BME 320 - Exam 2

Serous glands

watery solution that contains enzymes

Mucous Glands

secrete mucins that hydrate to form mucous

Mixed Exocrine Glands

contain more than one type of gland cell and may produce two different secretions – one serous and one mucous.

Goblet Cells

Secrete mucins – usually due to

irritating stimulus and not hormones

Secretory Sheet

Gland cells form an epithelium that releases secretions into an inner compartment (ie. Mucin secreting cells that line the stomach)

Connective tissue

most abundant, widespread and varied tissue type in the body

Common features of connective tissue

1. Specialized Cells

2. Extracellular Protein Fibers

3. Fluid known as Ground Substance

Functions of connective tissue

1. Establishing a framework for the body

2. Transporting fluids and dissolved materials

3. Protecting delicate organs

4. Supporting, surrounding and interconnecting other types of tissues

5. Storing energy reserves, especially in the forms of triglycerides

6. Defending the body from Invading microorganisms

Classifications of Connective tissue

1. connective tissue proper

2. Fluid connective tissue

3. Supporting connective tissue

Connective tissue proper

- includes many types of cells and extracellular fibers in syrupy ground substance
- Can have very different proportions in terms of # of cells and relative properties and amount of fibers to ground substance
- Loose (ie. Adipose) vs. Dense (ie. Tendon)

Fluid connective tissue

- Distinctive proportions of cells in a watery matrix that contains dissolved proteins

- Blood and Lymph

Supporting connective tissue

- Less diverse cell population and more densely packed fibers than seen in Connective Tissue Proper

- Cartilage and Bone

Limitation of prosthetic control

Limited number of sensor inputs and control features are decided during the initial design

Advantages of electronic prosthetic

various sensor inputs, complex control features via a microprocessor, and post-design feature additions.

C-Leg sensor inputs

knee angle and ankle moment

C-Leg software adjustment method

PC Sliders software used to optimize and adjust parameters

Genium knee feature

incorporates Inertia Motion Unit (IMU) for Optimized Physiological Gait (OPG)

C-Brace joint unit controls

microprocessor controls hydraulic valves based on knee angle, hydraulic force, and acceleration

Joint (articulation)

any place where two bones meet or join, controlling motion between them

Demands of joints

1. Stability

2. Mobility

3. Transfer of force (energy)

Simple joint function

stability, such as sutural joints in the skull

Complex joint function

mobility, such as glenohumeral complex

Synarthrosis joint mobility

Immovable

Amphiarthrosis joint mobility

Slightly movable

Diarthrosis joint mobility

Freely movable (synovial)

Fibrous Joint

To attenuate shock but permit little or no movement

Cartilaginous joint

To attenuate force and allow some movement

Bony Joint

Two bones fused together, resulting in a totally rigid, immovable joint

Location of gomphosis joint

binds teeth to bony sockets in the maxillae and mandible

synchondrosis joint

Articulating bones are held together by a thin layer of hyaline cartilage

syndesmosis joint connection

Bones are connected by a ligament

symphysis joint composition

plates of hyaline cartilage are separated and held together by fibrocartilage

Features of diarthrosis (synovial) joint

1. joint cavity

2. articular cartilage

3. articular capsule

4. synovial membrane

functions of synovial fluid

1. lubrication

2. nutrient distribution

3. shock absorption

Degrees of Freedom (DoF)

Number of independent coordinates required to completely specify the position of an object in space

Uniaxial

rotation about a single axis

Biaxial

Two dominant rotational motions are possible

Triaxial

Rotation is possible in three planes about three independent axes

Hinge joint

a type of synovial joint that allows movement in a single plane, like the opening and closing of a door

Pivot joint

a type of synovial joint that allows for rotation around a single axis, where a rounded or cylindrical end of one bone fits into a ring formed by another bone and a ligament

Condyloid joint

a type of synovial joint where an oval-shaped bone end fits into a similarly shaped hollow, allowing for movement in two planes: flexion/extension and abduction/adduction

Saddle joint

a type of synovial joint where the articulating bones have both concave and convex surfaces, interlocking like a rider in a saddle

Ball and socket joint

a type of joint where the rounded end of one bone fits into the cup-like depression of another bone, allowing for a wide range of motion in multiple directions. ex. hi

Instantaneous center of rotation

Hypothetical point for any rotating body where velocity is zero.

Convex-Concave Rule

The concave articulating surface moves in the same direction as the shaft of the bony lever

Knee joint compartments

medial and lateral

4 main knee ligaments

1. medial collateral

2. lateral collateral

3. anterior cruciate

4. posterior cruciate

Menisci function

1. deepen the joint

2. distribute load

3. aid in shock absorption

0 to 140 degrees

knee flexion range

LARS artificial ligament

made of polyethylene terephthalate (PET), which encourages biological tissue ingrowth

Shoulder joint composition

three synovial joints (sternoclavicular, acromioclavicular, glenohumeral) and the scapulothoracic gliding mechanism

Glenohumeral joint type

highly mobile, triaxial, ball and socket joint

Glenoid labrum

Fibrocartilage rim that increases the depth of the glenoid fossa articulation by 50%

Scapulothoracic joint

Crucial for allowing the full range of motion of the shoulder, contributing 60 degrees to the 180 degrees of abduction

Anterior dislocations

Account for 85-98% of shoulder dislocations in the ER

Nucleus pulposus

A central gelatinous mass that acts hydrostatically to cushion and distribute loads. the inner, gel-like center of the intervertebral discs in the spine. It is made mostly of water, type II collagen, and proteoglycans, which allow it to act as a shock absorber for the spine. It plays a key role in spinal flexibility and stability by absorbing and distributing the forces placed on the vertebrae.

Annulus fibrosus

Consists of about 90 concentric bands of collagenous tissue that restrain excessive motion

Shear stress

created by spinal rotation

Bone Function

1. support

2. storage of minerals

3. blood cell production

4. protection

5. leverage

Two types of bone

compact (dense/cortical) bone and spongy (cancellous/trabecular) bone

Bone matrix composition

2/3 hydroxyapatite crystals and 1/3 collagen fibers

Osteocyte

To maintain and monitor the protein and mineral content of the matrix and participate in bone repair

Osteoblasts

Produces new bone matrix (osteogenesis)

Osteoprogenitor cells

Mesenchymal stem cells that differentiate into osteoblasts

Osteoclasts

giant, multinucleated cells that break down bone matrix (osteolysis)

Osteon

(Haversian system) The functional and structural unit of mature compact bone

Compact bone concentric lamellae

Rings of bone that surround the central canal, making up the bulk of an osteon

Compact bone canaliculi

Tiny interconnecting channels that connect adjacent lacunae and the central canal, permitting cell communication

Spongy bone trabeculae

An open lattice of narrow rods and plates of bone, with space for red bone marrow between them

Periosteum 

1. isolates bone

2. provides a route for circulatory/nervous supply

3. participates in bone growth and repair

Endosteum

An incomplete cellular layer lining the marrow cavity that aids in bone growth, repair, and modeling

Anisotropic

elastic modulus depends on the direction of loading (strongest in compression)

Viscoelastic

Stress-Strain relationship depends on the rate of loading

Wolff’s Law

Bone remodels along lines of stress, changes in form and function lead to changes in internal architecture

Piezoelectric effect

Stress on bone produces small electrical fields, to which osteoblasts are sensitive, guiding remodeling

Parathyroid hormone effect

Increases blood calcium levels by stimulating osteoclasts and increasing intestinal absorption

Calcitonin effect

It decreases blood calcium levels by inhibiting osteoclast activity and increasing kidney excretion

Intramembranous ossification

The process where mesenchymal tissue is directly converted into dermal bone, forming bones like the flat bones of the skull, clavicle, and mandible

Endochondral Ossification

Bone develops from a pre-existing hyaline cartilage model, this is how most bones form. 

Fracture repair

1. Formation of a fracture hematoma (blood clot)

2. Formation of an external callus of cartilage and bone and an internal callus of spongy bone

3. Cartilage of the external callus is replaced by bone and struts of spongy bone unite the broken ends

4. Remodeling occurs over time, where the initial swelling marks the location of the fracture

Osteopenia

Condition where bones become thinner and weaker as a normal part of aging, starting between ages 30-40

Osteoporosis

Condition where bone mass is reduced enough to compromise normal function

Animal model

To predict how a treatment will behave in a human wound under clinical conditions

Pig model

Anatomic and physiologic similarities of of its skin to human skin

Porcine epidermis thickness

30-140 micrometers

human epidermis thickness

50-120 micrometers

Porcine skin

Lacks a significant panniculus carnosus, similar to humans, as they are not loose-skinned animals

reepithelialization

how pigs and humans close wounds

Partial thickness wound model

To evaluate the impact of wound agents on healing in the short term, essentially a safety test

Full thickness wound model

To evaluate an agents impact on healing and the nature of the resultant scar, often with induced infection

Apoptosis

Programmed cell death where cells fragment into membrane-bound particles, reducing the inflammatory response

Nanocrystal formation

formed using an advanced materials process called physical vapor deposition (PVD)

Features of connective tissue

1. specialized cells

2. extracellular protein fibers

3. fluid known as ground substance

Constituents of tissue matrix

1. extracellular protein fibers

2. ground substance

Connective tissue functions

1. Framework

2. fluid transport

3. organ protection

4. interconnecting tissues

5. energy storage

6. defense

Connective tissue classifications

1. connective tissue proper

2. fluid connective tissues

3. supporting connective tissues

CTP cell types

1. fibroblasts

2. fibrocytes

3. adipocytes

4. mesenchymal cells

5. melanocytes

6. mast cells

7. lymphocytes

8. macrophages

CTP fiber types

1. collagen fibers

2. reticular fibers

3. elastic fibers

Loose connective tissue

act as a packing material of the body