Structure formed by two or more tissues; has specific function and usually a recognizable shape
Skin consists of?
Dermis and epidermis
Epidermis is
Epithelium
Dermis is
CT layer
Papillary layer is
Superficial; loose CT
Reticular layer is
Deeper; dense irregular CT
What is hypodermis?
Subcutaneous layer or superficial fascia
Not part of the skin
What is the hypodermis composed of?
Loose CT and white adipose tissue
What is the function of the hypodermis?
Binds the skin to the underlying tissues and structure, stores fat, acts as a shock absorber, insulates the body, and protects the body
Fascia is what?
Fibrous membrane covering, support and separating muscles
What are the general functions of the skin?
� Protection
� Receive stimuli
� Excretion
� Temp regulation
� Synthesis is vit D
� Immunity
Skin + its derivatives = what?
Integumentary system
What is a system?
A set of interconnected or interdependent organs working together to perform a common function
What is the epidermis?
Outer layer of skin
What type of epithelium is the dermis?
Keratinized stratified squamous epithelium
What are the 4 types of cells found in the epidermis?
Keratinocytes
Melanocytes
Langerhan�s cells
Merkel cells
Keratinocytes are found?
Throughout the epidermis
Melanocytes are found?
In the deepest layer of the epidermis
Where are lagerhan�s cells (epidermal dendritic cells) found primarily?
Stratum spinosum
Name some characteristics about langerhan�s cells?
Star shaped
Bone marrow derive
Phagocytic cells (antigen presenting)
Interact with T cells (immune response)
Where are Merkel cell primarily found?
In the thin skin; epidermal and dermal junction (palms and soles)
Name some characteristics about Merkel cells
Structurally associated to langerhan�s cells but have small dense granules in cytoplasm
Associated with disc-like ending of a sensory nerve
Merkel cells + sensory nerve =
Merkel disc
Touch receptor
What are the layers of the keratinocytes in the epidermis of the think skin?
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
What is the stratum corneum?
Flattened non-nucleated, keratinized cells
�horny cells�
Protective layer
What is the stratum lucidum?
Thick skin, flattened dead cells, no nucleus, no organelles
What is the stratum granulosum?
2-5 rows of cells with granules, nucleus and organelles start designating
What is the stratum spinosum?
8-10 rows of cells; many junctional complexes, �prickle cells�
What is the stratum basale?
Base layer, single layer of cells, rest on the BL, mitosis is active, therefore continually renews cells
On the slides all skin areas will typically show:
Stratum basale, stratum spinousm, and stratum corneum
Meanocytes are located where?
Stratum basale and stratum spinosum or in the dermis
Melanocytes send processes between________.
Keratinocytes
Melanocytes produce _________?
Melanin
In the process of melanin production Tyrosinase converts
Tyrosine into a melanin precursor within a melanin granule
Melanin granules are transferred to
Kerinoctes
Granules accumulate in the __________________ region of the cytoplasm thus shielding the DNA of the dividing cell (and underlying tissue) from damage, potentially carcinogenic UV radiation.
Supranuclear
Melanin granules fuse with Lysosomes in the area; lysosomal enzymes breakdown the melanin and melanin is
Lost in upper epithelial cells.
What are the pigments that contribute to your skin color?
Melanin
Carotene
Hemoglobin
Melanin is?
The only pigment produced by the skin
Carotene is what?
Yellow to orange pigment
What area does carotene accumulate?
Stratum corneum and in hypodermis
What is hemoglobin?
Oxyhemoglobyn in erythrocytes � red
The number of Melanocytes per unit area is not influenced by sex or race. Differences in individual skin color may be related to?
Amount of pigment produced and dispersed
Number of melanin granules in Keratinocytes
(Rate of degradation)
Tanning refers to a darkening of the kin after exposure to UV light. This process involves?
Darkening of pre existing melanin and increase the rate of release
Increased rate of synthesis
UV light leads to an increase of Tyrosinase activity and increased melanin production
Albinism refers to the inability to produce melanin. What are some characteristics of this?
Inherited
Lacking Tyrosinase, or cant absorb tyrosine
Skin not protected from solar radiation, increased risk of skin cancer
Dermis is composed of CT, supports the epithelium, bound to the hypodermis, what does it contain?
BV, nerves, glands, and hair follicles
The dermo-epidermal junction is not smooth because of
Dermal papillae (DP)
Dermal papillae interdigitate with
Epidermal pegs
Epidermal pegs are?
Extensions of the epidermis into the dermas
Dermal papillae are?
Projections of the dermis into the epidermis
Dermal papillae increase the SA of contact and thusly
Reinforce the junction
The dermis has two layers with indistinct boundaries which are the
Papillary layer
Reticular layer
The papillary layer has what kind of thickness?
Superficial thin layer
The papillary layer has what kind of CT?
Loose CT � fibroblasts, mast cells and macrophages
Papillary layer has dermal papillae which may contain
Capillaries, free nerve endings and Meisners� corpuscle
Describe the Meissner�s corpuscle
Elongated receptor with a multilaminar stacking of supporting cells around a sensory nerve ending
Touch receptors
What is the reticular layer? And what kind of CT?
Deep thicker layer, dense irregular CT
Describe dense irregular CT found in the reticular layer?
Bundles of collagen and elastic fibers with fewer cells.
In between interlacing fibers of the CT in the reticular layer there are?
� White adipose tissue
� Nerves
� Vessels
� Epidermal derivatives
� Pacinian corpuscles
What is a Pacianian corpuscle?
Round receptor with a concentric layering of supporting cells around a sensory nerve ending
Pressure receptor
The fiber arrangement and composition of the reticular layer gives skin?
Strength, extensibility (ability to stretch), elasticity (ability to return to original shape and expands/contact
Innervations of the skin?
Afferent or sensory innervations
Efferent or motor innervations
What are adherent or sensory innervations?
Touch, pressure, temp and pain sensations
Meisner's and Pacinian � free nerve endings
Efferent or motor interaction?
Act on Integumentary effectors
Goosebumps or sweating
Effectors: muscle or gland
Rich blood supply of the dermis involves?
Rich capillary network in the papillary region � nourish epidermis � temp regulation
Epidermal derivates include
Structures formed for the epidermis � hair nails and skin
Integumentary glands
Sudoriferous or sweat glands
Sebaceous gland is associated with?
A hair follicle
What type of gland is a sebaceous gland?
Simple branched alveolar gland
Secretary portion in dermis
The duct of the sebaceous gland empties:
Neck of hair follicle, directly on skin
Sebum has what kind of secretion?
Holocrine
Accumulated lipids and cell fragments
Sebum acts as a?
Protective film
What does sebum do for the skin and hair?
Prevents drying, and keeps skin soft. Kills certain bacteria.
Sudorigerous or swear glands are widely distributed. There are 2 types
Eccrine sweat gland and apocrine sweat gland
Eccrine sweat glands are found everywhere except
Margins of lips, nipples, parts of external genitalia
What is the structure of the Eccrine?
Simple coiled tubular gland
What kind of secretion do Eccrine glands do?
Merocrine secretion
Describe the sweat of the Eccrine gland. And what it contains.
Watery; water, salts, and metabolic waster
What does the Eccrine gland help aid in?
Evaporative heat loss and waste elimination
Eccrine glands function thought-out life. True or false?
True.
Apocrine sweat glands are found where?
Axilla and anogenital regions
What is the structure of the apocrine gland?
Simple branched tubular
Describe the sweat of the apocrine gland. And what it contains
More viscous. Contains true sweat and fatty substances and proteins
Apocrine glands begin to function at puberty, true or false?
True
What is a modified sweat gland?
Ceruminous glands
Ceruminous gland is found where?
External auditory meatus
What is the structure of the ceruminous gland?
Simple coiled tubular gland
What kind of secretion does the ceruminous gland do?
Apocrine secretion
What is cerumen?
Ear wax
What is excreted by the cerumenious gland?
Semi solid fatty substance that prevents the eardrum from drying
Hair is what?
Elastic, cornified threads composed of protein
How does hair grow?
Discontinuously (periods of rest periods of growth) from hair follicle
The hair is associated with what?
Sebaceous gland and the arrector pili muscle
Nails are?
Flat cornified scales
What is the function of our nails?
Protective protein coverings over distal phalanges
Small injury in the skin involves the
Parenchyma
Cells enlarge and migrate across the wound
Cells continue to migrate until they are surrounded by other epithelial cells during skin wound healing what is it stopped by?
�contact inhibition�
Mitosis of basal epidermal cells occurs in response to
Epidermal growth factor which replaces migrated cells
The wound is resurfaced and there is ____________ when the parenchyma is involved.
No scar.
Large (deep) wound � involves?
Both the parenchyma and the stroma
What is the inflammatory phase in wound healing?
� Cot forms over the would and dries;
� Fibrin seals it;
� ends of cut held loosely together.
� Epithelial cells migrate under the clot..
� In the dermis : proliferation of cells and capillaries
What is the migratory and proliferative phases in large wound heading?
� Organization phase
� Clot becomes a scab
� Epidermis bridges wound
� Fibroblasts migrate along fibrin threads and synthesize fibers (scar tissue)
� Damaged BV will grow
� Form granulation tissue
Maturation phase or regeneration phase of the large wound healing.
� Scab soughs of
� Epidermis is restored
� Dermal scar remains
What is granulation tissue?
Area of active CT that fills the wound; delicate pink tissue that includes capillaries, macrophages and fibroblasts.
Skeletal tissue helps form?
The framework of the body
What is the function of skeletal tissue?
� Support
� Protect viscera
� Movement
� Provides sites of attachment for muscles
� Storage
� Houses bone marrow
What does skeletal tissue store?
Mineral salts (hydroxyaptites)
Red bone marrow gets its color from?
Presence of blood and blood forming cells
What is present in the red bone marrow?
Blood cells at different stages of development and some white adipose tissue
What is the only type of marrow in neonates? And what does it do?
Red bone marrow � active in production of blood
Where is red bone marrow found in adults?
Flat bones, sternum, ribs, clavicles, and part of os coxa
Proximal end of humerus and femur
What is the main function of red bone marrow?
� Hematopoiesis � production of blood cells
� Destruction of warn out erythrocytes
� Storage (in macrophages ) of iron � form hemoglobin in breakdown
Yellow bond marrow gets its color from?
Abundance of white adipose tissue
Most red bone marrow gradually changed into the yellow Varity and is present in?
Many cavities of the bones
Yellow bone marrow stored ?
White adipose tissue
Yellow bone marrow is not normally _________?
Hematopoietic
Yellow bone marrow can be replaced with red bone marrow if?
Severely bleeding or hypoxia
Osseous tissue is
Bone tissue
As a connective tissue, bone tissue has?
Matrix & cells
What is in the matrix of bone tissue?
Mineral salts, ground substance and collagen fibers
In the mineral salts of bone tissue that is
Hygroxyapatites = calcium salts
Calcium phosphate and calcium carbonate
In the ground substance of bone tissue there is?
Hylauronic acid and chondrotin sulfate
What are the types of cells in bone tissue?
Osteocytes
Osteobast
Osteoclast
What is an osteocyte?
Mature bone cell
What is an osteocyte encapsulated in?
Laminae of mineralized bond matrix � occupies a lacuna
What is a filopodial process?
Process of osteocyte
Fillopoial processes extend though? And are what?
Canaliculi, and are small tubular channels; radiate from lacunae
Processed of adjacent osteocytes are connected by junctional complexes which permit?
Intercellular flow of ions and small molecules
What is the function of the osteocyte?
Maintained of bone matrix
What is an osteobast?
Immature bone cell
What is the function of the osteoblast?
Synthesis of organic component of bone matrix � bone deposition � ground substance and collagen fibers therefore osteoid
Osteobasts are found where?
Only on the surface of the bone tissue
As osteobast release bone matrix what happens?
The cell becomes surrounded by matrix
Lacuna and canaiculi form.
Therefore it goes from osteoblast to osteocyte
What is an osteoclast?
Large, multinucleated, motile cell
Where is an osteocast located?
Only on the surface of bone tissue
What is the function of the osteoclast?
Bone resorption. Enzyme act on matrix and frees minerals
What is Howship�s lacuna?
Enzymatically etched depression
What does the periosteum do?
Covers outer surface of the bone except on the articular surfaces
What is compact bone?
Dense bone characterized by the presence of osteons
What is spongy bone?
Consists of bony spicules (trabeculae)
Bone spicules (trabeculae) are what?
Thin irregular plates of lamellar bone
What is endosteum do?
Lines cavities within bones
Osteon (haversains system) is what?
Structural and functional unit of compact bone; complex of concentric lamellae of bone tissue that surrounds a canal.
Central canal
Canal running though the core of each osteon; contains vessels and nerve fibers; runs parallel to the long axis of the bone; lined with endosteum
What is concentric lamellae?
Layers of bone matrix around the central canal
What is interstitial lemellae?
Layers of bone matrix that occur between osteons but are not associate with a central canal; remnant of a remodeled osteon
What is a perforating canal (Volkmann�s canal)?
Canal that runs at an angle across the long axis of a bone; connects the vascular and neural supplies of the periosteum to those in the central canals and marrow cavity; lined with endosteum
Long bone definition and example
Tubular: length > width
Body (shaft) + 2 ends (concave or convex)
Femur
Short bone definition and example
Cuboidal. Length = width
Usually 6 surfaces;
4 or less articular and 2 or more for tendon/ligament attachment or vessel entry
Carpal bone
Flat bone definition and example
Thin
2 plats of compact bone with spongy bone and marrow between them
Most fat bones help to for the walls of cavities
bones of calavaria and sternum
Irregular bone definition and example
Various shape
Vary in amounts o f compact bone and spongy bone
Vertebra
Sesamoid bone
Round or oval
Develops in tendons
Often round where tendons cross the end of llong bones in limbs (protects tendons from excessive wear and change angle of tends as it passes to attachment point)
Patella
Sutural or wormian bone
Small bone within the sutures of certain cranial bones
Accessory bones
Heterotrophic bone
Not part o the make skeleton
Ma develop in certain soft tissues and organs due to disease
May form in scars and with chronic inflammation
TB � bony tissue in lungs
Diaphysis is found what?
Shaft
Yellow bone marrow
Epiphysis is found where and is what?
Ends of long bones and is red bone marrow
Metaphysis is?
Where the epiphysis meets the diaphysis
Articular cartilage is
Hyaline cartilage on the articular surface
What is endosteum?
� Thin membrane that lines medullary cavity and canals
� Osteoblasts, osteogrenic cells, osteoclasts and reticular fibers
� Repair
What is the periosteum?
� Inner layer has osteoenic potency (osteoblasts present)
� Growth and repair
� Outer layer is dense fibrous CT structure
� Absent on articular surface
Line, definition, function, specific example.
Straight linear elevation
Attachment site
Intertrochanteric line
Ridge, definition, function, specific example.
Similar to a line, may be more pronounced
Attachment site
Medial supracondylar ridge
Crest, definition, function, and specific example.
Very prominent linear elevation
Attachment site
Iliac crest
Tuberacle , definition, function, specific example.
Small raised eminence
Attachment site
Greater tuberacle
protuberance, definition, function, specific example.
Swelling or knob
Attachment site
External occipital protuberance
Tuberosity , definition, function, specific example.
Large, round usually roughened elevation
Attachment site
Tibia tuberosity
Mallelous, definition, function, specific example.
Hammerhead-like elevation
Attachment site
Medial malleolus
Trochanter, definition, function, specific example.
Large blunt elevation; only on femur
Attachment site
Greater trochanter
Spine , definition, function, specific example.
Sharp, slender process
Attachment site
Ischia spine
Process, definition, function, specific example.
Prominence or projection
Forms joints and attachment sites
Transverse process
Facet, definition, function, specific example.
Small, smooth, fat areas or surfaces
Forms joints
Articular facet for the rib on a thoracic vertebra
Condyle , definition, function, specific example.
Large rounder articular prominence
Forms joints
Media condyle of femur
Head, definition, function, specific example.
Rounded articular projection supposed on a constricted portion
Forms joints
Head of humerus
Fossa, definition, function, specific example.
Shallow depression
Passageway; forms joints
Olecranon Fossa
Sulcus or grove, definition, function, specific example.
Long furrow or ditch like depression
Passageway
Intertubercular grove
notch, definition, function, specific example.
Indentation at the edge of a bone
Passageway; forms joints
Ulnar notch
Foramen, definition, function, specific example.
Hole
Passageway
Mental foramen
Canal definition, function, specific example.
Foramen that has length;; has an orifice at each end
Passageway
Hypoglossal canal
Meatus , definition, function, specific example.
Tube like passageway that enters a structure but does not pass thought it
Passageway
External auditory meatus
Fissure, definition, function, specific example.
Narrow, cleft like opening between adjacent parts of bones
Passageway
Superior orbital fissure
Epicondyle, definition, function, specific example.
Prominence above a condyle
Attachment site
Medial epicondle of the humerus
Paranasal sinus, definition, function, specific example.
Air filled cavity within a bone; connected to the nasal cavity
Produces mucus; lightens the skull bones; acts a s resonant chamber for sound
Frontal sinus
Ramus, definition, function, specific example.
Projecting part of elongated process of a bone.
Attachment site
Mandibular ramus
What does the axial skeleton incude?
� Vertebral column
� Skull
� Hyoid bone
� Ribs and sternum
� Auditory ossicles
Types of vertebrae?
True or movable
Fixed or false
Name the true or movable vertebra, its location and how many there are.
Cervical � neck � 7
Thoracic � chest � 12
Lumbar � lower back � 5
Name the false or fixed vertebra , the location and how many there are.
Sacral � sacrum � 5 fuse to form 1
Coccygeal � coccyx � 4 fuse to form 1
What are primary curvatures?
Present during fetal development
What do primary curvatures include?
Thoracic curvature and perice or sacral curvature
What are secondary curvature?
Develop postnatal
What do secondary curvatures incude?
Cervical curvature and lumbar curvature
Cervical curvature characteristics
Anteriorly convex
Develops when a child can hold its head up(3-4mos) and sit upright (9mos)
Lumbar curvature
Anteriorly convex
Develops when a child beings to walk
More often pronounced in females
Why might abnormal spine curvatures occur?
Defect, disease, pore posture, unequal pull on vertebra column
What is kyphosis?
Hunchback
Dorsally exaggerated thoracic curve
What is lordosis?
Sway back
Exaggerated lumbar curve
What is scoliosis?
�twisted� disease
Exaggerated lateral curve
Primarily in thoracic area.
Ligaments include:
Anterior longitudinal ligament
Posterior longitudinal ligament
Ligament flavum
Describe anterior longitudinal ligament
Strong fibrous CT band that runs longitudinally along the anterior surfaces of the intervertebral discs and vertebral centre � firmly fixed
Atlas and base of skull ? pelvis surface or sacrum
Prevents hyperflection of vertebral column
If severely stretched in neck = whiplash
Describe posterior longitudinal ligaments?
Narrow fibrous CT band that runs longitudinally along the posterior surfaces of interveterbral discs
Somewhat weaker then the anterior longitudinal ligament � loosely attached
Atlas to sacrum inside the vertebral column
Prevents hyperflection of vertebral column
Describe Ligamen flavum?
Broad, fibrous (elastic) CT bands joining laminae of adjacent vertebra
Axis to sacrum
Helps to preserve upright posture
Intervertebreal disc is a ?
Cushion like pad between vertebrae
Anulus fibrosus
Concentric layers of fibrocartilage
Holds adjacent vertebrae together, proved stability, and limits the expansion of the nucleus pulposus
Nucleus pulposus
Gelatinous core of intevertebral disc
Acts as a shock absorber (becomes broader when compressed)
Note: herniated (prolapsed) disc =
Rupture of annulus and protrusion of nucleus
What is a centrum (body)
Largest part
Anterior directed
Superior and inferior surfaces are roughened for disc attachment
Verebral foraman?
Opening posterior to centrum on a single vertebra.
When foramina are in series the vertebral canal is formed � houses spinal cord
Vertebral arch (neural)?
Ach of bone that bridges the vertebral foramen posteriorly
Vertebral arch consists of what parts?
Pedicles
Aminae
What is a pedicle?
Bases or sides of the vertebral arch
What is a laminae?
Roof of the arch
What are the processes on a typical vertebrae?
Spinous process
Transverse process
Articular process
What is the spinous process?
Projects posterior from the midline of the neural arch
Arises as the junction of the laminae
What is the transverse process?
Projects laterally from the point where each lamina meets its pedicle.
What is the superior articular process?
Projects cranially
Each has an articular facet 9smooth joint surface on the articular process)
What is the inferior articular process?
Projects caudally
Each has articular facet (smooth joint surface on the articular process)
The inferior articular process of one vertebra articulates with the superior articular process of the vertebra below.
Superior vertebra notch
Constrict on the superior border of the pedicle
Inferior vertebra notch
Constricts on the inferior border of the pedicle
The intervebral foramen serves as?
A place for the spinal nerves to pass thought
Points of articulation on vertebra
Superior articular process � 5th lumbar vertebra
Apex of sacrum - coccyx
Auricular surfaces � illium of os coxa
Articular lateral surface � sacroiliac joint
Dorsal surface ridges: Medial sacral crest
Midline formed by fusion of spinous process
Dorsal surface ridges: Lateral sacra crest:
Lateralmost; remnant of transverse process
Intermediate sacral crest
In between represents fused articular processes
Just medial to dorsa sacral foramina
What is the Dorsa Sacral Foramina?
A series of openings between the intermediate sacral crest and lateral sacral crest
What is the sacral hiatus?
an upside down V shaped opening at the inferior end; point where lower laminae failed to fuse
What is the sacral promontory?
Projection from anterosuperior edge of the centrum of the first sacral vertebra
What is the ventral (pelvic) sacral foramina?
A series of openings that face anteriorly
What is the transverse lines (ridges)
Series of ridges; represents function lines for sacral vertebrae
What is the sacral canal?
Continuation of the vertebral canal into the sacrum; deep to the medial sacral crest
Sacral hiatus at the inferior end of sacral canal
What is the coccyx?
Tail bone
Provides attachment site for muscles of the perineum and Gluteal group
What is the bony thorax?
Bony cage formed by sternum, ribs, costal cartilages, and centra of thoracic vertebra.
Name the components of the sternum.
� Manubrium
� Body
� Xiphoid process
� Juguar notch
� Clavicular notch
� Cotal notches
� Sternal angle
What are the components of the rib?
� Head, superior and inferior articular facets.
� Neck
� Tubercle with articular facet
� Angle of rib
� Body of rib
� Costal grove
� Costal end
How to tell if the rib is the right or the left one?
