Quiz 2 Flashcards
Histology
The study of tissues
4 main types of tissues
Epithelial, connective, muscular, and nervous
Epithelial tissue
Covers all surfaces of the body; external, inner lining of some organ systems, exocrine glands
Exocrine glands
Glands that secrete substances through a duct opening onto the epithelial surface (salivary, sweat, sebaceous/oil)
Epithelial tissue is characterized by…
Closely packed cells, little-no extracellular matrix, a basal layer which connects surface tissue to connective tissue, avascular, rapid replacement of damaged cells
Epithelial cell shapes
Squamous, cuboidal, columnar
Squamous cells
Very flat, scale-like cells in the upper part of the epidermis, which are constantly shed as new ones form
Cuboidal cells
Cube-shaped cells; found in the epithelium lining of the ducts and tubules
Columnar cells
Column-like/rectangular cells; some are ciliated, found in tissues and organs
Epithelial cell layers
Simple, stratified, pseudostratified
Simple cell layer
One layer; seen in diffusion/gas exchange
Stratified cell layer
More than one layer; seen in regions that are exposed to friction or stretch
Pseudostratified cell layer
Tissue with a single layer of irregularly shaped and sized cells, which gives the illusion of multiple layers; found in ducts of certain glands and the upper respiratory tract
Simple squamous epithelium
One layer of thin cells; allows materials to pass through by diffusion and filtration, and to create lubricating substances; prominent nucleus
Stratified squamous epithelium
Multiple layers of thin cells; lines areas where there’s a lot of abrasion
Simple cuboidal epithelium
One layer of cube-shaped cells; active in secretion and absorption of molecules in tubules, ducts, and glands because of their large surface area
Simple columnar epithelium
One layer of rectangular-shaped cells; specialized for in absorption in tissues and organs because of cilia (larger surface area)
Pseudostratified columnar epithelium
One layer of irregularly shaped and sized cells; nuclei of neighboring cells appears to be at different levels, giving the appearance of stratification; found in certain ducts and glands and the upper respiratory tract (goblet cells); secretes the main component of mucus
Connective tisse
Serves to hold in place, connect, and integrate the body’s organs and systems; consists of cells, ground substance, and protein fibers
Types of connective tissue
Dense, bones and cartilage, loose, and fluid
Dense connective tissue
Large amounts of fibers surrounding cells and provides elasticity and protection; includes tendons and ligaments
Bone and cartilage
Specialized cells (osteocytes and chondrocytes), very little ground substance
Ground substance
Fluid or semi-fluid portion of the matrix
Loose connective tissue
Shows little cell specialization and contains large amounts of ground substance and few fibers (also called areolar tissue); connects and surround organs, and makes up walls of blood vessels; includes adipose (fat) tissue
Fluid connective tissue
Blood and lymph fluid; specialized cells that circulate in a watery fluid containing salts, nutrients, and dissolved proteins; no fibers, only ground substance
Fibrocartilage
Thick collagen fibers surrounding the chondrocytes; provides compressibility between vertebrae, joints, and pubic bones, as it can take a lot of pressure
Elastic cartilage
Surrounds chondrocytes; has many more elastic fibers; provides firm support and elastic support (ex. outer ear and epiglotis)
Adipose connective tissue
Stores fat for energy and provides insulation; very little extracellular matrix; looks like simple squamous epithelial tissue, but nuclei are pushed off to the side and aren’t as obvious
Muscle tissue
Produces movement; capable of contracting and generating tension in response to stimulation
Muscle tissue is characterized by…
Excitability (receive and respond to stimulus), contractility (shorten with force), elasticity (recoil and return to original length), and extensibility (stretch/lengthen)
Muscle tissue is categorized by…
Cell type, location, and physiological activity
Types of muscle tissue
Skeletal, smooth, and cardiac
Skeletal muscle tissue
Cells are multinucleated and striated, under voluntary control, and usually attaches to bone
Cardiac muscle tissue
Cells are striated, single nucleated, and branched; under involuntary control; found only in the walls of the heart; connected by intercalated discs, which supports synchronized contraction of cardiac tissue (pumps blood)
Smooth muscle tissue
Not striated and are single nucleated; under involuntary control; makes up walls of interior organs; mixes and propels food through the digestive tract, moves urine through the urinary tract, and moves blood through blood vessels
Nervous tissue
Capable of sending and receiving electrical and chemical signals; part of the major communication system
Nervous tissue is composed of…
Neurons and glial cells
Neurons
Excitable neural cell that transfers nerve impulses; communication cell
Glial cell
Provides physical and chemical support to neurons and maintain their environment
3 parts of the neuron
Cell body (soma), dendrites, and axon
Integumentary system
Skin and its accessory structures (sweat and oil glands, hair, nails); covers and protects the body from the external environment
General functions of the integumentary system
protect against invasion and dehydration, regulation of body temperature, sensory detection, synthesis, excretion
Layers of the skin
Epidermis and demis
How does the integumentary system protect the body?
Keratinized barrier, immune cells, melanin, acid mantle
Integumentary system synthesis
Vitamin D3 from the sun, converted to calcitriol, which regulates bone growth
Integumentary system excretion
Sweat glands excrete salt, water, organic waste product of metabolism
Keratinization
Formation of a layer of dead, protective cells filled with keratin (surface of the skin)
Cutaneous membrane
Outer epidermis (superficial epithelial layer only containing epithelial cells) and dermis (beneath epidermis, mostly connective tissue)
Subcutaneous tissue
Loose connective tissue, hypodermis, not technically part of the cutaneous
Epidermal derivatives
cells that originally develop in the epidermis and sink inward during development to form hair, exocrine glands, and nail
Epidermis characteristics
Keratinized stratified squamous epithelium, avascular, and distinct layers
Cell types of the epidermis
Keratinocytes (produces keratin and most predominant cell in epidermis), melanocytes (produce melanin), langerhan cells (immune cells), and merkel cells (form touch receptors with sensory neurons)
Layers of the epidermis
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum
Stratum basale/germinativum
Deepest layer of the epidermis, made up of epidermal stem cells, single layer, firmly attached to the dermis below by the basement membrane
Stratum spinosum
Superficial to basale, 8-10 layers of keratinocytes bound by desmosomes
Stratum granulosum
Superficial to spinosum, 3-5 layers of flat dying cells, keratinization begins here
Stratum lucidum
Between granulosum and corneum, “clear” layer found only in thick skin of palms, soles, and digits; provides extra protection
Stratum corneum
Most superficial layer of the epidermis; 15-30 layers of flat dead cells filled with keratin; barrier to light, heat, water, chemicals, and bacteria; provides most of the epidermal thickness; continuously she and replaced in large groups or sheets of cells
Epidermal growth factor
Responsible for promoting the division of germinativum cells; accelerated production of keratin and stimulates epidermal growth and repair
Carotene
Orange-yellow skin pigment, accumulates in stratum corneum
Melanin
Yellow-brown, brown, or black skin pigment, produced by melanocytes, defense mechanism against UV radiation
Skin color and circulation
Hemoglobin is the protein in red blood cells; when circulation is good and blood vessels dilate, the skin is red; when circulation is poor and blood vessels constrict, skin pales
Jaundice
Yellow staining of skin and white part of eye
Pallor
Paleness
Cyanotic
Reduction in blood flow/oxygen; blueish tint
Erythema
Skin is red; infection, inflammation, allergies, etc.
Dermis
Located between the epidermis and the subcutaneous layer, composed mainly of connective tissue, contains blood vessels, hair follicles, glands, and nerves
2 components of the dermis
Papillary layer and reticular layer
Papillary layer
Superficial layer of the dermis; made of loose, areolar connective tissue; contains capillaries and sensory neurons
Reticular layer
Deep layer of the dermis; consists of dense irregular connective tissue (contains collagen and elastic fibers); contains blood vessels, lymph vessels, nerve fibers, smooth muscle, oil glands, sweat gland ducts, and hair follicles
Lines of cleavage
Linear clefts in the skin that indicate the direction of orientation of the underlying collagen fibers
Hypodermis
Connective tissue connecting the integument to the underlying bone and muscle (adipose and areolar connective tissue); stabilizes the position of the skin; provides insulation, shock absorption, and energy reserves
Major types of open wounds
Abrasions, incisions, lacerations, punctures, avulsions, and amputations
Abrasions
Scraping of skin on rough surface
Incisions
Sharp cut where edges are very clean
Lacerations
Cut that does not have clean edges
Punctures
Penetration of skin by sharp object
Avulsion
Skin is torn from tissues beneath is
Amputation
Removal of body part
Epidermal healing
Cells in stratum basale migrate to fill in where epidermal cells are missing, and divide rapidly until the wound is filled
Deep wound healing
Formation of blood clot; fibroblasts mobilize and proliferate to repair damaged tissue by depositing collagen fibers; blood capillaries increase blood circulation and oxygen supply, macrophages engulf foreign matter; scar formation
Scar
Collagen-rich skin formed after the process of wound healing that is different from normal skin
Keloids
Overproduction of collagen; raised scar
Skin graft
Surgically removed healthy skin that is used to cover a wound that cannot be closed with sutures or staples
Types of burns
Thermal, electrical, chemical, and radiation
First-degree/superficial burn
Only affects epidermis; localized redness, swelling, and pain; rarely serious and typically heal by themselves
Second-degree or partial thickness burn
Affect epidermis and upper portion of dermis; very painful; red, tan, white; listers abre characteristic (cause epidermis and dermis to separate and fluid enters the space)
Third-degree/partial thickness burns
Involve epidermis and all dermal layers/tissue; dry and leathery; gray-white, dark brown, black; charred appearance; very little to no pain, but surrounding areas are very painful
Fourth-degree/deep full-thickness burns
Extends past dermis to deep tissue, muscle, and bone; charred, hard to the touch; very severe; medical intervention necessary (surgery/skin grafts); permanent disability and often requires amputation
Hypothermia
Disruption of skin and its ability to thermoregulate; body temp drops below normal range and loses heat faster than it can produce
Hypovolemia
Severe loss of body fluid
Infection
Greatest risk of burn; keeping patients in a sterile environment, giving IV antibiotics, and debridement very important; can result in sepsis
Eczema
Group of medical conditions that causes inflammation and irritation of the skin; overactive immune system to irritants is expected cause
Psoriasis
Build up (plaques) of red patches covered with white scales
Acne
Skin condition due to infected sebaceous glands; inflammation of sebaceous glands
Decubitus ulcers
Sore on the skin that develops when regions of the body start necrotizing due to constant pressure and lack of blood supply
Impetigo
Bacterial infection most commonly caused by staph and strep
Viral infection examples
Herpes, chickenpox
Fungal infection examples
Athlete’s foot, ringowrm
Scabies
Parasitic infection; human mites infest the skin, burrow and lay eggs; eggs hatch and mite migrate to the surface
3 major types of skin cancer
Basal cell carcinoma, squamous cell carcinoma, and melanoma
Signs of aging on the integumentary system
Epidermal thinning, decrease number of immune cells, decreased vitamin D3 production, decreased melanocyte activity, reduced blood supply, decrease in subcutaneous fat, decreased function of hair follicles, reduction of elastic fibers, and slower repair rate
