Unit 2 Lecture Flashcards
What are the layers of skin in order from deep to superficial? Which is only found in thick skin? What are the cells found in each layer?
- Stratum basale - keratinocytes, melanocytes and tactile epithelial cells
- Stratum spinosum - keratinocytes, macrophages
- Stratum granulosum - flattered keratinocytes, lamellar granules, keratohylaine
- Stratum lucidum - ONLY IN THICK SKIN - dead keratinocytes w/ lots of keratin
- Stratum corneum - dead, flat keratinocytes that are mostly keratin
What are the cells found in the epidermis and what are their functions?
Keratinocytes - produces keratin
Melanocytes - produces pigment called melanin
Langerhans - recognize invading microbes and destroy them
Merkel - tactile disks that detect touch
What are the two regions of the dermis? What are the types of tissue found in the dermis?
papillary - superficial layer, areolar CT
reticular - deeper layer, dense irregular CT
Describe the papillary region of the dermis. What are dermal papillae?
dermal papillae - nipple like structures that increase the SA of the papillary region
- made of areolar CT
- has extensive blood network to supply stratum basale
- contains Meissner corpuscles - nerve endings that are sensitive to touch, and free nerve endings
complementary to epidermal rides - located on palms, soles, fingers (thick skin)
- increased grip and sensitivity for high mechanical stress
Describe the reticular region of the dermis. What are some of the things that reside in this layer?
made of thick bundles of collagen fibers fibroblast and wandering cells
- made of irregular dense CT
- contains some adipose, elastic fibers, blood vessels and nerves
- houses sebaceous glans and sweat glands
What is the hypodermis? What’s another name for it? What are some of its functions?
deep to the dermis, AKA subcutaneous
- contains adipose and areolar CT
- attaches the skin to underlying tissues and organs
What are the types of skin pigment? What are the types of melanin? Where is melanin produced?
melanin - produced by melanocytes in stratum basale
- pheomelanin - yellow to red
- eumelanin - brown to black
Hemoglobin - red pigment in RBC
Carotene - yellow organs pigment stored in stratum corneum and adipose tissue
What is hair made of and what influences its thickness and distribution?
composed of dead keratinized epidermal cells
genetic and hormonal factors determine thickness and distribution
What are the three major parts of hair?
Shaft - above skin surface
Follicle - below level of the skin
Root - penetrates the dermis, contains epithelial and dermal root sheath
Describe the layers of hair from inside out.
medulla - contains pigment
cortex - elongated cells
cuticle - thin
hair follicle:
- epithelial root sheath has external part (continuation of epidermis) and internal (tubular sheath of epithelium)
- dermal root sheath
Describe the layers of the hair bulb from the inside out.
Papilla of the hair - contains blood vessels
hair matrix - matrix keratinocytes proliferate to grow hair
- layer also contains melanocytes for pigment
forms medulla and has same layers as hair
What are the stages of hair growth?
Growth stage - cells of hair matrix divide
Regression - cells of matrix stop dividing
Resting stage - in between regression and growth - old hair falls out and new hair grow
What are the types of hair?
Lanugo - covers the fetus
Terminal - long, coarse pigmented hairs - eyebrows, lashes, scalp, post puberty: axilla, and pubic
Vellus - fine, short hairs on rest of body
- after puberty can change to terminal on face, limbs and chest of men
Describe sebaceous glands. Where are they? What do they secrete? What is their function? When are the onset?
Location: lips, glans penis, labia major, tarsal glands, small in trunk and limbs, absent in palms and soles
Secretes sebum - mix of triglycerides, cholesterol, proteins, inorganic salts
Function: prevents hairs from drying out, H2O loss, skin softening, inhibits some microbial growth
Onset - active during puberty
Describe the eccrine sweat glands. Where are they? What do they secrete? What is their function? When are the onset?
Location: throughout body, esp forehead, palms and soles
Secrete - perspiration: H2O, ions, urea, uric acid, ammonia
Function: regulated body temperature, waste removal, stimulated during emotional stress
Onset: soon after birth
Describe apocrine sweat glands. Where are they? What do they secrete? What is their function? When are the onset?
Location: axilla, groin, areolae, bearded region of face, clitoris and labia minora
Secrete: perspiration but with more lipids and proteins
Function: stimulated during emotional stress and sexual excitement
Onset: Puberty
Describe the ceruminous glands. Where are they? What do they secrete? What is their function? When are the onset?
Location: external auditory canal
Secrete: cerumen - ear wax
Function: impedes entrance of foreign bodies into external ear canal, waterproof, prevent microbes from entering cells
Onset: soon after birth
What are nails made of?
Describe the following of the nail: nail matrix, nail root, eponychium, lunula, nail bed, nail body, free edge, hyponychium
Keratinized epidermal cells
nail matrix - epithelium proximal to nail root, divides to grow nail nail root - portion not visible eponychium - cuticle lunula - white moon nail bed - below the nail plate nail body - visible portion of nail free edge - nail tip hyponychium - secures nail to finger tip
What are the functions of the skeletal system?
- provide support
- protests internal organs
- assist in movement with muscles
- mineral homeostasis - stores and releases Ca and P
- participates in blood cell production (hemopoiesis)
- stores triglycerides in adipose cells of yellow marrow
What are the different types of bones? Provide specific examples.
- flat bones - cranial, sternum, scapula, ribs
- long bones - femur, ulna, metacarpal, phalange
- short bones - tarsals and carpals
- irregular - vertebrae and sacrum
- sesamoid - patella
What are the different types of cartilaginous tissue in the epiphyseal plate?
From epiphyseal plate to diaphysis, there is the: zone of resting cartilage zone of proliferating cartilage zone of hypertrophic cartilage zone of calcified cartilage
Why is the periosteum such an important layer? Describe its structure and function.
helps bone growth, made of irregular CT
- outer periosteum layer contributes to the blood supply of your bones and the surrounding muscles and contains nerve fibers
- inner layer helps to protect your bones and stimulates repair after an injury or fracture
What is the physiological significance of the epiphyseal plate and line?
epiphyseal plate - growth plate between epiphysis and diaphysis - elongates bone
when person is no longer growth, epiphyseal plate becomes epiphyseal line
What is the difference between red and yellow marrow?
red bone marrow - blood stem cells that can become RBC, WBC or platelets
yellow bone marrow - consists mostly of fat
What are the structures and functions associated with dense bone vs. spongy/cancellous
bone?
dense
- osteon functional units
- outside of bone
- has concentric, external circumferential (closer to periosteum), internal circumferential (close to spongy) and interstitial lamellae
- good for providing protection and support
spongy
- contain trabeculae that support and protect red bone marrow
- lightweight and provides tissue support
What are the roles of osteoclasts, osteoblasts, osteocytes, mesenchymal cells.
osteoclasts - remodel bones and cause them to release calcium
osteoblasts - bone building cells that secrete matrix
osteocytes - mature bone cells
mesenchymal - stem cells in bone marrow - can become osetoprogenitor cells - bone stem cells that differentiate into other cells
Describe the chemical composition of bone. Compare and contrast the organic and inorganic
components.
bone contains an abundant amount of extracellular matrix
extracellular matrix is 15% water, 30% collagen and 55% crystalized mineral salts (mostly Ca and P)
Describe intramembranous ossification
occurs in flat bones when CT membrane is replaced by bones (babies)
- ossification center forms - osteoblasts secrete extracellular matrix
- calcification - Ca and other final salts deposited and extracellular matrix calcifies
- formation of trabeculae - extracellular matrix developed into trabeculae that come together to form spongy bone
- development of periosteum: mesenchyme ate the periphery of the bone develops periosteum
Describe endocondral ossification
replaces cartilage with bone in the developing embryo and fetus
- development of cartilage model: mesenchymal cells develop into chondroblasts
- growth of cartilage model: chondrocytes divide
- development of primary ossification center: in diaphysis, cartilage replaced by bone
- development of medullary cavity - osteoclasts break down bone to form cavity
- development of secondary ossification center at epiphysis of bone
- formation of auricular cartilage and epiphyseal plate - both made of hyaline cartilage
Describe calcium homeostasis and the negative feedback loop
receptors - parathyroid gland cells - detect low [Ca] in blood - input
Control center - parathyroid hormone gene
output - gene is turned on, releases PTH
effectors:
- osteoclast - increase bone resorption
- kidneys - retain Ca in blood, excrete P in urine, produce calcitriol
Describe the following hormones: parathyroid, calcitriol, calcitonin. How does vitamin D affect bone growth?
parathyroid hormone: stimulated osteoclasts and calcitriol to be released by the kidneys
calcitriol: form of vitamin D, increases Ca absorption in kidneys
calcitonin: secreted by thyroid, inhibits bone reabsorption by osteoclasts
Vitamin D: becomes active calcitriol
How does calcium regulation influence the regulation of phosphate? What hormone is
involved in phosphate regulation?
calcium regulation influences the regulation of phosphate because they react in opposite ways. when Ca levels rise, P levels fall
parathyroid hormone is involved with P regulation
Describe the role of the following hormones in bone remodeling: estrogen, testosterone,
growth hormone. What are somatomedins/IGF’s?
sex hormones: stimulate osteoblasts and promote sudden growth spurt in teenage years, also shorts down growth at epiphyseal plate around age 18-21, contributes to bone remodeling
growth hormone: secreted by pituitary gland, promotes general growth of all body tissue by stimulating production of insulin like growth factors
IGF’s: secreted by liver, bones and other tissue when stimulated by GH, promotes normal bone growth by stimulating osteoblasts and protein synthesis
What are the different types of fractures? Generally, describe each. What is a Colle and Pott
Fracture?
Open - breaks through the skin
Comminuted - bone splintered, many pieces
Greenstick - partial fracture, one side of bone breaks other bends, common in kids
impacted - compressed, one end of bone forcefully driven into the other
Pott - distal end of fibula
Colles - distal end of radius - common in kids and elderly
Describe the four steps involved in repairing fractures.
- Reactive phase - formation of fracture hematoma
- Reparative phase - Fibrocatilaginous callus formation, new blood vessels form
- Reparative phase - bony callus formation
- Bone remodeling phase - healed fracture
What are fontanelles and where are they on the skull?
soft membranous gaps in skull
Anterior - top of head
posterior - near lamboid suture
sphenoid - near squamous
mastoid - near occipital scalp
What are bone depressions? Describe what a fissue, foramen, fossa, sulcus and meatus is.
depressions/opening - sites allowing passage of soft tissue
fissure - narrow slit for blood vessels or nerves
foramen - hole where blood vessels, nerves or ligaments pass
fossa - shallow depression
sulcus - furrow along bone surface that accommodates a blood vessel, nerve or tendon
meatus - tube like opening
What are processes? Describe a condyle, a head and a facet
process - projections or outward growths that form joints or attachment points for connective tissue
condyle - large round protuberance with smooth articular surface at one end of the bone
facet - smooth, flat, slightly concave/convex articular surface
head - usually rounded projection supported on neck of bone
What are processes? Describe crest, epicondyle, line, spinous process, trochanter, tubercle, tuberosity
process - projections or outward growths that form joints or attachment points for connective tissue
crest - prominent ridge/elongated projection
epicondyle - roughened projection above condyle
line - long, narrow ridge/border
spinous process - sharp, slender projection
trochanter - very large projection
tubercle - variably sized round projection
tuberosity - variably sized projection that has rough, bumpy surface
What bones make up the pectoral girdle? What bones make up the pelvic girdle?
pectoral: the scapula and the clavicle
Pelvic: hip bones, sacrum, coccyx
What is the difference between male and female coccyx?
Male - immovable and curved inwart
women - flexible and straight
What is flatfoot?
Foot has 2 arches - longitudinal and transverse - hold body weight
when the ligaments and tendons of the foot that are hold the bones in an arch are weakened, the height of the medial longitudinal arch may decrease or “fall.” The result is flatfoot
What are the structural classifications of joints?
- Fibrous
- sutures: dense fibrous CT
- syndesmoses - more dense fibrous CT ex. gomphosis (bone to teeth)
- interosseous membranes - broad sheet of dense fibrous CT ex. ulna/radius - Cartilaginous
- synchondrosis - hyaline cartilage; no movement ex. epiphyseal plate
- symphysis - fibrocartilage; some movement ex. pubic symphysis - Synovial - most common, cavity in between 2 bones
- articular cartilage on ends of long bones, synovial cavity btw articulating bones ex. hip, knee shoulder elbow
What are the functional classification of joints? How do they relate to the structural classification?
SAD
Synarthroses - no movement
Amphiarthroses - little movement
DIathroses - freely moveable
All fibrous (sutures, syndesmoses, interosseous membranes) are Synarthroses - they don’t move
Cartilaginous:
- synchondrosis - synarthroses - does not move
- symphysis - amphiarthroses - some movement
Synovial - all diarthroses - can move freely
What are the specific types of diarthrotic joints? Where are they found in the body? Is each uniaxial, biaxial, etc.?
Hinge - uniaxial, ex. ankle, elbow
Plane joints - found on articulating surfaces of the body ex. carpal bones
- biaxial
Pivot - rotation around longitudinal axis (i.e. shaking head no, atlanto-axial), uniaxial
condyloid - oval shaped projection in oval shaped depression, biaxial, wrist
Saddle - one bone is saddle shaped, metacarpal of thumb, biaxial
Ball and socket - shoulder and hip, triaxial
What are the structures associated with synovial joints? What is the function of each?
synovial cavity - allow free movement
articular cartilage - reduces friction between bones
synovial fluid - lubricates the joint, absorbs shocks, supplies O2 and nutrients to and removing CO2 and metabolic wastes from the chondrocytes, contains phagocytic cells
What other structures are found in joints such as menisci, bursae, and tendinous sheaths?
menisci - pads of fibriocartilage that split the synovial cavity in two
- shock absorption, better fit for articulating surfaces, adaptable surfaces for combined movements, weight and synovial lubricant distribution
bursae - sac-like structures filled with synovial fluid that cushion movement of one body part over the other
tendon sheaths - tube-like bursae that wraps around tendons subject to a great deal of friction
Describe the movements of synovial joints: flexion, extension, hyperextension, abduction, adduction, circumduction, rotation (medial and lateral)
Flexion - bending, decreasing angle
extension - straightening, increasing angle
hyperextension - excessive increase of angle
abduction - away from midline
adduction - toward midline
circumduction - in a circle
medial rotation - away from midline
lateral rotation - toward midline
Describe the special movements at synovial joints
temporomandibular - depression and elevation, protraction and retraction
foot - inversion, eversion, dorsiflexion, plantar flexion
hand - supination, pronation, opposition
depression - lowering jaw, elevation - raising jaw
protraction - pushing jaw out, retraction - pulling jaw in
inversion - tilting foot inward, eversion - tilting foot outward
dorsiflexion - flexing toward face, plantar - flexing away from face
supination - palm anterior
pronation - palm posterior
opposition - thumb holding down finger of same hand
What parts of the metacarpal and that carpal form the carpometacarpal joints?
base of the metacarpal, distal end of carpal
Regarding the blood supply of the bone, what type of arteries ender the diaphysis through Volkman’s canal? What Kind of artery enters at the center of the diaphysis?
Periosteal arteries enter through Volkmann’s
Nutrient after enters through center of diaphysis
What does articular cartilage cover on long bones?
epiphysis
What vitamin is needed for synthesis of bone protein? What vitamin is produced by the kidney to increase Calcium absorption?
K - bone protein
D - calcium absorption
What is the first healing phase of bone formation?
fracture hematoma
What vitamin is needed for the activity of osteoblasts during bone remodeling? What vitamin is needed for synthesis of collagen?
A - osteoblasts need for bone remodeling
C. - collagen synthesis
How many vertebral column curvatures does a fetus have? Adult?
Fetus - 1
Adult - 4
What are the first 7 ribs called? Next 5? Last 2?
1-7 - vertebrosternal - think that they attach to sternum
8-10 - vertebrochondral
11-12 - vertebral ribs (floating)
The spinous process of the _______ vertebrae is short, projected posteriorly where are the spinous process of the _______ vertebrate is long, thin and project inferiorly.
Lumbar, thoracic
What are the 2 functions of intervertebral discs?
absorb shock and separate vertebrae
What are the 3 functions of the paranasal sinuses?
- resonating chambers to hep voice
- increase SA for mucus
- help moisten
What are the 3 bones that form the nasal septum?
- vomer
- perpendicular plate
- septal cartilage
What is the congenital defect of the vertebral column where the laminae do not develop normally?
Spina bifida
IN an intervertebral disc, what is the outer ring of fibrocartilage called? What is the inner, soft nucleus called?
outer ring - annulus fibrosis
soft nucleus - nucleus pulposus
What canal goes parallel with the bones? What canal goes through the layers of bones?
Parallel - central canal
perpendicular - perforating/Volkmann’s