HAP Exam II

Hormone production

-produce osteocalcin hormone -helps regulate insulin secretion and glucose homeostasis

Skin Color

Melanin- Darkening for UV resistance Carotene- Accumulates in the stratum corneum and in the fat of subcutaneous tissue (orange pigment) Hemoglobin- pinkish tint that comes from Red Blood cells

osteon

concentric bone layers called lamellae surrounds the Haversian canal

Bone Support

weight-bearing and space support (rib cage)

Stratum Granulosum

-1-5 layers -Keritinization begins

Stratum Corneum

-20-30 layers of dead keratinocytes filled with keratin -Protection from abrasion -Nearly waterproof (glycolipids) -No living cells (dissentegrated organs)

Squamous Cell Carcinoma

-2nd least Malignant -Second most common (~20% of all skin cancer) -Keratinocytes from stratum spinosum stop making keratin and divide like crazy -Possibly metastasize -Rapid Growth -Treat through surgical excision

Bone remodeling dynamics

-5-7% recycled bone mass weekly -0.5 grams of calcium exchanged daily -spongy bone replaced every 3-4 weeks -compact bone every 10 years -rates within a bone vary (ends vs the shaft)

Skin: Chemical Protection

-Acid mantle (kills pathogens) -Melanin (UV Protection) -Antibacterial

Skin: Temp Regulation

-Adipose tissue (insulation) -Sweat (evaporation) -Dermal BVs constriction and dilation (constrict to heat up, dilate to cool down)

Skin: Excretion

-Ammonia & Urea released in sweat

Skin: Blood Reservoir

-Approx. 5% of the blood reservoir

Papillary Dermis

-Areolar CT, fibroblasts, small BVs for support -Nerve endings, BVs, touch receptors. -Defense cells patrol for bacteria

Joint Injuries: Dislocation

-Bones forced out of normal alignment -Return to "normal" form

Synovial Joint

-Bones separated by fluid- containing a joint cavity -Allow for bones to be moved by muscles -Covered w/ articular cartilage -Shoulder, and knee -Fatty pad: hip/ knee cushion between fibrous layer and synovial membrane Articular discs/ menisci- divide synovial cavity into two: improves the fit between the bone ends to stabilize and minimize

Burns: Third Degree

-Burn through the dermis and pain receptors (full thickness) -Not painful -Skin may regenerate, but not before massive fluid loss (can cause kidney problems)

interstitial cartilage growth

-Chondrocytes divide and secrete ECM within lacunae -cells divide and more ECM inside -internal

Reticular Dermis

-Coarse, dense irregular CT, Elastic and collagen fibers. -Cleavage lines and fixture lines

Stratum Basale

-Deepest epidermal layer -Stem cells, Melanocytes, Keratinocytes -Single row of stem cells regenerating keratinocytes -Division and replication -Columnar cells

Skin: Biological Protection

-Dendritic cells (immunosurvalance) -Dermal Macrophage -Activate immune system

Dermis

-Dermal Papille (Areolar 20%) -Reticular Dermis (Dense Irregular CT 20%) -Support the Epidermis -Vascular

Skin: Physical Protection

-Desmosomes (anchoring joints) -Glycolipids (non-polar) -Lipid soluble substances can get across (organic solvents, some drugs)

Cartilaginous Joints

-Ends of bones protected from abrasion -Synchondroses- hyaline cartilage --> Immobile (connection joint) --> Sternum, epiphyseal plate -Symphyses- Fibrocartilage --> Allows small movement --> Pubic symphysis, vertebral discs --Shock absorbing

Burns: Second Degree

-Epidermis and upper dermis injured (partial Thickness) -Blistering, most painful

Burns: First Degree

-Epidermis is injured -Redness, swelling, a lot of pain

Sebaceous

-Exocytosis -Holocrine (Builds up and explodes) -Lubricate the skin and hair -Prevents water loss -Antibacterial -Secretes at the upper hair follicle -Secretes sebum (oil)

Eccrine

-Exocytosis -Merocrine (secretes slowly) -Sweat gland -Temp Control -Found everywhere especially palms, feet, forehead -Secrete at the skins surface

Apocrine

-Exocytosis -Merocrine (slowly secretes) -Sweat and sexual scent gland -Secrete at the upper part of hair follicle -Secrete fat and protein

Hair

-Hard Keratin -Grows from hair follicle then cells push outward -In to out: Medulla, cortex, cuticle

Syndesmosis

-Held together by ligaments -Two bones held together by ligaments -Ankle joints, radius, ulna

Melanoma

-Highly malignant -Can enter the blood system and move around the body -1% of skin cancer -Stems from melanocytes -Metastasizes -Rapid growth -Surgical excision if detected early, if not: immunotherapy, radiation, gene therapy

Gomphosis

-Hold teeth in place in the jaw -Peg in socket

Fibrous Joints

-Immobile joints -Bones are joined together by the collagen fibers of dense fibrous CT --> Sutures (Skull) --> Gomphosis (tooth) --> Syndesmosis (fibia and tibia at ankle) -No joint cavity

Basal Cell Carcinoma

-Least Malignant -Most common (80% of all skin cancers) -Stratum basale cells invade into the dermis and subcutaneous layer. -Rarely metastasize -Slow growth -Treat through surgical excision

Joint Injuries: Sprain

-Ligaments are either stretched or torn -Partial tears heal poorly because they are poorly vascular (can heal but it takes time) -Full tears are healed by sewing them together, grafts, or immobilization /time.

Both Bursae and Tendon Sheaths

-Lubricate certain surfaces and reduce friction between adjacent surfaces

Muscle Tone

-Muscle tendons are the most important stabilizer of joints

Hypodermis

-Not technically part of skin -Anchors dermis -Shock absorption, insulation, Energy Storage -Adipose (fat tissue)

Joint Injuries: Cartilage tear

-Occurs when the meniscus is under compression and shear stress simultaneously -Avascular which means the tears cannot be repaired -Arthroscopic surgery can be used to remove it

Suture

-Only in skill bones -Articulating the edges of bones; Junctions filled by connective tissue

Ligaments

-Prevent excessive of undesirable movement -"Overstretched" ligaments remain stretched

Functions of the skin

-Protection (physical, biological, chemical) -Temperature regulation -Cutaneous sensation -Metabolic functions -Blood Reservoir -Excretion

Articular surfaces

-Shapes and sizes both allow and prevent movement

Skin: Cutaneous Sensation

-Tactile cells (base of epidermis, feels mechanical force on skin) -Lamellar (feels deep bumps & pressure) -Hair follicle receptors (wind) -Pain (chemicals and extreme hot and cold)

Tendon Sheaths

-The elongated fluid-filled sac that wraps around a tendon to decrease friction -Longer than bursae and wrap around tendons

Bursae

-The fluid-filled sac decreases friction where a ligament would rub against bone -Contain synovial fluid

intramembranous ossification

-functionally he same with cartilage then bone -making of bone between connective tissue membranes 1. ossification centers develop in the fibrous connective tissue membrane 2. osteoid is secreted and calcified 3. periosteum form and blood vessels invade spongy bone 4. compact bone replaces the immature spongy bone, red marrow develops -occurs at a long piece of fibrous cartilage

Skin: Metabolic Functions

-Vitamin D Production

Osteoclast

-bone breaker -use enzymes to break down bone (resorption) -bone reabsorbing cell

Osteoblast role

-bone deposit -mechanical stimulus -Ca and P ion requirement -secretion of alkaline phosphate -help secrete calcium and phosphate

osteoblast

-bone maker -secrete bone matrix -responsible for bone growth

Osteoclast role

-bone resorption -multinucleated and ruffled edges -secrete protons and lysosomal enzymes -converts stored salts into soluble forms -some phagocytosis -not in bone development

Osteoporsis

-bone resorption occurs at a much greater rate than bone deposition which results in under mineralized bone -osteoclasts are overactive, breaking down bone and releasing minerals at a higher rate than they normally would -osteoblasts are under active not building up bone and not building minerlas

Appositional cartilage growth

-cells in the perichondrium secrete ECM proteins against external cartilage -osteoblasts lay down new layers of bone -grow outward, add layers o the outside

Yellow Marrow

-contain mesenchymal stem clue that produce cartilage, fat and bone -store fat

endosteum

-covers internal bone surfaces

Articular cartilage

-covers the ends of bones to prevent friction

perisoteum

-covers the external surface of the entire bone except for joint surfaces

Long bones

-diaphysis - shaft - thick collar of compact bone that surrounds central medullary cavity containing yellow marrow -epiphysis - bone ends - spongy calcaneus bone covered by a thin layer of compact bone - connected to diaphysis at the epiphyseal plate -periosteum - covers the external surface of the entire bon except for joint surfaces - outer fibrous layer and an inner osteogenic layer -endosteum - covers internal bone surfaces -nutrient foramen - artery that runs inward to supply nutrients to bone marrow and spongy bone

Hyalin Cartilage

-flexible and resilient -collagen fibers surrounded by chondrocytes -articular, costal, larynx and respiratory tract, nasal

osteocytes

-form bone cell lineage -mature osteoblast -monitor and maintain the bone matrix

What stimulates bone growth?

-growth hormone released by the pituitary gland that stimulates epiphyseal plate activity -sex hormones, trigger growth during adolescence and male/female skeletal differences, and epiphyseal plate closure

compact bone

-heavy, tough and compact -made up of osteons -fill the outer layer of bones -bone marrow cavity in the center -bone marrow stores fat -forms the shaft/diaphysis of long bones -osteon -lamellae -central canal - contains small blood vessels and nerve fibers -canaliculi - connect the different layers of lacunae and osteocytes

Red Marrow

-hematopoietic tissue (produces blood cells) -infants have more red marrow but in adults marrow is replaced with yellow marrow

fibrocartilage

-highly compressible -backed rows of chondrocytes with collagen fibers -vertebral discs, between pubic bones, meniscus

Bone remodeliing controls

-hormones - negative feedback loo with parathyroid hormone -Ca stores required for muscle contraction, nerve impulses, blood coagulation, gland secretion and cell division

Paget's

-increased osteoclast activity -increased osteoclast -areas with weak demineralized bone and other areas with thickened bone where it shouldn't be -results in areas that are under mineralized and areas that are over mineralized -something wrong with the osteocytes

Achondroplasia

-inhibition of growth of long bones -FGFR mutation (inhibits chondrocyte proliferation) -same cell types and interactions but chondrocytes are underachieve and less bone for osteoblast to put down

Spongy Bone

-light, spongy and soft -made of trebeculae -reistent to mechanical stress -fills inner layer of most bones -bone-marrow cavity absent -bone marrow produces blood cell stem cells -forms the ends of long bones

Long bones

-longer than wide -widen at ends

endochondral ossification

-making bone within cartilage -bone develops form fibrous membrane 1. bone collar (diaphysis) starts to calcify and mineralize bone 2. calcification and mineralization, deposit to make harder and begin to form cavities 3. Blood vessel invasion and spongy bone formation 4. 2 ossification centers, bone begin to deposit there and develop at both ends, medullary cavity formation 5. spongy bones, blood vessel growth and invasion, epiphyseal plate

elastic

-more elastic -has elastic fibers -found at the epiglottis and external ear, tip of nose

Functions of cartilage

-no nerves or blood vessels -primarily made of water -compression resilience -surrounded by perichondrium which has blood vessels to supply blood -surrounded by ECM, filed with holes (lacunae) where chondrocytes are

Stratum Lucidium

-only in thick skin -Few rows of flat dead keratinocytes -single translucent layer

osteomalacia

-osteoid is laid down fine but there is no mineral deposition -bones that are overly flexible and not that hard

Acromegaly

-overproduction of growth hormone after epiphyseal plate -facial bone, feet, and hands -same cells types as gigantism the only difference is it occurs after the epiphyseal plate

Short bones

-roughly cubed shaped -sesamoid bones form in a tendon (patella)

Stratum Spinosum

-several layers -Contain thick bundles of intermediate filaments which resist tension -Dendritic cells, desmosomes & melanocytes

Epidermis

-sheets of epithelia tissue -outermost protective shield of body -avascular

osteocyte role

-stressor for mechanical stress and Ca and PO4 levels - talks to osteoclast and blasts -osteoblasts come in when there is mechanical stress to build thicker bone

Function of the skeleton

-support -protection -anchorage -mineral storage -blood cell formation -triglyceride (fat) storage -hormone production

Flat Bone (structure)

-thin plates of spongy bone covered by compact bones -have no bone marrow but no marrow cavity -found in: short irregular and flat bones

flat bones

-thin, flattened, slightly curved -sternum

Gigantism

-too much growth hormone -overgrowth of long bones -occurs before epiphyseal plate closes -chondrocytes and osteoblasts are overworking -chondrocytes are laying down cartilage matrix and osteoblasts are laying down osteoid ultimately mineralizing

irregular bones

-vertebrae and hip bones

osteoprogenitor cells

-will Differentiate -stem cell

Synovial joint

Articular cartilage: Covers end of bone Joint= space containing synovial fluid Articular capsule= --> Fibrous ayer: continuous with the periosteum --> Synovial membrane: covers internal joint surfaces --> Ligament outside articular capsule to connect on either side of the bone Synovial fluid= Lubricant, weight bearing film, derived from blood filtration, phagocytic film Reinforcing ligaments= Capsular ligaments (Thickened fibrous layer) Nerves and BVs= --> Sensory nerves: monitor pain, stretch, position --> BVs: supply synovial fluid filtrate

Bone repair after injury

Cartilage first - cartilage matrix created and osteoblasts come in an make bone 1. Hematoma forms - accumulation of blood, death of cells and swelling 2. fibrocartilaginous callus forms - blood vessels recruited into cartilage where they regrow 3.bony callus forms - recruit osteoblasts and lay down osteoid 4. bone remodeling occurs, bony callus forms to make new bone, spongy bone, converted into compact bone, normal deposition and resorption

mineral storage

calcium and phosphate storage, continuous release and deposition

organic (bone)

cells osteoid - secreted matrix proteins (collagen, proteoglycans and glycoproteins), contributes to flexibility

lamellae

collagen fibers in alternating pattern: house osteocytes

Cartilage

consists of chondrocytes in lacunae un a jelly like extracellular matrix

secondary ossification center

epiphysis

blood cell formation

hematopoiesis occurs in red marrow

Primary ossification center

in diaphysis

Inorganic (bone)

mineral salts, calcium and phosphates -contribute to hardness/compression resistance

Anchorage

provides lever points so movement can occur

Protection

skull, rib cage protect organs

Fat storage (bones)

stored in yellow marrow in long bones