exam 2

What tissue type is commonly found in the subcutaneous layer?

Areolar and Adipose connective tissue.

What tissue type makes up the epidermis?

Keratinized stratified squamous epithelium.

List the 5 layers of the epidermis from outermost to innermost.

Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum basale.

Where is the only place you will find the stratum lucidum?

In thick skin, found on the palms of the hands and soles of the feet.

What significant event begins in the stratum granulosum?

The cells begin to die (undergo apoptosis/keratinization) as they are cut off from their nutrient supply.

Name the 3 layers of a hair.

Medulla, Cortex, Cuticle.

Name the 2 layers of a hair follicle.

Internal root sheath, External root sheath.

What is the layer that surrounds the follicle?

Connective tissue (or dermal) root sheath.

What is the unique characteristic of the cuticle?

It consists of a single layer of overlapping cells that resemble shingles on a roof.

Name the 4 accessory cell types found in the epidermis and their functions.

Keratinocytes (produce keratin), Melanocytes (produce melanin), Langerhans cells (ingest foreign substances), Merkel cells (touch receptors).

Describe the stratum basale.

The deepest layer, attached to the basement membrane, containing a single row of actively dividing cells.

Describe the stratum corneum.

The most superficial layer, consisting of 20-30 layers of dead, flattened, keratin-filled cells that are constantly shed.

Name the 4 types of glands.

Sebaceous (produces sebum), Eccrine sweat (produces sweat), Apocrine sweat (produces thicker sweat), Ceruminous (produces cerumen).

What is the function of sebaceous glands?

Produce sebum (oil); located everywhere except palms and soles.

What is the function of eccrine sweat glands?

Produce sweat (mostly water); located all over the body.

What are apocrine sweat glands known for?

They produce a thicker, milky sweat and become active at puberty.

What are the key types of integumentary disorders?

Burns, skin cancer, infections, inflammatory conditions, acne vulgaris.

What are the characteristics of burns?

Tissue damage from heat, chemicals, electricity, or radiation.

What is skin cancer?

Uncontrolled growth of skin cells, including basal cell, squamous cell, and melanoma.

List the functions of the skin.

Protection, body temperature regulation, cutaneous sensation, metabolic functions, blood reservoir, excretion.

Identify characteristics of 1st-degree burns.

Only the epidermis is damaged; redness, pain, edema.

Identify characteristics of 2nd-degree burns.

Epidermis and upper dermis are damaged; blister formation, severe pain.

Identify characteristics of 3rd-degree burns.

Entire skin thickness destroyed; appears blanched/blackened, often painless.

What do Pacinian corpuscles detect?

Deep pressure and vibration; located in the reticular layer.

What do Meissner’s corpuscles detect?

Light touch; located in the papillary layer.

Name the 3 pigments responsible for skin color.

Melanin, carotene, hemoglobin.

Which pigment ultimately determines a person's skin color?

Melanin (type and amount).

Describe the free edge of a nail.

The part that extends past the finger.

Describe the nail plate (body).

The visible attached part of the nail.

Describe the nail root.

The part embedded in the skin, proximal to the nail plate.

What is the lunula in a nail?

The whitish, crescent-shaped area at the base.

What is the cuticle (eponychium)?

The fold of skin that overlaps the nail proximally.

What is the nail bed?

The skin beneath the nail plate.

Describe the nail matrix.

The actively growing part of the nail (under the root).

What is the arrector pili muscle?

A bundle of smooth muscle fibers that causes goosebumps when it contracts.

List the two layers of the dermis from outermost to innermost.

Papillary layer (areolar connective tissue), reticular layer (dense irregular connective tissue).

Describe eccrine sweat characteristics.

99% water with some salts, vitamin C, antibodies, and metabolic wastes; hypotonic.

Describe apocrine sweat characteristics.

Contains fatty acids and proteins; odorless but can cause body odor.

Define lacunae in bone.

Small cavities in bone that contain osteocytes.

What are canaliculi?

Hair-like canals that connect lacunae to each other and to blood supply.

What is the Haversian canal?

Central canal running longitudinally in an osteon; contains blood vessels and nerves.

What are Volkmann's canals?

Perforating canals that run perpendicular to the Haversian canals.

What are osteons?

Structural unit of compact bone (Haversian system).

What is bone remodeling?

The ongoing process of bone resorption and deposition.

What are circumferential lamellae?

Layers of bone matrix that go around the entire bone, just deep to the periosteum.

What are interstitial lamellae?

Irregular regions of old osteons between intact osteons.

What are trabeculae?

Interconnecting rods or plates of bone in spongy bone.

List the steps of bone repair in order.

1. Hematoma formation, 2. Fibrocartilaginous callus formation, 3. Bony callus formation, 4. Bone remodeling.

Where can hyaline cartilage be found in the skeletal system?

Articular cartilage, costal cartilage, nasal cartilage, epiphyseal plates, tracheal and bronchial rings.

What are osteoblasts?

Bone-forming cells that build matrix.

What are osteocytes?

Mature bone cells that maintain the matrix.

What are osteoclasts?

Bone-destroying cells that break down/resorb bone.

What is osteoporosis?

Loss of bone mass, resulting in porous and brittle bones.

What is rickets (osteomalacia)?

Soft, weak bones due to lack of calcium or Vitamin D.

What is Paget’s disease?

Excessive and disordered bone remodeling, making bones enlarged and weak.

What are the types of fractures?

Greenstick, comminuted, spiral.

What is osteomyelitis?

Bacterial infection of bone.

What are the two types of ossification?

Intramembranous ossification and endochondral ossification.

What is intramembranous ossification?

Bone develops from fibrous membrane, producing flat bones of skull, mandible, clavicles.

What is endochondral ossification?

Bone replaces hyaline cartilage, producing most of the skeleton.

What are the two hormones responsible for controlling blood calcium?

Parathyroid hormone (PTH) and Calcitonin.

What does parathyroid hormone (PTH) do?

Increases blood calcium by stimulating osteoclasts and activating Vitamin D.

What does calcitonin do?

Decreases blood calcium by inhibiting osteoclasts.

What do testosterone and estrogen cause during growth?

They cause a growth spurt and eventually ossify epiphyseal plates.

What are the functions of bones?

Support, protection, movement, mineral storage, blood cell formation, energy storage.

Name the classifications of bones based on shape.

Long, short, flat, irregular, sesamoid.

What defines the axial skeleton?

Bones forming the longitudinal axis of the body (skull, vertebral column, rib cage).

What defines the appendicular skeleton?

Bones of the limbs and girdles that attach to the axial skeleton.

What is the periosteum?

CT covering of a long bone.

What is the endosteum?

CT lining of the inner cavity of a long bone.

What tissue type forms the outer wall of a long bone?

Compact bone.

What tissue type forms the ends of a long bone?

Spongy bone.

What are the structural classifications of joints?

Fibrous, cartilaginous, synovial.

What are the functional classifications of joints?

Synarthrosis, amphiarthrosis, diarthrosis.

What are the characteristics of fibrous joints?

No joint cavity; held together by dense fibrous connective tissue.

What are the three types of fibrous joints?

Sutures, syndesmoses, gomphoses.

What are the characteristics of cartilaginous joints?

No joint cavity; held together by cartilage.

What are the basic characteristics of synovial joints?

Articular cartilage, joint cavity, articular capsule, synovial fluid, reinforcing ligaments.

What are the axes of movement classifications?

Nonaxial, uniaxial, biaxial, multiaxial.

Name the special movements seen in the body.

Opposition, inversion/eversion, protraction/retraction, elevation/depression, supination/pronation, dorsiflexion/plantarflexion.

What are the six types of synovial joints?

Plane (gliding), hinge, pivot, condyloid (ellipsoidal), saddle, ball and socket.