musculoskeletal system 1

bones are dominated by what?

bone connective tissue

what two tissues do bones contain?

nervous tissue and blood connective tissue

bones contain what in articular cartilages?

cartilages

what are the functions of bones?

support, movement, protection, mineral storage, blood cell formation, and energy metabolism

what are the three types of cells in bone produce or maintain bone

osteoprogenitor cells, osteoblasts, and osteocytes

what are osteoprogenitor cells?

stem cells that differentiate into osteoblasts

what are osteoblasts?

bone forming cells; actively produce and secrete bone matrix

ex- bone matrix is osteiod

What are osteocytes?

mature bone cells that keep bone matrix healthy

What do osteoclasts do?

found within bone tissue, responsible for resorption of bone, are derived from a line of white blood cells, and secrete hydrochloric and lysosomal enzymes

what are long bones?

longer than they are wide; a shaft plus ends

what are short bones?

roughly cubed shaped

what are flat bones?

thin and flattened, usually curved

What are irregular bones?

various shapes; bones that do not fit into the other categories

whats a compact bone?

is the gross anatomy of bones and the dense outer layer of bones

whats a spongy bone?

internal network of bone

what does trabuculae mean?

little beams of bone; open spaces between trabeculae are filled with marrow

what does bone design and stress mean?

-anatomy of a bone reflects stresses

-compression and tension greatest at external surfaces

whats the structure of a typical long bone?

diaphysis, epiphysis, blood vessles, medullary cavity, and membranes.

whats the diaphysis?

shaft of bone

What's the epiphysis?

ends of a bone

What's the medullary cavity?

hollow cavity filled with yellow marrow

what do the membranes contain?

periosteum, perforating collagen fiber bundles, and endosteum

what are the three categories of bone markings?

projections for muscle attachment, surfaces that form joints, and depressions and openings.

what does compact bone contain?

little passageways for blood vessels, lymph vessels, and nerves

what is spongy bone?

less complex than compact bone, trabeculae contain layers of lamellae and osteocytes; they are too small to contain osteons

whats ossification?

bone tissue formation

whats endochondral ossification?

all bones except some bones of skull and clavicles, bones are modeled in hyaline cartilage, begins forming late in the second month of embryonic development, and continues forming until early adulthood

whats the epiphyseal plate?

holds the growth plate cartilage in long bones, providing strength and stability to it

describe the growth of endochondrial bones during childhood and adolescence

bones lengthen entirely by growth of epipheseal plate, cartilage is replaces with bone connective tissue as quickly as it grows, epiphyseal plate maintains constant thickness

describe the growth of endochondrial bones as adolescence draws to an end

epiphyseal plates become thinner, cartialge stops growing, replaced by bone tissue, long bones stop lengthening when diaphysis and epiphysis fuse, and growing bones widen as they lengthen

describe the growth of endochondrial bones during appositional growth

growth of a bone by addition of bone tissue to its surface

whats the growth hormone?

produced by the pituitary gland and stimulates epiphyseal plates with allow for growth

whats the thyroid hormone?

ensures that the skeleton retains proper proportions

whats the sex hormones (estrogen and testosterone)?

promote bone growth and later includes closure of epiphyseal plates

describe cartilage

found throughout the adult body, in external ear, nose, articular and costal cartilages, found in larynx and trachea, and intervertebral discs

what are the 3 types of cartilage?

hyaline, elastic, and fibrocartilage

what does hyaline cartilage do

most abundant cartilage, chondrocytes appear spherical, and provides support through flexibility and resilience

what does elastic cartilage do

contains many elastic fibers, able to tolerate repeated bending, and in epiglottis and cartilage of external ear

what does fibrocartilage do

resits strong compression and strong tension, intermediate between hyaline and elastic, located in pubic symphysis

what does the skeleton consist of

bones, joints, cartilage, and ligaments

what are joints also called?

articulations

how many bones are in the body?

206

what are the 2 divisions of bones

axial and appendicular

the axial skeleton has how many bones?

80

the appendicular skeleton has how many bones?

126

what is the body’s most complex bony structure and is formed by cranial and facial bones?

the skull

what do facial bones help with?

framework of the face, form cavities for sense organs of sight, taste, and smell, provide openings for air and food, hold teeth in place, and anchor muscles to face

the skull is formed of how many bones and what kinds?

8; paired and unpaired

what are the paired bones?

temporal and parietal

what are the unpaired bones?

frontal, occipital, sphenoid, and ethmoid

what bones form superior and lateral parts of the skull

parietal

what are the 4 sutures of the cranium

coronal, squamous, sagittal, and lambdoid

runs the coronal plane, located where parietal bones meet frontal bone

coronal suture

occurs where each parietal bone meets a temporal bone inferiorly

squamous suture

occurs where tight and left parietal bone meets superiorly

sagittal suture

occurs where the parietal bones meet the occipital bone posteriorly

lambdoid

what does the mandible bones do?

lower jawbone is largest and strongest facial bone, is the only moveable bone of skull

what does the maxillary bone do?

articulate with all other facial bones except mandible, forms part of the inferior orbital fissure, are the “keystone” bones of the face

what are the muscles of mastication

prime movers of jaw closure- masseter m and temporalis m

side to side and forward and back movement- pterygoid muscles- medial pterygoidm and lateral pterygoid m

whats the purpose of the hyoid bone

lies inferior to the mandible, the only bone with no direct articulation with any other bone, and acts as a moveable base for the tongue

the vertebrae has how many bones?

33

why does the vertebrae get wider towards the bottom?

has to hold weight

what are the 5 major regions of vertebrae

cervical- 7

thoracic- 12

lumbar-5

sacrum- 5

coccyx- inferior to sacrum

what are the cushionlike pads made of

nucleus pulposus and anulus fibrosus

what is the nucleus pulposus

gelatinous inner sphere and absorbs compressive stresses

what does the anulus fibrosus do

outer rings formed of ligament, inner rings formed of fibrocartilage, and contains the nucleus pulposus

name the intervertebral discs

vertebral arch, foramen, spinouus process, transverse process, and superior and inferior articular processes

what are the types of movement that occur between vertebrae

flexion and extension- lateral flexion and rotation in the long axis

C1-C7 are what 2 things

the smallest and lightest vertebrae

-C3-C7 body is wider laterally, spinous processes are short and bifid EXCEPT C7

C1 is the what

atlas; lacks a body and spinous process, supports skull, allows flexion and extension of neck

list key things about the axis

has body and spinous process, dens projects superiorly, acts as a pivot for rotation of atlas and skull, participates in rotating the head from side to side

what are the muscles of the neck

flexion- sternocleidomastoid

lateral flexion- splenius capitus and splenius cervicus

extension- trapezius and splenius

what does the thoracic vertebrae allow your hips to do?

move/twist

list the facts about T1-T12

-each side of the body of T1-T10 bears demifacets for articulation with ribs

-spinous processes are long and point inferiorly

-vertebral foramen are circular

-transverse processes articulate with tubercles of ribs

list the facts about the lumbar vertebrae L1-L5

-transverse processes are thin and tapered

-spinous processes are short, flat, and they point posteriorly

-vertebral foramen are triangular

-allows flexion and extension (bending down)

list the facts about the sacrum S1-S5

-shapes posterior walls of pelvis

-formed from 5 fused vertebrae

-center of gravity is 1cm posterior to sacral promontory

what is the sacral promontory

where the first sacral vertebrae bulges into pelvic cavity

what is aia

develops from fused rib elements

whats the 2 parts of sacral foramina

anterior sacral foramina- passage for ventral rami of sacral spinal nerves

posterior sacral foramina- passage for dorsal rami of sacral spinal nerves

what are the components of the thoracic cage

-thoracic vertebrae posteriorly

-ribs laterally

-sternum and costal cartilage anteriorly

what does the thoracic cage do?

protects thoracic organs, supports shoulder girdle and upper limbs, provides attachment sites for many muscles of the back

what are the 3 sections of the sternum?

-manubrium- superior section; clavicular notches articulate with medial end of clavicles

-body- bulk of sternum; sides are notched at articulations for costal cartilage of ribs 2-7

-xiphoid process- inferior end of sternum; ossifies around 40

what are the anatomical landmarks

jugular notch- central indentation at superior border of manubrium

sternal angle- a horizontal ridge where the manubrium joins the body

what are the 2 kinds of ribs

true ribs- superior 7 pairs; attach to sternum by costal cartilage

false ribs- inferior 5; ribs 11-12 are known as floating ribs

list the disorders of the axial skeleton

-scoliosis; abnormal lateral curvature

-kyphosis; exaggerated thoracic curvature

-lordosis; an accentuated lumbar curvature

whats the diaphragm most important for

respiration

what does the diaphragm seperate

thoracic and abdominal cavities

diaphragm does what as it contracts

flattens

external intercostal muscles do what

lift rib cage

internal intercostal muscles do what

aid expiration during heavy breathing

what are the lateral and anterior muscles of abdominal wall

serratus anterior, transversus abdominis, internal oblique, external oblique, and rectus abdominus

the abdominal wall contracts during what

defecation- laughing, urination, childbirth, and vomiting

whats the erector spinae group

largest of deep back muscles; keeps integrity and support of spine; forms columns

whats trunk extension

deep muscles of the back; maintain normal curvatures, form a column from sacrum to skull