Compendium 2 - How do cells do what they do? Flashcards
1
Q
Organelles of a cell
A
- plasma membrane
- cytoskeleton
- nucleus and nucleolus
- ribosomes
- golgi apparatus
- lysosomes
- mitochondria
- centrosome
- flagella
- microvilli
- cytoplasm and cytosol
- endoplasmic reticulum
2
Q
Plasma membrane
A
- encloses and supports cellular contents
- composed of a lipid bilayer with phospholipids, cholesterol and some proteins embedded in the membrane
- controls entry and exit of substances, have a function in intercellular communication, cell recognition
3
Q
Cytoskeleton
A
- provides shape and strength
* supports cell and organelles
4
Q
Nucleus
A
- control centre of the cell, contains genetic information (DNA)
- regulates protein synthesis and chemical reactions of the cell
5
Q
Nucleolus
A
•produces ribosomes
6
Q
Ribosomes
A
• involved in protein synthesis
7
Q
Golgi apparatus
A
• modifies, packages and distributes proteins and lipids for use within the cell, or to secrete them
8
Q
Lysosomes
A
• vesicles with digestive enzymes that dispose of cellular waste
9
Q
Mitochondria
A
• site of ATP synthesis, produces energy for the cell (when oxygen is available)
10
Q
Centrosome
A
- where centrioles are found
- centrioles form the basal bodies of cilia and flagella
- centrioles assist in cell division (mitosis and meiosis)
11
Q
Flagella
A
• one long extension of the plasma membrane which propels to move a cell (in humans, this is only found in sperm cells)
12
Q
Microvilli
A
• increase the surface area of the plasma membrane for greater absorption and secretion
13
Q
Cytoplasm and cytosol
A
• cytoplasm: thick fluid that all organelles are contained in, made of cytosol
• cytosol: the fluid portion of cytoplasm (ions and proteins in water)
- includes cytoplasmic inclusions (aggregates of chemicals) and cytoskeleton
14
Q
Rough ER
A
- involved in manufacturing and modifying proteins
* transports proteins to golgi
15
Q
Smooth ER
A
- produces steroids, fats and carbs
- involved in detoxification
- converts glycogen to glucose
16
Q
What makes up the environment of a cell
A
- intracellular fluid: fluid inside the cell
- extracellular fluid: fluid outside of the cell
- intercellular fluid: fluid in between cells
- similar cells will surround a cell, making up part of their environment
- cell environment depends on cell type (e.g. stomach cells are surrounded by acid)
17
Q
What happens to a cell if an organelle stops working
A
• if one organelle stopped working, the whole function of the cell would be disrupted
18
Q
Are all the cells in the body the same
A
- yes, because most cells have a similar structure and the same organelles which have the same functions
- no, because different cells have different roles (e.g. cells in heart will have more ATP because they need more energy to keep pumping than other cells)
19
Q
4 primary tissues
A
- epithelial
- connective
- muscular
- nervous
20
Q
Functions and characteristics of epithelia
A
- covers and protects
- distinct cell surfaces
- avascular but innervated
- has the ability to regenerate
21
Q
Location of epithelial tissues
A
- lungs, tubules of kidneys, serous membranes, Fallopian tubes, bladder
- almost every organ
22
Q
Types of cell surface modifications in epithelia
A
- cilia: move substances across the surface of the cell
* microvilli: assist with absorption and secretion
23
Q
Simple squamous epithelia
A
• simple squamous: one layer of thin, flat cell
- involved in diffusion, filtration and some secretion
- found in alveoli of lungs to help with CO2 and O2 diffusion
- found in tubules of kidney for filtration
- makes up serous membranes to secrete serous fluid to stop friction
• squamous cells are ideal because they are thin and allow for quick diffusion, filtration and secretion
24
Q
Simple cuboidal epithelia
A
• simple cuboidal: one layer of cube shaped cells
- involved in absorption, secretion and movement
- found in tubules of kidneys (these cells have microvilli to assist with absorption)
- found in terminal bronchioles (these cells have cilia for movement of substances across surface)
25
Simple columnar epithelia
• simple columnar: one layer of column shaped cells
- function in absorption, secretion and movement
- found in duodenum for secretion of mucous to neutralise acid
- found in fallopian tubes for movement of egg
- found in gastrointestinal tract (these cells have microvilli for absorption)
26
2 types of stratified squamous epithelia
• keratinised:
- found on the soles of feet, palms of hands and skin on body
- acts to protect underlying tissue
- is waterproof
•non-keratinised:
- found in mouth, oesophagus, anus and vagina
- areas where there is lots of friction and waterproofing is not needed
27
General characteristics of connective tissue
* most abundant and widely distributed primary tissue
* has many functions (binding together, support, strengthen, protect, insulate, compartmentalise etc.)
* found in all organs (quantity and type is different in each organ)
* made of cells, ground substance and fibres
* 4 classes: connective tissue proper, cartilage, bone, blood
28
Classes of connective tissue
* connective tissue proper (loose and dense)
* cartilage
* bone
* blood
29
Loose connective tissue proper
* areolar
* adipose
* reticular
30
Dense connective tissue proper
* regular
* irregular
* elastic
31
Areolar connective tissue
* loose packing
* supports and binds other tissues
* connective tissue that epithelia of skin rests on
32
Adipose connective tissue
* loose
* nutrient-storing ability
* shock absorption and protection
* insulation
* fat beneath the skin, surrounding kidneys, breasts, abdomen and hips
33
Reticular connective tissue
* loose
* forms a framework to support free blood cells (white blood cells, mast and macrophage cells)
* located in lymph nodes, spleen, bone marrow
34
Regular connective tissue
* dense
* used for attachment
* in tendons to attach muscles to bones
* in most ligaments to attach bones to bones
35
Irregular connective tissue
* dense
* provides strength and stretching
* located on the dermis of the skin
* located on fibrous coverings surrounding bones, cartilages, muscles and nerves
36
Elastic connective tissue
* dense
* has high recoil and strength
* located in the walls of arteries and ligaments between spinal vertebrae
37
Composition of connective tissue
* cells make up ground substance and fibres
| * ground substance and fibres make up the extracellular matrix
38
Composition of connective tissue (cells)
* adipose cells: energy source and cushioning
* fibroblasts: secrete fibres and ground substance
* mast cells: immunity
* white blood cells: repair injury and fight off infection (e.g. neutrophils)
* macrophages: phagocytose (eat up) foreign molecules
39
Composition of connective tissue (ground substance)
• fills the space between the cells of the connective tissue
40
Composition of connective tissue (fibres)
* collagen
* elastic
* reticular
41
Histology
• the study of tissues
42
Cell layers
* simple: a single layer of cells
* stratified: more than one layer of cells (top layers look more squashed)
* pseudostratified: one layer of cells that appears to look like more than one layer (all cells sit on the basement membrane)
43
Cell shapes
* squamous: thin, flat cells from a side view, look like paving stones when seen in a surface view
* cuboidal: cube shaped (square in most views), usually with large, round nuclei
* columnar: tall cells, usually with oval nuclei toward their base
* transitional: can change shape from columnar to cuboidal or squamous (only found in the bladder for expansion)
44
Characteristics of muscle tissue
* highly cellular, well vascularised and responsible for most body movement
* muscle tissue needs to be highly vascular as a lot of energy is used through the tissue and oxygen is needed for metabolic reactions
* skeletal, cardiac and smooth muscle
45
Characteristics of nervous tissue
* consist of brain, spinal cord and nerves
* nervous tissue is the main component of the nervous system
* neurons are nerve cells
* neuroglia are supporting cells
NEURONS
• cell body is called the soma
• dendrites: structures that receive signals from other cells, large surface area to receive as much info as possible
• axon: conduct or transmit info away from the soma
