2nd Semester - Integumentary System Flashcards
This term is used to describe a group of cells found together in the body. The cells within a tissue share a common embryonic origin.
Microscopic observation reveals that the cells in a tissue share morphological features and are arranged in an orderly pattern that achieves the tissue’s functions.
It may be also be described
as a group of cells that have similar structure and that function together as a unit.
Tissue
Four broad categories of
tissues:
- epithelial
- connective
- muscle
- nervous
A disruption of the structure is a
sign of injury or disease. Such changes can be detected through _, the microscopic study of tissue appearance, organization, and function.
Histology
The Four Types of Tissues
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
- Epithelial tissue is also referred to as _.
epithelium
, also referred to as epithelium, refers to the sheets of cells that cover exterior surfaces of the body, lines internal cavities and passageways, and forms certain glands
Epithelial tissue
_, as its name implies, binds the cells and organs of the body together and functions in the protection, support, and integration of all parts of the body.
Connective tissue
_ is excitable, responding to stimulation and contracting to provide movement, and occurs as three major types: skeletal (voluntary) muscle, smooth muscle, and cardiac muscle in the heart.
Muscle tissue
Three major types of Muscle tissue:
- skeletal (voluntary) muscle
- smooth muscle
- cardiac muscle in the heart
_ is also excitable, allowing the propagation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body.
Nervous tissue
The next level of organization is the _, where several types of tissues come together to form a working unit.
organ
The four types of tissues are exemplified in:
- nervous tissue
- stratified squamous epithelial tissue
- cardiac muscle tissue
- connective tissue in small intestine
brain, spinal cord, nerves
Nervous tissue
cardiac muscle, smooth muscle, skeletal muscle
Muscle tissue
Lining of GI tract organs and other hollow organs, Skin surface (epidermis)
Epithelial tissue
Fat and other soft padding tissue, Bone, Tendon
Connective tissue
Embryonic origin of tissues and major organs. What are the three germ layers?
Ectoderm, Mesoderm, Endoderm
Outside germ layer | Epidermis, glands on skin, some cranial bones, pituitary and adrenal medulla, the nervous system, the mouth between cheek and gums, the anus
Ectoderm
Skin cells
Neurons
Pigment cell
Ectoderm
Middle germ layer | Connective tissues proper, bone, cartilage, blood, endothelium of blood vessels, muscle, synovial membranes, serous membranes lining body cavities, kidneys, lining of gonads
Mesoderm
Cardiac muscle
Skeletal muscle
Tubule cell of kidney
Red blood cells
Smooth muscle
Mesoderm
Inner germ layer | Lining of airways and digestive system except the mouth and distal part of digestive system (rectum and anal canal); glands (digestive glands, endocrine glands, adrenal cortex)
Endoderm
Lung cell
Thyroid cell
Pancreatic cell
Endoderm
Note that _ originates in all three layers, whereas nervous tissue derives primarily from the ectoderm and muscle tissue from mesoderm.
epithelial tissue
Note that epithelial tissue originates in all three layers, whereas _ derives primarily from the ectoderm and muscle tissue from mesoderm.
nervous tissue
Note that epithelial tissue originates in all three layers, whereas nervous tissue derives primarily from the ectoderm and _ from mesoderm.
muscle tissue
A _ is a thin layer or sheet of cells that covers the outside of the body (for example, skin), the organs (for example, pericardium), internal passageways that lead to the exterior of the body (for example, abdominal mesenteries), and the lining of the moveable joint cavities.
tissue membrane
Membranes within connective tissue membrane:
Synovial membranes
The two broad categories of tissue membranes in the body are:
(1) Connective tissue membranes
(2) Epithelial membranes
Membranes within epithelial membranes:
- Mucous membranes
- Serous membranes
- Cutaneous membranes (skin)
These membranes line the body cavities close to the exterior of the body: the peritoneal, pleural, and pericardial cavities.
Serous membranes
These membranes line the digestive, respiratory, urinary, and reproductive tracts. They are coated with the secretions of mucous glands.
Mucous membranes
_, or the skin, covers the body surface.
Cutaneous membrane
The _ is formed solely from connective tissue.
connective tissue membrane
A _ is a type of connective tissue membrane that lines the cavity of a freely movable joint.
synovial membrane
These connective tissue membranes encapsulate organs, such as the _, and line our _.
kidneys; movable joints
_ line joint cavities and produce the fluid within the joint.
Synovial membranes
The _ effectively traps available water to form the synovial fluid, a natural lubricant that enables the bones of a joint to move freely against one another without much friction.
hyaluronan or hyaluronic acid or hyaluronate
_ in the inner layer of the synovial membrane release hyaluronan into the joint cavity.
Fibroblasts
Synovial membranes surround the joints of the _, _, and _.
shoulder, elbow, and knee
These mucous membranes line the body cavities and hollow passageways that open to the external environment, and include the _, _, _, and _ tracts.
digestive, respiratory, excretory, and reproductive tracts
The hyaluronan or hyaluronic acid or hyaluronate effectively traps available water to form the _, a natural lubricant that enables the bones of a joint to move freely against one another without much friction. This readily exchanges water and nutrients with blood, as do all body fluids.
synovial fluid
The _ is also a composite of connective and epithelial tissues.
mucous membrane
A substance found in the body that plays a key role in the structure and function of tissues.
Hyaluronic acid
The _ is composed of epithelium attached to a layer of connective tissue, for example, your skin.
epithelial membrane
_, produced by the
epithelial exocrine glands, covers the epithelial layer.
Mucous
Sometimes called _, these mucous membranes line the body cavities and hollow passageways that open to the external
environment, and include the digestive, respiratory, excretory, and reproductive tracts.
mucosae
A serous membrane is an epithelial membrane composed of mesodermally derived epithelium called the _ that is supported by connective tissue.
mesothelium
The underlying connective tissue, called the _ (literally “own layer”), help support the fragile epithelial layer.
lamina propria
_ secreted by the cells of the thin
squamous mesothelium lubricates the membrane and reduces abrasion and friction between organs.
Serous fluid
_ line the coelomic cavities of the body, that is, those cavities that do not open to the outside, and they cover the organs located within those cavities.
They are essentially membranous bags, with
mesothelium lining the inside and connective tissue on the outside.
Serous membranes
The skin is an epithelial membrane also called the _. It is a stratified squamous epithelial
membrane resting on top of connective tissue.
The apical surface of this membrane is exposed to the external environment and is covered with dead, keratinized cells that help protect the body from desiccation and pathogens.
cutaneous membrane
The _, is the serous
membrane in the abdominal cavity that covers abdominal organs and forms double sheets of mesenteries that
suspend many of the digestive organs.
peritoneum
Serous membranes are identified according to locations:
- three serous membranes line the thoracic cavity
- the two pleura that cover the lungs
- the pericardium that covers the heart
- the peritoneum
type of tissue that serves to hold in place, connect, and integrate the body’s organs and systems
connective tissue
connective tissue membrane
connective tissue that encapsulates organs and lines movable joints
skin; epithelial tissue made up of a stratified squamous epithelial cells that cover the outside of the body
cutaneous membrane
outermost embryonic germ layer from which the epidermis and the nervous tissue derive
ectoderm
innermost embryonic germ layer from which
most of the digestive system and lower
respiratory system derive
endoderm
epithelium attached to a layer of connective tissue
epithelial membrane
type of tissue that serves primarily as a covering or lining of body parts, protecting the body; it also functions in absorption, transport, and secretion
epithelial tissue
tissue membrane that is covered by protective mucous and lines tissue exposed to the outside environment
mucous membrane
microscopic study of tissue architecture, organization, and function
histology
areolar connective tissue underlying a mucous membrane
lamina propria
middle embryonic germ layer from which connective tissue, muscle tissue, and some epithelial tissue derive
mesoderm
type of tissue that is capable of contracting and generating tension in response to stimulation; produces movement.
muscle tissue
type of tissue that is capable of sending and receiving impulses through electrochemical
signals.
nervous tissue
type of tissue membrane that lines body cavities and lubricates them with serous fluid
serous membrane
connective tissue membrane that lines the cavities of freely movable joints, producing synovial fluid for lubrication
synovial membrane
group of cells that are similar in form and perform related functions
tissue
thin layer or sheet of cells that covers the outside of the body, organs, and internal cavities
tissue membrane
embryonic cells that have the ability to differentiate into any type of cell and organ in the body
totipotent
The integumentary system is the body system which surrounds you, both literally and metaphorically speaking.
integumentary system
The integumentary system is composed of the following parts:
- Skin
- Skin appendages
o Hairs
o Nails
o Sweat glands
o Sebaceous glands - Subcutaneous tissue and deep fascia
- Mucocutaneous junctions
- Breasts
The _ is the largest component of this system. It is an extensive sensory organ, which forms an outer, protective coat around the entire external surface of the body.
Skin
In fact, the skin is the largest organ of the human body, covering an area of _. It has a thickness between _, depending on location.
2 square meters; 1.5 and 5 mm
Functions of the skin:
- effective barrier against potential pathogens
- protects against mechanical, chemical,
osmotic, thermal and ultraviolet radiation damage (through melanin) - biochemical synthetic processes (vitamin D production and the production of cytokines and growth factors)
- controlling body temperature by increasing or decreasing the blood flow
- containing a large number of nerve terminals for touch, temperature, pain and other stimuli
- assists in locomotion and
manipulation
The skin is anatomically organized as follows, from superficial to deeper layers:
(Memorize these layers with the mnemonic: “British and Spanish Grannies Love Cornflakes”)
- Epidermis
o Stratum basale
o Stratum spinosum
o Stratum granulosum
o Stratum lucidum
o Stratum corneum
The _ (also called the stratum germinativum) is the deepest epidermal layer and attaches the epidermis to the basal lamina, below which lie the layers of the dermis.
stratum basale
The cells in the stratum
basale bond to the dermis via intertwining collagen fibers, referred to as the _.
basement membrane
The stratum basale is also called?
stratum germinativum
A finger-like projection, or fold, known as the _ is found in the superficial portion of the dermis. _ increase the strength of the connection between the
epidermis and dermis; the greater the folding, the stronger the connections made.
dermal papilla
The stratum basale is a single layer of cells primarily made of _.
basal cells
This is a cuboidal-shaped stem cell that is a precursor of the keratinocytes of the epidermis.
All of the keratinocytes are produced from this single layer of cells, which are constantly going through mitosis to produce new cells. As new cells are formed, the existing cells are pushed superficially away from the stratum basale.
basal cells
Two other cell types are found dispersed among the basal cells in the stratum basale:
- Merkel cell
- Melanocyte
This functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch.
These cells are especially abundant on the surfaces of the hands and feet.
Merkel cell
As the name suggests, the _ is spiny in appearance due to the protruding cell processes that join the cells via a structure called a desmosome.
stratum spinosum
A cell that produces the pigment melanin. Melanin gives hair and skin its color, and also helps protect the DNA in the nuclei of living cells of the epidermis from ultraviolet (UV) radiation damage.
Melanocyte
The _ interlock with each
other and strengthen the bond between the cells. It is interesting to note that the “spiny” nature of this layer is an artifact of the staining process. Unstained epidermis samples do not exhibit this characteristic appearance.
desmosomes
The stratum spinosum is composed of _ layers of keratinocytes, formed as a result of cell division in the stratum basale.
eight to 10 layers of keratinocytes
Interspersed among the keratinocytes of this layer is a type of dendritic cell called the _, which functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer.
Langerhans cell
The _ has a grainy appearance due to further changes to the keratinocytes as they are pushed from the stratum spinosum.
stratum granulosum
The cells (three to five layers deep) become flatter, their cell membranes thicken, and they generate large amounts of the proteins _, which is fibrous, and _, which accumulates as lamellar granules within the cells.
These two proteins make up the bulk of the keratinocyte mass in the stratum granulosum and give the layer its grainy appearance.
keratin; keratohyalin
The _ is a smooth, seemingly translucent layer of the epidermis located just above the stratum granulosum and below the stratum corneum. The keratinocytes that compose the stratum lucidum are dead and
flattened.
stratum lucidum
This thin layer of cells of stratum lucidum found only in the thick skin of the _.
palms, soles, and digits
These cells are densely packed with _, a clear protein rich in lipids, derived from
keratohyalin, which gives these cells their transparent (i.e., lucid) appearance and provides a barrier to water.
eleiden
The _ is the most superficial layer of the epidermis and is the layer exposed to the outside environment.
stratum corneum
The increased _ (also called cornification) of the cells in this layer gives it its name. There are usually _ layers of cells in the stratum corneum.
keratinization; 15 to 30 layers
The cells in this layer can
still be anchored to each other by _ which is why the peeling that occurs with a sunburn peels the damaged epidermal layers in one sheet.
The entire layer is replaced during a period of about _. Cosmetic procedures, such as microdermabrasion, help remove some of the dry, upper layer and aim to keep the skin looking “fresh” and healthy.
desmosomes; 4 weeks; microdermabrasion
The _ might be considered the “core” of the integumentary system (derma- = “skin”), as distinct from the epidermis (epi- = “upon” or “over”) and hypodermis (hypo- = “below”).
It contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands.
dermis
The epidermis is _ and cells of this layer must get their oxygen and nutrients from capillaries in the dermis.
avascular
The _ is made of loose, areolar connective tissue, which means the collagen and elastin fibers of this layer form a loose mesh with abundant ground substance supporting the hydration of the skin.
This superficial layer of the dermis projects into the stratum basale of the epidermis to form finger-like dermal papillae.
papillary layer
The dermis is made of two layers of connective tissue that compose an interconnected mesh of elastin and collagenous fibers, produced by _.
fibroblasts
Within the papillary layer are fibroblasts, a small number of ___. In addition, the papillary layer contains _, defensive cells that help fight
bacteria or other infections that have breached the skin. This layer also contains _,
_, and touch receptors called the _.
fat cells (adipocytes), and an abundance of
small blood vessels;
phagocytes:
lymphatic capillaries, nerve fibers, and Meissner corpuscles
Underlying the papillary layer is the much thicker _, composed of dense irregular connective tissue which resists forces in many directions attributing to the flexibility of the skin.
This layer makes up around 80% of the dermis and is well vascularized and has a rich sensory and sympathetic nerve supply. The reticular layer appears reticulated (net-like) due to a tight meshwork of
fibers.
reticular layer
Several areas of the body that are devoid of hairs:
palms, soles, flexor surface of the digits and specific parts of the reproductive organs
_ provide structure and tensile strength, with strands of collagen extending into both the papillary layer and the
hypodermis. In addition, collagen binds water to keep the skin hydrated.
Collagen injections and Retin-A creams help restore skin turgor by either introducing collagen externally or stimulating blood flow and repair of the dermis, respectively.
_ provide some elasticity to the skin, enabling movement.
Elastin fibers
The _ (also called the subcutaneous layer or superficial fascia) is a layer directly below the
dermis and serves to connect the skin to the underlying fascia (fibrous tissue) surrounding the muscles. It is not strictly a part of the skin, although the border between the hypodermis and dermis can be
difficult to distinguish.
The hypodermis consists of well-vascularized, loose, areolar connective tissue
and abundant adipose tissue, which functions as a mode of fat storage and provides insulation and cushioning for the integument.
Hypodermis
Hypodermis is also called?
subcutaneous layer or superficial fascia
_ is a thick connective tissue wrapping that surrounds skeletal
muscles anchoring them to surrounding tissues and investing groups of muscles.
Fascia
_ are filamentous cornified structures which grow out of the skin and cover most of the body surface.
Hairs
Two major types of hairs:
vellus and terminal
Hairs are important in ___.
sensing, thermoregulation and protection against injury and solar radiation
This hair type
is most easily observed on children and adult women and is colloquially known as _.
“peach fuzz”
The germinal matrix consists of _, which gives rise to the upper bulb.
pluripotent keratinocytes
The _ is the sac containing the hair, out of which it grows. It is actually a downgrowth of the dermis and contiguous with the epithelium. The hair follicles go through a cyclic activity of hair growth and loss.
hair follicle
_ do not project beyond their follicles in some of the areas, however, they are short and narrow and cover most of the surface of the body.
Vellus hairs
The _ is the lowest expanded extremity of the hair follicle that fits like a cap over the dermal hair papilla, enclosing it.
The dermal hair papilla is a cluster of mesenchymal cells giving rise to several capillaries, which form a capillary loop.
The hair bulb generates the hair and its inner root sheath.
hair bulb
_ are longer, thicker and more heavily pigmented. They are mostly observed on males but also in the axillary and pubic regions of both sexes.
Terminal hairs
The bulb consists of two parts:
germinal matrix
upper bulb
The _ is the structure out of which the nail plate grows. Cornified cells from the matrix are gradually extruded distally to form the nail plate.
nail matrix
_ are homologous to the stratum corneum of the epidermis and contain a variety of minerals, such as
calcium.
They consist of compacted and layered keratin-filled squames (scales). The arrangement and cohesion of the squames are responsible for the hardness of nails.
It consists of: the nail plate, nail
folds, nail matrix, nail bed and hyponychium.
Nails
The _ extends between the lunula (crescent shaped, white area of the nail bed) and the hyponychium (area under the free edge of the nail plate).
nail bed
As the cells from the matrix migrate
apically and differentiate further, they form several structures and layers. From the interior to the exterior, these include:
- Hair shaft
o Medulla
o Cortex
o Cuticle - Inner root sheath
o Cuticle
o Huxley’s layer
o Henle’s layer - Outer root sheath
- Glassy membrane (basement membrane of hair follicle)
The nail bed consists of two layers:
epidermis
dermis
Two types of sweat glands:
eccrine and apocrine
The distal margin of the nail bed is called
the _. There is a perfect match between the nail bed and plate, forming a seal, which
prevents microbial invasion and debris collection.
onychodermal band
The _ is directly attached to the periosteum of the distal phalanx and it is richly vascularized.
It also contains numerous sensory nerve endings, such as Merkel endings and Meissner’s corpuscles.
dermis
_ are small, tubular structures located in the skin. They are exocrine glands, hence they secrete substances on the epithelial surface via ducts. The glands produce sweat, which is important for thermoregulation.
Sweat glands
The majority of sweat glands are _.
They are long, unbranched, tubular structures with a highly coiled secretory portion situated deep in the dermis. A narrower duct emerges from the gland and it opens via a pore on the skin surface.
eccrine
These are large glands specifically located in the axillae, perianal region, nipples, periumbilical region,
prepuce, scrotum, mons pubis, labia minora, nail bed, penis and clitoris.
Similar to eccrine glands, these also consist of a secretory coil. However, the duct emerging
from the gland opens inside the pilary canal above the duct of the sebaceous gland or directly on the surface of the skin.
apocrine glands
_ are small saccular structures located in the dermis, which cover most of the body.
They consist of a cluster of secretory acini, which is continued by a duct which opens into the dermal pilary canal of the hair follicle.
The ducts can also open directly on the surface of the skin, as seen on the lips and buccal mucosa.
Sebaceous glands
Sebaceous glands secrete _, which is an oily and fatty secretion. _ is crucial in the epidermal barrier and the skin’s immune system.
Sebum
The _, also called the hypodermis, is a layer of adipose tissue attached to the deep
aspect of the dermis.
It increases the mobility of the skin, it thermally insulates the body, acts as a shock absorber and is a source of energy.
The hypodermis is filled with subcutaneous nerves, vessels and lymphatics. It specifically contains the platysma muscle in the head and neck.
subcutaneous tissue
These are regions of the body where there is a transition from mucosa to skin. At such regions, epithelium transitions to epidermis, lamina propria changes to dermis and smooth muscle becomes skeletal muscle.
They occur at orifices in areas like the lips, nostrils, conjunctivae, urethra, vagina,
foreskin and anus.
Mucocutaneous junctions
The _, also known as the mammary glands, are prominent, superficial structures on the anterior thoracic wall, seen especially in women. They also occur in men but are functionless.
They are located in the subcutaneous tissue overlying the pectoralis major and minor muscles.
breasts
genetic disorder that affects the skin, in which there is no melanin production
Albinism
type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis
basal cell
structure that forms an impermeable junction between cells
desmosome
extension of the papillary layer of the dermis that increases surface contact
between the epidermis and dermis
dermal papilla - (plural = dermal papillae)
layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing
blood vessels, hair follicles, sweat glands, and other structures
dermis
fibers made of the protein elastin that increase the elasticity of the dermis
elastin fibers
clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent
water loss
eleiden
outermost tissue layer of the skin
epidermis
connective tissue connecting the integument to the underlying bone and muscle
hypodermis
skin and its accessory structures
integumentary system
type of structural protein that gives skin, hair, and nails its hard, water-resistant properties
keratin
cell that produces keratin and is the most predominant type of cell found in the epidermis
keratinocyte
granulated protein found in the stratum granulosum
keratohyalin
specialized dendritic cell found in the stratum spinosum that functions as a macrophage
Langerhans cell
pigment that determines the color of hair and skin
Melanin
intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis
Melanosome
receptor cell in the stratum basale of the epidermis that responds to the sense of touch
Merkel cell
cell found in the stratum basale of the epidermis that produces the pigment melanin
Melanocyte
superficial layer of the dermis, made of loose, areolar connective tissue
papillary layer
deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen
and elastin fibers
reticular layer
skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an
autoimmune reaction that leads to loss of color in patches
vitiligo
