Zoology Chp 38- Skeletal system

hydrostatic skeleton, exoskeleton, endoskeleton

List the three major types of skeletons found in animals

exoskeleton

hard outer covering

endoskeleton

internal support structure- made of bone and/or cartilage

hydrostatic skeleton

what kind of skeletal system do these organisms have?

soft-bodied invertebrates: earthworms, jellyfish, sea anemones, and nematodes

exoskeleton

what kind of skeletal system do these organisms have?

insects, crustaceans, spiders, and many mollusks (shells)

endoskeleton

what kind of skeletal system do these organisms have?

echinoderms and vertebrates (fish, amphibians, reptiles, birds, and mammals)

made of chitin (arthropods) or calcium carbonate (some mollusks)

exoskeleton is made up of…

protects against predation and desiccation

advantages of an exoskeleton

limits the maximum body size and must be molted to allow growth

limitation of an exoskeleton

endoskeleon

grows with the organism

protects internal organs

provides strong support for large body size

allows complex movement

support, protection, movement, production of blood cells, storage of mineral and fats (lipids)

5 major functions of the skeletal system

axial and appendicular

what are the two major division of the human skeleton

axial skeleton

forms the central axis of the body

appendicular skeleton

bones attached to axial skeleton

axial skeleton

protects the brain, spinal cord, heart and lungs

axial skeleton

provides attachment for muscles

supports posture

performs respiratory movements

appendicular skeleton

grasping and manipulating objects

movement and locomotion

weight bearing

skull, ossicles, hyoid bone, thoracic cage, vertebral column

the structures of the axial skeleton

hyoid bone

bone that lies below the mandible at the front of the neck

connected to the muscles of the jaw, larynx, and tongue

acts as a movable base for the tongue

controls opening of airway and gut

in the axial skeleton

ossicles

located in the middle ear

transmits sounds from the air as vibrations to the fluid-filled cochlea

in the axial skeleton

malleus (hammer), incus (anvil), stapes (stirrups)

auditory ossicles

vertebral column

surrounds/protects the spinal cord

supports head

acts as an attachment point for ribs and muscles of the back and neck

in the axial skeleton

cervical, thoracic, lumbar, sacral, coccyx

regions of the vertebral column

7

how many vertebrae does the cervical spine have?

12

how many vertebrae does the thoracic spine have

5

how many vertebrae does the lumbar spine have

5 fused into 1

how many vertebrae does the sacral have

3-4 fused into 1

how many vertebrae does the coccyx have

intervertebral discs

allows some movement and acts as a cushion

ribs, sternum, costal cartilage

structures of the thoracic (rib) cage

costal cartilage

attachment points

allows for expansion for breath

found in the thoracic cage

rib cage

protects internal organs

attachment site for diaphragm, muscles of back, chest, neck, and shoulders

provides support for shoulder girdles and upper limbs

enables breathing

in the axial skeleton

pectoral girdle, arm, hand, pelvic girdle, leg, and foot

structures of the appendicular skeleton

pectoral girdle (shoulder)

includes clavicles and scapulae

provides an attachment point for the upper limbs

shoulder, arm, forearm, wrist, and hand

bones of the upper limbs (upper extremities)

pelvic girdle

responsible for bearing the weight of the body and locomotion

attached to axial skeleton by strong ligaments

in the appendicular skeleton

pelvis, femur, patella, tibia, fibula, and the bones of the foot

bones of the lower limbs

bone

mineralized connective tissue (osseous tissue)

mineral salts (calcium phosphate crystals), collagen fibers, cells

bones contain…

calcification

the process of depositing mineral salts in collagen fibers

crystalize and hardens tissue

long, short, flat, irregular, sesamoid

5 main types of bone

long bone

the femur, humerus and tibia are what type of bone

long bone

bones that are longer than they are wide

short bone

bones that are nearly equal in length and width

flat bones

the sternum, ribs and scapula are what kind of bone

flat bones

thin, flattened bones that are often curved

irregular bones

vertebrate, facial and pelvic bones are what type of bone

irregular bones

bones that are complex/unusual shapes

sesamoid bone

what type of bone is the patella

sesamoid bone

small, round bones that are embedded in tendons

diaphysis, epiphysis, articular cartilage, medullary cavity, periosteum, endosteum

structures of a long bone

diaphysis

part of the long bone

shaft

contains medullary cavity (endosteum → contains yellow bone marrow)

outside lined with periosteum walls made of compact bone

epiphysis

part of the long bone

poximal and distal ends

expanded regions at ends

contains spongy bone (red bone marrow)

covered by third layer of compact bone

articular cartilage

in long bone

lines ends of epiphysis

provides cushion and support in joints

periosteum

outer covering in the long bone

endosteum

inner lining of the long bone

compact and spongy

what are the two types of bone tissue

compact bone

forms diaphysis and outer part of epiphysis

dense tissue

solid and smooth in appearance

provides strength and protection

spongy bone

tissue inside the epiphysis

looks lacy and delicate but firm and strong

osteon

basic structural unit of compact bone

cylindrical structure that runs parallel to the bone shaft

compact bone

highly organized bone tissue that is composed of osteons

central (haversian) canal

located in the center of each osteon

contains blood vessels and nerves

volkmann’s (perforating) canals

run perpendicular to central canals

connect blood vessels between osteons

link central canals to periosteum and medullary cavity

lamellae

concentric rings in the osteon made of mineralized bone matrix

lacunae

in the osteon

small spaces between lamellae

contains osteocytes

canaliculli

in the osteon

tiny channels connecting lacunae

connect osteocytes to each other and central canal

allows nutrients and waste exchange

osteocytes

mature, living bone cells

maintain the bone matrix

located inside lacunae

endosteum

thin membrane lining central canal

contains osteoblasts and osteoclasts

osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts

4 main types of bone cells

osteoprogenitor cells

type of bone cell

located in periosteum and endosteum

stem cell that gives rise to osteoblasts

osteoblasts

type of bone cell

found on bone surfaces

builds new bone matrix

becomes osteocytes when trapped in matrix

osteocytes

type of bone cell

mature bone cells trapped in matrix

located in lacunae

maintain bone tissue

osteoclasts

large, multinucleated cells

found on bone surface

breaksdown (“crashes”) bone

osteoblast

bone-forming cell

osteoclasts

bone-resorbing cell

bone remodeling

continuous process where old bone replaced by new bone

keeps the skeleton strong and balanced

bone remodeling

the process of getting rid of old bone and forming new bone

long

what kind of bone are phalanges, metacarpals, and metatarslas

short

what type of bone are carpals and tarsals

they break down bone to release calcium and phosphate into blood

role of osteoclasts in remodeling

makes new bone matrix

role of osteoblasts in remodeling

joint

areas where two or more bones meet

responsible for movement and stability

structure and function

what are the two ways to classify joint

fibrous, cartilaginous, synovial

structural classification of joints

synarthrosis, amphiarthroses, diarthroses

functional classification of joints

synarthrosis

functional classification of joints that are immovable

amphiarthroses

functional classification of joints that allow slightly movable

diarthroses

functional classification of joints that allow free movement

fibrous joints

connected by dense connective tissue

no joint cavity

very little or no movement

bones held tightly together

fibrous joints

sutures of the skull, ankle joint, and tooth in the socket are examples of what type of joint

cartilaginous joints

connected by cartilage

no joint cavity

slight movement allowed

strong but flexible

cartilaginous

intervertebral discs, pubic symphysis, and epiphyseal (growth) plates are example of what kind of joints

synovial joints

most movable type

have a joint cavity

contain synovial fluid

surrounded by a joint capsule

ends of bone covered with articular cartilage

synovial

the knee, shoulder, elbow, and hip is what kind of joint

medullary cavity

the central hollow space within the shaft (diaphysis) of long bones, such as the femur or humerus.

yellow bone marrow

the medullary cavity in a long bone contains…