Download - The Integumentary System: The Skin
The Integumentary System:The Skin
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
EpidermisDermis
Skin
Your skin is your largest organ It is your first line of defense against
disease and damage It is made of several layers
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)
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
Remember…
Four basic types of tissue
Epithelium – epidermis just discussedConnective tissue - dermisMuscle tissueNervous tissue
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
Skin Layers
Subcutaneous Layer- lies below the dermis layer, not really a skin layer
Contains Fat cells Fibers used to attach skin to muscle
*Dermis layers
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*Dermal papillae
Skin Color
Skin pigmentsMelanin- 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
Skin color Three skin pigments
Melanin: the most importantCarotene: from carrots and yellow vegiesHemoglobin: the pink of light skin
Melanin Variations in colorProtection from UV light by producing vitamin
D
How does our skin protect us?
Forming callus- a thickened area of epidermis caused
by rubbing or pressureBlisters- area of skin when the layers of skin
separate due to excessive friction or intense heat
Melanin produces vitamin D- “natural sunblock”
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
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 bundlesof fibers are directed
The dermis is the receptive site for the pigment of tattoos
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
BurnsFirst-degree(epidermis only; redness)
Second-degree(epidermis and dermis,with blistering)
Third-degree(full thickness, destroying epidermis, dermis, often part of hypodermis)
SKELETAL SYSTEMSKELETAL SYSTEM
BONES & JOINTSBONES & JOINTS
Functions of the Bones
1. Support2. Protection3. Movement4. Storage (minerals like calcium and phosphorous)
5. Hematopoiesis (makes new blood cells in the bone marrow)
Fig. 6.21
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)
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
J O I N T S
JOINTS= a site where 2 or more bones = a site where 2 or more bones
come together with or without come together with or without movementmovement
JOINTS1. Hinge joints 1. Hinge joints
= bend in only one direction, like a door hinge= bend in only one direction, like a door hingeflexion & extension movements possibleflexion & extension movements possible
e.g.: elbow, kneee.g.: elbow, knee2. Gliding Joints-2. Gliding Joints-
= allows bones to slide across one another, and = allows bones to slide across one another, and allows allows some twisting movementsome twisting movement
Like the bones between the vertebraeLike the bones between the vertebrae3. 3. Ball & socket joints Ball & socket joints
= = ball – shaped head of one bone fits into a ball – shaped head of one bone fits into a socket – like concavity of anothersocket – like concavity of another
= free movements possible:= free movements possible:e.g. shoulder and hipe.g. shoulder and hip
4. Pivot Joint- 4. Pivot Joint- =allows for some circular movement=allows for some circular movemente.g. The two bones of the forearm near the elbowe.g. The two bones of the forearm near the elbow
5. 5. FFused Joints-used Joints-= = do not allow any movementdo not allow any movement
They become permanently fused togetherThey become permanently fused togethere.g. Bones of the skulle.g. Bones of the skull
Joints
Muscles
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!
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
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
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
Muscular System
Muscles are responsible for all types of body movement
3 basic muscle types are found in the bodySkeletal muscleCardiac muscleSmooth muscle
Types of Muscles
Voluntary: muscles you can control, they are subject to one’s willSkeletal muscles- move your skeleton/bonesHave striations- they have a banded pattern,
appears layered
Characteristics of the Skeletal Muscles
Most are attached by tendons to bones
Striated – have visible banding
Voluntary – subject to conscious control
Anatomy of skeletal muscles
Skeletal muscle fiber (cell)
Muscle Fascicle
Surrounded by perimysium
Surrounded by endomysium
endomysium
perimysium
Skeletal muscle
Surrounded by epimysium
epimysiumtendon
Play IP Anatomy of Skeletal muscles (IP p. 4-6)
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
Smooth Muscle CharacteristicsSmooth 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
Smooth Muscle
Comparison of Muscle Tissue
How Muscles Work
Skeletal muscles work in pairsWhen your bicep contracts your triceps relaxWhen the triceps contract your bicep relaxes
Many skeletal muscles extend across at least one joint to 2 different bonesThe Sartorius (longest muscle in body)
attaches to the top of the hip bone and extends across the hip and knee connecting to the tibia
How Muscles Work
Some muscles do not extend across joints but rather movement in skin or other musclesTongue and throat muscles do not extend
over joints but they move to allow swallowing
Sternoclediomastoid
FrontalTemporalis
MasseterObicularis orisObicularis oculi
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
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
Goose Bumps
How Muscles Work
Muscles need energy to function, so where does that energy come fromEnergy 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
How Muscles Work
When the muscles break down sugar, with the use of oxygen, it is aerobic respirationThe 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
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
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