Intro to cells, tissues and organs Flashcards Preview

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Flashcards in Intro to cells, tissues and organs Deck (20)
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1
Q

What is a cell?

A

Fundamental units of life, capable of independent existence

2
Q

Differences between prokaryotic and eukaryotic cells

A

Pro: smaller, no nuclear envelope, no nucleoli, no histones, few intracellular membranes, 60-70S ribosomes

Euk: larger, prominent nuclear envelope, nucleoli present, DNA complexed with histones, many membrane bound organelles, 70-80S ribosomes

3
Q

Properties of cells

A
Irritability - react to environment
Conductivity
Contractility
Absorption and assimilation 
Excretion and secretion
Respiration
Growth
Reproduction
4
Q

From cells to systems

A

Cells -> simple tissue -> compound tissue -> organ -> system

5
Q

What is a tissue?

A

An assemblage of cellular and extra cellular elements in which one or more types of cell or fibre usually predominates to form material basis of one of the functional systems of the body

6
Q

How do tissues arise?

A

Zygote -> morula -> blastocyst 1st then 2nd week -> conceptus with 3 germ layers developing

7
Q

Derivatives of the Primary germ layers

A

Ectoderm
Endoderm
Mesoderm

8
Q

What are the primary tissues

A
  1. Epithelia
  2. Connective tissues
  3. Nervous tissues
  4. Muscular tissues
9
Q

Epithelia

A

Sheets of closely-packed cells derived from one of 3 germ layers
Cover or line the surface of an organ
Sheets: simple or compound/stratified

10
Q

Connective tissues

A

Cells derived from mesoderm

Produce extra cellular matrix of fibres and ground substance

11
Q

Nervous tissue

A

Develop from neuro-ectoderm

Consist of cells which mainly possess processes called neuritis which conduct impulses when stimulated

12
Q

Muscular tissues

A

Derived from mesoderm

Composed of cells (multinucleated syncytia) whose cytoplasm contains filaments made of contractile proteins

13
Q

Secretion

A

Cells take up and release molecules to the environment without compromising its integrity
Endocytosis and exocytosis

14
Q

Endocytosis

A

Inwards

  1. Invagination: fusogenic proteins
  2. Adherence
  3. Fusion
15
Q

Exocytosis

A

Outwards

  1. Apposition
  2. Adherence: fusogenic proteins
  3. Fusion
16
Q

Uptake of materials by cells

A

Diffusion
Active transport
Endocytosis: phagocytosis, pinocytosis

17
Q

Main membrane bound organelles

A

Golgi apparatus, lysosomes, endoplasmic reticulum

18
Q

Lysosome function

A

Contain digestive enzymes
Destroys material from outside and within cell
Produced from ER and Golgi
Destructive enzymes separated from rest of cell by specialised membrane
Acid pH

19
Q

Peroxisome

A

Type of lysosome containing catalase

Converts hydrogen peroxide to water

20
Q

Proteosome

A

Degrades ubiquitinated proteins