BIOL212 - Activities 6/7/8/9/10/14 - Mixed

What is Appositional Growth?

Growth in Width

What is Interstitial Growth?

Growth in Length

What are the 2 Methods of Bone Development?

• Intramembranous Ossification

• Endochondral Ossification

How does the bone GROW in Intramembranous Ossification?

Only by Appositional Growth

How does the bone GROW in Endochondral Ossification?

Both by Appositional and Interstitial Growth

What is the tracing for Intramembranous Ossification?

Step 1: Intramembranous Bone Development

Mesenchyme —>

Mesenchymal cells differentiate into osteoblasts —>

Osteoblasts secrete matrix (osteoid) —>

Osteoblasts surrounded by matrix become osteocytes trapped in lacunae —>

Spicules formed —>

Spicules unite to form spongy bone (endosteum forms around spongy bone) —>

Remodeling of spongy bone forms compact bone (periosteum forms around bone)

What is the tracing for Endochondral Ossification?

Step 1: Hyaline Cartilage Model Development (All cartilage develops via this process)

Mesenchyme —>

Mesenchyme differentiates into chondroblasts —>

Chondroblasts secrete matrix —>

Chondroblasts surrounded by matrix become chondrocytes trapped in lacunae —>

Cartilage model formed by perichondrium

Step 2: Endochondral Ossification (Bone Development)

Hyaline cartilage model (continued from above) —>

Blood vessels of perichondrium bring in osteoblasts to form periosteum collar —>

Hypertrophy (increase in cell size) & Death of cartilage cells at primary ossification center —>

Invasion of blood vessels and osteoblasts at primary ossification center —>

Bone begins to replace cartilage (osteoblasts form spicules) —>

Formation of secondary ossification center in epiphysis —>

Bone replaces cartilage at 2° ossification center —>

Hyaline Cartilage remains in the epiphyseal plate (until growth is completed) and on the articular surface for life

What is the Origin of a muscle?

Muscle attachment that is:

• Closest to the midline OR More Proximal to the region of the body

• Also Less movable

What is the Insertion of a muscle?

Muscle attachment that is:

• Further from the midline & More distal from Origin

• More movable

• Attaches to skin

Sliding Filament Theory Tracing

1. ATP binds to Myosin Cross-bridge Head, which splits ATP into ADP and P energy. Energy is used to swivel the Cross-bridges to a “high-affinity” position.

2. Motor Neuron at neuromuscular junction released Acetylcholine, which binds to receptors on Motor End Plate of the Sarcolemma, causing an action potential.

3. Action potential spreads throughout the Sarcolemma and down the T-Tubules.

4. This causes the Sarcoplasmic Reticulum (SR) channels to open and release Calcium Ions (Ca²⁺).

5. Ca²⁺ binds to protein on Actin, exposing binding sites for Myosin heads.

6. Myosin heads attach to Actin forming Cross-bridges. Myosin heads release P and ADP causing Myosin heads to swivel, pulling actin and their Z-lines towards the cell center, shortening the Sarcomere.

What are the OIAs of the Frontalis?

Origin: Galea Aponeurotica

Insertion: Skin and muscles of forehead

Action: Raises the eyebrows/Wrinkles forehead

What are the OIAs of the Temporalis?

Origin: Temporal Fossa

Insertion: Coronoid Process of the Mandible

Action: Closes Jaw / Elevates Mandible

What are the OIAs of the Obicularis Oculi?

Origin: Medial margin of bony orbit

Insertion: Eyelids

Action: Close Eyelids

What are the OIAs of the Orbicularis Oris?

Origin: Maxilla and Mandible

Insertion: Skin surrounding the Mouth

Action: Closes and purses lips (kiss)

What are the OIAs of the Depressor Anguli Oris?

Origin: Anteriolateral surface of the mandibular body

Insertion: Angle of the mouth

Action: Depresses angle of mouth (frown)

What are the OIAs of the Buccinator?

Origin: Alveolar process of Mandible and Maxilla

Insertion: Angle of Mouth

Action: Compresses cheek against molars

What are the OIAs of the Masseter?

Origin: Zygomatic Arch

Insertion: Mandibular angle and Ramus

Action: Mastication / Closer (elevates) and retracts mandible

What are the OIAs of the Platysma?

Origin: Skin of lower neck and upper thorax

Insertion: Lower mandible and skin of the lower face

Action: Tenses skin of neck, depresses mandible

What are the OIAs of the Sternocleidomastoid?

Origin: 2 heads: manubrium of sternum and clavicle

Insertion: Mastoid Process of Temporal Bone

Action: Flexes and rotates cervical vertebral column

What are the OIAs of the Zygomaticus Major?

Origin: Zygomatic Bone

Insertion: Angle of mouth

Action: Raises Angle of mouth / Smile

What is the Lymph Tracing if the fluid came from the Right Upper Half of the body?

Tissue (interstitial fluid) —>

Lymphatic capillaries (lymph) —>

Lymphatic Vessels —>

Lymph Nodes —>

Lymphatic Vessels —>

(Lymph may enter a series of lymph nodes before continuing —>

Right lymphatic duct —>

Right subclavian vein —>

Heart

What is the Lymph Tracing if the fluid came from the Left Upper Half of the body?

Tissue (interstitial fluid) —>

Lymphatic Capillaries (lymph) —>

Lymphatic Vessels —>

Lymph Nodes —>

Lymphatic Vessels —>

(the lymph may enter a series of lymph nodes before continuing) —>

Left lymphatic duct —>

Left subclavian vein —>

Heart

What is the Lymph Tracing if the fluid came from the Lower Limbs or Lower Torso?

Tissue (interstitial fluid) —>

Lymphatic Capillaries (lymph) —>

Lymphatic Vessels —>

Lymph nodes —>

Lymphatic Vessels —>

(the lymph may enter a series of lymph nodes before continuing) —>

Cisterna Chyli —>

Thoracic Duct —>

Left Lymphatic Duct —>

Left subclavian vein —>

Heart