Histology

which is more common in vertebrates, loose or connective tissue? What does it do?

In vertebrates, the most common type of connective tissue is loose connective tissue. It holds organs in place and attaches epithelial tissue to other underlying tissues.

what are goblet cells? where might you find them?

goblet cells produce mucous. they can be found respiratory tract, where they help moisten and humidify airway. They are also crucial inside lining of stomach where they protect stomach from HCl.

what is cartilage? where is it found?

is a flexible connective tissue found in areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the bronchial tubes and the intervertebral discs. It is not as hard and rigid as bone but is stiffer and less flexible than muscle, because of its rigidity, cartilage often serves the purpose of holding tubes open in the body. Examples of this include the cartilaginous rings of the trachea, including the cricoid cartilage

what are the 2 types of broad terms used for connective tissue?

loose connective and dense connective

what are the 2 types of glands? what are their roles

2 types are endocrine and exocrine. Endocrine glands secrete their product into the extracellular space. Exocrine glands secrete their products into a duct that then delivers the product to the lumen of an organ or onto the free surface of the epithelium.

name the 2 types of stratified squamous. What are the differences between them. Where is each found?

2 types are keratinized and non-keratinized. Keratinized contains layers of dead cells towards the top. Keratinized makes up epidermis hence the skins ability to slough off. It is found in areas prone to abrasion. eg oral cavity, vaginal and anal cavity. Non-keratinized has no dead cells. It is found in areas where the cells are bathed in fluid, such as the inside of the mouth. microscopically it has a brown layer of melanin.

name the types of specialized connective tissues?

Adipose, cartilage, bone, blood, lymph

How are glands formed ?

Glands are formed from the invagination/infolding of epithelium and subsequent growth in the underlying connective tissue.

name the types of loose connective tissue

Loose connective tissue is named based on the "weave" and type of its constituent fibers. There are three main types: Collagenous Fibers- made of collagen and bundles of fibrils that are coils of collagen molecules. Elastic Fibers - made of the protein elastin and are stretchable. Reticular fibers - join connective tissues to other tissues.

what are macrophages?

Most of our tissues contain a generous supply of macrophages, cells responsible for devouring particulate matter.

define cilia. Where might you find it? what is their role

cilia are fine motile hairs. Used to propel things. Found in airway linings, fallopian tubes etc. resemble hairs in that they lie on top of the tissue. they are used for propulsion.

where would you find columnar cells? what is their role?

columnar cells secrete mucous. You will find them in stomach lining where they protect against HCl acid and in intestines. they must be taller to increase surface area.

blood cells are considered to be what type of tissue?

connective

what is the role of connective tissue in the body?

connects, supports and binds parts of the body.

embryologically where does epithelium arise from?

ectoderm (epidermis) ->endoderm (GI tract) ->mesoderm (lining of body cavities)

why does epithelial tissue have no basement membrane?

epithelial tissue is avascular, therefore it is always located with connective tissue. The basement membrane is where epithelial and connective tissue join, and provides the blood supply.

name the 4 types of tissue we have

epithelial, connective, muscle and nervous

where would you find simple squamous? what is its role

found lining areas where passive diffusion of gases occur. e.g. walls of capillaries, linings of the pericardial, pleural,and peritoneal cavities, as well as the linings of the alveoli

what is the mucociliary escalator? why do we have it

innate immunological defense mechanism involving beating of cilia and flow of mucus from bronchioles, through the bronchi and trachea to the larynx, by which particulate matter is removed from the respiratory tract.

What are microvilli. Where might you find them?

microvilli are designed to increase surface area for absorption. Found in lining of intestine. sometimes called a brush border.

what does pseudostratified mean, where might you find it?

pseudostratification indicates that the many nuclei are found at different heights, so it appears to be multilayered. Found in respiratory system. Frequently found with goblet cell.

name the parts of nerve cell

soma- the body of the cell. cell membrane bound, contains mitochondria and other organelles. Dendrites- responsible for transmission of signals. Axon-long process that carries signals away from the nerve cell.

what are the 3 shapes of epithelial tissues. describe them.

squamous-flat, cuboidal- wider than they are tall, columnar-must be tall to maximize secretion/excretion.

define tendon

tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension

where would you find simple cuboidal? what is its role?

these cells tend to secrete, excrete or absorb. examples include small collecting ducts of kidney,pancreas and salivary gland.

where is the only place you find transitional epithelium, and why is it unique to that area?

transitional epithelium is only found lining the urinary bladder. it is called transitional because it transitions from cuboidal shape when bladder is empty to squamous when stretched by full bladder.

are the cells in connective tissue tightly or loosely packed.

unlike tightly packed epithelials, connective tissue tends to have cells scattered throughout an extracellular matrix of fibrous proteins and glycoproteins attached to a basement membrane.