Session 5: Glands 2 and connective tissues proper

Question 1

Describe the difference between simple and compound

Answer 1

Simple: single layer of cells
Compounds: multiple layers of cells, seen by several layers of nuclease

Question 2

Describe the difference between acinar and tubular

Answer 2

Acinar: alveolar shape seein in exocrine glands( which have ducts), releases mucus
Tubular: tube-like shaped glands

Question 3

Describe between serous and mucous

Answer 3

Serous cells secrete enyzmes( which stain darker as they contain proteins)
Mucous cells secrete mucus which dont stain, so looks clear

Question 4

What is the function of a goblet cell(unicellular gland) in the jejunum and colon?

Answer 4

Produces and maintains layer of mucin- a glycoprotein which offers a procetive mucus blanker over small intestine layer. Mucin proteins then produce mucus which helps movement of substances with cilia.

Question 5

What is the function of parotid glands?

Answer 5

Major salivary glands below and in front of each ear, on left side of head, produces salva for digestion and lubrication

Question 6

What is the function of submandibular glands?

Answer 6

Lubricates and moisturizes mouth and throat. Aids in digestion- breaks down food with moisture and enzymes.

Question 7

Function of liver

Answer 7

Secretes bile which is stored in gall bladder- which emulsifies fat. Alcohol detoxification, excretion of bilrubin etc.

Question 8

Explain the location and function of myoepithelial cells in relation to eocrine gland secretion

Answer 8

Some of the cells at the secretory ends of ducts change into myoepithelial cells- cells that have features of both a smooth muscle cells and an epithelial cell. Helps to eject( squeeze) secretions from the duct.

Question 9

How are mumps formed?

Answer 9

Viral infections causes parotid glands to swell, leads to intense pain. Treatment: abcess drainage or surgery. Swelling of this gland could also occur due to blockage due to bacterial infection- solved with antibiotics.

Question 10

Difference between parasympathetic and sympathetic secretion

Answer 10

Parasympathetic: large volume of watery, enzyme rich saliva
Sympathetic: small volume, thick, mucus rich saliva
Note that salivary secretion is neural

Question 11

What occurs in the liver lobule?

Answer 11

Deoxygenated blood from hepatic vein and oxygenated blood from hepatic artery mix in the liver accinus and comes into contact with the wall of hepatocytes( which have membrane transport). Large molecules enter through fennestrated endothelial cells, other go back through hepatic vein.

Question 12

Describe a Kupffer cell and its function

Answer 12

Type of macrophage in sinusoidal lining. Traps and destroys erythroycytes after 120 days- similar to role of spleen. Migrates into site when there is inflammation or damage in liver.

Question 13

Describe the role of stellate cells in liver failure

Answer 13

Stellate/Ito cells undergo transformation when liver is damaged to form myofibroblasts and collagen which leads scar formation at site. Sinusoids loose fenestrations, and this leads to liver fibrosis.

Question 14

What do hepatocytes contain?

Answer 14

Peroxisomes( contains oxidising agents), free ribosomes, RER, SER, golgi apparatus, glycogen deposits. Lots of regeneration power- up to 50% damage can be repaired in 8 days.

Question 15

What does the liver store?

Answer 15

Iron, copper, lipid soluble vitamins A,D,E,K, and glucose

Question 16

List some anabolic and catabolic functions of the liver

Answer 16

Anabolic: Produces albumin, amino acids
Catabolic: Poisons/ alcohol, hormones( insulin/glucagon)

Question 17

Define connective tisue

Answer 17

Joins together other tissues, supports body and its structures to provide protection for its underlying organs. Consists of extracellular matrix( ground substance and fibres) and cells( like fibroblasts and adipocytes)

Question 18

Cite examples of connective tissues and explain their functions

Answer 18

Tissue binding and support: fibroblasts, important in wound healing process, formation of scars
Protection: Macrophage, antigen presenting cells, presents foreign substances to T cell to be destroyed
Fuel storage: Adipocytes
Transport of substances: Mast cells, release large ammounts of inflammatory mediators when inflammation occurs.

Question 19

Describe the function of extracellular matrix and its components

Answer 19

Extracellular matrix is the network of ground substance and fibres
Ground substance: gelatinus material consisting of glycoproteins, lipids and water
Collagen fibres:flexible with high tensile strength
Recticular: spongy, provides supporting framework, absent in areolar tissue
Elastic fibres: allows tissues to recoil after stretch or distension

Question 20

What is the difference between loose and tense connective tissue? In terms of components and tissue function

Answer 20

Loose connective tissue: few cells, low collagen, high ground substance, thin, more variety of cells. Function: attaches epithelial tissues to underlying tissue
Regular dense connective tissue: many cells, high collagen, low ground substance, thick, less variety of cells. Function: links bones together at joints

Question 20

What is the difference between loose and tense connective tissue? In terms of components and tissue function

Answer 20

Loose connective tissue: few cells, low collagen, high ground substance, thin, more variety of cells. Function: attaches epithelial tissues to underlying tissue
Regular dense connective tissue: many cells, high collagen, low ground substance, thick, less variety of cells. Function: links bones together at joints

Question 21

Classify different types of loose and dense connective tissue

Answer 21

Loose: fascia, a connective tissue and has 3 types- Superficial, deep and visceral. Fascia is made up of fibrous connective tissue and is flexible and can resist unidirectional tension
Dense: 2 types- regular and irregular. Irregular: contains collagen 1 fibres in all directions, can resist stress in all directions. Example: deep layer of dermis, submucosa of intestine. Regular: collagen 1 fibres parallel, can only resist stress in 1 direction. Example: tendons, ligaments.
Dense is harder to cut through than loose.

Question 22

Function of irregular dense connective tissue

Answer 22

Non-parallel collagen 1 fibre bundles resists forces in multiple directions to prevent tearing. Skin can return to original form after it is bent.

Question 23

Describe the structure and function of the areolar tissue

Answer 23

It is a loose connective tissue- therefore consists of extracellular matric( ground substance and fibres) and different types of cells. It holds vessels that supply fluids, acts as packaging around organs and is involved in inflammation pathways( mosq bite)- it has the facility to swell and expand, then return to original size

Question 24

Describe the structure and function of mucoid connective tissue

Answer 24

Shapeless, loose connective tissue only found in umbilical cord. Contains 2 arteries and a vein. Arteries carry deoygenated fetal blood to the placents while vein carries oxygenated blood to fetus.

Question 25

Describe the structure and function of adipocytes

Answer 25

Consist of multiple small lipid droplets with nuclues, cytoplasm, and organelles all squeezed to centre of cell in brown adipocytes. Function: provides insulation and energy reserve

Question 26

White vs brown adipose tissue

Answer 26

White: single lipid droplet, normal mitochondria count, peripheral nucleus. In adults- slow breakdown and heat only generated after shivering induced.
Brown: multiple lipid droplets, increased number of mitochondria, central nucleus. In neonates and young children- faster lipid breakdown, oxidative phosphorylation is uncoupled to produce heat. Calories generated can double.

Question 27

Describe the structure and function of elastic fibre in lungs

Answer 27

Very fine fibres that surround alveoli of lungs. In COPD, these fibres are irreversibly destroyed- leads to exhaling difficulties when individual is under stressful conditions

Question 28

Describe the structure and function of recticular fibres in lymph nodes

Answer 28

They are fine branching threads made of collagen type 3. Usually arranged in network and attached to collagen 4. Forms major organ structure of lymphoid tissues and liver.

Question 29

What happens to lymph nodes during an infection

Answer 29

Antigen presenting cells show antigens in blood stream to lymphocytes at lymph nodes. Lymphocytes respond by proliferating, which leads to swelling in neck, shoulder, armpits and groin.

Question 30

Explain the causes, mechanism, signs and symptoms of scurvy

Answer 30

Vitamin C deficiency leads to scurvy, a condition that involves poor wound healing and impaired bone formation. This is due to the synthesis of abnormal collagen that lacks its usal strength

Question 31

Explain the causes, mechanism, signs and symptoms of Marfan’s syndrome

Answer 31

Caused by mutations in the fibrillin 1 gene and elastic tissue is abnormal. Leads to tisse irregularities like long bones. At risk of aortic rupture, and a span greater than their height.

Question 32

Explain the causes, mechanism, signs and symptoms of osteogeneis imperfecta

Answer 32

‘Brittle bone disease’: due to mutated colleagen fibres that dont knit together or insufficient amount produced. Results in weakened bones, presence of blue sclera(outside pupil area), hearing loss, loose joints, flat feet, poor teeth development