Anatomy Exam 2 pt. 1

Auburn- Shobnom A&P 1 (skin, skeletal 1&2)

What are the different types of skin markings?

friction ridges, flexion lines, freckles & moles, and hemangiomas

Friction ridges

fingerprints; unique pattern formed during fetal development that doesn’t change; allows manipulation of small objects

Flexion Lines

Flexor surfaces of the dights, palms, wrists, & elbows; marks sites where skin folds

Freckles & Moles

tan to black aggregation of melanocytes

Hemangiomas (birthmarks)

patches & discolored skin caused by benign tumors of dermal capillaries

What are the 3 types of hairs?

Lanugo, Vellus, Terminal

What is the function of hair?

warmth, sensation, protection from sun, signify sexual maturity, guard hair, eyelashes & eyebrows

Lanugo

fine, downy, unpigmented hair that appears on fetus in the last 3 weeks of development

Vellus

fine, replaces lanugo by birth; 2/3 of womens hair 1/3 of mens hair

Terminal

longer, coarser, and usually heavily pigmented

What are the 3 zones of hair?

Bulb, root, & shaft

What are the structures of hair & follicle?

medulla, cortex, and cuticle

Bulb

A swelling at the base where hair originates in dermis

Root

the remainder of the hair follicle

Shaft

the portion above the skin surface

Medulla

core of loosely arranged cells & alr spaces

Cortex

constitutes bulk of the hair;m consists of several layers of elongates keratinized cells

Cuticle

thin, scaly cells that overlap each other; free edges directed upward

What are the 3 stages of the hair cycle?

Anagen, Catagen, & Telogen

Anagen

growth stage; 90% of scalp follicles at any given time

Catagen

degenerative stage, mitosis in the hair matrix ceases & sheath cells below the bulge die

Telogen

resting stage

Alopecia

thinning of the hair or baldness

Hirsutism

excessive or undesirable hairiness in areas that are not usually hairy

male pattern baldness

the condition in which hair loss occurs from specific regions of scalp

What are the parts of the nail?

free edge, nail body, & nail root

What makes up fingernails & toenails?

stratum corneum packed with keratin

What are the different exocrine glands of the skin?

merocrine sweat , apocrine sweat, sebaceous, ceruminous, and mammary

Merocrine Sweat Glands

Simple tubular glands; watery perspiration that helps thermoregulation

Apocrine Sweat Glands

ducts that lead to nearby hair follicles; produce sweat that is thicker, milky, & contains fatty acids

sebaceous glands

sebum: oily secretion; glands with ducts opening into hair follicles

Ceruminous glands

produces ear wax; only in external ear canal

Mammary glands

milk producing glands that develop only during pregnancy & lactation

What are the 2 parts of a bone?

compact & spongy bone

What is the primary framework of the body?

skeletal system/ bones

Compact bone

dense or cortical bone; 80% of bone mass

Spongy Bone

cancellous or trabecular bone, located internal to the compact bone; appears porous; 20% of bone mass

What are the 2 types of cartilage

hyaline & fibrocartilage

What makes up hyaline cartilage?

attaches ribs to sternum, covers ends of some bones, within growth plates, model for bone formation

What makes of fibrocartilage?

weight-bearing that withstands compression; intervertebral discs, pubic symphysis, medisci of knee

Where is dense regular connective tissue used?

ligaments connect bone-bone, tendons connect muscle-bone

What are the functions of our bones?

support & protection, levers for movement, hematopoiesis, blood cell production, occurs in red bone marrow, storage of mineral & energy reserves, calcium & phosphate

What are the different classifications of bones?

long bones, short bones, flat bones, irregular bones

What is the gross anatomy of the long bone?

diaphysis, medullary cavity, epiphysis, metaphysis, epiphyseal plate

What is bone tissue (osseous)?\`

connective tissue that consists of cells, fibers, & ground substances

What is the hardening process of bone called?

mineralization or calcification

What does the diploe do?

spongy layer in the cranium; absorbs shock & marrow spaces lined with endosteum

What makes up spongy bone?

spicules & trabeculae; filled with red bone marrow

Red bone marrow

hematopoietic, reticular CT, developing blood cells, & adipocytes, in children( spongy bone & medullary cavity, in adults/only in selected areas of axial skeleton

Yellow bone marrow

product of red bone marrow degeneration as children mature, fatty substance, may convert back

What are the 4 different bone cells?

osteogenic, osteoblasts, osteocytes, osteoclasts

Osteogenic Cells

stem cells found in endosteum, periosteum, & in central canals

Osteoblasts

bone forming cells

Osteocytes

osteoblasts that have become trapped in the matrix

Osteoclasts

bone-dissolving cells found on the bone surface(ruffled border)

What are the 2 types of bone development?

Intramembranous ossification & Endochondral Ossification

Intramembranous ossification

Produces flat bones of skull & clavicle

Endochondral Ossification

during infancy & childhood, the epiphysis fill with spongy bone; cartilage limited to the articular cartilage covering each joint surface, & growth plate

What type of growth widens and thickens bones?

appositional growth

appositional growth

bones increase in width throughout life

\-deposition of new bone at the surface

\-osteoblasts lay down matrix in layers parallel to the surface

\-osteoclasts of endosteum enlarge marrow cavity

What percent of your bone are remodeled a year?

10%

What is bone remodeling?

repairs microfractures, releases minerals into blood stream, reshapes bones in response to use & disuse

Wolff’s Law

bone density determined by mechanical stresses placed on it & bones adapt to withstand those stresses

What happens during mineral deposition?

crystallization process, osteoblasts produce collagen fibers become encrusted with minerals

\-osteoblasts neutralize calcification inhibitors in bone matrix

\-first few crystals attract more calcium & phosphate from solution

What happens with abnormal calcification?

may occur in the lungs, brain, eyes, muscles, tendons, or arteries

\-calculus: calcified mass in an otherwise soft organ such as lung

How does mineral resorption work?

the process of dissolving bone & releasing minerals into the blood

\- performed by osteoclasts at the ruffled border

\-hydrogen pumps secrete hydrogen into the space between the osteoclasts & bone surface

\-acid phosphates enzyme digests the collagen

What is calcium homeostasis?

Phosphate is a component of DNA, RNA, ATP, phospholipids, & pH buffers

What is calcium needed for in the body?

Neuron communication, muscle contraction, blood clotting, exocytosis

What regulates calcium in the body?

calcitriol, calcitonin, & parathyroid hormone

What is hypocalcemia?

Vitamin D deficiency, diarrhea, underactive parathyroids, pregnancy & lactation, accidental removal during thyroid surgery

How much phosphate does the average adult have in their body?

500-800g

What lowers blood phosphate level by promoting its urinary excretion?

PTH

What are the 2 principle forms of phosphate?

HPO4-2 & H2PO4-

Why is their rapid growth during puberty & adolescence?

surges of growth hormone, estrogen, testosterone occur & promote ossification

Why do anabolic steroids cause growth to stop?

epiphyseal plate “closes” prematurely & results in an abnormally short adult stature

What are the 2 types of dwarfism?

achondroplastic & pituitary

Achondroplastic dwarfism

long bones stop growth in childhood; normal torso, short limbs

\-failure of cartilage in metaphysis

\-spontaneous mutation produces mutant dominant allele

Pituitary Dwarfism

lack of growth hormone; normal proportions with short stature

Rickets

soft bones due to deficiency of calcium salts

Osteogenesis Imperfecta

excessively brittle bones due to lack of protein & collagen

Stress fracture

break caused by abnormal trauma to a bone; ex. falls, athletics, & military combat

Pathological fracture

break in a bone weakened by some other disease; ex. bone cancer or osteoporosis

What are the 4 stages of healing bone fractures?

1: hematoma forms in the fracture

2: soft callus & new blood vessels form in the fracture

3: spongy bone forms & a hard callus surrounds

4: spongy bone converts to compact bone

When treating a fracture what is closed reduction?

procedure in which the bone fragments are manipulated into position without surgery

When treating a fracture what is open reduction?

Involves surgery to realign the bone with plates, screws, & pins

What is the most common bone disease?

osteoporosis

What is osteoporosis?

severe loss of bone density

What is the best treatment for osteoporosis?

estrogen replacement to slow bone resorption

What risks come along with starting estrogen replacement treatment?

increase risk of breast cancer, stroke, & heart disease