Nakamura Human Anatomy ch 5 and 6

Question 0

Study skin structure diagram (study)

Answer 0

All the structures (nerves, muscles, glands) located in dermis

Question 1

Skin

Answer 1

●our largest organ
●Accounts for 7% of body weight
●Acts as a mini-excretory system
●Screens out UV rays from the sun
●Contains sensory receptors associated with nerve endings
-protection
●Divided into 3 distinct layers
        ●Epidermis
        ●Dermis
        -hypodermis

Question 2

Hypodermis

Answer 2

Lies deep to the dermis

Question 3

Epidermis

Answer 3

●Contains four main cell types
     ●Keratinocytes
     ●Melanocytes: produces melanin
     ●Merkel cells (Tactile epithelial cells)
     ●Dendritic cells (Langerhans cells)

Question 4

Keratinocytes

Answer 4

●most abundant cell type in epidermis
●Arise from deepest layer of epidermis
●Produce keratin – a tough fibrous protein
●Produce antibodies and enzymes
●Keratinocytes are dead at skin’s surface

Question 5

Study epidermal cells diagram

Answer 5

.

Question 6

Layers of the epidermis

Answer 6

●Stratum corneum
●Stratum lucidum (only in thick skin)
●Stratum granulosum
●Stratum spinosum
●Stratum basale (stratum geminativum)
See only 4 sub layers in thin skin, 5 in thick skin.

Question 7

Dermis

Answer 7

●Second major layer of the skin (main layer)
●Strong, flexible connective tissue
●Richly supplied with blood vessels and nerves
●Has two sublayers
●Papillary layer – includes dermal papillae (more superficial, closer or stratum basale of epidermis)
●Reticular layer – deeper layer – 80% of thickness of dermis (vessels and nerves)

Question 8

Hypodermis

Answer 8

●Deep to the skin – also called superficial fascia
●Contains areolar and adipose connective tissues
●Anchors skin to underlying structures
●Helps insulate the body
Normal body temperature is 98.6 or 37 Celsius

Question 9

Skin color

Answer 9

Three pigments contribute to skin color
●Melanin – most important pigment – made from tyrosine
●Carotene – yellowish pigment from carrots and tomatoes
●Hemoglobin – Caucasian skin contains little melanin
●Allows crimson (deep purplish red) color of blood to show through

Question 10

Sweat glands

Answer 10

●(sudoriferous glands) are widely distributed on body
●Sweat – is a blood filtrate
●99% water with some salts
●Contains traces of metabolic wastes (protein waste. Ammonia)

Question 11

Burns

Answer 11

Classified by degree of severity

Question 12

First degree burn

Answer 12

Only epidermis is damaged

Question 13

Second degree burn

Answer 13

Upper part of dermis is also damaged
-blisters appear
-skin heals with little scarring
Nerves and vessels damaged

Question 14

Third degree burn

Answer 14

Consume entire thickness of skin

-burned areas appear white, red, or blackened

Question 15

Skin cancer

Answer 15

Basal cell carcinoma
Squamous cell carcinoma
Melanoma

Question 16

Basal cell carcinoma

Answer 16

Least malignant and most common

Question 17

Squamous cell carcinoma

Answer 17

Arises from keratinocytes of stratum spinosum

Question 18

Melanoma

Answer 18

A cancer of melanocytes
The most dangerous type of skin cancer
Dark spot and suddenly gets bigger

Question 19

Types of cartilage

Answer 19

Hyaline cartilage
Elastic cartilage
Fibrocartilage
Main difference btwn them is % of fibers

Question 20

Hyaline cartilage

Answer 20

(Glass) Most abundant cartilage
Provides support through flexibility
Almost no fibers
Examples: nose, articular cartilage of a joint, costal cartilage, respiratory cartilages in neck and thorax,

Question 21

Elastic cartilage

Answer 21

Contains many elastic fibers
Able to tolerate repeated bending
External ear

Question 22

Fibrocartilage

Answer 22

Resists strong compression and strong tension
Lots of fibers
More fibers the stronger it is
Ex. Cartilage in intervertebral discs. Meniscus (padlike cartilage in knee joint, Pubic symphysis )

Question 23

Stratum corneum

Answer 23

• Cells are dead
• represented only by flat membranous sacs filled with keratin
• glycolipids in Extracellular space

Question 24

Stratum granulosum

Answer 24

- Cells are flattened - organelles deteriorating - cytoplasm full of lamellated granules and keratohyaline granules

Question 25

Stratum spinosum

Answer 25

cells contain thick bundles of intermediate filaments made of pre-keratin

Question 26

Stratum basale

Answer 26

- Cells are actively mitotic stem cells | - some newly formed cells become part of the more superficial layers

Question 27

Malignant

Answer 27

Life threatening

Question 28

Diagram of cartilages (study)

Answer 28

.

Question 29

Function of bones

Answer 29

●Support – provides hard framework ●Protection of underlying organs ●Movement – skeletal muscles use bones as levers ●Mineral storage – reservoir for important minerals (phosphates, calcium, etc) ●Blood-cell formation – bone contains red marrow (production site of w/r blood cells and platelets)

Question 30

Classification of bones (study)

Answer 30

``` Long bone (ex. Humerus Short bone (Ex. Trapezoid) Flat bone (ex. Sternum) Irregular bone (ex. Vertebra) ```

Question 31

Structure of a typical long bone

Answer 31

●Diaphysis – “shaft” of a bone, contains medullary cavity ●Epiphysis – ends of a bone, covered in articular (hyaline) cartilage ●Blood vessels – well vascularized ●Medullary cavity – hollow cavity – filled with marrow ●Membranes – periosteum (outside layer), Sharpey’s fibers (connects periosteum to compact bone), and endosteum (inner layer, lines medullary cavity)

Question 32

Structure of a long bone (diagram)

Answer 32

Compact bone surrounds spongy bone

Question 33

Microscopic structure of compact bone

Answer 33

- blood capillaries contained in Osteons, but continue through central canal and perforating canal to spongy bone all the way to into the medullary cavity, which contains bone marrow - Circumferential lamella - volkmann canals - lacuna

Question 34

Lamella

Answer 34

a thin layer (platelike) in compact bone tissue.

Question 35

Osteon

Answer 35

a central canal containing blood capillaries and the concentric osseous lamellae around it occurring in compact bone.

Question 36

Circumferential lamella

Answer 36

a bony lamella that encircles the outer or inner surface of a bone.

Question 37

Volkmann canal

Answer 37

vascular canals in compact bone that, they run for the most part transversely, perforating the lamellae of the haversian system, and communicate with the canals of that system.

Question 38

Lacuna

Answer 38

a small space, cavity, or depression. | Btwn lamella

Question 39

Chemical composition of bone

Answer 39

●35% organic components (whose molecules contain carbon, such as proteins, fats, and carbohydrates -sugars) ●Composed of cells, fibers, and organic substances ●Collagen – abundant ●65% inorganic mineral salts (why bones are tough) ●Primarily calcium phosphate ●Resists compression

Question 40

Ossification

Answer 40

- Also called osteogenesis (osteo: bone, genesis: formation/creation) - bone-tissue formation

Question 41

Chondroblasts

Answer 41

A dividing cell of growing cartilage tissue

Question 42

Intramembranous ossification steps

Answer 42

1. centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center in the fibrous connective tissue membrane 2. Osteoblasts begin to secrete osteoid (bone matrix)within the fibrous membrane. It is mineralized in a few days. Trapped osteoblasts become osteocytes 3. Woven bone and periosteum form 4. Bone collar of compact bone forms and red marrow appears

Question 43

Osteoid

Answer 43

newly formed organic bone matrix prior to calcification.

Question 44

Osteoblast

Answer 44

a bone-forming cell that is derived from mesenchymal osteoprognitor cells

Question 45

Woven bone

Answer 45

the collagen fibers of the matrix are arranged irregularly in the form of interlacing networks in bony tissue

Question 46

Trabeculae

Answer 46

a meshwork; one of the supporting bundles of fibers traversing the substance of a structure

Question 47

Bone collar

Answer 47

The part of bone?

Question 48

Intramembranous ossification diagram by Nakamura

Answer 48

Mesenchymel cell to osteoblast Osteoblast makes both osteoid and osteocyte Osteoid (pre calcified bone matrix) which then becomes calcified to make regular bone matrix Osteocyte and bone matrix together form bone tissue

Question 49

Endochondral vs Intramembranous ossification

Answer 49

●The distinction depends on whether a cartilage model serves as the precursor of the bone (endochondral ossification) ●Endochondral ossification: proliferation (rapid increase) and aggregation (gathering) of mesenchymal cells at the site of the future bone that differentiate into chondroblasts that, in turn, produce cartilage matrix.

Question 50

Endochondral ossification bones example

Answer 50

●The bones of the extremities and those parts of the axial skeleton that bear weight (e.g., vertebrae) develop by endochondral ossification.

Question 51

Intramembranous ossification bone examples

Answer 51

●The flat bones of the skull and face, the mandible, and the clavicle develop by intramembranous ossification.

Question 52

Hormones regulate bone growth

Answer 52

●Growth hormone – produced by the pituitary gland ●Stimulates epiphyseal plates ●Thyroid hormone – ensures that the skeleton retains proper proportions ●Sex hormones ●Promote bone growth ●Later induces closure of epiphyseal plates (grow no taller -- F: 18 Y; M: 21 Y) -vitamin D, activated by sunlight, important for calcium absorption -have to have activated vitamin and to form bone tissue

Question 53

Bone remodeling

Answer 53

●Bone deposit and removal occurs at periosteal and endosteal surfaces ●2 parts of Bone remodeling ●Bone deposition: depositing more bone/calcium (osteoblasts) ●Bone reabsorption: removing bone/calcium (osteoclasts) (osteoclast →dissolve bone tissue→reconstruction)

Question 54

Osteoclast

Answer 54

-bone degrading cell -●A giant cell with many nuclei ●Crawls along bone surfaces ●Breaks down bone tissue (also removes calcium) ●Secretes concentrated hydrochloric acid ●Lysosomal enzymes are released

Question 55

Lysosomal enzyme

Answer 55

An enzyme in an organelle called the lysosome within the cell. The lysosomal enzymes do not normally damage the cell itself.

Question 56

Osteoporosis

Answer 56

●characterized by low bone mass Occurs when ●Bone reabsorption outpaces bone deposition (more is removed than is created) so bone structure becomes weak ●Occurs most often in women after menopause (hormonal changes)

Question 57

Things that increase bone formation

Answer 57

●Dietary calcium ●Vitamin D (needed for calcium absorption) ●Exposure to sunlight (activates vitamin D) ●Exercise (stimulates bone development)

Question 58

Things that speed up bone loss

Answer 58

●Estrogen deficiency (has to do with hormone regulation) ●Pregnancy (another hormone change, also calcium is given to baby) ●Nursing ●Lack of exercise

Question 59

Estimating burns using the rule of Nines

Answer 59

Head and neck: 9% (anterior: 4.5% posterior: 4.5%) Trunk: 36% (anterior: 18% posterior: 18%) Upper limbs (both arms): 18% (anterior of one arm: 4.5%, posterior of one arm: 4.5%, anterior and posterior of each arm is 9% ) Perineum: 1% Lower limbs(both legs): 36% (anterior of one leg: 9%, posterior of one leg: 9%, anterior and posterior of each leg is 18%)

Question 60

What does the rule of nines do?

Answer 60

It allows you to estimate the body surface area on an adult that has been burned by using multiples of 9. Helps you decide the kind of treatment they need

Question 61

Red blood cells

Answer 61

Carry oxygen and carbon dioxide | Have anemia when not enough (no energy)

Question 62

White blood cells

Answer 62

Fight infection | Problem is can't fight infection if don't have enough

Question 63

Platelets

Answer 63

Stop bleeding (clot blood)

Question 64

2 types of ossification

Answer 64

Intramembranous ossification ●Membrane bones – formed directly from mesenchyme -flat (skull), irregular, short bones Endochondral ossification (in a long bone) -(endo: within, chondral: cartilage ) ●develop initially from hyaline cartilage

Question 65

Intramembranous ossification step 3 elaborated

Answer 65

Formation of woven bone: Osteoid (bone matrix before calcification) is laid down between embryonic blood vessels forming a random network. Results in a in network of trabeculae (woven bone) instead of lamellae Formation of periosteum: vascularized mesenchyme condenses onto external surface of woven bone and becomes periosteum

Question 66

Intramembranous ossification step 4 elaborated

Answer 66

Trabeculae just deep to periosteum thickens, forming a compact bone layer lamella. This layer is layer replaced by mature lamellar bone -spongy bone persists internally and it's vascular tissue becomes red marrow

Question 67

Example of bone remodeling

Answer 67

Bone breaks. Ends of break overlap. Doctors immobilize bones the way they are. After two weeks the ends have connected and the extra bone is gone, few weeks later bone is smooth as it was originally. This is remodeling. Osteoclasts removed the extra bone and the osteoblasts added bone

Question 68

Stages in Endochondral ossification

Answer 68

1. Hyaline cartilage with bone collar 2. Cartilage matrix deteriorating 3. Primary ossification center forms in diaphysis. Spongy bone is forming 4. Medullary cavity formed. Secondary ossification center formed in epiphysis 5. Only cartilage is left on the ephiphysis and in Epiphyseal plate (closure of epiphyseal plates/ replaced by bone (grow no taller -- F: 18 Y; M: 21 Y)

Question 69

Epiphyseal plate

Answer 69

Helps distinguish if male/ female. | Transparent on X-ray