Exam #3 Flashcards
Different cells involved with the skin
Keratinocytes
Melanocytes
Dendritic cells
Merkel cells
Keratinocytes
Executors of the re-epithelialization process, where keratinocytes migrate, proliferate, and differentiate to restore the epidermal barrier.
Melanocytes
Melanin production
Dendritic cells
Professional antigen presenting cells that inform the fight against invasive pathogens while enforcing tolerance to self and harmless environmental antigens.
Merkel cells
Essential for light touch sensation and found in the skin of vertebrates.
Strata
The order of epidermal layers
Superficial to deep
Stratum corneum
Stratum licidum
Stratum granulosum
Stratum spinosum
Stratum basale
What cells are found in each of the epidermal layers
Keratinocytes
Melanocytes
Dendritic cells
Tactile epithelial cells
Epidermis
Stratified squamous epithelium
Dermis
Loose areolar
Dense irregular connective tissue
Subcutaneous tissue
Deepest layer of your skin
Function of subcutaneous tissue
Stores fat
Anchors skin to underlying structures
Shock absorber
Layer of insulation
What are the cells that make up skin color
Melanin
Carotene
Hemoglobin
Albinism
Inherited inability to produce melanin
Melanocytes lack the enzyme tyrosinase
Melanin absent in hair skin and eyes
There are different types of albinism
Vision problems occur abnormal development of retina
Vitiligo
Partial or complete loss of melanocytes in areas of the skin
Patchy white spots
Thought to be an autoimmune disease
Basal cell carcinoma
Epidermal cells invade into dermis
Squamous cell carcinoma
Second most common starts in stratum spinosum may spread to any other layer
Melanoma
Most deadly starts from melanocytes
Can develop in lungs and brain
Can travel through blood vessels
Eccrine sweat glands
Function throughout life
Most numerous widely distributed
Secretion sweat 99% water
Nacl, Vitamin C, Antibodies, Waste, Lactic acid, and Dermcidin
Regulation of body temp and excretion
Apocrine sweat glands
Located mainly in armpits and groin
Become active at puberty
Secretion is viscous and odorless
Same composition as sweat plus organic substances proteins and fats
Activity during periods of pain stress and sexual excitement
What produces earwax
Ceruminous glands
Functions of the skin
Protection chemical physical and biological
Regulation of body temp
Cutaneous sensation
Metabolic functions
Blood reservoir
Excretion
Describe the hair follicle
Hair
Shaft
Root
Bulb
Hair papilla
Hair matrix
Sebaceous gland sebum
Arrector pili muscle
What are the different cells located in bone tissue
Osteoprogenitor cells
Osteoblast cells
Osteoclast cells
Osteoprogenitor
Stem cells dividing cells
Found on bone surfaces in the periosteum and endosteum
Some differentiate into osteoblasts
Osteoblast cells
Bone forming cells
Dividing cells on bone surfaces
Secrete organic components of matrix
Help mineralize the bone matrix calcification
Osteoclast cells
Bone destroying cells
Break down bone
Parathyroid hormone increases their activity
Compact Bone
Osteon
Structural unit
Run parallel to bones long axis
Lamellae layers
Central canal blood vessels nerve fibers
Perforating canals volkmann’s canals
Canaliculi osteocytes in lacunae
Spongy bone
No osteons
Network of trabeculae thin bony plates contain lamellae osteocytes in lacunae and canaliculi
Align along lines of stress
What are the different parts of osteon
Lacunae: tiny spaces that contain the osteocytes, or bone cells
Canaliculi: small tunnels that connect one lacunae to another lacunae
Lamellae: sheets of mineralized collagen that extend over hundreds of bone tissue
Haversian canals: a series of tubes around narrow channels formed by lamellae
What is the process of intramembranous ossification
Ossification centers develop in the fibrous connective tissue membrane
Osteoid is secreted and calcifies
Immature spongy bone and periosteum form
Compact bone replaces immature spongy bone just deep to the periosteum red marrow develops
What is the process of endochondral ossification
Bone collar forms around the diaphysis of the hyline cartilage model
Cartilage in the center of the diaphysis calcifies and then develops cavities
The periosteal bud invades the internal cavities and spongy bone forms
The diaphysis elongates and a medullary cavity forms secondary ossification centers appear in the epiphyses
The epiphyses ossify when completed hyaline cartilage remains only in the epiphyseal plates and articular cartilages
Where are the ossification centers located for primary and secondary
Primary forms in the diaphyseal region of the periosteum
Secondary ossification centers are located in the epiphyses
What tissues are involved in endochondral ossification
Begins with mesenchymal tissue transforming into a cartilage intermediate which is later replaced by bone and forms the remainder of the axial skeleton and the long bones
Left side of long bone
Proximal epiphysis
Diaphysis
Distal epiphysis
Right side of long bone
Articular cartilage
Spongy bone
Epiphyseal line
Periosteum
Medullary cavity lined by endosteum
Osteoporosis
Is a group of diseases in which bone
resorption exceeds deposit
Matrix remains normal, but bone mass declines
Spongy bone of spine and neck of femur most susceptible
Vertebral and hip fractures are common
Osteomalacia
Soft bones
Rickets
A lack of vitamin D or calcium in a child’s diet bowed legs and deformation of the pelvis, skull and
ribcage are common
Pagets disease
Disruption in normal remodeling
Initially, old bone breaks down faster than new bone can be rebuilt
later new bone is produced at a faster than normal rate more spongy bone
Results in enlarged and deformed bones in one or more regions of the skeleton
Cause unknown may be initiated by a virus
What are the functions of the bones
Support
Protection
Anchorage
Mineral Storage
Blood Cell Formation red bone marrow
Storage of fats yellow marrow
Hormone production osteocalcin
Hematopoiesis
Hematopoiesis is the process by which the body produces blood cells It occurs in the hematopoietic system which includes organs and tissues such as the bone marrow liver and spleen
Organic materials of compact bone
Organic Components 1/3 is osteoid
ground substance proteoglycans and glycoproteins
Collagen fibers provides flexibility and tensile strength
Inorganic materials of compact bone
Inorganic Components 2/3 of matrix
Mineral Salts hydroxyapatite calcium phosphate crystals
Provides hardness and compression
resistance weight bearing strength
What’s the difference between periosteum and endosteum
Periosteum and endosteum are both layers of tissue that cover bones
The periosteum covers the outer surface of bones while the endosteum lines the inner surface of the medullary cavity
What are the compact bone parts and their functions
Osteoblasts: bone cells that produce new bone tissue
Lamellae: layers of tissue that form concentric circles around the osteon
Central canal: a tube-like passage that contains blood vessels and nerve fibers
Lacunae: small spaces that contain bone cells osteocytes
What happens to a long bone as an individual reaches skeletal maturity
When an individual reaches skeletal maturity the growth of their long bones stops
This happens because the cartilage in the epiphyseal plate which is the growth layer of a long bone is replaced by bone
The chondrocytes in the epiphyseal plate divide during development and when they stop dividing the bone stops growing in length.
What are the different horomones involved in bone growth
Thyroid hormone
Estrogen and testosterone
