibers are directed

The dermis is the receptive site for the pigment
of tattoos
15
Disorders of the integumentary system

• Burns
• Threat to life
• Catastrophic loss of body fluids
• Dehydration and fatal circulatory shock
• Infection
• Types
• First degree epidermis redness (e.g. sunburn)
• Second degree epidermis and upper dermis
  blister
• Third degree - full thickness
• Infections
• Skin cancer

16
(No Transcript)
17
Burns
First-degree (epidermis only redness)
Second-degree (epidermis and dermis, with
blistering)
Third-degree (full thickness, destroying
epidermis, dermis, often part of hypodermis)
18
SKELETAL SYSTEMBONES JOINTS
19
(No Transcript)
20
Functions of the Bones

1. Support
2. Protection
3. Movement
4. Storage (minerals like calcium and phosphorous)
5. Hematopoiesis (makes new blood cells in the bone
   marrow)

21
Fig. 6.21
22
Bones

• The adult human skeleton has 206 bones
• Bones store minerals (calcium) and make blood
  cells (in the center of the bone, bone marrow)
• Are made of mineral deposits of calcium and
  phosphorous
• There small spaces that contain blood vessels
  (veins, arteries, and capillaries)
• The blood vessels and surrounding bone materials
  makes up an osteon (bone cell)

23
(No Transcript)
24
Broken Bones

• A broken bone is a fractured bone
• Bones can break in many ways
• Incomplete fracture- when there is only a crack,
  but not a break
• Complete fracture- when the bone breaks
  completely in two
• Comminuted fracture- fractures that splinter the
  bone

25
(No Transcript)
26
J O I N T S
27
JOINTS

• a site where 2 or more bones
• come together with or without movement

28
JOINTS

• 1. Hinge joints
• bend in only one direction, like a door
  hinge
• flexion extension movements possible
• e.g. elbow, knee
• 2. Gliding Joints-
• allows bones to slide across one another, and
  allows some twisting movement
• Like the bones between the vertebrae
• 3. Ball socket joints
• ball shaped head of one bone fits
  into a
• socket like concavity of another
• free movements possible
• e.g. shoulder and hip

29
Joints

• 4. Pivot Joint-
• allows for some circular movement
• e.g. The two bones of the forearm near the
  elbow
• 5. Fused Joints-
• do not allow any movement
• They become permanently fused together
• e.g. Bones of the skull

30
Muscles
31
My muscles are important because they

• Hold my organs in place
• Hold my bones together so that I can move
• Help me chew my food
• Open and close my eyelids
• Pump my blood
• Allow me to run and play
• Help me to smile!

32
Muscles the Skeleton

• Skeletal muscles cause the skeleton to move at
  joints
• They are attached to skeleton by tendons.
• Tendons transmit muscle force to the bone.
• Tendons are made of collagen fibres are very
  strong stiff

33
Functions of the Muscular System

• The characteristics of muscle tissue enable it to
  perform some important functions, including
• Movement both voluntary involuntary
• Maintaining posture
• Supporting soft tissues within body cavities
• Guarding entrances exits of the body
• Maintaining body temperature

34
Muscular System

• This system is responsible for movement of the
  body
• But it cannot do this alone. Help is required
  from the nerves, joints, and bones.
• They work together as an orchestra, each
  playing their part in perfect harmony
• Muscles work by pulling never pushing

35
Muscular System

• Muscles are responsible for all types of body
  movement
• 3 basic muscle types are found in the body
• Skeletal muscle
• Cardiac muscle
• Smooth muscle

36
Types of Muscles

• Voluntary muscles you can control, they are
  subject to ones will
• Skeletal muscles- move your skeleton/bones
• Have striations- they have a banded pattern,
  appears layered

37
Characteristics of the Skeletal Muscles

• Most are attached by tendons to bones
• Striated have visible banding
• Voluntary subject to conscious control

38
Anatomy of skeletal muscles
epimysium
perimysium
tendon
Muscle Fascicle
Surrounded by perimysium
endomysium
Skeletal muscle
Skeletal muscle fiber (cell)
Surrounded by epimysium
Surrounded by endomysium
Play IP Anatomy of Skeletal muscles (IP p. 4-6)
39
Characteristics of Cardiac Muscle

• Similar to skeletal muscle cardiac muscle has
  striations
• These striations are not as pronounced in cardiac
  muscles as in skeletal muscle
• It is the only involuntary muscle that is
  striated
• Found only in the heart

40
Smooth Muscle Characteristics

• Has no striations
• Involuntary no conscious control
• Found mainly in the walls of hollow organs
• Stomach, intestines, blood vessels, and other
  internal organs
• The heart is involuntary, but not smooth muscle
• Slow, sustained and tireless
• They are constantly in motion and do not tire as
  do skeletal muscles

41
Smooth Muscle
42
Comparison of Muscle Tissue
43
How Muscles Work

• Skeletal muscles work in pairs
• When your bicep contracts your triceps relax
• When the triceps contract your bicep relaxes
• Many skeletal muscles extend across at least one
  joint to 2 different bones
• The Sartorius (longest muscle in body) attaches
  to the top of the hip bone and extends across the
  hip and knee connecting to the tibia

44
How Muscles Work

• Some muscles do not extend across joints but
  rather movement in skin or other muscles
• Tongue and throat muscles do not extend over
  joints but they move to allow swallowing

45
Frontal
Obicularis oculi
Temporalis
Obicularis oris
Masseter
Sternoclediomastoid
46
Functions of Muscles

• Muscles keep you warm by contracting
• When you are cold your body shivers in an attempt
  to warm you up by increasing muscle contractions
  and thereby producing heat
• They keep your body erect (standing up)
• Even when you are still, standing or sitting,
  your muscles are working and thereby can keep
  your body warm
• This is why yoga is so effective in working
  muscles, prolonged muscle contractions

47
More Muscle Functions

• When muscles in your skin contract making the
  hair follicles stand upright your skin around the
  hair follicle also stands up and causes
• Goose bumps

48
Goose Bumps
49
How Muscles Work

• Muscles need energy to function, so where does
  that energy come from
• Energy is stored in the body as glucose (sugar)
• It is carried by the blood to the muscles where
  the muscles break down the glucose into usable
  energy
• In order to break down glucose the body needs
  oxygen

50
How Muscles Work

• When the muscles break down sugar, with the use
  of oxygen, it is aerobic respiration
• The oxygen comes to the muscles from the lungs
  via arteries so that they muscles can break the
  sugar down into usable energy for the body

51
How Muscles Work

• When you work or play hard, like when running,
  you begin to breathe faster in attempts to bring
  more oxygen into your blood so that your muscles
  can continue to work (break down sugar)
• When you do not have sufficient oxygen your
  muscles undergo lactic acid fermentation
  producing lactic acid in the muscles

52
How Muscles Work

• A build up of lactic acid in your muscles causes
  them to become sore or cramp up
• have you gotten tired or sore muscles the day
  following a hard workout or a day of hard play?
• This is also how you get a Charlie horse