AP Test #2

Ectoderm

(outer layer) forms skin & nervous system

Mesoderm

(middle layer) forms muscle, bone, blood

Endoderm

(inner layer) forms digestive & respiratory tracts

Epithelial

covers surfaces, lines organs (protection, secretion, absorption)

Connective

supports & binds (bone, blood, fat)

Muscle

movement (skeletal, cardiac, smooth)

Nervous

sends electrical signals (brain, nerves)

Totipotent

can become any cell (early embryo)

Pluripotent

many types (blastocyst stage)

Multipotent

limited (blood stem cells)

Simple cuboidal

secretion (kidneys)

Simple squamous

gas exchange (lungs)

Stratified squamous

protection (skin, mouth)

Transitional

stretch (bladder)

Pseudostratified columnar

moves mucus (respiratory tract)

Epidermis

outer layer (no blood vessels)

Dermis

thick middle layer (blood, nerves, glands)

Hypodermis (subcutaneous

fat layer

How Skin Gets Oxygen

From diffusion via blood vessels in the dermis.

Melanin

• Protects against UV radiation.

• Gives skin, eyes, and hair color.

Shivering & vasoconstriction

warm you up.

Skin Functions

Protection, temperature regulation, sensation, vitamin D production, and excretion.

Albinism

Genetic lack of melanin production.

Sweating & vasodilation

cools you down.

Keratin

• Tough protein in epidermis.

• Waterproofs and strengthens skin, hair, and nails.

Epiphysis

ends of bone (spongy bone, red marrow)

Tendons connect

muscle to bone

Ligaments connect

bone to bone

Endosteum

inner lining of medullary cavity

Periosteum

outer covering, contains blood vessels

Articular cartilage

covers joint surfaces (smooth movement)

Osteoblasts

help form bone by secreting substances that comprise the bones matrix

Osteoclasts

break down bone

Osteocytes

mature bone cells

Fibroblasts

produce collagen in connective tissue

Bone vs Connective Tissue

• Bone is a type of connective tissue with a solid matrix (calcium/phosphorus)

Calcium & Bones

• Needed for strength; stored in bones.

Excess Weight & Bones:

• Increases stress, can lead to joint pain or damage.

Greenstick

partial break (common in kids)

Comminuted

shattered

Spiral

twisted

Compound (open

breaks through skin

Simple (closed)

doesn’t break skin

Axial

skull, spine, ribs

Appendicular

limbs, shoulders, pelvis

Temporal

sides

Sphenoid

base of skull

Occipital

back of head

Parietal

top/sides

Cribriform plate

part of ethmoid bone (smell)

Zygomatic arch

cheekbone

Orbit (eye socket)

Made by multiple facial bones.

Facial Bone Foundation

• Maxilla, mandible, zygomatic, etc.

Skull Fusion

Completely fused = adult skull (sutures close)

Vertebral Column Sections

• Cervical (7), Thoracic (12), Lumbar (5), Sacrum, Coccyx

Amphiarthroses

slightly movable (pubic symphysis)

Scoliosis

sideways curve. lateral curvature of the spine, most often in the thoracic region.

Kyphosis

hunchback, exaggerated thoracic curvature. resulted from poor posture. also common to those with osteoporosis.

Fibrous

immovable (sutures)

Lordosis “swayback”

exaggerated lumbar curvature. osteoporosis, poor posture, or abdominal weight gain.

Synovial

freely movable (knee, shoulder)

Synovial fluid

lubricates

Joint capsule

encloses joint

Cartilage

cushions

Ligaments

stabilize

Condyloid

an oval convex surface on one bone fits into a similarly shaped depression on another. ex. the articulation of the distal end of the radius with the carpal bones of the wrist as well as the joints at the base of the fingers. allow flexion and extension as well as side-to-side movement.

Ball-and-socket

The ball-shaped head of one bone fits into a cup-like socket of nather bone to form this joint, offers widest range of motion of all joints. ex. shoulder and hip joints

Rotator Cuff

Group of muscles/tendons stabilizing shoulder joint

Osteoarthritis

Cartilage wears down, causing joint pain

Skeletal

voluntary, striated

Cardiac

involuntary, heart only

Smooth

involuntary, in organs

Endomysium

wraps each muscle fiber

Perimysium

wraps bundles (fascicles)

Epimysium

wraps entire muscle

Muscle to Muscle

Connected by aponeuroses (flat tendons) Strong, rarely break, can however be pulled away from a bone.

direct attachment

mustle fibers merge with the periosteum of the bone, forming a strong attachment

indirect attachment

the epimysium extends past the muscle as a tendon (a strong, fibrous cord). The tendon ther merges with the periosteum.

Muscle Contraction

Requires calcium and ATP

Actin & myosin filaments slide past each other

Mesoderm differentiation

Gives rise to connective and muscle tissue (Cardiac muscle, skeletal muscle, bone, blood, smooth muscle (gut)

Endoderm differentiation

Produces mucous membrane of respiratory tract, hydroid gland, secretory parts of pancreas. Lung tissue, thyroid tissue, pancreatic tissue.

Ectoderm differentiation

Gives ride to epidermis and nervous system. Epidermis, and nervous tissue.