Tissue Types - Answers

Arlo Guthrie — Thu, 02 Apr 2009 14:28:55 GMT

Current Revision posted to Revision Guide For Student Nurses - Part 1 by Arlo Guthrie on 4/2/2009 2:28:55 PM

ANSWERS

State the size of an average tissue cell.
10-100u in diameter.
Define a tissue.
A collection of cells with a common function. One type of cell predominates.
List the 4 groups of tissue and state the function of each.
- Epithelial - covering.
- Connective - support and binding.
- Nervous - awareness.
- Muscular - movement.
What are the 3 main components of a tissue?
- Cells.
- Intracellular material.
- Fluid.
What is an organ?
A group of tissues where one type predominates in order to perform a particular function.
What is a system?
A collection of tissues, organs and structures related by position or function.
What are the differences between loose and dense connective tissue?
- Loose (areolar) connective tissue - A loose network of delicate and flexible fibres; it is found in the hyperdermis and connects the skin to the underlying body tissue forming the superficial fascia. It functions as a packing material and supports nerves. Also known as yellow elastic tissue. Loose connective tissue is also found in the lymph nodes, spleen and liver.
- Dense (fibrous) connective tissue - strong and inelastic; it is found in the dermis and epidermis and forms the deep fascia around the skeletal muscles. It functions as a component of muscles and tendons and encapsulates organs. Also known as white fibrous tissue. Dense connective tissue is also found in the kidney capsule and testis.
What are the 2 main functions of adipose (fatty) tissue?
- Food reserve.
- Insulation.
Where does adipose tissue occur?
- Surrounding the eye.
- Surrounding the kidney.
- Between the skin and underlying structures.
What is the chief constituent of dense fibrous tissue?
Collagen.
What is the chief constituent of loose connective tissue?
Elastin.
Name the 2 types of dense connective tissue.
- Irregular - a dense interwoven network.
- Regular - parallel bundles.
Briefly describe muscle tissue.
Muscle tissue is contractile and contains a high proportion of long, thin, threadlike cells which are collectively concerned with the movement of the body. There are 3 types:
- Skeletal (or striated) - the muscular tissue attached to the skeleton (comprised of cylindrical cells arranged in parallel bundles).
- Smooth - found in the gut and other areas associated with involuntary actions (comprised of spindle shaped cells).
- Cardiac - confined to the heart.
What is an alternative name for smooth muscle tissue?
Involuntary muscle tissue.
What is an alternative name for skeletal (or striated) muscle tissue?
Voluntary muscle tissue.
What is the function of intrinsic muscle?
Intrinsic muscle alters the position of parts of the region in which the muscle lies. An example is closing an eye.
What is the function of extrinsic muscle?
Extrinsic muscle runs from one body region to another and alters the position of one region in relation to another. An example is turning the head.
What tissue type holds the skeletal muscle tissues together?
Connective tissue.
What is the main similarity between tendons and ligaments?
Both are made from regular dense connective tissue.
What is the function of tendons and ligaments?
- Tendons - attach a muscle to a bone.
- Ligaments - attach a bone to a bone at a joint
In addition to muscles, tendons and ligaments; list the 6 other types of connective tissue.
- Blood.
- Bone.
- Cartilage.
- Haemopoeitic tissue.
- Lymph.
- Tissue fluid.
What are the 3 types of cartilage? Where would you find each?
- Fibro-cartilage - strong and rigid; intervertebral discs, costal cartilages, laryngeal cartilages, menisci of stifle & temporomandibular joint.
- Hyaline cartilage - smooth; articular surfaces of synovial joints & tracheal rings.
- Elastic cartilage - flexible; pinna, epiglottis & nasal septum.
What is the perichondrium?
The membrane responsible for the supply of blood to cartilage.
What is the name of the series of canals running along the length of bone which carries blood vessels, nerves and lymphatics?
Haversian systems.
How does cancellous (spongy) bone and compact bone differ?
In cancellous bone, the Haversian canals are spread more widely apart than in compact bone and the spaces are filled with red bone marrow.
List the constituents of bone.
- Calcium phosphate.
- Collagen fibres.
- Mucopolysaccharide polymer.
- Osteocytes (bone cells).
What are the lacunae?
Spaces within the bone lamellae.
What is a sesamoid bone? Give an example.
A bone that develops within a tendon or ligament. An example is the patella.
Give an example of an irregular bone.
Vertebra.
Give an example of a flat bone.
Scapula (shoulder blade).
What is the function of Haemopoeitic tissue?
The making of blood. Myeloid tissue produces erythrocytes and granular leukocytes in the bone marrow, whilst lymphoid tissue produces agranular leukocytes in the lymphatic system and spleen.
What are the main cell types that comprise connective tissue?
- Fibroblasts.
- Fibrocytes.
Name the 2 types of nervous tissue.
- Motor (efferent) fibres - which lead away from the brain.
- Sensory (afferent) fibres - which lead towards the brain.
What is the correct name for a nerve cell?
A neuron.
NB. A nerve consists of many neurons bound together in a connective tissue sheath.
Describe a neuron.
A neuron consists of a cell body (with a nucleus), a number of bodies called dendrites from which nervous impulses leave the cell, and one long process - the axon - where nervous impulses enter the cell.
What is the name given to the connective tissue that runs between neurons?
Neuroglia.
What is the neurilemma?
The sheath of connective tissue that surrounds the axon.
What are the nodes of Ranvier?
Gaps in the myelin sheath along the axon where the axon is in direct contact with the neurilemma.
NB. The insulating myelin enables nervous impulses to travel more quickly.
Briefly describe the function of epithelial tissue.
Epithelial tissue covers the outside of the body, and is also found lining the inner cavities and tubes. Its main function is that of protection. There are 3 main types:
- Simple - a single layer of cells.
- Compound (or stratified) - several layers of cells.
- Transitional - elastic cells.
Where might the following types of simple epithelial tissue be located: squamous, cuboidal and columnar?
- Squamous - Bowman's capsule.
- Cuboidal - Kidney nephron.
- Columnar - Uterine tubes.
Where would you find compound epithelium?
The skin.
Compound epithelium may be keratinised. What does this mean, and where would you find keratinised compound epithelium?
Keratinised epithelium is strengthened and waterproofed with protein and is found in areas such as the nose and pads of the feet.
Where is transitional epithelial tissue found?
- Ureters.
- Urinary bladder.
What is the main property of transitional epithelial tissue?
It stretches.
What special property is possessed by intermediate epithelial cells?
They are able to change in shape (such as those of the mammary glands).
Epithelial cells often possess cilia; why?
Cilia are microscopic filaments whose wave-like motions assist the removal of mucus and foreign particles.
Where does ciliated columnar epithelium occur?
The respiratory tract.
The uterine tubes (assisting the passage of the ovum).
What is a gland?
An organ or cell which secretes fluid prepared from the blood for use in the body or for excretion as waste material.
What is an exocrine gland? Give 2 examples.
A ductless gland which secretes hormones; usually has a connection with an epithelial surface.
- Sudiferous (sweat) glands.
- Salivary glands.
What is an endocrine gland? Give 2 examples.
A gland with ducts which secretes enzymes; usually some distance away from the epithelial surfaces.
- Thyroid glands.
- Testes.
What is a mixed gland? Give an example.
A gland which contains several types of cell which function independently. An example is the pancreas - the alpha cells secrete glucagon, whilst the beta cells secrete insulin.
What is a goblet cell?
The simplest type of exocrine gland; the function of goblet cells is mucus secretion and they are found lining the digestive tract.
Name 2 sites where simple tubular exocrine glands are found.
- Stomach.
- Intestine walls.
Give an example of a compound alveolar gland.
Salivary gland.
Give an example of a compound tubular gland.
Duodenal gland.
Which glands are coiled?
The sudiferous (sweat) glands.
Give an example of a simple saccular (alveolar) gland?
Sebaceous gland.