Luke Anatomy Lecture Exam 2

Skeletal System Functions

Support, Protect, Movement, Electrolyte Balance, Acid-Base Balance, Blood Formation

4 Principle Types of Bone Cells

Osteogenic Cells, Osteoblasts, Osteocytes, Osteoclasts

Osteogenic Cells

Stem cells, form and regenerate bone tissue

Osteoblasts

Build bone

Osteocytes

Maintain bone health and structure

Osteoclasts

Dissolves bone (bone remodeling) - maintains calcium balance in body

The Bone Matrix is made up of

Osseous tissue, 1/3 organic and 2/3 inorganic

Calcium salts make bones rigid and collagen gives bones some degree of flexibility

Rickets

Soft bones due to deficiency of calcium salts

Osteogenesis Imperfecta

Brittle bone disease; lack of protein and collagen

Spongy Bone Provides:

Strength with minimal weight

Bone Marrow

Soft tissue that occupies the marrow cavity; red and yellow bone marrow

Red Marrow

Hemopoietic tissue - within spongy bone

Yellow Marrow

In adults; replaces much red marrow

Types of Forces on a Bone

Compression, Tension, Shear, Torsion, Bending

Compression

⇅

Tension

↕

Shear

→←

Torsion

Twisting

Bending

↕⇅

Ossification or Osteogenesis

Bone formation

2 Methods of Bone Development

Intramembranous ossification

Endochondral ossification

Intramembranous ossification

Bone develops from a fibrous membrane

Endochondral ossification

Process in which bone develops from pre-existing cartilage

Primary Ossification Center

Diaphysis; starts to develop blood supply

Secondary Ossification Center

Epiphysis

Ossification Continues...

Throughout your entire life (bone remodeling)

Interstitial Growth

Bones increase in length; stops when growth plate closes

Appositional Growth

Bones increase in thickness; exercising

Bone Remodeling does...

Repairs microfractures, releases minerals into blood

Wolff's Law of Bone

Architecture of bone determined by mechanical stresses placed on it and bones adapt to withstand those stresses

(Exercise thickens bones)

Mineral Resorption

The process of dissolving bone and releasing minerals into the blood (performed by osteoclasts)

Calcium Homeostasis

Regulation of calcium levels in the body.

Hypocalcemia

Blood calcium deficiency

Causes muscle tremors, spasms

Hypercalcemia

Blood calcium excess

Causes sluggish reflexes, depression

Calcitrial

Synthesized from Vitamin D

Required for calcium absorption

Calcitonin

Secreted by thyroid gland when calcium concentration rises too high

Inhibits osteoclasts

Lowers blood calcium concentration

Reduces bone loss in women during pregnancy and lactation

Parathyroid Hormone (PTH)

Raises blood calcium levels

Secreted by parathyroid glands

Stress Fracture

Break caused by abnormal trauma to the bone

Pathological Fracture

Break in a bone that is weakened by some other disease

Ex. Break a bone when you have osteoporosis

Types of Bone Fractures

Closed/Simple

Open/Compound

Greenstick

Comminuted

Impacted

Closed/Simple

Break, but bones stay together

Open/Compound

Break where bones come apart

Usually go through skin, but don't have to

Greenstick

Cracks along one side, but doesn't break all the way through the bone

Happens to infants and children with softer bones

Comminuted

Breaks into 3 or more pieces

Impacted

Break, but stay together, caused by ⇅

Steps to Healing of Fractures

1. Bleeds, blood clots and creates hematoma

2. Soft callus formation - collagen and hyaline cartilage

3. Hard callus formation - deposits a temporary bony collar; mineralizes

4. Bone remodeling - converts to compact bone

Axial Skeleton

Skull, Vertebrae, Ribcage

Appendicular Skeleton

Pectoral and pelvic gIrdle, arms, and legs

Types of Bones

Long bone, short bone, flat bone, irregular bone, sesamoid bone

How Many Bones in the Skull?

22

8 Cranial

14 Facial

Auditory Ossicles

Malleus, Incus, Stapes

Fontanels

Soft spots of connective tissue within the skull during infancy when skull is growing

When Does Skull Reach Adult Size?

8 or 9 years old

Vertebral Column Functions

Support skull and trunk

Protect spinal cord

Allow movement

Provide attachment points

How many vertebrae? In each section?

33

7 Cervical

12 Thoracic

5 Lumbar

5 Fused Sacral

3-5 Fused Coccyx

Spinal curvatures

Cervical - C

Thoracic - Ↄ

Lumbar - C

Pelvic - Ↄ

Intervertebral Discs Are Made Up of...

Fibrocartilage

Ring of the Intervertebral Disc is Called...

Annulus Fibrosus

Inside of Intervertebral Disc is Called...

Nucleus Pulposus

How Many True, False, Floating Ribs?

1-7 True

8-12 False

11,12 Floating

Pectoral Girdle is Made Up Of...

Clavicle and Scapula

Brachium

Upper arm - humerus

Antebrachium

Forearm - radius and ulna

Carpus

Wrist - Carpals, 8 small bones arranged in 2 rows

Manus

19 bones in 2 groups, 5 metacarpals and 14 phalanges

Male Pelvis Has What Shape and Female Pelvis Has What Shape?

Male: V

Female: U

Femoral Region

Thigh - femur and patella

Crural Region

Lower leg - tibia and fibula

Tarsal Region

Ankle

Pedal Region

Foot - 7 tarsal bones, 5 metatarsals, 14 phalanges

Patella is What Type of Bone?

Sesmoid

2 Foot Arches

Longitudinal Arch - the normal foot arch you think about

Transverse Arch - sideways/horizontal

Joint Types

Fibrous, Cartilaginous, Synovial

Fibrous Joints

Non-moveable

Bound by collagen fibers

Ex. Sutures in skull

Cartilagenous Joints

2 bones linked together by fibrocartilage

Have limited movement

Ex. Pubic symphysis, intervertebral discs

Synovial Joint

Freely moveable

2 bones separated by a joint cavity and surrounded by a synovial fluid filled sac

Ex. Glenohumeral Joint

Articular Cartilage

A layer of hyaline cartilage that covers the surfaces of 2 bones that face each other on the joint

Joint (Articular) Cavity

Separates the articular surfaces

Synovial Fluid

Fluid that lubricates joints; in the joint cavity

Joint (Articular) Capsule

Connective tissue that encloses the cavity and retains the fluid

Tendons Connect...

Bone to muscle

Ligaments Connect

Bone to bone

Bursa

Fibrous sac filled with synovial fluid, located between adjacent muscles, where tendon passes over bone, or between bone and skin

Levers Enhance Either...

Distance or power

Mechanical Advantage of a Lever

The ratio of its resistance force to its effort force

First Class Lever

The fulcrum is between the effort and resistance

Second Class Lever

The load is between the fulcrum and the effort

(Amplifies Power), ex. standing on your toes, calf muscle lifting body weight up

Third Class Lever

The effort is between the fulcrum and load

(Amplifies Distance), ex. bicep contracting and lifting a dumbell (load) in you hand

Forces Equation

E(Ea) = R(Ra)

Range of Motion is Determined By:

Structure of articular surfaces

Strength and tautness of ligaments and joint capsules

Muscle tone

Monaxial Joint

Only moves on one axis

Ex. Knee

Biaxial Joint

Has 2 axis of movement

Ex. Wrist

Multiaxial Joint

Has 3 or more axis of movement

Ex. Shoulder

Ball and Socket Joints are...

Multiaxial joints. Ex. Femur and acetabulum

Plane (Gliding) Joints

Flat articular surfaces in which bones slide over each other

Usually biaxial joints

Ex. Carpal bones of wrist, tarsal bones of ankle

Hinge Joints

One bone with convex surface fits into a concave depression of another bone

Monoaxial joints

Ex. Knee, elbow (humeroulnar)

Pivot Joints

One bone has a projection that is held in place by a ring-like ligament; bone spins on longitudinal axis

Monaxial Joints

Ex. Radioulnar Joint

Meniscus Are Made Up Of...

Fibrocartilage

Grade 1 Sprain

Ligament stays intact

Grade 2 Sprain

Ligament partially tears