Lab 4/Chapter 5: Tissues and Integumentary System Flashcards
Define “tissue”
a group of similar cells and cell products that arise from the same region of the embryo and work together to perform a specific structural or physiological role in an organ.
Name the 4 primary tissues types.
- epithelial
- connective
- nervous
- muscular
Define “histology”
the study of tissues and how they are arranged into organs
Define “extracellular matrix”
extracellular material (non-cellular component of tissues and organs–especially of connective tissue)
- made of fibrous proteins and a clear gel called “ground substance”
- hard matrix: cartilage and bone
- liquid matrix: blood and lymph
- fibrous matrix: (connective tissue proper) loose and dense
- ground substance contains interstitial fluid, proteins, and proteoglycans–typically refers to connective tissue
What are the functions of the integumentary system?
- regulation of body temperature
- (sweating, vasodilaton/constriction of blood cells)
- Protection
- against bacteria, chemicals, UV, light, abrasion, dehydration
- sensory receptors
- (touch, itch, temperature, pressure, pain, vibration)
- excretion and absorption
- pain patch, excrete waste)
- synthesis of Vitamin D
What are the two distinct regions of the integumentary system?
Skin (cutaneous membrane)
- epidermis
- dermis
Subcutaneous Layer
- hypodermis / superficial facia
- NOT a part of the skin!
What are the two layers of the dermis?
Papillary region
- finger-like projections (dermal papillae)
- Meissner’s (tacticle) corpuscles for light touch
Reticular Region
- oil glands, sweat glands, hair follicles
- lamellar / Pacinian corpuscles used for pressure (deep touch)
What are the five distinct layers of the epidermis?
- stratum corneum
- flat, dead cells filled with Keratin
- stratum lucidum (thick skin ONLY)
- clear layer
- stratum granulosum
- transitim (grainy) layer
- above this layer is dead, below it is alive
- stratum spinosum
- looks “spiny” on a slide
- stratum basale
- single layer of stem cells
- melanocytes are here
Identify the following: hair, arrector pili muscle, sebaceous gland, sudoriferous (sweat) glands, tactile (Meissner’s) corpuscles, and lamellar (Pacinian) corpuscle
…..
Give the function of the following:
hair, arrector pili muscle, sebaceous gland, sudoriferous (sweat) glands, tactile (Meissner’s) corpuscles, and lamellar (Pacinian) corpuscle
- Hair: vestigial, retain heat
- arrector pili: pulls hair upright
- sebaceous gland: secrete oil for hydration, empty into hair
- sudoriferous gland: apocrine for scent-stress and stimulation, merocrine/eccrine for cooling
- tactile corpuscles: light touch/sensory
- lammelar corpuscle: pressure / deep touch
Skin reference sheet
What is the location and function of epithelial tissue?
Location:
- epidermis
- inner lining of digestive tract
- liver and other glands
Function:
- protection (covers surface and lines body cavities)
- sensory input, absorption, makes up glands, filtration, and secretion
What are the characteristics of epithelial tissue?
- avascular (without blood supply)
- annervated
- fit closely together
- held by “watertight junctions” and desmosomes
- has a top (apical surface) and a bottom (basement membrane; basal surface on top of it)
- may have microvilli or cilia on apical
- good regenerative powers
What is the naming convention for epithelial tissue and what are the two exceptions?
- First name: number of layers, second name: shape of cells
- Exception: pseudostratified columnar epithelium (looks like baby trees growing next to tall trees–looks like many layers but is one) and transitionial epithelial tissue (bladder / ureters only)
What is the location and function of connective tissue?
Location
- most abundant and widespread tissue in the body
- various types and functions
Function
- Binding of organs
- support (bone)
- physical protection
- immue protection (battlefield under skin)
- movement (bone)
- storage (fat and bone)
- heat production (brown fat)
- transport (blood)
What are the characteristics of connective tissue?
- derived from mesenchyme (embryonic connective tissue)
- usually vascular (has blood vessels)
- except cartilage, ligaments, and tendons–only on membrane above
- good nerve supply
- cell separated by large amount of nonliving, extracellular matrix
What are the types of fibrous connective tissue?
Loose connective tissue
- more gel-like substance between cells
- areolar, reticular, and adipose
Dense connective tissue
- fibers fill spaces between cells
- dense regular connective tissue and dense irregular connective tissue
Describe the structure, function, and location of the following 3 loose connective tissue: areolar, reticular, and adipose
Areolar
- loose mesh, all 3 fibers
- wraps and cushions organs
- between muscles, passageway for blood and nerves, under epithelia
Reticular
- highly branched, retains shape
- mainly reticular fibers
- soft internal skeleton for lymph nodes, spleen, and bone marrow
Adipose
- fat
- like areolar but sparse fibers
- provides energy, insulation, and padding
- brown feat produces heat (juvenils only)
Describe the structure and location of the 2 dense connective tissues
Dense regular
- very strong
- mainly collagen, fibers run in one direction (parallel)
- tendons, ligaments
Dense Irregular
- mainly collagen, fibers run in all directions
- dermis, organ capsules
What are the 3 types of fibers?
- collagenous (tough, flexible, resist stretching)
- reticular (thin, spongelike / highly branched framework)
- elastic (thinnest) (tendency to recoil when tension is released)
What is the structure and function of hyaline cartilage connective tissue?
- most abundant cartilage
- rubbery matrix
- contains chondrocytes in lacunae
- costal (ribs) cartilage
- articular cartilage
- respiratory cartilage (nose, trachea, very breakable)
What is the structure and function of elastic cartilage connective tissue and fibrocartilage connective tissue, respectively?
Elastic cartilage
- similar to hyaline but elastic fibers
- flexible support
- outer ear, epiglottis
Fibrocartilage
- similar to hyaline but more collagen fibers
- strongest cartilage
- made to compress, shock absorber
- interverterbal discs, pubic symphysis, discs in knee (menisci)
What is the structure and function of osseous connective tissue and blood as connective tissue?
Osseous tissue
- bone tissue
- flexible
- hard, calcified matrix with collagen
- osteocytes in lacunae
- support, protection
- (work with muscles for movement, storage of fat and calcium, make blood cells)
Blood
- RBC and WBC in fluid matrix
- cardiovascular and immue systems
- plasma–blood’s ground substance
Photomicrograph of areolar connective tissue
Photomicrograph of adipose connective tissue
Photomicrograph of osseous connective tissue
Photomicrograph of blood connective tissue
What is meant by nervous and muscular tissues being “excitable” tissues?
they respond to stimuli by changing membrane potential
- membrane potential is electrical charge difference (voltage) that occurs across cell membrane
- in nerve cells ,changes in voltage result in rapid transmission to other cells
- in muscle cells, changes in voltage cause contraction
What are the 2 types of nervous tissue cells?
Neurons
- transmit electrical impulses
- a neuron will either go down a dendrite into the cell body or in axon away from cell body
Neuroglia
- support, protect, provide nutrients to neurons
What are the 3 types of muscle tissue and their characteristics?
Skeletal muscle
- striatied, multinucleate, voluntary
Cardiac Muscle
- striated, uninucleate, involuntary
Smooth (or visceral) muscle
- nonstriated, uninucleate, involuntary
What are the 2 types of fibrous connective tissues?
Loose connective tissue
- more gel-like ground substance between cells
- areolar, reticular, adipose
Dense connective tissue
- fibers fill spaces between cells
- regular/irregular
What are the specialized cells / membranes of connective tissue?
- fibroblasts (make fibers)
- chondroblasts (make cartilage)
- chondrocytes (cartilage cells trapped in lacunae)
- osteoblasts (make bone)
- perichondrium: membrane of dense irregular connective tissue that surrounds elastic and most hyaline cartilage (not articular) and contains reserve population of chondroblasts (to make more cartilage if needed)
What are the 3 types of cell junctions?
Tight junctions
- seal off intercellular space, “watertight”
- make it difficult for substances to pass between cells
- (e.g. hold urine in bladder)
desmosomes:
- keeps cell from pulling apart
- resist mechanical stress
- e.g. skin, cardiac muscle
Gap junctions
- communicating junction (for rapid communication)
- formed by ring-like connexon
- e.g. 4 regions of the heart know to contract at the same time
What are exocrine glands, their types, their structures, and examples?
- maintain their contact with surface of epithelium by way of a duct
- can be internal or external
-
merocrine gland: products are secreted by exocytosis
- used by eccrine sweat glands (cooling)
- suderiferous/apocrine gland: scent sweat gland
-
apocrine: fat droplets bud off plasma membrane
- (e.g. milk fat secretion from mammary)
-
holocrine: products are secreted by rupture of whole gland cell
- e.g sebaceous gland (oil)
-
merocrine gland: products are secreted by exocytosis
What are endocrine glands?
Glands that secrete hormones into the blood.
What are unicellular glands?
- glands found in an epithelium that is predominantly nonsecretory
- can be exocrine or endocrine
- e.g. mucus secreting goblet cells in trachea
What are membranes and their two types / substrates?
Membranes are thin sheets of tissue.
- Epithelial membranes
- 2 layers of epithelial tissue over connective tissue
- serosa, mucosa, and cutaneous membrane
- Connective tissue membranes
- made only of connective tissue
- synovial membranes (around every joint), meninges (brain and spine), periosteum (bone), perichondrium (cartilage)
Describe the strucure and function of the 3 epithelial membranes
- Mucosa
- lines cavities with connection to the outside
- produces mucus
- e.g. digestion, respiratory, urinary, reproductive
- Serous (serosa)
- lines cavities with no connection to outside
- visceral
- parietal
- produces watery serous fluid
- lines cavities with no connection to outside
What are the two forms of tissue repair?
- regeneration: replacement of dead or damaged cells by the same type of cell as before
- fibrosis: replacement of damaged cells with scar tissue (does not restore function)
What tissues are good / bad at repair?
- Good: epithelial, bone, areolar, dense irregular
- Moderate: dense regular, smooth muscle
- Poor: cartilage, skeletal muscle
- Almost none: cardiac muscle, neurons
What are the functions of epithelial tissue?
- line cavities, surfaces of organs, skin
- sensory input
- secretion and absorption
- makes up glands
What are the functions of connective tissue?
- protection
- binding and support
- insulation
- transportation
- most adundant and widespread tissue in the body
