A&P Exam 2

Three major skin regions

Epidermis, Dermis, Hypodermis (subcutaneous layer)

Epidermis

Layers (Deep→Up)

1.Stratum Basale

2.stratum Spinosum

3.stratum Granulosum

4.stratum lucidum

5.stratum corneum

Function

water resistant/Handles abrasion

Dermis

Layers

Papillary layer→ loose Areolar connective tissue

Reticular layer → Dense irregular connective tissue

Function

Houses blood cells/nerves/glands

strength/resistance from multi directions

Hypodermis

Tissues

Areolar (packing)

Adipose (Fat)

Function

Anchors skin

padding protection/energy resevior/thermal insulation

stratum corneum

Feature

-Top 20-30 layers dead flat keratinocytes

Contribution

-strength/reistance to water/abrasion

-reduce water loss

stratum lucidum

Feature

-ONLY in thick skin (Palms of feet/hands)

-clear flat layer

Contribution

-high friction

stratum Granulosum

Feature

-last living layer

-keratinization starts

Contribution

-hardens/flattens from keratinization

-water protection

stratum Spinosum

Feature

-living

-cells held together by desmosomes

-Langerhan cells (immune defence)

Contribution

-strength

-flexibility

Stratum basale

Feature

-bottom

-single row of cells

-keratinocytes, melanocytes, merkle cells (touch)

Contribution

-mitotically active (constantly replacing)

Dermis Layers

Top

Papillary layer→ loose Areolar connective tissue

-Dermal papillae supply nutrients to avascular epidermis cells

-so close to basal layer that needs constant nutrients/energy for mitosis

Deeper

Reticular layer → Dense irregular connective tissue

-bundles of collagen fibers

-handle force from multi direction

Hair structure

Hair bulb

(Whole bottom region)

• epithelial cells

Hair matrix

(First layer surrounding hair)

• mitocially active cells produce hair

Hair papilla

(seed)

• contain capillaries for blood supply

Hair root

(in skin)

Hair shaft

(out of skin)

Arrector pilli muscle

• contracts (piloeration)= goosebumps

Glands sweat

Eccrine

• Sweat: hyotonic filtriate of blood

• secretes: skin surface

• function: temp control/anti bacterial

Apocrine

• sweat: filtriate blood w/ added protiens+ fatty substances

• Secrets:upper hair follicle

• Function: sexual scent

Sebaceous

• sweat: sebum

• Secrets: upper hair follicle

• Function: lubricate hair/skin, prevent water loss, anti-bacterial

How body promotes heat loss?

Blood vessels:become wider (Vasodilation) and when warm blood is closer to surface to skin allowing head to escape

Eccrine glands: relace sweat that is evaporated by your hot skin taking away heat

Disorder of epidermal-dermis connection?

Epidermolsis bullosa (EB)

-weakened junction/anchoring system → friction pulls apart layers → fluid fills space → blister forms

-jobs they cant do: mechanical stress, fluid retension, preventing infection

Skin cancers (Worst to best)

Melanoma (evolving dark spots)

Orgin: melanocytes

Growth: less common but likey to metatize

Why: early detection important

squamous cell carcinoma(scaley crusty red)

Orgin: epidermal keratinocytes

Growth: more likey to spread

Why: Uv exsposure

Basal call carcinoma(bump)

Orgin: stratum basale

Growth: slow/rarely metatize

Why: most common

Major skeletal tissues

Compact (cortical bone)

Dense smooth solid

Spongy (cancellous/tuberular bone)

porous and deep inside compact bone

Hyaline cartilage

forms base of fetal tissue

fibro cartilage

bears weight/resists compression

ligament

bone → bone

tendon

muscle →bone

(Both made from dense irregular connective tissue: packed/multi direction)

Function of skeletal system

-Structural support, protects interanl organs, produce movement

-Stores calcium/phosphate

-yellow bone marrow→ lipids energy

-red bone marrow→ blood cell production

Major bone cells

Osteoprogenitor(start)→ osteoblast(builds)→ osteocyte(monitors)

Osteoclast(eats bone cells to release calcium in blood)

Bone tissue organization diagram

Osteon (whole thing)

central canal (tube in center w/blood vessels+ nerves)

lamellae (Layers/rings of bone matrix)

lacunae (space inbetween ^) canaliculi (channels exchange nutrients/waste)

periosteum (outside growth repair) endosteum (lines inside spongy bone)

Thermoregulation

Vitamin D synthesis

sensation

Immune defence

Water balance

Protection

Thermoregulation

-sweat gland evaporation

-basal dilation

Vitamin D synthesis

-Uv exsposure

-Kerationocytes

sensation

-Merkle cells/touch cells (in basal)

-pacinian corpuscles

-free nerve endings

Immune defence

Langerhans cells (in stratum spinosum)

Water balance

kertiization creates water resistance and secrets glycolipids

Protection

stratified cells help abrasion (In epidermis/ stratum corneum)

Thermoregulation

-sweat gland evaporation

-basal dilation

Vitamin D synthesis

-Uv exsposure

-Kerationocytes

sensation

-Merkle cells/touch cells (in basal)

-pacinian corpuscles

-free nerve endings

Immune defence

Langerhans cells (in stratum spinosum)

Water balance

kertiization creates water resistance and secrets glycolipids

Protection

stratified cells help abrasion (In epidermis/ stratum corneum)

Inorganic Bone Matrix

Mineral salts:hydroxyapatite crystals

-calcium/phosphate

-hardness/resistance to compression

Organic Bone Matrix

Osteoid:collagen fibers

-tensile strength (maximum stretch without breaking)

-resist stretch/twist

Intramembranous ossification

connective tissue→ bone

-Starts inside grows more out

-osteoblasts build bone gets trapped and becomes osteocytes

Endochondral ossification

Cartiliage→ bone

-most bones/long bones

-Bone forms around hyaline tissue and calcifies (dies/starves) and leave cavities for blood vessels

Steps of cartilage interstitial growth

Resting →proliferation(cartilage cells do mitosis)→ hypertophic(older cartilage cells get bigger)→ calcification(matrix calcifies/cartilage dies)→ ossification (new bone)

Bone deposition

Osteoblasts → deposit new osteoid bone

mineral salt ADD strength to matrix

Bone resorption

osteoclasts remove existing bone matrix

matrix relaces → to body

Bone related hormones

Growth hormone IGF-1

bone growth

Sex hormones

adolesent bone growth

Parathyroid (PTH)

Promtes Ca in blood

Calcitoral

raise intestine Ca absorption

calcitonin

lowers osteoclast activity

Calcitoral

raise intestine Ca absorption

calcitonin

lowers osteoclast activity

Responce to low blood Ca?

Parathyroid gland notices low Ca²⁺ and releases PTH.

• Bones: PTH increases calcium release from bone into the blood.

• Kidneys: -PTH increases calcium reabsorption → less Ca²⁺ lost in urine. - PTH stimulates the kidneys to activate vitamin D into calcitriol →increases Ca²⁺ absorption in the small intestine

Fractures

closed simple (skin intact)

open compound (exsposed through skin)

complete (break extends entire bone)

incomplete (breaks not extend entire bone)

greenstick (one side breaks other bends)

comminuted (multi fragments)

compression

spiral

pathlogic (weakened by disace)

stages of bone repair

1. hematoma forms

2. soft fibrocartliage callus forms + blood vessels

3. hard bony callus forms

4. Compact bone is remodeled

Osteomalacia

-Deficency of vitamin D or malsorption disorders cauce soft and weak bone

-minerlization of osteoids is impared

Osteogenesis

-genetic mutations cauce hard but brittle bones and growth deficency

-effects type 1 collagen and intramembranous/endocrondrial ossification

Axial vs Appendicular

Axial: Support/protection

appendicular: Movement manipulation

Know each bone is part of_?

When Adult spinal curvature develops and primary or secoundary?

Thoracic:1st/ Birth

Sacral:1st/ Birth

Cervical:2nd/ infancy (holding head up)

Lumbar:2nd/ infantcy (standing/walking)

Functions of spine?

-maintain balance

-support upright posture

-absorb/distribute mechanical forces

Abnormal spinal curvatures

Hyperkyphosis(Hunchback): Posterior

Hyperlordosis(Big belly): Anterior

scoliosis: lateral w/vertebral rotation

Bone shapes

Long: lever (femur/humorous)

Short: cube shaped/stability (carpals/tarsals)

Flat: protects organs/muscle attachment (sternum,ribs,cranial bones)

Irregular: articulation/support/protection/muscle attachment (vertebrae)

Sesamoid: develops w tendons/ leverage/modifies pull of quadriceps tendon (patella)

Bone markings

trochanter: Large

tuberosity:Large roughened

Tubercle: small rounded

crest/line: ridge

spine: sharp/slender

process: an projection

head: exspanded rounded end

condyle: rounded articular

facet: flat surface

Bone markings (holes)

Foramen: Opening through bone for nerves/blood

Fissure: narrow slit like opening for nerves/blood

meatus: canal through bone

fossa: shallow despression to accomadate another structure

notch: indentation at edge for another structure

what is an articulation?

Joint, where 2 bones meet

bone-bone

muscle-tendon-bone

bone-ligament-bone

articulation

transfers force for movement

connection/stability

more mobile, less stable

true

Factors that influenece moveability at an articulation?

Shape of articulating surfaces

how bones connect

supporting structures around it

what is a joint?

Any two skeletal structures meeting

Bone-bone

bone-cartilage

bone-tooth

What are classifications of joints?

1. Structural

-fiberous

-cartiligainos

-synovial

2. Functional

-synarthrosis

-amphiathrosis

-diarthrosis

fibrous

fiberous connnective tissue

no joint cavity

immobile/slightly

cartilaginous

cartiliage

no joint cavity

immobile/slightly

synovial

joint capsule surrounding a cavity

yes joint cavity

freely mobile

Types of fibrous joints

Gomphosis: Tooth-jaw (synarthrosis)

Suture: sonnects skull bones (synarthrosis)

sydesmosis: membranes inbetween bones (Amphiathrosis)

functions of frontelles in fetal skull

-allow deformation of skull during birth

-allow rapid skull growth in infancy

craniosynostosis

premature suture fusion restricts skull growth perpendicular to the fused suture

saggital synotsis

Skull becomes too long

coronal syntosis

skull becomes too wide

cartilaginous joint types

Synchondrosis: hyaline cartilage (synarthrosis)

• Costochondrial joints:rib-costal

• rib-sternum

symphysis: fibro cartilage(amphiarthrsis)

• pubic symphyisis

• intervertebral

Interververtebral-disc structure

Anulus fibrosus: (touch outer ring of fibrocartilage) resists tension

nucleus pulposus: (gel in center) distributes compression

Intervertebral disc: ( fibrocartilage pad in between vertebrae) shock absorption/load distribution/limited spinal movement

Whats a herniated disc?

“protrusion” of nucleus into anulus fibrosus→ irrates nearby nerves

synovial joint structures

Articular cartilage: reduces friction/distributes load

joint cavity: space allowing surface to move

Synovial fluid: nourishes articular cartilage

articular capsule: encloses/stablizes joint

ligaments: reinforce/limit exsessive movemnt of joint

What feature of synovial jointt determines directions it can move?

Shape

Synovial joint types

Plane: non axial glide/tarsal

hinge: uniaxial/elbow

pivot: uniaxial rotation/

condylar:biaxial/ wrist/mcp

saddle: biaxial/thumb cmc

ball-socket: multiaxial/ shoulder/hip

flexion/extension/hyperextension

smaller angle/bigger angle between two bones

extension past anatomical position

rotation/circumduction

tunrs bone around axis/moves distal end of limb in circle

adbduction/adduction

limb away median/towards median

supination/pronation

palm up/palm down

radius over ulna/ parallell

opposition

finger clap

dorsififlexion/plantar flexion

toes up /pointed foot

inversion/eversion

in medially/out laterally

elevation/depression/protraction/retraction

mandible up/down/forward/back

How muscle move skeleton?

Skeletal muscles pull not push, becauce they contract not lengthen.

Muscles cross a joint or else they cant?

Directly move it

origin/insertion

origin: attachment dosnt’t move

insertion: attachments moves towards origin.

Roles of muscles

Agonist: produces most force (Biceps brachii during elbow flexion)

antagonist: opposes movement (triceps brachii during elbow flexion)

synergist: assists/resists (brachloradials assist biceps during elbow flexion)

fixator: stabilizes ( scapular helps scapula during arm movement)

Parts of lever system

fulcrum:joint around movement

effort

load

Classes of levers

1st(effort-FULCRUM-load):Force or ROM

-Scissors/neck

2nd(fulcrum-LOAD-effort): Force

-calf raise/wheelbarrow

3rd(load-EFFORT-Fulcrum):speed/ROM

-tweezers/biceps

What level is most common in body and why?

3rd is most efficent

shoulder joint

elbow joint

ball-socket

deltoid abduction

hip joint

hinge

biceps exstension

knee joint

ball-socket

gluteous maximus extension

ilopsoas flexion

ankle joint

hindge at talocrinal joint

gastronemius plantar flexion

soleus pushoff

Temporomandibular joint (TMJ)

modified synovial joint

masseter

temporals

exstention of mandible

Parts of a general bone

• Diaphysis = shaft of the bone. This is the long, middle portion.

• Epiphysis = ends of the bone. These are the rounded ends, near the joints.

• Metaphysis = transition area between the shaft and each end. This is where the growth plate is located in growing bones.

• Articular cartilage = smooth covering on the ends of bones where they meet at joints. It reduces friction during movement.

Types of bone growth

• Appositional growth: Bones grow thicker and wider by adding new bone tissue to the outer surface. Think of adding layers to a tree trunk.

• Closing of the epiphyseal plate: The growth plate closes when a person finishes growing in length.

• Epiphyseal plate closure: The growth plate stops allowing lengthwise growth.