Lab -Tissues Flashcards
Four primary tissue types and their roles
the EPITHELIAL tissue:
covers the body surfaces; lines hollow organs, ventral body cavities and ducts and forms glands.
the CONNECTIVE tissue:
protects and supports the body and its organs, binds organs together, stores energy and provides immunity.
the MUSCLE tissue:
is responsible for movement and the generation of force.
the NERVOUS tissue:
carries information very quickly from one side of the body to the other.
2 basic types of epethilium
covering and lining epithelia
glandular epithelia
Where you can find Covering-lining epethilial cells :5 places
form a continuous layer over all the free surfaces of the body:
o the outer layer of the skin;
o the inner surface of the digestive and respiratory cavities;
o the inner surface of the heart and blood vessels;
o the walls and the organs of the closed ventral body cavities;
o the ducts of the exocrine glands.
What are the histological characteristic common to all epethilial tissues
- They are made of many cells close to each other (there is little extracellular material between epithelial cells).
- Several types of junctional specializations unite adjacent epithelial cells (tight junctions, desmosomes and gap junctions).
- With the exception of endocrine glands, o All epithelia have one free surface, called the apical surface, which is exposed at the body surface or at the lumen (space) of the body cavity, duct, tube or vessel.
o The lower surface of an epithelium (or basal surface) rests on a basement membrane: a non-living adhesive material secreted by the epithelium and the underlying connective tissue.
o There are no blood vessels within the epithelial layer.
o These cells are often characterized by frequent cell division because they are exposed to wear and tear and injury, necessitating replacement
Covering epethilium functions
- Epithelia protect underlying tissues against physical damage, drying out, chemical injury and infection.
- Epithelia allow and regulate the passage of materials (diffusion, absorption, filtration, secretion, excretion) into and out of the deeper tissues of the body which they cover or line. Oxygen, water, food, and waste must pass through one or more epithelial layers.
- Specialized epithelia form sensory parts of organs such as the eye, ear, mouth (taste buds), and nose (olfactory epithelium).
WHat is the material secreted by mot glands and some examples of products
The material secreted is usually a watery fluid containing substances such as salts, enzymes, hormones, mucus, fats, etc. The functions of glandular secretions are exceedingly diverse. Milk, insulin, sweat, saliva, calcitonin, tears and bile are all products of glands.
The classification of covering and lining epithelium is based on two or three features ___
- The number of cell layers
- The shape of cells
- Specialization of their cell surfaces (cilia, microvilli,etc.)
Two subsclasess in number of cell layers
one layer: simple epithelium
o several layers: stratified epithelium.
Classification of epethilium according to its shape
flat: squamous epithelium,
o square: cuboidal epithelium,
o rectangular: columnar epithelium,
o if the shape changes depending of the degree of stretching of the tissue: transitional epithelium.
Most often, it is very hard to distinguish the cell’s boundary on a light photomicrograph.. Nuclei are flat and parallel to the free surface: type of epithelium?
Squamous epithelium
Nuclei are oval and parallel to the axis of the cell and situated at its base: type of epithelium
Columnar
the nuclei are round and situated in the middle of the cell: type of epithelium
cuboidal epithelium.
Describe simple epithelium: how many cell layers, where found, function
Being composed of one layer of cells only, they are very thin. They are found in areas of minimum wear and tear. Their main function is to allow passage of substances between the lumen and the surrounding tissues.
Describe stratified epithelium: how many cell layers, function
Being composed of several layers of cells, they are very thick. Their main function is to protect the tissues that they cover. The shape of the cells closest to the basement membrane is quite different from that of the cells at the top, near the lumen.
how can you further classify the stratified epithelia? if they have different type of cells in the base and int he lumen
stratified epithelia are further classified according to the shape of the cells at the free surface.
Simple squamous epithelium has how many layers, what nucleus
One layer of flat cells (one flat nucleus)
Where simple squamous epithelium is found
in the alveoli of the lungs, in the kidney glomeruli, in the lining of the heart, blood vessels and lymphatic vessels and in the lining of the ventral body cavities
Structure of simple squamous epithelium allows it (function)
Because this epithelium is the thinnest of all, it is well adapted for diffusion (for example gas exchange between alveoli and blood in the lung or exchange of waste and nutrients between blood and surrounding tissues), filtration (of plasma in the kidney glomeruli to produce urine), and secretion (of a lubricating substance in the lining of the body cavities).
Simple cuboidal epithelium is composed of
one layer of cuboidal cells (having one round nucleus).
Where simple cuboidal epithelium is found
small glands, kidney tubules and ovary surface.
Function of simple cuboidal epithelium
adapted for secretion and absorption of substances (for example to give urine its final composition, it moves substances in and out of the kidney tubule).
Structure of simple squamous epithelium
composed of one layer of columnar cells (having one oval nucleus). They can be ciliated or non-ciliated.
What structure does non-ciliated simple columnar epithelium has and what is its function
The non-ciliated, simple columnar epithelium contains microvilli on the apical surface of its cells. Microvilli increase the surface area of the epithelium
Where non-ciliated simple columnar epithelium is found
lining the digestive tract and is involved in absorption of digested food products and in secretion of mucus, enzymes and other substances. It is also found lining the ducts of some glands.
Where ciliated simple columnar epithelium is found and function
in the small bronchi, the uterine tubes and part of the uterus. It is involved in the secretion of mucus and other substances and in moving mucus or female reproductive cells.
How many cells is there in simple pseudostratified epithelium
This epithelium has only one layer of cells: all its cells rest on the basement membrane, but it appears stratified because the cells are of different heights and their nuclei are at different levels. They
Where is non-ciliated pseudostratified epithelium is found
lining part of the male urethra and ducts of large glands.
Ciliated pseudostratified epithelium found in
It is found in the trachea, primary bronchi and in most of the upper respiratory tract and is involved in secretion and propulsion of mucus.
Composition of stratified squamous epithelium
has several layers of epithelial cells, but the surface layer of this epithelium is composed of flat cells. It is the thickest of all the epithelia and its function is protection.
The cells of the surface layer may or may not contain keratin, a tough protective protein which prevents water loss, is resistant to friction and repels bacteria.
Keratinized epithelium is found in
forms the epidermis of the skin.
non-keratinized stratified squamous epithelium lines ___
wet surfaces subjected to abrasion, such as the lining of the mouth, esophagus, tongue, part of the epiglottis and vagina
Where is stratified cuboidal epithelium is found and its role
It is found in the largest ducts of sweat glands, mammary glands, salivary glands and in parts of the male urethra.
Role is protection
Role of stratified columnar epithelium and where it is found
Very rare: it lines part of the urethra, large ducts of some glands, portion of the conjunctiva of the eye.
Its roles are protection and secretion.
Stratified transitional epithelium is found and function
It is found lining surfaces of organs subjected to stretch, such as the bladder, the ureters and part of the urethra.
It allows for distension of the urinary organ.
How transitional epithelium will look like in stretched and unstretched states
It will look like a stratified squamous epithelium if it is stretched or a stratified cuboidal epithelium if it is unstretched.
Endocrine glands secrete what and where
their products, called hormones, are secreted directly into the blood and circulate throughout the body to their target areas
Most endocrine glands are ____ derivatives
Epithelial
How endocrine glands are formed
invagination from an epithelial sheet and initially have ducts connecting them to the free surface of the epithelial sheet. During embryonic development, they will lose their ducts and thus are called ductless glands
How will you see endocrine glands
they look like any stratified epithelial tissues with one big difference: THEY DO NOT HAVE A FREE SURFACE…. and are surrounded directly by other tissues
Exocrine glands excrete their products where
release their products onto the free surface of the skin or of the open cavities of the body such as the digestive, respiratory or reproductive tracts
What is the most abundant of primary tissues
Connective tissues
What is the distinguishing characteristic of connective tissue
Far apart and a lot ECM
Where do you find connective tissue?
everywhere in the body
4 functions of connective tissue
- Binding,support and packaging
- Protection,defense,repair
- Insulation
- Transportation
What connective tissue surround and bind organs and tissues
Connective tissue fibers form capsules and membranes which surround organs, and form
ligaments and tendons which bind bones to each other or to muscles. They also form the 3-
dimensional fibrous mesh which supports cells inside large soft organs such as the liver and spleen.
Bone and cartilage support body organs. The delicate and fragile areolar connective tissue forms a soft
packing around organs.
What is scar tissue
Type of connective tissue which fills the space where the original tissue does not regenerate
What the skull
a bony chamber which protects the soft brain tissue.
What is an inflammation
a defensive response of connective
tissue at the site of infection or injury.
What types of connective tissue is used as insulation
Fat cells or adipose tissue is a connective tissue which not only cushions body organs but also
insulates them and provides reserve energy fue
ECM between cells in connective tissue usually includes ___
fibers of one or more types
embedded in an amorphous ground substance.
4 classes of connective tissue
BLOOD, BONE, CARTILAGE, and CONNECTIVE TISSUE
PROPER.
3 criteria on the bases of which these tissues are identified
- The cells found in connective tissues
- Fibers
- The ground substance
2 subcategories in the cells found in connective tissues
the cells of the connective tissue per se which secrete the matrix or maintain it.
the accessory cells which are supported by the connective tissue.
What is the function of undifferentiated cells that end with -blast
This cell retains its capacity for division and secretes the matrix that is characteristic of the
tissue.
When cells turn form -blast to -cyst
once the matrix is produced, the undifferentiated cells lose their
capacity for cell division and become mature cells
Function of -cyste
mature cells are
less active and in general are responsible for maintaining the matrix in a healthy state.
Name some examples of -blast cells
Fibroblasts are
the primary blast cells of the connective tissue proper; hemocytoblasts are the primary blast cells of
the blood; chondroblasts and osteoblasts are the primary blast cells of cartilage and bone,
Where you can find accessory cells in connective tissue
Loose connective tissue
Name some accessory cells in the connective tissue
- Fat storing cells
- white blood cells; mast cells; macrophages; antibody-producing plasma cells
ECM is composed of
interstitial fluid, cell adhesion proteins
and proteoglycans
What is the role of fibers in matrix
Provide strength
Three types of fibers that are found connective tissue
Collagen
Elastic
Reticular (special type of collagen fibers ex; spleen and lymph nodes)
Collagen fibers: characterstics and function, other name
Extremely tough
They provide high tensile strength, which is the ability to resist longitudinal stress.
-White fibers
Elastic fibers: other name, where found, properties
can be stretched to one and one-half times their length, but recoil
to their initial length when released. They are found where greater elasticity is needed such as
the lungs and the blood vessel walls
-Yellow fibers
Role of reticular fibers
form a delicate branching network
supporting soft organs such as the liver and spleen.
ECM or
Ground substance
Role of cells adhesion proteins
allow the connective tissue cells to attach themselves to
matrix elements.
Role of proteoglycans
proteins to which polysaccharides are attached
These
polysaccharides can trap more or less water depending on their nature and form a substance that
varies from a fluid to a semi-stiff hydrated gel.
The more polysaccharides, ______ ground substance
The stiffer the ground substance is
Proper connective tissue subdivides into 2 groups
Loose Dense (tendons)
Loose connective tissue subdivides into
- Areolar
- Adipose
- Reticular
Dense connective tissue divides into
Regular
Elastic
Irregular
Cartilage subdivides into 4 categories
-Hyaline (trachea rings, joint surface of bone, larynx
)
-elastic(ear,epiglottis)
-Fibrocartilage (symphysis pubis joint; annulus fibrosus; menisci)
Two types of bones
Compact
Spongy
What are the histological characteristics common to ALL MUSCLE TISSUES?
- They are made of many cells close together (there is little extracellular material between muscle cells).
- They are well vascularized (lots of blood vessels).
- The cells are elongated.
- The cells contain myofilaments (contractile proteins)
How can you distinguish skeletal muscles
- very long rod-like cells(up to 30cm)
- striations perpendicular to the axis of the cell
- several nuclei present on the periphery of the cell
Striations in skeletal muscles reflect
the regular pattern of distribution of the myofilaments (contractile proteins) inside the cells
How skeletal muscles are bound together, where they attach to
Skeletal muscle cells are arranged in parallel, in bundles
tied together by connective tissue and anchored at both ends by tendons to bones or directly to kin (in the face)
What is the outcome of muscle constant contraction
-Maintaining a constant body temperature
How cardiac muscles can be described if seen under the microscope
- long cylindrical cells whose ends are split longitudinally
into a small number of branches - stiations perpendicular to the axis of the cell
- one or two nuclei present in the center of the cell
- intercalated discs
Intercalated discs have ___ jucntions
anchoring
desmosomes and gap junctions
How can see smooth muscles under the microscope
- spindle-shaped cells
- NO STRIATIONS
- one nucleus located in the center of the cell
Smooth muscles are found in
the walls of hollow organs (digestive and urinary tract organs, blood
vessels, uterus, etc…)
3 functions of nervous system
- it constantly monitors changes occurring both inside and outside of the body;
- it processes and interprets information and makes decisions about what should be done at each moment
- it carries the order of what should be done to muscles and glands.
What are the histological characteristics of the NERVOUS TISSUE?
- It is made of many cells packed closely together (there is little extracellular material between cells);
- Most of the cells are strongly branching
2 main cell groups in nervous tissue
Neurons
Glial cells
Role of neurons
they respond to stimuli - they conduct electrical impulses to and from all body organs and
from one area of the Central nervous System to another -
Structure of neurons
made of a cell body (containing the nuclei
and most of the organelles) and of cytoplasmic ramifications: the dendrites that receive stimuli and the axon
that generates nerve impulses and transmit them from one part of the body to another.
Function of glial cells
support, protect and bind neurons
Where do you find nervous tissue
- the brain
- the spinal cord
- the nerves and their associated ganglia.
- Sensory organs
What 2 cavities epithelial tissue cover
Thoracic
Abdominal
Functions of epithelial
Protection Sensory function Secretion- glandular epithelium Absorption Excretion
Epithelial layer attaches to an underlying layer of connective tissue by the basement membrane and is ___
Avascular
Mast cell function
Anti-inflammatory response
Macrophage role
Removal of cell debris
Glycosaminoglycans role
a major component of joint cartilage, joint fluid, and other soft connective tissue.
Describe stomach epithelial
Very thick mucosa, at the base if mucosa -glands
What is fascia
a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches, stabilizes, encloses, and separates muscles and other internal organs
name layers in stomach
Mucosa,submucosa, muscularis(mucsles)serosa
What is serosa
The inner layer that covers organs (viscera) in body cavities is called the visceral membrane. A second layer of epithelial cells of the serous membrane, called the parietal layer, lines the body wall.
Two kind of muscles in stomach
Circular
Longitudinal
Difference between serosa and adventitia
A serosa is a smooth membrane, composed of a simple squamous epithelium and a sparse layer of loose connective tissue, covering the external surface of an organ such as the stomach and small intestine.
An adventitia is a layer of loose connective tissue (fibrous and/or adipose) covering the external surface of an organ, serving to hold the organ in place and bind it to adjacent tissues and organs
WHat peptic cell secrete and when its enzyme is activated
Peptic cells are cells in the stomach that releases pepsinogen and chymosin. Pepsinogen is activated into the digestive enzyme pepsin when it comes in contact with acid produced by gastric parietal cells.
What cells secrete HCl
Parietal cells
How you determine if the tissue is simple or stratified
When 2 or more layers are present, of which the superficial most cells do not reach the basement membrane, the epithelium is classified as stratified
2 parts of kidney
Cortex and medulla
When do you find Brownman’s capsule
) is a cup-like sack at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine. A glomerulus is enclosed in the sac
Describe the structure of one nephron
Renal capsule is connected to proximal convoluted tubule and then distal convoluted tubule
What is crypt of Lieberkuhn
Glands which secrete various enzymes
8 endocrine glands
Pineal gland Pituitary gland Thyroid gland Thymus Adrenal gland Pancreas Ovary Tests
Types of grandular epithelium
- Apocrine
- Holocrine
- merocrine (eccrine)
How the product is released from apocrine gland
product pinches off and is released from Apex.
Examples of apocrine glands
- mammary
- hair follicle sweat
- goblet
Where hair follicle sweat glands are found
) located at the junction of the dermis and subcutaneous fat, from which a straight portion inserts and secretes into the hair follicle; produce an odorless, oily, opaque secretion that gains its characteristic odor upon bacterial decomposition
How the product if holocrine gland is released
Product collect in the cell, then when product is released the plasma membrane ruptures.
Example of holocrine gland
Sebaceous gland
How the product is released from merocrine glands and examples
secrete product through plasma membrane. Most common type.
Ex: salivary glands, gastric glands, sweat glands in body acting in cooling system (distinctly different than the apocrine sweat gland, it produces a clear, odorless substance, consisting primarily of water and NaCl.)
Sebaceous gland produce ___ to ____
Serum to lubricate skin and hair
By what type sweat glands are lined
The secretory parts are lined by simple cuboidal epithelium. The ducts are lined by stratified cuboidal epithelium
In spongy bone there is
Mineralized ECM
Loose connective tissue is found around
Blood vessels
Cartilage differs from other tissue in
that only one cell type is present this is the chondrocyte
What are lacunae house cells
lacuna hole or pit - is a small space containing a chondrocyte in cartilage or an osteocyte in bone.
Unlike other connective tissue, cartilage does not have ___
Blood vessels
Why cartilage heal slowly
The chondrocytes are supplied by diffusion, helped by the pumping action generated by compression of the articular cartilage or flexion of the elastic cartilage. Thus, compared to other connective tissues, cartilage grows and repairs more slowly.
explain stages of evolution of chondroblasts
The extracellular matrix of cartilage is secreted by chondroblasts, (chondro = cartilage), which are found in the outer covering layer of cartilage. As the chondroblasts secrete matrix and fibers, they become trapped inside it, and mature into cells called chondrocytes.
How can you see hyalurinic acid
Bluish matrix with tint-> gives the shiny appearance
What is perichondrium
a layer of dense irregular connective tissue that surrounds the cartilage of developing bone
role of dense fibers that fill the matrix of fibrocartilge
Shock-absorbing
Ens of the bone is called
Epiphysis
On the tip of epiphysis there is
Articular cartilage
There is a line inside spongy bone, what is it
Ephiphyseal line
The middle part of the bone is called
Diaphysis
What cells are embedded in calcified matrix of bone
Osteocytes
Growth of bones closes around (epiphysis line closes)
20 years
What is Haversian Canal
Blood vessels,nervesm connective tissue
What is Canaliculi
Small canal allowing for nutrients to travel between lacunae
What are lamallae
Concentric rings-form the bone matrix
Where osteocytes are located
Lacunae- spaces in the bone
How many percent in blood is plasma and formed elements
Plasma-55%
Formed elements-45%
Functions of blood
Transportation Regulation of body temperature Regulation of body pH White blood cells destroy bacteria Circulating blood tissue is formed in the red bone marrow by a process called hematopoiesis
Skeletal muscles are ___, when smooth muscles are ___
Multinucleated
One nucleas
What is pararosaniline-toluidine
is a dye with high affinity for acidic tissue components. It stains nucleic acids blue and polysaccharides purple and also increases the sharpness of histology slide images
In what cut you need to be in order to see tissues normally
Longitudinal
Nervous tissue is ___ in origin
Ectodermal
Specialized characteristics of nervous tissue
- Excitability
- Conductivity
Function of myelin
a substance rich in lipids (fatty substances) and proteinsthat forms layers around the nerve fibers and acts as insulation
Structure of neuron
Cell body: also called the soma, is the spherical part of the neuron that contains the nucleus.
Axon —transmits nerve impulse away from the cell body
Dendrites (one or more)—transmit nerve impulse toward the cell body and axon
Where is pia meter and arachnoid meter in the spinal cord
Pia meter- sharp ends of butterfly wings
Arachnoid meter- round ends
In white matter there is only ___
Glial cells
What is the most abundant cell type in sub-mucosa of stomach
fibroblast
What is mucous?
An important lubricant that protects the epithelium and also serves to bind the dehydrated ingesta to form feces, produced by goblet cells
Tubules in the kidney are lined with
Simple cuboidal epithelial cells
The capsule of the kidney is (epithelium)
Simple squamous
Fat is ___ (blood vessels)
Vascularized
Name different types of leucocytes and draw them
Lymphocyte Monocyte Eosinophil Basophil Neutrophil
Four main functions of glial cells
-Surround neurons and hold them in place
Supply nutrients and oxygen to neurons
Insulate( by producing myelin) one neuron frfom another
To destroy and remove dead neurons
Glial cells are ___ present than neurons
More
Hyaline cartilage is ___ of all types of cartilages, when fibrocartilage is ____, because
The weakest, the strongest
because it has alternating layers of hyaline cartilage matrix and thick layers of dense collagen fibres oriented in the direction of functional stresses.
Fibrocartilage does not have ___
Perichondrium
Where chondrocytes are found in elastic fibres
in a threadlike network of elastic fibres within the matrix.
Elastic cartilage has ___
Perichondrium
