Structural organisation in animals

Question 1

Tissue level organisation is first seen in?

Answer 1

Coelenterates/cnidaria

Question 2

Examples of simple squamous epithelium

Answer 2

Respiratory zone(alveoli), bowman’s capsule and descending LH, endothelium of blood vessels and mesothelium of body cavity.

Question 3

Examples of normal cuboidal epithelium

Answer 3

Germinal epithelium of gonads, vesicles of thyroid gland, tubules and ducts of glands, ascending LH, DCT and CD.

Question 4

Brush border epithelium

Answer 4

Have microvilli on their free body surface, present in PCT.

Question 5

Cilia and microvilli are only seen in?

Answer 5

Cuboidal and columnar epithelium.

Question 6

Goblet cells

Answer 6

Single celled glands present inside columnar epithelium, secrete mucus.

Question 7

Describe nucleus in columnar epithelium

Answer 7

Oval nucleus is present in the base.

Question 8

Normal columnar epithelium

Answer 8

Glands of GIT

Question 9

Brush border columnar epithelium

Answer 9

Small intestine and gall bladder

Question 10

Kinociliated columnar epithelium

Answer 10

Upper respiratory tract, fallopian tube.

Question 11

Stereociliated columnar epithelium

Answer 11

Epididymis, vas deferens and cochlea(internal ear)

Question 12

Glandular epithelium is?

Answer 12

Modified cuboidal or columnar epithelium.

Question 13

Unicellular glands

Answer 13

Goblet cells(mucus) and paneth cells(antibacterial lysozyme).

Question 14

Exocrine glands

Answer 14

Have specialised ducts for secretions.
Ex:- milk, mucus, saliva and enzymes releasing glands.

Question 15

Endocrine glands

Answer 15

Ductless glands, pour secretions in blood.
Example:- all hormone releasing glands.

Question 16

Heterocrine glands

Answer 16

Show secretions via duct and ductless means.
Example:- pancreas, testes and ovaries.

Question 17

Tight junctions

Answer 17

To stop leakage across tissue.
In epithelial cell only.

Question 18

Adherens junction

Answer 18

Aka desmosomes, glue 2 cells.
In epithelial tissue only.

Question 19

Gap junctions

Answer 19

For rapid transport of ions, small particles and even some large particles.
Like plasmodesmata.
In epithelial, muscular and nervous tissue.

Question 20

Most abundant tissue?

Answer 20

Connective tissue

Question 21

Matrix of connective tissues is composed of?

Answer 21

The matrix of connective tissues is made of mucopolysaccharides (hyaluronic acid and glycoaminoglycans)

Question 22

Describe all 5 types of cells in connective tissues.

Answer 22

1/Mesenchymal cells- stem cells that change into fibroblast, osteoblast and chondroblast.
2/Fibroblast- largest cells in connective tissue that secrete matrix and fibres.
3/Macrophage- phagocytic cells
4/Mast cells- like basophils that scerete heparin(anticoagulant), histamine(vasodilator) and serotonin(bronchio constrictor).
5/Plasma cells- activated B lymphocytes taht form antibodies.

Question 23

Describe loose connective tissue

Answer 23

Loose connective tissues have more matrix and less fibre.
They are further divided into areolar and adipose.
1/Areolar- parking tissue between body organs and cavity, are used to fill areola(space) and attach skin to muscles.
2/Adipose- fat storing cells(adipocytes), present beneath skin, around heart, kidneys and eyeballs to help in shock absorption, are great insulators and can metabolise the fat in them for energy.

Question 24

Describe dense connective tissue

Answer 24

Dense connective tissues have less matrix and more fibres. They are divided into regular and irregular based upon the pattern of fiber present in them.
Regular connective tissue
1/Tendon- muscles to bone, made of white collagen.
2/Ligament- joins bones to bones, yellow elastin and some collagen.
Irregular connective tissue
1/Yellow- covering of lungs
2/White- pericardium, periosteum, perichondrium and glisson’s capsule(liver cells sheath).

Question 25

White fat

Answer 25

As a single big drop of fat with few mitochondria, which makes it difficult to digest the drop. Present in adults, yellow bone marrow, blubber (thick fat layer of animals like whale) and hump of camel.

Question 26

Brown fat

Answer 26

Many mitochondria with small fat drops which makes it easier to digest them. Present in newborn babies and hibernating animals.