Tissues Flashcards
Epithelium types and functions?
epithelial- covering
connective- support
muscle- movement
nervous-control
Epithelial function?
- covers body surface or lines body cavity
- forms parts of most glands
- protection
- excretion/ secretion
- forms slippery surfaces
- absorption, filtration, and ion transportation
Special characteristics of epithelial tissue?
- cellularity: composed of cells with minimal matrix
- specialized contacts: cells joined by junctions
- polarity: cell regions of apical surface differ from basal surface
- supported by connective tissue
- avascular but innervated: epithelia receive nutrients from connective tissue
- regeneration: lost cells replaced by cell division
How do you classify epithelial tissue?
simple: one layer
stratified: multiple layers
squamous: wider than tall, flat
cuboidal: square
columnar: taller than wide, column
Types of epithelial tissue?
- simple squamous
- simple cuboidal
- simple columnar
- pseudostratified
- stratified squamous
- transitional
Types of simple squamous epithelium?
Endothelium: inner covering, lining hollow organs in circulatory system
Mesothelium: middle covering, lines peritoneal, pleural, and pericardial cavities and covers visceral organs
Function simple squamous epithelium?
- passage of materials be passive diffusion, osmosis, and filtration
- secrete in mucous membranes
Location of simple squamous epithelium?
- renal corpuscles
- alveoli of lungs
- lining of heart and blood vessels
- lining of ventral body cavities
Function and location of simple cuboidal epithelium?
- secretion and absorption
- kidney tubules, secretory portions of small glands, ovary surface
Function of simple columnar epithelium?
- may contain goblet cells
- absorption; secretion of mucous, enzymes
- ciliated type propels mucous or reproductive cells
Location of simple columnar epithelium?
ciliated: lines small bronchi, uterine tubes, and uterus
non-ciliated: lines digestive tract, gallbladder, ducts of some glands
Why is it called pseudostratified epithelium?
- nuclei lie at varying height giving the false stratified look
- only tall cells reach apical surface since they originate at basement membrane
Function of pseudostratified epithelium?
-secretion of mucous and propulsion of mucous by cilia
Location of pseudostratified?
ciliated: lines trachea, and upper respiratory tract
non-ciliated: ducts of male reproductive tubes and glands
Function of goblet cells?
- to secrete and produce mucin onto skin or into digestive tube
- mucous protects and lubricated body surfaces
- H2O + mucin= mucous
Properties of stratified epithelium?
- contains 2+ layers of cells
- major role of protection
- regenerate from basal layer
Types of stratified squamous epithelium?
keratinized and non-keratinized
Keratinized stratified squamous epithelium
- contains keratin (for protection)
- waterproof
- surface cells are dead, dry, and full of keratin
Non-keratinized stratified squamous epithelium
- apical layer and deeper layers remain moist
- forms moist lining of body openings
Functions of keratinized and non-keratinized stratified squamous epithelium?
- forms epidermis
- forms lining of mucous membranes (esophagus, mouth…)
Transitional epithelium
- basal cells cuboidal or columnar
- apical cells are squamous
- stretches and permits distension of urinary bladder
- lines inside of hollow urinary organs
What is the purpose of microvilli?
-increase SA which is important for secretion and absorption
Where are microvilli abundant?
in epithelial tissue of small intestine and kidneys
Purpose of cilia?
-to produce directed movement of material over the surface of epithelial tissue
What is the basement membrane?
- noncellular supporting sheet between the epithelial tissue and connective tissue
- selective filtering and scaffolding
Kartagener’s syndrome
- immotile cilia syndrome
- dynein arms fail to form
- leads to respiratory infections because cilia can’t sweep inhaled bacteria out of respiratory tract
What happens if diabetes is left untreated?
- basement membrane will thicken due to built up glucose
- evident in eye and kidneys
Types of connective tissue?
- connective tissue proper
- bone tissue
- blood tissue
- cartilage
Function of connective tissue?
- binding and support
- transportation
- compartmentalization
- protection and insulation of organs
- major site of body energy reserves
What makes up the extracellular matrix of connective tissue?
Ground substance:
-cushions/ protects, withstands compression or bathe all cells in body
Fibres:
-provide support
Where does connective tissue originate from?
mesenchyme (embryonic tissue)
Types of fibres that make up connective tissue?
collagen: tough and resist pulling forces
elastic: can stretch and return to original shape
reticular: strong but allow more give than collagen fibres, present in basement membrane
Types of connective tissue proper?
loose connective tissue
-adipose and areolar
dense connective tissue
-DICT, DRCT, elastic
What fibres and cells make up areolar connective tissue?
collagen, elastic, reticular fibres
fibroblasts (secrete matric and fibres), macrophages and mast cells (WBC)
fibres slow down harmful bacteria so WBC have time to get rid of them
Function of areolar connective tissue?
- wraps/ cushions organs
- holds/ conveys tissue fluid
- role in inflammation and infection
Where is areolar connective tissue found?
- under epithelia
- packages organs
- surrounds small nerves and blood vessels
- borders all other tissues in body
Function and location of adipose tissue?
- provides reserve food fuel
- insulates
- supports and protects organs
-under skin, around kidneys, behind eyes, within abdomen, in breasts, and heart
What fibres and cells make up DICT?
- irregularly arranged collagen fibres
- some elastic fibres
- fibroblasts
Function and location of DICT?
- withstand tension in many directions
- provide structural strength
- dermis of skin
- submucosa of digestive tract
- fibrous capsules of joints and organs
What fibres and cells make up DRCT?
- parallel collagen fibres
- elastic fibres
- fibroblasts
-poorly vascularized
Function and location of DRCT?
- attaches muscles to bone/ bone to bone
- withstands stress in one direction
- tendons/ ligaments
- fascia around muscles
Function and location of elastic connective tissue?
made up of elastic fibres
- allows recoil after stretching
- within walls of arteries and surrounding bronchial tubes
What cells make up cartilage?
chondroblasts and chondrocytes
Does cartilage have blood vessels or nerves?
No. They get their blood supply from surrounding perichondrium.
-no pain, but also no healing
Types of cartilage?
- hyaline
- elastic
- fibrocartilage
What fibres and cells make up hyaline cartilage?
- collagen fibres
- chondroblasts which produce matrix
- chondrocytes which lie in lacunae
Function and location of hyaline cartilage?
- supports and reinforces
- cushions
- resists repetitive stress
- fetal skeleton
- ends of long bones
- costal cartilage of ribs
- cartilages of nose, trachea, larynx
What fibres make up elastic cartilage?
-elastic and collagen
Function and location of elastic cartilage?
- maintains shape of structure
- allows great flexibility
- support external ear
- epiglottis
What fibres make up fibrocartilage?
- thick collagen fibres
- matric is similar but less firm than hyaline
Function and location of fibrocartilage?
-tensile strength and ability to absorb compressive shock
- intervertebral discs
- pubic symphysis
- discs of knee joint
What fibres and cells make up bone tissue?
- collagen fibres
- osteoblasts which secrete collagen fibres and matrix
- osteocytes which are mature bone cells in lacunae
- solid matrix
- well vascularized
Function and location of bone tissue?
- supports and protects organs
- provides levers and muscle attachment site
- stores Ca2+, minerals and fat
- marrow= bone cell formation site
-bones
What fibres and cells make up blood tissue?
- no fibres
- erythrocytes, leukocytes, platelets
Function and location of blood tissue?
- transport respiratory gases, nutrients, and waste
- within blood vessels and heart
What is scurvy?
- vitamin C deficiency
- vit. C is necessary for proper cross linking of molecules which make up collagen fibres
- result is weakened collagen and the supportive connective tissues in the body
Cutaneous membrane
- dry
- skin
Mucous membrane
- wet
- lines hollow organs that open to the exterior of the body
- epithelial sheet underlain with layer of lamina propria (areolar connective tissue)
Serous membrane
-wet
-simple squamous epithelium lying on areolar connective tissue
-line closed cavities
(pleural, peritoneal, pericardial)
What are the types of muscle tissue?
- skeletal
- cardiac
- smooth
Function and location of skeletal muscle tissue? Appearance?
- voluntary movement
- manipulation of environment
- facial expression
- skeletal muscles attached to bones
- multinucleate, obvious striations
Function and location of cardiac muscle tissue? Appearance?
- contracts to propel blood into circulatory system
- involuntary control
-occurs in walls of heart
- striated
- uninucleate
- cells interdigitate at intercalated discs
Function and location of smooth muscle tissue? Appearance?
- propels substances along internal passageways
- involuntary control
-walls of hollow organs
- spindle shaped with central nuclei
- no striations
- form sheets
What cells make up nervous connective tissue?
neurons
neuroglia (glue)
Function and location of nervous tissue?
- transmit electrical signals from sensory receptors to effectors
- brain, spinal cord, nerves
