Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Body Logistics > 3. Cells, Tissues, Organs > Flashcards

3. Cells, Tissues, Organs Flashcards

1
Q

When do cells first coalesce?

A

During embryogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What three cell types does the epiblast produce?

A

Three Germ Layer:

  • Ectoderm: epidermis and neural systems
  • Mesoderm: Muscle, blood, kidney etc
  • Endoderm: Gut Tube - liver, GI tract etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What holds cells together?

A

Cell-cell adhesions
Extracellular matrix proteins (fibres)
Internal-external scaffolding
Close proximity (pressure effects)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe connective tissue organisation

A

Extracellular matrix is plentiful with connective tissue.
Cells are sparsely distributed within it.
Forms matrix rich in fibrous polymers e.g. collagen
Cells attached to matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe epithelial tissue layers organisation

A

Cells are tightly bound into sheets (this is epithelia)
Consists mainly of basal lamina than EM.
Basal lamina is underneath epithelia.
Cells attached to each other - cell to cell adhesions.
Specialised junctions from crossing of protein filaments, surface of cells tied to each other or basal lamina.
Contains cytokeratin (16 and 7) - strong adhesions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the primary cell of connective tissue?

What does it produce?

A

Mesenchymal stem cell

It produces most extracellular fibres that anchor cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the three components of connective tissue?

A

Cells, fibres and ground substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the components of fibres in connective tissue?

A

Includes collagen, elastin and reticular fibres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is ground substance made up of?

A

Glucosaminoglycans e.g. hyaluronic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are functions of connective tissue?

A 
Binding and supporting
Protecting - shock absorber
Insulating - fat underlying skin
Storing reserve fuel and cells - bone marrow, fat
Transporting substances within the body
Separation of tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the definition of an organ?

A

More than one tissue coming together for specific purpose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where are epithelial cells found in broad terms?

What do specialised junctions do?

A

Epithelial cell sheets line all cavities and free surfaces.

The specialised junctions between cells make barriers. This inhibits movement of water, solutes and cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Epithelia rest on what? (Almost always)

A

A bed of connective tissue.

Epithelial sheet contains basal lamina below which then sits on bed of connective tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What adherence systems are present within the lateral surface of epithelial cells?

A 
Tight junctions
Adherens junctions
Desmosomes (adhesion plaques)
Gap Junctions
Cell Adhesion Molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What adherence systems are present within the basal surface of epithelial cells?

A 
Hemi-desmosomes
Focal adhesions
Integrins
Proteoglycans
Cell Adhesion Molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are tight junctions?

What is their role?

A

They are always at the top of the cell nearest to the apical surface in the lateral border (side at top)
Contain only two attachments.
Role is to prevent movement of larger molecules through the lumen into deeper tissue, seals neighbouring cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do tight junctions do in the small intestine?

A

Can be opened to allow movement of sugars and water across epithelial barrier, requires ATP.
Known as paracellular transport.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are adhesion junctions?

A

Found in pairs, one-third distance from luminal surface, in lateral surface. Joins actin bundles.
Formed from intracellular actin filaments, linked to E-cadherin proteins in adhesion belt.
Only in epithelial and endothelial cells, tissue stabilising and transport barrier.

19
Q

What is a desmosome?

A

Strongest cell-to-cell adhesion. To provide strength.
Halfway between top and bottom of epithelial cells.
Found in tissues with intense mechanical stress.
Only cell to cell adhesion in epidermal cells.
Anchoring proteins come out either side like hairs.

20
Q

What are gap junctions?

A

Found close to base of epithelial cells, in cardiac and smooth muscle cells. For communication.
In smooth muscle allows wave of electrical impulse.
Made of cylinder of proteins in hexagonal pattern.
Connexin 45 to 34 - childbirth movement of signal for uterine contraction.

21
Q

What is a hemi-desmosome?

A

Only in basal surface of epithelial cells, attach to layer of extracellular matrix e.g. fibronectin, collagen, laminin.
Anchors epithelial cells to basal lamina, and prevent loss to external surface.
Cytokeratin fibres come together, attach to plasma membrane, integral proteins bind to laminin which binds to elastin to collagen.

22
Q

What are focal adhesions?

A

Similar to hemidesmosomes - attach to basal lamina.
Uses actin filaments instead of cytokeratin, but does use integrins. Binds to fibronectin instead of laminin - when binds conformational change allows binding to collagen.

23
Q

What are integrins?

A

Transmembrane receptors that facilitate cell-extracellular matrix adhesion. Upon ligand binding they activate transduction signal pathways. Hold tissues together.
Phosphorylated by focal adhesion kinase.

24
Q

What is the mucosal membrane?

A

Lines all moist hollow internal organs of the body.
Continuous with the skin at various openings.
Secretes mucus.
Combination of epithelium, basal lamina and lamina propria.

25
Q

What is the function of the mucosal membrane?

A

Stop pathogens and dirt entering the body.
Prevent bodily tissues from becoming dehydrated.
Lubricate the surface.

26
Q

What are some examples of mucosal membranes?

A

GI tract, urinary tract, respiratory tract.

27
Q

What are the GI tract layers?

A

Mucosa - epithelial cell lining
Muscularis mucosae - smooth muscle layer
Submucosa - layer of connective tissue that contains blood vessels, lymph vessels and nerves.
Muscularis externae - circular and longitudinal smooth muscle.
Serosa - connective tissue covering, lubricates outside of GI tract.

28
Q

What is the structure of the oesophagus?

A

Muscularis externa - smooth muscle layers, moves bolus of food by peristalsis
Submucosa - subtending layer of connective tissue containing mucus-secreting glands
Mucosa - epithelium, lamina propria, mucosae

29
Q

What is the structure of the stomach?

A

Gastric mucosa secretes acid, digestive enzymes and the hormone gastrin.
submucosa and muscularis mucosae,
muscularis externa contains 3 layers of smooth muscle, oblique longitudinal and circular.
rugae - folds of gastric mucosa forming longitudinal ridges in empty stomach.

30
Q

What is the jejunum?

A

Part of the small intestine between duodenum and ileum. Contains all GI layers, plus villi.
Jejunal mucosa consisting of simple columnar epithelium and lamina propria plus muscularis mucosae.

31
Q

What is the structure of the large intestine?

Colon

A

Contains aggregations of lymphoid tissue and numerous crypts of Lieberkuhn. The simple columnar epithelium of the crypts of epithelium produces mucus and supplies cells to the surface. Surface epithelial cells absorb water and electrolytes.

32
Q

What are functions of the GI tract mucosa?

A

Absorb substances from the lumen
Prevent ingress of pathogens
Move contents and expel waste

33
Q

How do structures of the GI tract mucosa aid its functions?

A

Epithelial cells specilisations - folding of mucosa, villi allow absorption and prevent pathogens.
Lamina propria contains lymphatic tissue for pathogens.
Muscularis mucosae folds mucosa to increase surface area. Muscular externa performs peristalsis.

34
Q

Describe the structure of the urinary tract

A

Corpuscle lining flattened with squamous epithelium.
Lining of collecting ducts contains cuboidal epithelium.
Thick basal lamina acts as barrier preventing leaking.
Proximal tubes contain ciliated surface.

35
Q

What is the structural unit of the kidney?

Describe its structure

A

The nephron
Distal tubule contains macula densa
Continuously lined with epithelial cells

36
Q

Where within the urinary tract system does muscle first appear?

A

Not until the ureter and the bladder
In the kidney, is not mucosa as no muscle layer.
Inner longitudinal muscle not well defined as does not need peristalsis.

37
Q

Describe the structure of the bladder.

A

Umbrella cells on surface secrete mucus on inside of the bladder. Epithelial cells produce mucus.
Urothelium cells - cells different in different layers.
Lumen, transitional epithelium, lamina propria, muscular layer and then adventitia with fat cells.
Fat cells act as shock absorber to stop interactions with other tissues when bladder shrinks and expands.

38
Q

Describe urethra histology

A

Epithelium changes from transitional to stratified along its length; stratified in centre by lumen, keratinised at surface of body. Lamina propria in between contains mucous epithelial glands.
Functionally very similar to the GI tract, absorb essential nutrients in the kidney, prevent pathogen entry, remove waste products.

39
Q

Describe respiratory tract structure

A

Divided into two parts - conducting portion and respiratory portion.
Conducting portion is naval cavity to bronchioles.
Respiratory portion of respiratory tract - bronchioles to alveoli.

40
Q

Describe the structure of the pharynx and trachea

A

Pharynx does not have a mucus membrane, skeletal muscle, contains stratified epithelium.
The trachea contains hyaline cartilage ring.
Perichondrium collagen, chrodrogenic layer cartilage.
Sermucus glands in submucosa and pseudostratified epithelium. Thin lamina propria. Watery mucus thickens during infection. No outer layer of smooth muscle.

41
Q

Describe the bronchial secretions

A

Secretions are from epithelium and submucosal glands of the trachea and bronchi.
Contains mucins and water for mucus, serum proteins lubrication, lysozymes and anti-proteases.

42
Q

What is the process that produces a cilia wave?

A

Movement of mucus to the oral cavity where material can then be swallowed - mucocilliary escalator.
Cilia beat at 12 Hz beneath viscoelastic mucus blanket.
Goblet cells produce mucus, thick basement membrane.

43
Q

Describe the histology of secondary and tertiary bronchi.

A

Cartilage rings no longer present as full circles.
Bounded by smooth muscle, epithelium pseudostratified and ciliated. Submucous glands in the submucosa.
No outer layer of smooth muscle.

44
Q

Describe the alveolus structure

A

Capillaries lined with flattened specialised epithelial cells, attached to fusal basal lamina. Basal lamina same for each alveoli cell. Folds to allow expansion.
Collagen at junctions add rigidity, elastin fibres for recoil.
Connective tissue muscle layer by collagen and elastic.

Body Logistics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions