Skeletal System

Describe the anatomy & function of intervertebral disks.

Anatomy: made up of fiber cartilage & lots of areolar soft tissue Functions: Shock absorbance & movements

Compare the process of bone elongation with appositional growth. How does exercise affect each process?

Bone elongation requires the epiphyseal (growth) plates Appositional Growth increases bone density & requires the osteoblasts from the periosteum Exercise that builds stronger muscles results in stronger bones (appositional growth)

Identify the bones of the pelvic girdle.

Sacrum Coccyx Ilium (hip bone) Ischium (hip bone) Pubis

Describe Intramembranous Ossification

very thin membrane; bone growth in a membrane Mesenchymal CT is converted into bone tissue -->> Mesenchymal CT -->> Dense Irregular CT -->> Bone Tissue) Produces flat bones of the skull Makes up the soft spots of the baby's skull

Where are herniated disks most likely to occur? Why?

>> 95% occur at L4/L5 and L5/S1 >> bone degeneration

Discuss the modifiable & nonmodifiable risk factors of Osteopororis

>> Modifiable Risk Factors: Smoking & alcohol, High protein diets, sedentary lifestyles, excessive exercise, some drugs (e.g. cortisol), anorexia or bulimia >> Non-Modifiable Risk Factors: Being female (early menopause, being post-menopausal), Thin and/or small framed, Advanced age, Family history, Caucasian/Asian descent

Why is the pain associated with a herniated disk often in an arm or leg?

>> When pressure is placed on a nerve that contains axons that serves pain receptors in the arm/leg >> When impulses are sent to the brain it interprets the pain as coming from the pain receptors.

What evidence exists that the anatomical change in the skeletal system that occurs with age affects skeletal system function?

Incidence of bone fracture per 100k shows age 60 will encounter fractures at a rate of 100/100k & dramatically increases with age

What are the 2 methods of Ossification & their commonality?

Intramembranous & Endochondral Both begin with an embryonic soft tissue called mesenchyme.

What is Ossification?

bone formation

How may the incidence of osteoporosis within a population be reduced?

calcium rich diet, weight training, avoidance of risk factors

How are bones classified on the basis of structure.

classified by their shape

What bones make up the upper extremity?

clavicle, scapula, humerus, radius, ulna, wrist, carpals

Medullary (Marrow) Cavity

contains the bone marrow (red &/or yellow)

What are herniated disks? (slipped or ruptured)

cracking of the annulus fibrosus allows the nucleus pulposus to ooze out sometimes putting pressure on a spinal nerve root/spinal cord

Compact (Osseous) Bone Tissue

dense white osseous tissue that makes up the outer shell of the bone; 75% of bone

Epiphysis

expanded at each end of diaphysis

What are Wormian bones?

extra bone pieces that occur within a suture in the cranium

Curves of vertebral column & arches of the foot maintained by _________.

ligaments & tendons

Spongy Bone Tissue

located at the ends of the diaphysis before the epiphysis & the epiphyseal line

Articular (Hyaline) Cartilage

made up of Hyaline cartilage that covers the ends of bones where they come together to form joints & enables ease of joint movements

Diaphysis

shaft of long bone

Describe the 2 Components of intervertebral disks.

1) Annulus Fibrosus (fibrocartilage) outer-ring of disc 2) Nucleus Pulposus (areolar ct; gelatinous)

Name four structures, each at the organ level of organization, that are the major components of the skeletal system. Briefly describe the basic functions of each structure.

1) Bones: provide support to the body and muscles 2) Ligaments: hold bones together 3) Cartilages: covers many joint surfaces in the mature skeleton 4) Joints (Articulations): joins bones, teeth, and cartilage of the body to one another.

What is the structure of "long bones"?

1) Diaphysis 2) Epiphysis 3) Articular (Hyaline) Cartilage 4) Periosteum 5) Medullary (Marrow) Cavity 6) Spongy Bone Tissue 7) Compact (Osseous) Bone Tissue

What are factors that regulate bone growth?

1) GROWTH hormone 2) THYROID hormone --> Activates Growth hormone 3) SEX hormones >> Estrogens & Testosterone (Androgens): --- stimulates (osteoblasts) elongation & appositional growth >> Starts and Stops bone growth --- Starts growth during early onset of puberty --- Stops growth later in puberty 4) Vitamin A: crucial for cell metabolism 5) Vitamin C: enzyme co-factor that promotes collagen synthesis 6) Vitamin D: needed for calcium absorption by the small intestine & reduces urinary loss

What are the bone classifications & examples?

1) Long Bones: humerus, femur, tibia, ulna (important to body movement) 2) Short Bones: wrist & ankle bones (both has a total of 30 short bones) 3) Irregular Bones: vertebrae, sphenoid & ethmoid bones 4) Flat Bones: parietal, frontal, occipital bones (most of the cranial bones) 5) Sesamoid Bones: patella & sesamoid bones of foot, & pisiform of wrist 6) Wormian Bones: sutural bones; sutures of skull

Describe the arches of the foot; how are they maintained?

1) Longitudinal (Lateral & Medial) - 2) Transverse (at the level of the cuboid) o maintained by the ligaments, muscles/tendons, & plantar fascia

Describe the basic change that occurs in the skeletal system with age. Compare the change seen in men and women.

1) Loss of calcium, collagen, bone density & strength 2) Women's boss loss is greater compared to men, much more so after menopause

What are the major functions of the skeletal system?

1) Support & Protection 2) Movement 3) Mineral Storage: main calcium & phosphate; releases minerals when levels drop 4) Blood Cell Production: Red Bone Marrow is the major producer of blood cells & most cells of the immune system

Of what advantage to a baby (and mother) is this type of ossification?

1. Allows COMPRESSION of the skull which makes child birth easier for both baby & mother 2. Allows for EXPANSION of the skull to allow brain growth

What function do the arches of the foot serve?

Acts as shock absorbers

Describe the four curvatures of the spinal column & their development and functions.

Cervical, Thoracic, Lumbar, & Sacral o Newborn: Thoracic & Sacral o 6 months: Cervical (raising the head), Thoracic, & Sacral (crawling) o 1 year: all 4 curves - Lumbar (standing/walking)

Identify the bones of the pectoral girdle.

Clavicle & Scapula

Name the paranasal sinuses & their functioins.

Frontal, Maxillary, Ethmoid Air Cells, & Sphenoid - Decreasing the weight of the front of the skull - Increasing resonance of the voice. - Acts as shock absorbers by providing a buffer against facial trauma

What are the classic symptoms of Osteopororis?

Hip, Wrist, & Vertebral fractures

What is the process of Endochondral Ossification.

Hyaline cartilage converted into bone

What plays an important role in establishing the foot arches?

Ligaments

What are the major structural differences between male and female skeletons?

Males bones are typically heavier and their pelvic cavity is narrower

What bones make up the lower extremity?

Pelvic girdle, Femur, Tibia, Fibula, Tarsals

Define osteoporosis

a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture for your age

What are Sesamoid bones?

a small independent bone or bony nodule developed in a tendon

Periosteum

a tough & dense sheet of vascular connective tissue covering most of the bone except at the surfaces of the joints

Identify the bones of the thorax

sternum, ribs & costal cartilages, thoracic vertebrae & intervertebral discs