Star points test #1

Question 1

definition of tissues

Answer 1

group of cells of similar structure that perform a common function.

Question 1

four basic types of tissues

Answer 1

epiethelium, connective, muscle, nervous

Question 1

functions of epithelial tissue

Answer 1

lining of surfaces

Question 1

functions of connective tissues

Answer 1

• connecting tissues and organs
• form the basis of the skeleton,
• store and carry nutrients,
• surround all the blood vessels and nerves,
• lead the immune system.

Question 1

function of muscle tissue

Answer 1

movement

Question 2

functions of nervous tissue

Answer 2

communication

Question 3

tight junctions

Answer 3

-form the closest contact between adjacent cells known in nature.
-so tight that some proteins in the plasma membrane are fused.
-Found in the apical region around the cell’s circumference, like a belt.
-these prevent molecules from passing.
(plays a role in secondary immune response because antigens ‘tighten’ the cell junction.)

Question 4

desmosomes

Answer 4

• localized adhesive function and connect the plasma membrane to intermediate filaments in the cytoplasm.
• the connections are especially important in stratified epithelium as it helps form an internal tension-reducing networks of fibers.

Question 5

gap junction

Answer 5

• consist of intercellular channels in the plasma membrane of adjacent cells.
• Small molecules can diffuse across the channel and into the cytoplasm of the other cell.
• “communicating junction” allows passage.

Question 6

cell size is what size and what determines it?

Answer 6

• normally 5-20 micrometers

* limited by reliance on diffusion

Question 7

definition of epithelium

Answer 7

Tissue that covers or lines surfaces and cavities of the body
or
(2) forms glands/ secretory structures

Question 8

general characteristics of epithelium (7)

Answer 8

• Cellularity:
• Make specialized contacts
• Display polarity - apical, basal (e.g. goblet cell - secretes mucus)
• Basement membrane (anchors epithelium to the underlying connective tissue)
• Ability to regenerate quickly
• Avascular = no blood vessels • Innervated

Question 9

functions of epithelium

Answer 9

• Absorption and Secretion (active transport)
-microvilla and cilia
• Diffusion and Filtration (passive transport)
• Sliding
• Protection
• Sensory reception


Question 10

how do we classify epithelium?

Answer 10

by layering: simple vs stratified

by shape: squamous, cuboidal, columnar.

Question 11

definition of a gland

Answer 11

structure whose cells are specialized for secretion

Question 12

exocrine

Answer 12

type of gland that secretes products onto body body surfaces or into body cavities,
- contains ducts that carry these protiens to the surface (except the single celled goblet cells)

Question 13

endocrine

Answer 13

glands that secretes hormones into the blood.

Question 14

properties of reticular fibers

Answer 14

1] composed of type III collagen secreted by reticular cells.
[2] Reticular fibers crosslink to form a fine meshwork (reticulin). This network acts as a supporting mesh in soft tissues such as
-liver,
-bone marrow,
-tissues and organs of the lymphatic system.
-used at boundaries of tissues.
[3] Forms delicate networks with lots of spaces • Allows smooth gliding / deformation

Question 15

areolar connective tissue

Answer 15

most widespread, ‘generic’, gel like matrix, lots of fluid, ADJOINS ALL EPITHELIAL, is a loose connective tissue

Question 16

goblet cell

Answer 16

unicellular exocrine gland that is shaped as a goblet, secrets mucin that dissolves when secreated to form mucus

Question 17

basal lamina

Answer 17

thin noncellular sheet that consists of proteins secreted by epithelial cells.

Question 18

basement membrane

Answer 18

consists of the basal lamina and reticular fibers of the underlying connective tissue.

Question 19

microvilla

Answer 19

almost every moist epithelia. but most abundant in small intestine (absorbs nutrients) and transport ions (kidneys).

Question 20

cillia

Answer 20

• whiplike centoles projection from the apical surface of certain epithelial cells
• wavelike movement moves mucous (or reproductive cells) over the area in one direction only.

Question 21

four main classes of connective tissue

Answer 21

connective tissue proper ( fat tissues, fiberous tissues et), cartilage, bone tissue, blood.

Question 22

all connective tissues share the same structural plan.

Answer 22

• few cells, lots of extracellular matrix
• matrix composed of ground substance and fibers (elastic, collagen, reticular)
• all originate from the embrionic tissue, mesenchyme.

Question 23

types of fibers found in the extracellular matrix

Answer 23

collagen- resists tension (bundles of thinner fibrils)
reticular- meshlike specialty collegen fibrils, covers and supports stuctures boardering the connective tissue. glide freely and provide more ‘give’ than collagen fibers.
elastic- stretch and recoil,

Question 24

ground substance

Answer 24

the other component of the extracellular matrix.

-produced by cell type (fibroblasts, chondroblasts, osteoblasts)

Question 25

two subclasses of connective tissue proper

Answer 25

loose connective tissue (areolar, adipose and reticular)

dense connective tissue (dense regular, dense irregular and elastic)

Question 26

areolar connective tissue

Answer 26

gellike matrix with all three fiber types
cells: fibroblasts, macrophages, mast cells, some white blood cells
function: wraps and cushions organs, roll in inflamtion and immunity based on cell types, holds and conveys tissue fluid.
Location: widely distributed under epithelia of the body, surrounds organs, capillaries, forms lamina propria.

Question 27

adipose connective tissue

Answer 27

loose connective tissue proper
matrix as in areolar but very sparse
closely packed fat cells,
function: provides reserve food fuel, insulates against heat loss, supports and protects organs
location: under the skin hypodermic, around kidneys and eyeballs, within abdomen, in breasts.

Question 28

reticular connective tissue

Answer 28

loose connective tissue proper, loose ground substance, fibers lie on the network

function: stroma (soft internal skeleton) that supports other cell types including white blood cells, mast cells and macrophages.
location: lymphoid organs (bone marrow, spleen, lymph nodes)

Question 29

types of cartilage

Answer 29

hyaline, elastic, fibrocartilage

Question 30

hyaline cartilage

Answer 30

• amorphorous but firm matrix
• collagen fibers form the matrix
• mature chondrocytes lie in the lacunae
  function: supports and reinforces, resilient cushioning properties, resists compression
  location:
• forms most of the embryonic skeleton, covers the ends of long bones,
• forms costal cartilage on the ribs, nose, trachea and larynx

Question 31

elastic cartilage

Answer 31

similar to hyline cartilage but more elastic fibers in matrix.
function: maintains shape while allowing flexibility
Location: external ear and epiglottis.

Question 32

fibrocartilage

Answer 32

matrix similar to hyaline but thick collegen fibers predominate.

function: tensile strength woth the ability to absorb shock.
location: intervertebral disks, pubic symphasis, discs of the knee joint.

Question 33

dorsal body cavity

Answer 33

divided into two cavities, cranial (brain) and vertebral (spinal cord)

Question 34

ventral body cavity

Answer 34

the organs it contains are called visceral/visera. divided into two cavities:
Thoratic and abdominopelvic , these are divided by the diaphragm.

Question 35

cutaneous membrane

Answer 35

skin, outer epithelium is the thick epidermis and the inner connective tissue is the dense dermis.

Question 36

mucous membrane or mucosa

Answer 36

• lines the inside of every hollow internal organ that is continuous to the outside world (respiratory, digestive, urinary and reproductive.)
• produces mucous and enzymes by secretion.

Question 37

serous membrane

Answer 37

• lines the closed pericardial, pleural and peritoneal cavities.
• is the mesothelium ( simple squamous epithelium)

Question 38

What are the differences between reticular cells, tissues (ct), reticular fibers and the dermis layer?

Answer 38

Cells- are fibroblasts within the ret. ct. Lie along the network of this tissue
CT- resembles areolar ct but the fibers are reticular fibers, fine and form a basic skeleton like the framework of a house. Create many caverns that hold free cells ( located in bone marrow, spleen and lymph nodes)
Fibers- they are bundles of a special collagen fibril. That cluster into a mesh like structures that are like fuzzy nets over capillaries and form part of the basement membrane for epithelium. These individual fibers glide easily and provide more give than other collagen fibers.
Dermis- contains interlacing fibers of elastic and collagen fibers that run on different planes. Ret. here means network and does not denote special forms of ‘reticular fibers.

Question 39

Special characteristics of epithelium

Answer 39

• basal lamina
• cell junctions
• cilia and microvilla