AP1 LAB 2- INTEGUMENTARY SYSTEM AND SYNOVIAL JOINTS
Stratum Corneum
- 20 to 30 layers thick to keep everything out that will harm us - prevents water loss - Can responsively increase - Accounts for 3/4 of epidermal thickness
Hypodermis
- Acts as cushioning/ padding to protect organs - Acts as insulation o retain body heat - Stores of fat (lipid) soluble vitamins - Stores surplus kilocalories as fat from overeating
synovial membrane
- Are composed entirely of connective tissue - Contain NO epithelial cells - Are only found lining the cavities of freely moveable (synovial) joints - Secrete a lubricating fluid called synovial fluid to reduce friction
Stratum Germinativum (A.KA. Stratum Basale)
- Base layer of skin - One cell layer - Always under division - Active "stim cell" like cell
Melanocytes
- Cells that produce melanin - UV radiation barrier
Physical Barrier
- Effective against entry of microbes such as bacteria and viruses and against water loss - Not effective against lipid soluble substances - Certain medications are absorbable through the skin b/c they are lipid soluble
Biological barrier
- Evidence suggests that dendritic (Langerhans) cells are macrophages of the dermis that "hunt down" invaders and engulf them by phagocytosis before they enter deeper tissues - Macrophages called APCs "present" antigens to your immune system, to initiate an immune response. Dendritic cells are a form of APC
Hypodermis (subcutaneous layer or superficial fascia)
- Not a true layer of the skin - Mainly of adipose (fat) tissue
Chemical Barrier
- Oily sebum contains antibacterial compounds - The dark pigment melanin absorbs UV radiation providing some protection
Dendritic cells
- Part of the immune system - Not considered white blood cells - First line of cellular defense
Keratinization
- Protein synthesis of a protein called keratin - The cells create, engage, and eventually become a bag of keratin
Sensory Receptors
- Respond to different touches, pressure, temperature and pain
The skin is composed of:
- Superficial epidermis composed of epithelial tissue - Underlying dermis composed of connective tissue
Dermis
- The deeper layer of skin - Highly vascular - Contains a variety of structures and sensory receptors
Epidermis
- The most superficial layer of the skin - most of the cells are dead but still very useful - Is avascular - Nutrients are received by diffusion from underlying issues
Functions of joinst
- They hold our bones together via ligaments and joint capsules - Allows the skeletal system flexibility so that body movements can occur
rheumatoid arthritis
2nd most common form of arthritis
On average, how often does your epidermis completely replace itself through mitosis
6 - 8 weeks
Patellar groove on femur
A groove on the anterior side of the distal end of the femur between the two condyles.
arrector pili muscle
An involuntary muscle fiber attached to the underside & base of the hair follicle
Capillaries
Are about the exchange of nutrients and wastes
Arteries
Bring in nutrient rich oxygenated blood "Fresh blood"
Veins
Carry away blood poor in oxygen and nutrients , Carrying waste product
Predominant tissue type that makes up the dermis is ______________
Connective or Reticular
If the menisci were not present at the knee joint predict what effect would this have on the stability and life of the joint?
Decrease life span and decrease stability
Reticular layer
Deeper layer of the dermis that supplies the skin with oxygen and nutrients
Lymphatic vessels
Extra water that isn't put back into blood pulled through the vessels and drain it away.
dermal papillae:
Finger like projections from the most superficial layer of the dermis that serve to anchor the dermis to the epidermis above it
cartilaginous joints
Have no joint cavity and the bones are connected by a pad of cartilage allowing only slight movement EX: Pelvis, ribs to sternum, ribs to vertebrae, intervertebral discs.
Why are the arrector pili muscles in the dermis of little value in humans?
It serves as a way to keep warm but we have to little hair for it
How does synovial fluid get into the joint cavity and its function
Joint lubricating fluid secreted by the synovial membrane
The predominate (most abundant) cell type of the epidermis is _________________
Keratinocytes
blood reservoir
Large volumes of blood [5% of total] can be held in dermis
"The skin is considered an organ." Why is this true?
Made of several types of tissues that work together for a common purpose
Sebaceous glands (Secretion is called Sebum)
Oil based secretin that travels on the skin on the hair follicle has chemicals that are antimicrobial
Thermoregulation
Process of maintaining an internal temperature within a tolerable range.
Synovial membrane layer
The inner more delicate layer of the capsule. Lines all cavity surfaces that are not covered with articular cartilage. Secretes synovial fluid as a lubricant for the joint. Richly supplied with blood vessels
Keratinocytes
The most abundant epidermal cells, they function mainly to produce keratin.
Fibrous capsule layer
The outer layer of the capsule. Made of dense irregular connective tissue. Helps hold the bones in proper position.
Why do keratinocytes multiply by mitosis again and again?
To create new skin cells
Condyles on femur
Two rounded knobs at distal end of femur. Covered with articular cartilage
Papillary layer
Where the dermas goes up and down like waves
Vitamin D synthesis
You need Vitamin D to absorb calcium
Articular (Joint) capsule
a continuation of the periosteum that surrounds and encapsulates the joint separating the joint from the rest of the body
articular cartilage
a layer of hyaline cartilage that covers the ends of the bones or surfaces of bones where they articulate with other bone surfaces. Appearance is smooth shiny pearly white - This tissue is avascular, but it receives nourishment
Joint cavity
a space within the synovial joint that contains synovial fluid
quadriceps femoris tendon
above the patella
Articular (hyaline) cartilage
cartilage covering ends of bone where they come together to form joints
Dislocation
displacement of a bone from its joint
Sensation
due to the presence of various sensory receptors
bursae and tendon sheaths
fluid-filled structures strategically placed to minimize friction in some joints
Fibrous joints
have no joint cavity and essentially no movement between the bones EX: Sutures of skull, tooth sockets and where tibia and fibula join distally
gouty arthritis (gout)
inflammation and painful swelling of joints caused by excessive uric acid in the body
Bursitis
inflammation of a bursa usually caused by a blow or friction
Tendonitis
inflammation of a tendon
Synovial joints
joints where the bone are separated by a fluid filled joint cavity and lined with synovial membrane resulting in the greatest degree of freedom of movement EX: shoulder, elbow, wrist, fingers, hip, knee, ankle, toes, and where the lower jaw connects to the skull
NSAIDs
nonsteroidal anti-inflammatory drugs
weeping lubrication
pressure on joints squeezes synovial fluid into and out of articular cartilage
Sprain
stretching or tearing of ligaments
reinforcing ligaments
strong bands of connective tissue connecting bone to bone and preventing motion in certain directions. Tendons are also connective tissue but they bind muscle to bone rather than bone to bone
Excretion
the process by which wastes are removed from the body
Sweat glands
water based secretion and no antimicrobial chemicals in it. Most numerous type
osteoarthritis
wear and tear arthritis
Avascular
without blood vessels