A&P Exam 2

  1. List the components of the integumentary system

    1. Skin: the largest organ in the human body

    2. Accessory structures

      1. Hair

      2. Nails

      3. Sweat glands

      4. Sebaceous (oil) glands

  2. List and describe the six functions of the integumentary system

    1. Protection

    2. Body temperature regulation

    3. Sensory perception

    4. Synthesize vitamin D for calcium absorption

    5. Blood reservoir

    6. Excretion of waste

  3. List and describe the 4 types of cells in the epidermis

    1. Keratinocytes

      1. Produce keratin

      2. Major cells of the epidermis

        1. Tightly connected by desmosomes

        2. Millions fall off everyday

    2. Melanocytes

      1. Produce melanin

      2. Major cells of the epidermis

        1. Give skin and nails color

        2. Protect against UV damage

        3. Get packages into melanosomes then transferred to keratinocytes

      3. Spider shaped

    3. Tactile/merkel cells

      1. Act as sensory receptors that stimulate nerve cells that the brain perceives as touch

      2. Sense low frequency vibrations (5-15 Hz)

      3. Also known as type I cutaneous mechanoreceptors

    4. Dendritic/ langerhans cells

      1. Resident immune cells

      2. Similar to macrophages

        1. Phyagocytic

        2. Antigen presentation

  4. List the layers of the epidermis

    1. Stratum corneum

    2. Stratum lucidum

    3. Stratum granulosum

    4. Stratum spinosum

    5. Stratum básale

  5. Discuss the regions and components of the dermis

    1. Papillary layer

      1. Meissners corpuscle

      2. Loose, areolar CT

      3. Dermal papillae: finger like projections~finger prints

    2. Reticular layer

      1. Pacinian corpuscle

      2. ~80% of dermal thickness

      3. Dense irregular CT

        1. ECM contains pockets of adipose tissue

    3. Cutaneous plexus

      1. Network of blood vessels between reticular layer and hypodermis

  6. Describe the structure and function of the hypodermis

    1. Subcutaneous layer deep to skin

    2. Not technically part of the skin

    3. Includes adipose tissue

  7. Discuss the contribution of melanin, blood H/B, and carotene to skin color

    1. Melanin

      1. More sun exposure=more melanin produced

      2. Skin color differences are due to amount and form of melanin

    2. Carotene

      1. Yellow to orange pigment

      2. Accumulates in stratum corneum and hypodermis

    3. Hemoglobin

      1. Pinkish hue of fair skin is due to lower levels or melanin

      2. Bruises are a result of clotted blood beneath skin

  8. Discuss the structure and function of sebaceous glandS

    1. Are everywhere except for palms and soles

    2. Most developed from hair follicles and secrete into hair follicles

    3. Inactive until puberty

    4. Secrete sebum

      1. Bacterial-killing properties

      2. Softens hair and skin

  9. Compare and contrast Eccrine and apocrine sweat glands

    1. Eccrine sweat glands

      1. Most abundant on palms, soles and forehead

      2. Ducts connect to pores

      3. Function in thermoregulation

      4. Secrete sweat

    2. Apocrine sweat glands

      1. In armpit and genital region

      2. Usually milky/yellowish that contains fatty substances and proteins

        1. Bacteria breaks down sweat, leading to body odor

      3. Larger than eccrine sweat glands with ducts emptying out to hair follicles

      4. Begin functioning at puberty

  10. List the function of bones

    1. Support the body

    2. Facilitate movement

    3. Protect internal organs

    4. Produce red blood cells

    5. Store and release minerals and fat

  11. Describe the cell sin the bone tissue

    1. Osteogenic cells develop into osteoblasts

    2. Osteoblasts build bone

    3. Osteocytes are mature osteoblasts

    4. Osteoclasts chew bone

  12. Compare and contrast compact bone and spongy bone

    1. Compact bone

      1. Stronger

      2. Can withstand more compressive forces

    2. Spongy bone

      1. Lighter

      2. Supports shifts in weight distribution

  13. Describe the process of intramembranous ossification and list the bones that are formed by this type os ossification

    1. Forms the bones of the skull and clavicles

      1. Messenchymal stem cells turn into osteoblasts

      2. Calcification

        1. Osteoblasts into osteocytes

      3. Periosteum and immature spongy bone form

      4. Compact bone replaces immature spongy bone

        1. Red bone marrow develops

  14. Describe the process of the endochondral ossification and list the bones that are formed by this type of ossification

    1. Forms all bones inferior to the base of the skull except clavicles

      1. A thin bone layer forms around the diaphysis

      2. Middle cartilage calcifies and develops cavities

      3. Periosteal bud enters, spongy bone starts forming

      4. Bone lengthens and a hollow medullary cavity develops

        1. Secondary ossification centers appear in epiphyses

      5. Epiphyses ossify

        1. Only cartilage left=growth plates+articular cartilage

  15. Describe how bones grow in length

    1. Happens at the epiphyseal plate. Chondrocytes make new cartilage on the epiphyseal side. Cartilage on the diaphysis side is replaced by bone. Pushes the bone apart and the bone grows longer. Stops when the epiphyseal plate closes and is now the epiphyseal line

  16. Describe how bones grow in width

    1. Happens under the periosteum. Osteoblasts add new bone to the outside surface. Osteoclasts remove bone from the endosperm. Bone gets thicker and stronger. Continues throughout life.