Anatomy And Physiology Ch 7

Front 1

Tissue types in Skeletal System

Back 1

Bone and Cartilage (major), fibrous and loose connective tissue, blood, nervous tissue, epithelium, lymphatic tissue, myeloid tissue (bone marrow), and adipose tissue.

Front 2

Bone Tissue

Back 2

Compact (dense and solid appearance)

Spongy bone (characterized by open space partially filled by assemblage of needle-like structures)

Front 3

4 types of bone

Back 3

Long: extended longitudinal axes. Examples are femur of thigh/humerus of arm

Short: long as they are wide, cube/box shaped. Examples are wrists (carpals) and ankle (tarsals)

Flat: board and thin, flattened/curved surface. Examples are skull bones, scapulae, ribs, sternum. Many flat bones have spongy bone in them, and red marrow that fills their space.

Irregular bones: clustered in groups, and come in various sizes and shapes. Examples are the vertebral column, facial bones.

Sesamoid: they are irregular bones, but they appear singly. They are usually found embedded in substances like tendons that are close to the joints. Examples are patella.

Front 4

Identify parts of Long Bone

Back 4

Diaphysis, epiphyses, articular cartilage, periosteum, medullary (marrow) cavity, and endosteum

Front 5

Diaphysis

Back 5

It is the main long shaft-like portion of the long bone. It is hallow, and there is thick, compact bone that composes it. This structure is able to provide support with too much cumbersome weight.

Front 6

Epiphyses

Back 6

They are found on either sides of long bone. They are big bulb like structures that allow enough space for muscle attachment, and also provides stability for joints.

It is made of spongy bone, which is filled with a specialized soft connective tissue called red marrow

Front 7

Epiphyseal Plate

Back 7

This plate separated the diaphysis from the epiphysis during early development. Metaphysis is the name of the region of the ephiphyseal plates in mature and growing bone.

Front 8

Articular cartilage

Back 8

It is a thin layer of hylaine cartilage that is around the joint surfaces of epiphysis.

This material is resilient and cushions against jolts and blows.

Front 9

Periosteum

Back 9

It is a dense, white fibrous membrane that covers the bone all the way, except the joint surfaces as the articular cartilage covers that.

This is very important for bone formation and remolding that continues throughout life

Muscle tendon fibers also interlace with the periosteal fibers, and this helps anchor the muscles firmly to the bone since the periosteum penetrates the underneath the bone.

The periosteum also contains (depending on its location) bone destroying/bone building cell.

This membrane also has blood vessels incorporated into it. It is used for initial development and remolding and repair of the bone.

Front 10

Medullary (marrow) cavity

Back 10

It's the hollow space in the diaphysis of the long bone.

In an adult, this medullary cavity is filled with connective tissue that is rich in fat called yellow marrow.

Front 11

Endosteum

Back 11

This is a think membrane.

It lines the medullary cavity of long bones.

Front 12

Bone Tissue

Back 12

It is made of cells, fibers, and extraceullar material (matrix). But in bone, the matrix dominates and it is all hard and calcified. It also contains a lot of collagen fibers.

It is very strong, high tensile strength, yet it is very light for its function.

Front 13

Osteopororisis

Back 13

Declining estrogen levels, loss of bone mineral density. increased bone fragility.

Front 14

Bone matrix

Back 14

It is made of inorganic salt (hard and calcified. They resist stress and mechanical deformation. Sometimes radiation or harmful chemicals can also get incorporated into bones and thus will cause radiation and could lead to cancers/diseases.)

Organic salts (collagen fibers, mixture of protein and polysaccharides). There is also ground substance that aids in growth and cellular respiration in bone

Front 15

Types of bone cells

Back 15

Osteoblasts (they come from osteogenic stem cells)
Osteoclasts
Osteocytes

Front 16

Osteoblasts

Back 16

They come from the osteogenic stem cells(these are found in the endosteum). They make the ground substance of bone from a specialized organic matrix called osteoid. This results in mineralized bone.

Front 17

Osteoclasts

Back 17

They are giant multi-nucleated cells. Responsible for active erosion of bone minerals. These cells contain large amounts of lysomomes and mitchondria. These cells continuously break bone down, while osteoblasts build them up again by depositing osteoid under the surface.

This illustrates the continuous remolding that is achieved by the bone.

Front 18

Osteocytes

Back 18

These are mature/non dividing cells that are found in the lacunae. They are surrounded by matrix, and the cell's extracelluar matrix extends into the canaliculus.

Front 19

Bone Marrow

Back 19

It's a specialized type of soft, diffuse connective tissue.

it is called myeloid tissue.

It is a site for the production of blood cells and it is found in the medullary cavity of long bones/spongy bones.

Front 20

Life cycle of bone marrow

Back 20

Child: there is a lot of red bone marrow present

Adult: as the person ages, the red bone marrow accumulates fat and becomes yellow marrow. But places such as the hipbone, ends of humerus, pelvis, femur, ribs, bodies of vertebra still maintain some red bone marrow. In times of too much blood loss or anemia, yellow marrow will be converted to red bone marrow for the use of the body.

Old age: during old age, the yellow marrow is again converted into a gelatinous consistency.

Front 21

Bone marrow transplant

Back 21

This could be a life saving surgery if it is not rejected by the body. This is administered when there is damaged to the bone marrow.

Front 22

5 functions of the bone

Back 22

1) support (it serves as a framework for the body, contributes to its shape/alignment/positioning of body parts)

2) protection (it protects delicate organs such as heart and brain)

3) movement (there is a lot of lever action due to the joints and bones. when muscles contract it in turn pulls on the bone)

4) mineral storage (it is a major reservoir for CA, P, and other minerals. also helps to maintain thermostatic blood calcium levels).

5) hematopoiesis:(the red blood cell formation that is carried out by red marrow is located in the bones. in adults this is mostly in the epiphysis of long bones, flat bones in the skull, ribs, sternum)

Front 23

Regulation of Blood Calcium Levels

Back 23

the bone has 98% of the body's calcium reserves.

Osteoblasts take out calcium from the blood to build up bone, but osteoclasts break down bone to release calcium back into the blood.

Balance of blood calcium levels is very essential for: normal blood clotting, transmission of nerve impulses, maintenance of skeletal and cardiac muscle contractions

Two hormones essential for normal blood calcium levels: parathyroid and calcitonin

Front 24

Parathyroid and Calcitonin

Back 24

Parathyroid: very important in maintaining the level of calcium hemostatis. When low caclium levels are detected, it stimulates the osteoclasts to break down the bone and help bring the blood calcium levels back to normal. Low blood calcium deduction by this hormone also stimulates better absorption of calcium from urine, and stimulates synthesis of vitamin D so calcium can be better absorbed from the intestines. [This gets released when Blood Calcium level is LOW] released by Parathyroid Gland

Calcitonin: stimulates osteoblasts to deposit calcium into bone. [This gets released when Blood Calcium level is HIGH] released by Thyroid Gland

Front 25

development of bone

Back 25

Infant before birth has not bones, but cartilage and fibrous structures.

Real bones are formed when the cartilage is replaced by calcified bone matrix, calcification process.

this continuous bone-forming and bone-resorbing action allows the bones to change as different stress or injury occurs.

Front 26

Osteogenesis

Back 26

The procress of bone forming (osteoblasts) and bone-resorbing (osteclasts) help sculpt bones into adult form.

Front 27

Two types of ossicification

Back 27

Endochondral and Intramembranous

Front 28

Endochondral Ossification

Back 28

They are formed from cartilage molds, and long bones in the body are formed this way.

1) Periosteum develops and forms a ring and wraps itself around the middle of the bone (diaphysis area).

2) osteogenic cells from the periosteum differientate into osteoblasts and start forming bone to the cartilage.

3) this contributes to a bone collar, which is a thin layer of bone around the layer of periosteum. This starts the cartilage to calcify.

4) A blood vessel enters in the middle of the diaphysis during this time of rapidly calicifying cartilage. This appear of the blood vessel starts the "Primary Ossification center"

5) The periosteum ring collar started at the diaphysis start to move extend towards the epiphysis."Interstitial Growth" occurs, which is the process that makes the bone grow in length

6) Blood vessels appear in the middle of the epiphysis which starts the Secondary Ossification Center. This bone growth starts at the epiphysis and goes towards the diaphysis;

Front 29

Epiphyseal Plates

Back 29

Until the bone growth is complete, 25, there is a layer of cartilage called epiphyseal plates that remain between the epiphysis and diaphysis.

During periods of growth, this plate contributes to it. There are 4 layers of cells that make up epiphyseal plates

Front 30

Four layers of the epiphyseal plates

Back 30

First Layer: ones closest to the epiphysis are "resting: cartilage cells.this layers serves as a point of attachment, it joins the epiphysis firmly to the bone.

Second layer: poliferating zone. because of this section, the plate thickens and the bone elongates

Third layer: zone of hypertrophy. this layer is composed of older, elargered cells that are degenerating because of the calcium that are being deposisted in them

Fourth Layer: This is the layer closest to the diaphysis.This is a layer that consists of dead/dying cells that are rapidly calcifying, and as this layer and contributes to the growth of the bone.

When growth is over, these are completely calcified.

Front 31

Intramembranous Ossification

Back 31

This takes place within a connective tissue membrane. Osteogenic stem cells differeniate into groups of osteoblasts which help give rise to flat bones.

These groups of osteoblasts are called" Centers of ossification".

Front 32

centers of ossification

Back 32

Groups of osteoblasts

The golgi in the osteoblasts give rise to mucopolysaccharides and the ER gives rise to collagen.

These two material get mixed up with ground substance, and accumulate around each osteblast.

Front 33

Appositional Growth

Back 33

Osteclasts help enlarge the medullary cavity by eating away the bones surrounding the medullary cavity. The osteoblasts in the periosteum build new bone from outside of the bone.
This helps the bone increase in diameter.

Front 34

Formation of Osteon

Back 34

They are formed when osteoclasts in the periosteum are activated and they eat away from the outside till a blood vessel is reached. Then a layer of cells surround it, and the new osteon is created.

Front 35

Fracture

Back 35

Break in the continuity of bone.

Front 36

Fracture Repair

Back 36

They are activated by bone death/damage to the periosteum and the Haversian system blood vessels that carry nutrients to osteocytes.

1) There is a pooling of blood, like a blood clot at the point of injury called "hematoma".

2) This hematoma then develops fibrin mesh, specialized inflammatory cells, fibroblasts, bone/cartilage forming cells, and new capillaries. Hematoma also becomes into a soft mass of granulation tissue

3) Procallus forms, a type of cartilagious tissue that helps archor the end of the fractured bone together.

3) Increase in osteoblast cells increase bone forming, and the formation of bony callus helps to bind and the fracture even more and helps to further continue bone repair.

4) if no complications arise, the callus bone should be replaced by compact bone.

Front 37

3 types of cartilage

Back 37

a) hylaine cartilage

b) elastic cartilage

c) fibrocartilage

Front 38

Differences between bone and cartilage

Back 38

-- cartilage is avascular while the bone is completely vasculated.

-- in cartilage, fibers are embedded in firm gel, while bone is in calcified cement substance.

Front 39

Chondrocytes

Back 39

These are cartilage cells.

Cartilage cells, like bone cells lie in the lacunae. And since there is no vasculature in these parts, nutrients are reached to these cells through diffusion from capillaries.

These capillaries are from the fibrous membrane covering the cartilage "perichondrium".

Front 40

Perichondrium

Back 40

Fibrous covering of the cartilage.

Front 41

Hyaline cartilage

Back 41

Most abundant. This was thought to be the precursor for the other two types of cartilages (fibroblast/elastic).

It is made from mesenchymal stem cells that get crowded together (centers of chrondrification) in the embryo.

Like the bone, it's a mixture of ground substance and collagenous fibers.

Covers the articular surface of bones, coastal ribcage, cartilage rings around trachea, bronchi of lings, and tip of nose. And it is secreted from chondrocytes.

Front 42

Fibroblast cartilage

Back 42

Most tensile strength. highest number of collagenous fibers. Small number of matrix.

Associated with dense connective tissue like symphysis pubis, intervertebral disks, near the point of attachment of some large tendons to bone.

Front 43

Elastic cartilage

Back 43

elasticity and firmness. Rise to external ear, epiglottis that covers the opening of respiratory tract when swallowing, and eustachian (auditory tubes that connect middle and nasal cavity).

More opacity than hylaine, less collagenous fibers than hylaine.

Front 44

Overview of the functions of cartilage

Back 44

a) sustains great weight

b) shock absorbing

c) strong/pliable flexibility

d) permits growth in length

Front 45

Growth of cartilage

Back 45

Just like bones it has "interstitial growth" and "appositional growth"

Interstitial: chondrocytes begin to divide internally and is seen in early adolesense, and contributes to growth.

Appositional: chondrocytes deep in the perichondrium begin to divide and secrete additional matrix. This matrix is deposited on the surface of the cartilage and helps to grow in size.

Front 46

Compact Bone

Back 46

Constitutes 80% of the total bone mass.

Lamellae, Lacunae, Canaliculi, Harversian canal.

Lamellae: cylinder-shaped layers of calcified matrix. Remnants of older osteons.

Lacunae: small spaces that contain bone cells imprisoned in them, between the hard layers of lamellae.

Canaliculi: Ultrasmall canals that radiates in all directions and connects all the lacunae.

Haversian canal: it extends lengthwise through center of the Haversian system and contains blood vessels, lymphatic vessels, and nerves.

Front 47

Frontal Bone

Back 47

Forms the forehead and the anterior part of the cranium

It also contains frontal sinuses (mucus-lined, air-filled spaces)

Front 48

Paranasal Sinuses

Back 48

Front sinuses, also in spheniod, ethmoid, maxillae have narrow channels that open into the nasal cavity.

Front 49

Condyle

Back 49

It is a rounded process that usually articulates with another bone.

Example: Occipital condyle of the occipital bone that articulates with Atlas in the back of the head

Front 50

Epicondyle

Back 50

It is a projection situated above a condyle

Example: Medial epicondyle and later epicondyle of the humerus. It is located on either sides of the bone where the joint articulates with the radius and ulna (distal ends).

Front 51

Fontanel

Back 51

It is a soft spot in the skull where membranes cover the space between bones in the fetal and newborn infant.

As the baby develops, the plates fuse and form the suture lines. There are 6 such areas located at angles of the parietal bones.

Allows for the rapid brain growth, and compression during birthing process.

Front 52

Foramen

Back 52

An opening through a bone that usually servers as a passageway for blood vessels, nerves, or ligaments.

Example: Foramen magnum of the occipital bone located in the backside of the head, for the spine to pass through.

Front 53

Head

Back 53

An enlargement on the end of the bone. It's a disk shaped process forming the proximal end of the radius. It articulates with the capitulum of the humerus and with the radial notch of the ulna

Example: it is found on the head of the radius and humerus.

Front 54

Linea

Back 54

A narrow ridge.

Ridge of roughened surface on the posterior aspect of the femur, to which are attached muscles and intermuscular septum.

Example: Linea aspera of the femur

Front 55

Meatus

Back 55

A tubelike passageway within a bone.

Example: external auditory meatus of the ear.

Front 56

Process

Back 56

A prominent projection on a bone.

Example: Mastoid process of the temporal bone, posterior to ear

Front 57

Sinus

Back 57

A cavity within a bone

Example: Frontal sinus of the frontal bone

Front 58

Spine

Back 58

A thornlike projection

Example: Spine of the scapula. It's the sharp ridge running diagonally across the posterior surface of the shoulder blade.

Front 59

Sutures

Back 59

An interlocking line of union between bones. they are immovable joints between skull bones, and is the mature version of fontanel

Example: Lamddoidal suture between the occipital and parietal bones

Front 60

Trochanter

Back 60

A relatively large process.

Example: Greater trochanter of the femur. It is located inferior and laterally (away from the midline of body) to the head. There is also a lesser trochanter of the femur which is located inferior and medial to the greater trochanter.

Front 61

Tuberosity

Back 61

A knoblike process usually larger than a tubercle.

Example: the radial tubertosity that is located inferior to the radius head and rest near the ulna.

It's a roughened projection on the ulnar side, a short distance below the head and biceps muscle inserts here.

Front 62

Temporal Bone

Back 62

This bone houses the middle and inner ear structures.

Has mastoid sinuses.

Front 63

Occipital Bone

Back 63

it has immovable joints with parietal, temporal and sphenoid. And one movable joint with first cervical vertebra.

Front 64

Sphenoid Bone

Back 64

Keystone in the architecture of the cranium and anchors the frontal, parietal, occipital, and ethmoid.

Contains air filled spaces, sphenoid sinuses.

Front 65

Carotid Canal

Back 65

It is the main blood supply to the brain.

Moving from the top to the bottom (formen magnus), it is the first up, superior to jugular foramen.

There are 2 carotid canals on either sides of the head.

Front 66

Jugular Foramen

Back 66

It is the main exit of blood from the brain.

There are 2 jugular formen on either sides of the head.

Front 67

Cranial Bones

Back 67

8 bones:
-- Frontal (1)
-- Parietal (2)
-- Occipital (1)
-- Temporal (2)
-- Sphenoid (1)
-- Ethmoid (1)

Front 68

Frontal

Back 68

There is one frontal bone and forms the forehead, roof of nasal cavity, and roofs of orbits.

Its special features are: Supraorbital foramen, and frontal sinuses.

Front 69

Parietal

Back 69

There are 2 of these bones.

They form the side walls and roof of cranium.

Its special features are that it is fused at midline along the sagittal suture.

Front 70

Occipital

Back 70

There is one occipital bone and it forms the back of the skull and base of cranium.

Its special features are that it has the foramen magnum, occipital condyles.

Front 71

Temporal

Back 71

There are 2 temporal bones and they form side walls and floor of cranium

Its special features is that it has external auditory meatus, mandibular fossa, mastoid process, styloid proess, zygomatic process.

Front 72

Sphenoid

Back 72

It is 1 bone and forms parts of base and cranium, sides of skull, and floors and sides of orbits.

Its special features are sella turcica, sphenoidal sinuses.

Front 73

Ethmoid

Back 73

It is made of one bone and it forms parts of roof and walls of nasal cavity, floor of cranium, and walls of orbits.

its special features are cribriform plates, perpendicular plate, superior and middle nasal conche, ehtmoidal sinuses, crista galli

Front 74

Benefits of facial sinuses

Back 74

They make the head less heavy, and even though they are more susistable to injury, the "crush zone" absorbs some of the impact and thus reduces the direct impact on the brain.

Front 75

Joints

Back 75

There are three types

-- Fibrous (articulating bones are fastened together by thin layer of dense connective tissue containing many collagenous fibers)

-- Cartilaginous (articulating bones connected by hyaline cartilage or fibrocartilage)

-- Synovial (articulating bone surrounded by a joint capsule of ligaments and synovial membrane. The ends of articulating bones are covered by hyaline cartilage and separated by synovial fluid.