The Skeletal System Flashcards
A ___ is an organ made up of several different tissues working together: osseous, cartilage, dense CT epithelium, adipose tissue and nervous tissue. The entire framework of bones and their cartilages constitute the ___ system.
Bone; skeletal
List the 6 functions of bone tissue
Support, protection, assist in movement, mineral homeostasis, blood cell production, triglyceride storage.
How does bone tissue support the body?
Bones support the soft tissues and provide attachment sites for muscles, thereby serving as the structural framework for the body.
Describe how bone tissue protects the body.
Many of the body’s internal organs are protected by bony coverings.
Describe how the bone tissue assists in movement.
Bones assist skeletal muscles in producing movement.
Describe how bone tissue contributes to mineral homeostasis.
Bones store and release several minerals, especially calcium and phosphorus, to help maintain mineral homeostasis.
Describe how bone tissue contributes to blood cell production.
Hemopoesis, blood cell formation, occurs in the red marrow of bones
Describe how bone tissue contributes to triglyceride storage.
The yellow marrow of adult boned serves as a site of triglyceride storage.
Long bones
Consist of a shaft with 2 ends. Ex: the femur and humerus
Short bones
Are cube-like. Ex: carpals and tarsals
Flat bones
Are thin and usually curved. Ex: skull bones and ribs
Irregular bones
Are not long, short or flat. Ex: vertebrae
A typical long bone consists of the following 7 parts:
Diaphysis, epiphysis, metaphysis, articular cartilage (hyaline cart.), periosteum, medullary cavity (marrow cavity), and the endosteum.
The __ is the shaft of the long bone.
Diaphysis
The __ are the ends of the bone.
Epiphyses
The __ are the areas between the epiphysis and diaphysis and include the epiphyseal plate in growing bones.
Metaphyses
__ __ (__ __) at the ends of the bones reduces friction and absorbs shock at freely moveable joints.
Hyaline cartilage (articular cartilage)
The __ is a CT that covers the surface of the bone; it contains osteogenic cells, protects bone; it contains osteogenic cells, protects bone, assists in fracture repair, helps nourish bone tissue and serves as an attachment point for ligaments and tendons.
Periosteum
The space within the diaphysis is the __ __.
Marrow cavity (medullary cavity)
__ marrow is the site of blood production.
Red
__ marrow is the site of fat storage.
Yellow
The __ is the lining of the medullary cavity.
Endosteum
Bone (osseous) tissue consists of widely separated cells surrounded by large amounts of matrix. The 4 principal types of bone cells are the following:
Osteoprogenitor, osteoblasts, osteocytes, and osteoclasts.
Osteoprogenitor
Are precursor cells
Osteoblasts
Are bone building cells
Osteocytes
Are mature bone cells, the principal cells of bone tissue
Osteoclasts
Are derived from monocytes and serve to break down bone tissue
The __ of the bone contains inorganic salts, primarily hydroxyapatite and some calcium carbonate and collagen fibres.
Matrix
A __ bone is covered by __ __ at its proximal and distal epiphyses and by periosteum around the remainder of the bone
Long; articular cartilage
Which part of a bone reduces friction at joints?
The articular cartilage
Which part of a bone produces blood cells?
Red bone marrow
Which part of a bone lines the medullary cavity?
The endosteum
__ lie in lacunae arranged in concentric circles around a central canal in compact bone and in lacunae arranged irregularly in the trabeculae of __ bone
Osteocytes; spongy
The process of __ occurs only in the presence of __ fibres.
Calcification; collagen
As people age, some osteonic canals may become blocked. What effect would thus have on the osteocytes?
Because the central canals are the main blood supply to the osteocytes, their blockage would lead to death of osteocytes.
Compact bone is arranged in units called __ or __ __. Osteons contain blood vessels, lymphatic vessels, nerves and osteocytes, along with calcified matrix.
Osteons or Haversian systems
__ are aligned in the same direction along the lines of stress. The lines can change as the __ of the bone change.
Osteons; stresses
The process by which bone forms is called __
Ossification
__ __ involves the formation of bone within the mesenchyme arranged in sheet-like layers that resemble membranes.
Intramembranous ossification
During __ __ bone gradually replaces a cartilage model.
Endochondral ossification
Spongy (cancellous) bone does not contain __.
Osteons
Spongy bone consists of __ (columns or beams of bone), which surround many red-marrow-filled spaces.
Trabeculae
Which bones of the body develop by intramembranous ossification?
The flat bones of the skull, mandible, and part of the clavicle
Which structure signals that bone growth in length has stopped?
The epiphyseal lines
__ bone forms most of the structure of short, flat and irregular bones; and the epiphyses of long bones. __ bone is light and supports and protects the red bone marrow.
Spongy; spongy
Define the term ossification
Bone formation is termed osteogenesis or ossification; it begins when mesenchymal cells provide the template for subsequent ossification.
Intramembranous ossification
Is the formation of bone directly from or within the fibrous CT membranes.
Endochondral ossification
Is the formation of bone from hyaline cartilage models
Endochondral ossification involves the replacement of cartilage by bone and forms:
Most of the bones of the body
Discuss the 4 steps in intramembranous ossification
1 osteoblasts cluster at the centre of ossification. 2 osteoblasts secrete the matrix. 3 osteoblasts become osteocytes and lay down bone spicules called trabeculae to form spongy bone. 4 the outer surface is covered w/periosteum.
Discuss the several steps involved in endochondral ossification
Bone growth occurs in length and thick. Bone grows in length due to epiphyseal plate. When e.plate closes, replaced by bone which the e.line appears indicating growth completion. Bone can only grow in thickness by appositional growth.
Long bones grow in length and thickness. Growth in length occurs at the __ line. Growth in width occurs at the __.
Epiphyseal; perichondrium
Bone is a dynamic tissue constantly being broken down and replaced by a process called __.
Remodeling
What are some of the nutrients and hormones involved in bone growth?
Large concentrations of calcium and phosphorus. Vitamins C, K, B12 and A. Insulin Mike growth factors (hGh) in childhood and thyroid and insulin in adults. Estrogen and testosterone.
Release of __ from bone extracellular matrix and retention of __ by the kidneys are the 2 main ways that blood __ level can be increased.
Calcium
What body functions depend on proper levels of Ca2+ ?
Heartbeat, respiration, nerve cell functioning, enzyme functioning, and blood clotting
The adult human skeleton consists of __ bones grouped into axial and appendicular divisions.
206
Name the main bones in the axial skeleton (80)
Skull, hyoid bone, auditory ossicles, vertebral column, thorax
Name the main bones in the appendicular skeleton (126)
Pectoral (shoulder girdles), upper limbs, pelvic (hip girdle), lower limbs
The skull consists of 2 sets of bones:
8 cranial bones from the cranial cavity and 14 facial bones form the face.
What are the names of the 8 cranial bones?
Frontal, parietal, occipital, sphenoid, ethmoid, and temporal bones
What is the largest foramen in the skull?
The foramen magnum
The __ bone forms most of the posterior and inferior portion of the cranium.
Occipital
The __ bone is called the Keystone of the cranial floor because it articulates with all other cranial bones, holding them together.
Sphenoid
The __ bone is the major supporting structure of the nasal cavity.
Ethmoid
Suture
A suture is an immovable joint in most cases in an adult that holds skull bones together.
What are the 4 prominent skull sutures?
The coronal suture, the sagittal suture, the lambdoid suture, the squamous sutures.
__ __ are mucous membrane lined spaces in the frontal sphenoid, ethmoid, and maxillary bones that connect to the nasal cavity.
Paranasal sinuses
What are 2 main functions of the paranasal sinuses?
Produce mucous and serve as resonating chambers for vocalization.
The adult vertebral column typically consist of 26 vertebrae within 5 subcategories which are:
7 cervical vertebrae 12 thoracic vertebrae 5 lumbar vertebrae 1 sacrum 1 coccyx
What are the 3 main functions of the vertebrae.
Permits movement; encloses and protects the spinal cord, serves as a point of attachment for the ribs and muscles of the back.
The cervical vertebrae are found in the __ region.
Neck
A vertebra consists of a __, a vertebral __, and several __.
Body; arch; processes
Which bones permit the movement of the head to signify no?
The Atlas and axis
What are the functions of the vertebral and invertebral foramina?
The vertebral foramina enclose the spinal cord, and the intervertebral foramina provides spaces for spinal nerves to exit the vertebral column.
Lumbar vertebrae are found where?
In the lower back
Why are the lumbar vertebrae the largest and strongest in the vertebral column?
Support more weight than the thoracic and cervical vertebrae
The __ is formed by the union of 5 sacral vertebrae, and the coccyx is formed by the union of usually 4 coccygeal vertebrae.
Sacrum
What is the function of the sacral foramina?
They are passageways for nerves and blood vessels.
The term __ refers to the entire chest. The skeletal portion of the thorax, the __ cage, is a bony cage formed by the sternum, costal cartilages, ribs and the bodies of the thoracic vertebrae.
Thorax; thoracic
The bones if the __ enclose and protect organs in the thoracic cavity and upper abdominal cavity.
Thorax
The __ girdles attach to the bones if the upper limbs to the axial skeleton
Pectoral
The __ girdle attached the bones if the upper limb to the axial skeleton.
Pectoral
Which bones make up a pectoral girdle?
A clavicle and a scapula
The __ is the longest and largest bone if the upper limb.
Humerus
The __ is in the medial aspect (little finger side) of the forearm and is longer than the radius.
Ulna
With which part of the scapula does the humerus articulate?
The glenoid cavity of the scapula articulates with the humerus.
In the forearm, the longer __ is on the medial side, and the radius is on the lateral side.
Ulna
What part of the ulna is called the elbow?
The olecranon
The __ is located on the lateral aspect (them side) of the forearm.
Radius
The __ is the proximal region of the hand and contains 8 small bones, the __, held together by ligaments.
Carpus; carpals
The skeleton of the hand consists of the __, __, and the __.
Carpals; metacarpals; and phalanges
MNEMONIC for carpal bones:
Stop Letting Those People Touch The Cadaver’s Hand
Scaphoid, lunate, triquetrum, pisiform (proximal row)
Trapezium, trapezoid, capitate, hamate (distal row)
*Lateral to medial
What part of which bones are commonly called the knuckles?
The heads of the metacarpals
The __ girdle consists of the 2 hip bones, also called the __ bones.
Pelvic; coxal
The __ bones are united in front at the pubic symphysis and in back at the sacrum.
Hip
What part of the pelvis surrounds the pelvic organs in the pelvic cavity?
The true pelvis surrounds the pelvic organs in the pelvic cavity.
The 2 __ bones form the __ girdle, which attaches the lower limbs to the axial skeleton and supports the vertebral column and viscera.
Hip; pelvic
Which bone fits into the socket formed by the acetabulum?
The femur fits into the acetabulum
The head of the __ articulates with the acetabulum of the hip bone to form the hip joint.
Femur
With which bones does the distal end of the femur articulate?
The tibia and the patella
The __ articulates with the femur and fibula proximally and with the fibula and talus distally, while the fibula articulated proximally with the __ below the knee joint and distally with the talus.
Tibia
MNEMONIC for location of tibia and fibula: the fibuLa is LAteral.
Tibia is the shin bine, the larger, medial, weight bearing bone if the leg
Which leg bone bears the weight of the body?
The tibia
The skeleton if the foot consists of the __, __ and __.
Tarsals, metatarsals and phalanges.
MNEMONIC for tarsals:
Tall Centres Never Take Shots From Corners
Talus, calcaneus, navicular, third cuneiform, second cuneiform, first cuneiform, cuboid.
Which tarsal bone articulates with the tibia and fibula?
The talus
__ help the foot support and distribute the weight of the body and provide leverage during walking.
Arches
What structural aspect of the arches allows them to absorb shocks?
The arches are not rigid, yielding when weight is applied and springing back when weight is lifted to allow them to absorb the shock of walking and running.
Factors that influence bone metabolism:
Minerals, vitamins, hormones, exercise and aging
What are the contributions of the skeletal system for all body?
Bones provide support and protection for internal organs, bones store and release calcium, which is needed for proper functioning of most body tissues.
Osteoporosis
A condition of porous bones. The basic problem is that bone resorption (breakdown) outpaces bone deposition (formation).
Older women suffer from osteoporosis more often than men for 2 reasons:
Women’s bones are less massive than mens bones and production of estrogens in women declines dramatically at menopause, while production of the main androgen, testosterone, in older men wanes gradually and only slightly.
