C. 7-9

Eighty-year-old Eva takes a bisphosphonate drug once a month to keep her bones strong. What condition does she most likely have?

Osteoporosis

What change occurs with aging?

Decrease supply of myoglobin

What enzyme degrades acetylcholine, keeping it from accumulating in the synapse?

Acetylcholinesterasea

What two bones form the hard palate?

Maxillary and palatine bones

Compact bones have _____ while spongy bones have _____

osteons; trabeculae

The soleus muscle forms part of the __________

Calf

Which of the following bones are found within the axial skeleton?

The skull, hyoid bone, thoracic cage, and vertebral column

Which ligament is not associated with the glenohumeral joint?

Humeral collateral ligament

Muscle fibers generally have only one motor end plate, but a single motor neuron can innervate many different muscle fibers in a group. How does this arrangement affect muscle contraction?

A signal from one motor neuron can potentially stimulate multiple fibers in a group to contract, generating more force.

Joints can be classified as synarthrotic, amphiarthrotic, or diarthrotic. What characteristic was used to classify the joints?

Degree of movement possible at the joint

Which of the following is not a step in endochondral bone formation?

Hyaline cartilage changes to adipose tissue.

Which of the following correctly pairs a term with its definition?

Abduction—lifting the arm out to the side of the body so that it is parallel to the ground

Which of the following describes the clavicles?

Provide attachments for muscles of the back, chest, and upper limbs

The term __________ refers to an increase in the number of motor units activated as a result of more intense stimulation

Recruitment

What bony feature cradles the pituitary gland?

Sella turcica

What neurotransmitter(s) can stimulate smooth muscle cells?

Both norepinephrine and acetylcholine

The talus, calcaneus, navicular, cuboid, and lateral, intermediate, and cuneiform bones are all part of the _________

Foot

When you walk up the stairs, your hip and knee joints __________ to lift your body weight

Extend

What movements are permitted by the elbow joint located between the humerus and the ulna?

Flexion and extension

What is the relationship between ATP and creatine phosphate?

Creatine phosphate supplies energy to produce ATP from ADP and phosphate.

Suppose the pubic symphysis did not exist in the pelvic girdle and the two pubic bones were fused in the middle. Which of the following best describes the way the region would be affected if this joint was removed?

Childbirth would have a high mortality risk because the pelvic girdle would be rigid and unmoving.

What three bones fuse to form the hip bone?

The ilium, the ischium, and the pubis.

What would be the effect on bone growth of insufficient dietary calcium?

The bone matrix would be softer.

The processes of which two bones form the zygomatic arch?

Zygomatic and temporal bones

Which of the following describes the female pelvis compared to that of the male?

The distance between the female ischial spines is greater.

Osteoblasts deposit compact bone under the periosteum. Osteoclasts remove bone from inside. Bone becomes thicker without closing medullary cavity

Bone growth in thickness

The bones of the skeletal system composed of many tissues

bone tissue, cartilage, dense connective tissue, blood, and nervous tissue

Support and protect softer tissues. Movement. Blood cell formation. Mineral storage

Bones are alive and multifunctional

Bone markings

Serves as articulating surfaces

Inorganic Salt Storage → About 70% of bone matrix consists of inorganic mineral salts. Most abundant salt is

Crystals of hydroxyapatite (calcium phosphate)

Since calcium is vital in nerve impulse conduction and muscle contraction, blood calcium level is regulated by

Parathyroid hormone and Calcitonin

Osteogenesis imperfecta

Hereditary collagen defect, in which forming bones are brittle, and fetus may have many bone fractures

Begin as masses of hyaline cartilage. Most bones of the skeleton, such as femur, humerus, radius, tibia, phalanges, vertebrae.

Endochondral Bones

1-Zone of resting cartilage

Layer closest to end of epiphysis. Resting cells; anchor epiphyseal plate to epiphysis

2-Zone of proliferating cartilage

Rows of young cells, undergoing MITOSIS

3-Zone of hypertrophic cartilage

Older cells are left behind when new cells appear; the epiphyseal plate THICKENS, lengthening the bone. Matrix calcifies, cartilage cells (chondrocytes) die

4-Zone of calcified cartilage

Thin layer of dead cartilage cells and calcified matrix

Hematopoiesis - blood cell formation

Occurs in red bone marrow. Red blood cells, white blood cells, and platelets are produced in red bone marrow.

Bone marrow transplants are used to treat a variety of conditions. What happens to red bone marrow with age?

Some red bone marrow is replaced by yellow bone marrow, which stores fat but does not produce blood cells. In adults, red marrow remains in the skull, ribs, sternum, clavicles, vertebrae, and hip bones.

(14 weeks) Intramembranous ossification (FLAT bones of the skulls)

Clavicles, sternum, and facial bones (mandible, zygomatic, maxilla) by replacing embryonic connective tissue, not cartilage. FLAT primitive tissues.

Mesenchymal cells differentiate into osteoblasts → osteoblasts deposit bone matrix → osteoblasts surrounded by matrix become osteocytes in lacunae → outer mesenchyme forms the periosteum

Steps of intramembranous ossification

Endochondral ossification

Forms long bones and most of the skeleton by replacing a hyaline cartilage model with bone. Begins as a hyaline cartilage model.

The primary ossification center forms first in the diaphysis, where bone first replaces cartilage. Secondary ossification centers form later in the epiphyses and produce spongy bone

Primary vs. secondary ossification centers

Epiphyseal plate

A band of cartilage between the primary and secondary ossification centers where long bones grow in length.

Bone remodeling (homeostasis)

Bone is continually remodeled throughout life by osteoblasts and osteoclasts.

Bone Resorption

Removal of bone by osteoclasts.Deposition and resorption occur on the periosteum and endosteum.

Bone Deposition

Formation of bone by osteoblasts. 10% to 20% of skeleton is replaced each year

Nutrition, sunlight exposure, hormone levels, and physical exercise all affect bone development, growth, and repair

Factors Affecting Bone Development

Vitamin D

calcium absorption; deficiency causes rickets, osteomalacia

Vitamin A

osteoblast and osteoclast activity; deficiency stops bone development

Vitamin C

collagen synthesis; deficiency results in slender, fragile bones

GH stimulates cartilage cell division. Growth hormone Insufficiency-

In a child can result in pituitary dwarfism

Growth hormone Excess

causes gigantism in child, acromegaly in adult

Thyroid Hormone

Causes replacement of cartilage with bone in epiphyseal plate, osteoblast activity

Parathyroid Hormone (PTH)

Stimulates osteoclasts, bone breakdown

Sex Hormones (estrogen, testosterone)

Promote bone formation; stimulate ossification of epiphyseal plates

Physical Stress

Stimulates bone growth

Traumatic Fractures

Fracture caused by injury

Spontaneous or pathological fractures

Fracture caused by disease

Simple (closed) Fractures

Fracture protected by uninjured skin (or mucous membrane)

Compound (open) Fractures

Fracture in which the bone is exposed to the outside through opening in the skin (or mucous membrane).

Remodeling 1- Hematoma

Large blood clot; forms right after the fracture occurs

Remodeling 2- Cartilaginous (soft) callus

Osteoblasts invade and produce spongy bone, phagocytes remove debris, and fibrocartilage is produced

Remodeling 3- Bony (hard) callus

Cartilaginous callus breaks down, osteoblasts invade, hard callus now fills space

Remodeling final step

Bone restored close to original shape, as osteoclasts remove excess bone

Wiith age, osteoclasts remove more bone than osteoblasts deposit

Can result in osteopenia (bone loss) or progress to osteoporosis (severe bone loss that leaves spaces and canals in bone, weakens them)

Polydactyly

A congenital condition. Person is born with extra fingers or extra toes

Axial Skeleton

80 bones.

Appendicular Skeleton

126 bones

Pectoral girdle

Scapula and clavicle; upper limb movement

Upper limbs

Humerus, radius, ulna, hand

Pelvic girdle

Hip bones; lower limb movement; forms pelvis

Lower limbs

Femur, patella, tibia, fibula, foot

Ilium (largest, most superior part) has Iliac crest, Iliac spines, Greater sciatic notch. Ischium (L-shaped, lowest part) supports weight while sitting, Ischial spines, Ischial tuberosity. Pubis (anterior portion) has pubic symphysis & Pubic arch

Acetabulum is the depression for head of femur

Iliac bones are more flared; pubic arch angle is larger; sacrum is shorter and flatter; lighter than the male pelvis

Female pelvis characteristics

Metatarsals has five bones that make up part of the foot;Toe phalanges

14 bones. (proximal, middle, and distal, except the big toe has only proximal and distal).

Fibrous

Held together by dense connective tissue. Dense connective tissue containing many collagen fibers. Found in bones in close contact

Cartilaginous

Held together by hyaline cartilage or fibrocartilage.

Synarthrotic

Immovable

Amphiarthrotic

Slightly movable

Diarthrotic

Freely movable

Three types of fibrous joints

Syndesmosis, suture, and gomphosis.

Fibrous joint where bones are connected by an interosseous membrane or ligament. It is amphiarthrotic (slightly movable) and is found between the tibia and fibula

Syndesmosis

A cartilaginous, synarthrotic joint where bones are united by hyaline cartilage. It may be temporary (epiphyseal plate) or permanent (first rib to manubrium)

Synchondrosis

A cartilaginous, amphiarthrotic joint with a pad of fibrocartilage between bones and hyaline cartilage covering the articular surfaces. Examples include the pubic symphysis and intervertebral discs

Symphysis

The most common type of joint. All synovial joints are diarthrotic (freely movable) and have a more COMPLEX structure than fibrous or cartilaginous joints

Synovial joints

Articular cartilage, joint capsule, ligaments, synovial membrane, synovial cavity, synovial fluid, and in some joints a meniscus and bursae

General structure of a synovial joint:

Sutures are thin layers of connective tissue (sutural ligament), what;s an example?

Synarthrotic (immovable) between flat bones of skull

A cone-shaped bony process in a socket. Root of a tooth in maxilla or mandible held in place by periodontal ligament

Gomphosis is Synarthrotic (immovable)

There are 2 types of cartilaginous joints

Synchondrosis and Symphysis

Synovial joint capsule consists of 2 layers → Outer fibrous layer, composed of ligaments

Inner layer, synovial membrane, which secretes synovial fluid

Round head in cup-shaped cavity. Widest range of motion. Multiaxial, plus rotation. Hip, shoulder

Ball-and-Socket Joint (spheroidal joint)

Condylar Joint (Ellipsoidal joint) are oval condyle fits into elliptical cavity. Back-and-forth, side-to-side movement. Biaxial— no rotation

Metacarpals and phalanges

Gliding joint. Almost flat. Back-and-forth and twisting. Nonaxial. Intercarpals, intertarsals. Wrist and ankle joints

Plane Joint, SIDE TO SIDE.

Hinge Joint are onvex surface fits into concave surface of other bone. Uniaxial movement (in 1 plane). Elbow, phalanges

Knees, elbow, ankle, distal interphalangeal joints

Pivot Joint are cylindrical surface rotates within ring of other bone. Uniaxial (movement in 1 plane, rotation only)

Atlas (C1) and dens of axis (C2)

Saddle Joint (Sella joint) is when both bones have concave and convex surfaces. Biaxial movement (in 2 planes)

Carpal and metacarpal of thumb

Origin

Relatively fixed end of a skeletal muscle

More movable end of a skeletal muscle. Movement at a joint occurs when a muscle contracts, and its fibers pull the insertion toward the origin

Insertion

Circumduction is body in circular path

Flexion, extension, adduction, and abduction. Ball and socket, saddle, and condyloid.