Cells & Tissues Flashcards
(178 cards)
1
Q
Define ‘anatomy’
A
Study of the structures that form the body
2
Q
Define ‘physiology’
A
How the parts of the body work
3
Q
Define ‘pathology’
A
The study of abnormalities from normal function
4
Q
Define ‘metabolism’
A
The sum of all the chemical processes in the body
5
Q
Define ‘responsiveness’
A
The ability to respond to changes in the environment
6
Q
List some of the characteristics of life
A
Metabolism Responsiveness Movement Reproduction Growth Differentiation Vital force / life force / Qi
7
Q
List some of the characteristics of death
A
Loss of heartbeat
Absence of breathing
Loss of brain function
No life force / Qi
8
Q
What is homeostasis?
A
The condition of equilibrium / balance in the body’s internal environment, maintained by its own regulatory processes
9
Q
Which physiological variables must be kept within narrow parameters in order for the body to remain in homeostasis?
A
Core temperature (36.5 - 37.5) Water & electrolyte concentrations pH of body fluids Blood glucose levels Blood & tissue O2 & CO2 levels Blood pressure Flow of life force / Qi
10
Q
What is a ‘normal’ core body temperature?
A
36.5 - 37.5 degrees
11
Q
Body fluids are either ‘intracellular’ or ‘extracellular’. List some extracellular fluids.
A
Blood plasma
Synovial fluid
Lymph fluid
Interstitial fluid
12
Q
List the 4 things that homeostatic control systems are made up of.
A
- DISRUPTORS (change homeostatic parameter)
- DETECTORS (receptors that detect the disruption - usually nerves)
- CONTROL CENTRE (determines limits within which parameters should be maintained. Evaluates input and generates output.
- EFFECTORS (structures that receive the output and generate the response)
13
Q
What is a feedback system?
A
A group of receptors and effectors communicating with their control centre.
14
Q
Define negative feedback
A
Where the output reverses the input.
Example: core body temperature is too high (input), so we begin to sweat (output) to cool down.
15
Q
Define positive feedback
A
Where the output further strengthens the input / strengthens the change in one of the body’s controlled conditions.
Example: pressure from baby’s head on the cervix during childbirth makes labour contractions stronger, which increase the pressure from baby’s head (through the release of oxytocin)
16
Q
In a negative feedback system, does the effector response increase or decrease the effect of the original stimulus?
A
Decreases it
17
Q
List some of the physiological variables that are controlled by NEGATIVE feedback systems
A
Body temperature
Blood glucose
Blood pressure
18
Q
List some of the physiological variables that are controlled by POSITIVE feedback systems
A
Childbirth Milk production Enzyme reactions Immunity Blood clotting
19
Q
What are the smallest living units in the body?
A
Cells
20
Q
What are tissues?
A
Groups of cells that work together to perform a function
21
Q
What are organs?
A
Groups of tissues working together to perform a function(s)
22
Q
What are systems?
A
Groups of organs that have a common / shared function
23
Q
List the 12 systems of the human body
A
Skeletal system Muscular system Respiratory system Cardiovascular system Digestive system Endocrine system Lymphatic system Integumentary system Urinary system Reproductive system Nervous system Immune system
24
Q
The body’s organs are primarily located within 4 cavities. List these cavities.
A
Cranial
Thoracic
Abdominal
Pelvic
25
What is the diaphragm and what 2 areas of the body does its presence differentiate?
The diaphragm is the main muscle of breathing.
| Its presence differentiates the thoracic cavity (above it) from the abdominal cavity (below it).
26
What is the difference between cytology and histology?
Cytology is the study of cells.
| Histology is the study of tissues.
27
Cells contain hereditary information. What is this in the form of, and how is it passed from cell to cell?
Cells contain hereditary information in the form of DNA. It is passed from cell to cell during cell division (mitosis or meiosis)
28
What do all cells in the body come from?
Pre-existing cells (stem cells) via cell division
29
In which body structure does all energy flow of life (metabolism and life force) occur?
Within cells
30
Describe 'cell memory'
The ability of our cells to remember experiences which influence the Vital Force in our cells and body.
Traumatic experiences and even negative beliefs may be stored as a negative charge of energy in cells.
31
Vital force is free-flowing throughout the body in a healthy person, but it can become blocked, creating the possibility of disease.
List some things that can cause disruption of energy through cells / stagnation of energy.
Dietary choices
Lifestyle influences, i.e, smoking, not enough sleep
Drugs
Exposure to harmful substances, i.e, radiation
32
List 3 heavy metals that can accumulate in the body and cause damage to cells.
Mercury, aluminium, lead
33
Which metal has been linked to Alzheimers, brain neuron damage and breast cancer, and where is it found in everyday life?
Aluminium.
It can be found in kitchen foil, pans, anti-perspirants, baking soda, and it's also a key ingredient in vaccines.
34
What does 'cytotoxic' mean?
Poisonous / toxic to cells
35
What is 'oxidative damage / stress'?
Damage of a structure by a molecule containing oxygen.
36
What are free radicals?
Free radicals are unstable and highly reactive oxygen-containing molecules, which lack an electron in their atomic structure.
37
How do antioxidants reduce oxidative stress in the body?
By donating one of their electrons to the unstable free radicals that are causing the oxidative stress.
38
List some examples of antioxidants
Vitamin C, E and beta carotene (vitamin A precursor)
| Quercetin, EFA's.
39
Why is oxidative stress a problem in the body?
It can damage cell membranes, blood vessels and tissues.
It can influence and damage certain cell structures
It can cause genetic mutation (including cancer)
40
Cells are classified as being either P........ or E.........
| fill in the blanks
Prokaryotic or Eukaryotic
41
Describe the differences between prokaryotic and eukaryotic cells
Prokaryotic cells have NO NUCLEUS and no membrane-bound organelles. They are smaller, divide via binary fission (rapid mitosis) and are generally bacteria. They have a cell wall.
Eukaryotic cells contain a nucleus and lots of membrane-bound organelles. They are bigger, divide via mitosis and are generally human/animal cells (although they also appear in plants/fungi). They do not have a cell wall, unless in plants/fungi.
42
What do 'DNA' and 'RNA' stand for?
Deoxyribonucleic Acid
| Ribonucleic Acid
43
The cell membrane is a flexible, semi-permeable membrane which separates the cell's internal and external environments. It is a bilayer.
Describe the arrangement / components of this bilayer.
The phospholipid bilayer of the cell membrane has 2 layers of:
- Hydrophobic (water hating) lipid tails on the inside
- Hydrophillic (water loving) phosphate heads on the outside
44
What is the purpose of the cell membrane?
1. Transport and control of substances going in and out of cells
2. Immunological identity
3. Contains receptors for hormones, etc
45
What is an ion? Give some examples.
An ion is a molecule with an electrical charge.
e.g, Hydrogen, Potassium, Sodium
46
Where might you find transmembrane proteins and cholesterol?
In cell membranes.
47
When do autoimmune diseases occur?
When white blood cells target our own cell membrane proteins.
48
Define 'hypoxia'
Hypoxia is a lack of oxygen
49
Which organs detect hypoxia?
Kidneys
50
What are atoms made up of?
Neutrons, protons and electrons
51
What creates vibrational energy?
Electrons moving rhythmically around the outside of their atoms
52
70% of the immune system is located where?
Within the digestive system
53
What is it that governs what type of cell a stem cell becomes?
Which genes are activated within the DNA of the stem cell.
54
What is a gene?
A sub-section of DNA
55
How long is the DNA in every cell?
About 6 feet long! This is why it is curled up and condensed inside the cell.
56
Where is the DNA / RNA found in a) a prokaryotic cell, and b) a eukaryotic cell?
Prokaryotic cell = in the cytoplasm (they don't have nuclei)
Eukaryotic cell = in the nucleus
57
What are cell organelles?
Mini structures / organs within the cell
e.g, ribosomes produce proteins
58
Name the 2 types of cell division
Mitosis & Meiosis
59
What is cytosol?
Basic, watery fluid inside a cell
60
What is cytoplasm?
All cell contents EXCLUDING the nucleus.
| Includes the cytosol and organelles.
61
Which cell structure controls what comes in and goes out of the cells?
Cell Membrane
62
How do ions / charged particles get in and out of cells?
Via transmembrane proteins (channel proteins)
63
What happens in autoimmune diseases?
Our white blood cells attack our own cell membrane proteins.
64
What are cell junctions?
Contact/communication points between the adjacent cell membranes of tightly packed cells.
65
List 2 types of cell junction and where they are found in the body
1. Tight junctions (stomach, intestines, bladder)
| 2. Gap junctions (nerves)
66
Explain how tight junctions create a protective barrier
Tight junctions occur where transmembrane proteins in adjacent cells interlock / fuse together (at cell junctions) to create a tight seal. They completely seal off any passageways, creating a protective surface and preventing any leaking (i.e, in the intestines).
67
What is the name given to the GIT pathology caused by weak tight junctions in the intestinal cell wall?
Leaky gut
68
What is the difference between tight junctions and gap junctions?
Gap junctions have a small quantity of fluid between them. Tight junctions do not and are completely sealed.
69
List 4 key organelles found in body cells
```
Nucleus (and nucleolus) - the brain
Mitochondria - the power plant
Ribosomes - the protein factory
Endoplasmic Reticulum (ER) - fat & protein factory
Golgi Apparatus - the post office
Lysosomes - the recycling plant
Cytoskeleton - the cell scaffolding
```
70
Describe the appearance of the Endoplasmic Reticulum (ER)
The ER is a series of foldings, divided up into 2 parts:
The rough ER has lots of dots (ribosomes) on it
The smooth ER doesn't have any ribosomes studded into it.
71
What do lysosomes do?
Help us recycle and break down old cell components
72
What is the importance of the cell nucleus?
| Describe its shape.
The nucleus is a spherical structure that contains the body's genetic information in the form of DNA.
73
Which type of body cell is the only one to not contain a nucleus?
Red blood cells do not contain a nucleus.
74
Why do red blood cells lose their nucleus during development?
To maximise the space available to carry oxygen in the blood.
75
Why is the nucleus called the brain of the cell?
Because it controls all cell functions.
76
Which cell structure produces RNA?
The nucleolus
77
What is DNA?
Deoxyribonucleic acid.
A self-replicating material present in living organisms as the main constituent of chromosomes, carrying genetic information.
The long sequence of genetic information found in every cell in the body (except red blood cells).
78
What is RNA and what is it essential for?
Ribonucleic acid.
| It is essential for protein synthesis.
79
Why are red blood cells shaped like a flattened donut?
Because they have lost their nucleus, to accommodate a larger amount of oxygen.
80
How much oxygen can 1 red blood cell carry?
A single red blood cells can carry over 1.2 billion molecules of oxygen
81
Which organelle tells the cell what to do?
The nucleus
82
Where in the cell is the nucleolus, and what does it produce?
Inside the nucleus. It produces RNA.
83
Describe the nuclear membrane.
The nuclear membrane is a double-layered phospholipid membrane that surrounds the nucleus, separating it from the cytoplasm. It is continuous with the rough endoplasmic reticulum.
84
What are nuclear pores?
Little holes within the nuclear membrane, which allow the movement of substances in and out of the nucleus.
85
How do DNA and RNA leave the nucleus?
Via nuclear pores in the nuclear membrane
86
What are chromosomes and where are they found?
Chromosomes are threadlike structures of nucleic acids and protein.
Found in the nucleus of most living cells.
87
There is 6 feet of DNA contained in every human cell. True or false?
True
88
What are somatic cells and gametes?
Somatic cells are normal human body cells. Gametes are human sex cells.
89
How many chromosomes do somatic body cells contain?
46 chromosomes (23 pairs)
90
Where in the body do you find genes and what are they?
Genes are arranged along chromosomes (the coiled up DNA found in cells).
They are hereditary units.
91
Describe the appearance of a strand of DNA.
A strand of DNA looks like a twisted/coiled ladder. A double helix.
92
What are chromosomes?
A simple, condensed form of genetic material.
93
How many chromosomes do gametes have, and why?
Gametes (sperm and eggs) only have 23 chromosomes each, because when they fuse together, they create a full cell with the full 46 chromosomes / full genetic sequence.
94
How many chromosomes are there in a full genetic sequence?
46 (23 pairs)
95
What is a gene?
A gene is a sub-unit of DNA.
Genes give the recipe to create a particular protein.
They hold the information to build and maintain cells, and pass genetic traits to offspring.
96
Which structure in the body can be described as a 'double helix'?
DNA
97
What are 'histones'?
The proteins that DNA wraps around.
| "DNA forms a double helix which coils around proteins called histones."
98
What is a nucleotide?
A nucleotide is a single DNA base (amino acid).
99
How many nucleotides are there in DNA? What are their names?
4 - A,T,C,G
Adenine, Thymine, Cytosine, Guanine
100
Which nucleotides are always paired with each other in a DNA sequence?
Adenine & Thymine ('apple and tree')
| Cytosine & Guanine ('car and garage')
101
Which pair of chromosomes controls the inheritance of sex / gender?
The 23rd pair of chromosomes controls gender.
102
How does the 23rd pair of chromosomes differ in males and females?
In males, the 2 sex chromosomes in the 23rd pair are different (XY)
In females, the 2 sex chromosomes are the same (XX)
103
If someone has XY chromosomes in their 23rd chromosome pair, what gender are they?
Male.
104
Where are genes located?
Along chromosomes. There are thousands of genes per chromosome.
105
What 2 things do genes hold the information/coding for?
1. Building and maintaining cells
| 2. Passing genetic traits to offspring.
106
One gene codes for the production of one protein.
| True or false?
True
107
Are all genes switched on / working in every cell?
No. Only certain genes are working depending on the cell's job.
108
What can influence gene expression in cells?
The external cell environment / what the cells are bathed in (epigenetics).
109
What is 'epigenetics'?
How the environment influences genes.
110
Describe what the cytoskeleton is, and list its 3 functions.
```
The cytoskeleton is a network of protein filaments that extends through the cytosol.
These protein filaments:
1. Help the cell to generate movement
2. Physical support and shape
3. Assist in cell division
```
111
How do the protein filaments of the cytoskeleton assist in cell division?
They move the chromosomes apart in mitosis.
112
Why are mitochondria known as the 'cell powerhouses'?
Because they generate ATP (energy)
113
What is ATP?
Adenosine Triphosphate. The body's energy currency.
114
Do mitocondria contain a single or double layered membrane?
Double layered membrane
115
What are the folds in the inner membrane of the mitochondria called?
Cristae
116
What are Cristae, where are they found, and what is their purpose?
Cristae are folds in the inner membrane of mitochondria. Their purpose is to increase the surface area for ATP production.
117
Which type of body cells contain the most mitochondria?
Muscle cells (including the heart)
118
How do mitochondria create ATP?
They take oxygen and react it with a number of molecules (usually glucose), in a process called aerobic respiration.
119
What nutrient/substance does our body use as a first/primary source of energy?
Glucose (then fatty acids, then amino acids)
120
What is the equation for ATP production?
(Glucose) + Oxygen = Carbon Dioxide + water + ATP
121
What are the 2 byproducts/outputs of aerobic respiration?
Carbon dioxide and water
122
What are ribosomes?
Small round structures that make up around 25% of the total cell mass. They act as the sites of protein synthesis and there are thousands of ribosomes per cell.
123
Where are ribosomes found in the cell?
Free (mobile) ribosomes are found in the cytoplasm.
| Bound (stationery) ribosomes are found within the rough ER.
124
What is the difference in function between free ribosomes and those found on the rough endoplasmic reticulum?
Free ribosomes - make proteins for use inside the cell
| Rough ER ribosomes - make proteins for use outside the cell.
125
What is the role of the rough endoplasmic reticulum?
It produces proteins (via the ribosomes attached to it) to be used outside of the cell.
126
Describe the endoplasmic reticulum.
The ER is a network of membranes in the form of flattened sacs. It extends from the nuclear envelope/membrane, throughout the cytoplasm to the cell membrane. It comprises of the rough and smooth ER.
127
What is the role of the smooth endoplasmic reticulum?
It synthesises lipids (fats) and steroid hormones.
128
What is the main difference between rough and smooth endoplasmic reticulum?
The rough ER is studded with ribosomes and produces proteins for use outside the cell.
The smooth ER is smooth in appearance and produces lipids/fats and steroid hormones. It also helps with detoxification (i.e, in the liver cells, enzymes of the smooth ER detoxify alcohol & drugs).
129
What is the name for lipid-based hormones?
Steroid hormones (i.e, oestrogen, testosterone, cortisol)
130
What is the role of smooth ER in muscle cells?
To store and release calcium for muscle contraction.
131
What is the role of the golgi apparatus?
The post office!
It sorts, packages and transports proteins from the rough ER so that they can be sent out of the cell (i.e, it makes the protein a specific shape)
Most cells have several golgi apparatus.
132
How do proteins from the rough ER get to the golgi apparatus for sorting and sending out of the cell?
A transport vesicle buds off from the rough ER and moves to the goggle apparatus, releasing the proteins into it.
133
What are lysosomes?
Cell organelles that perform a key role in 'cell digestion'.
They contain up to 60 powerful enzymes, which fuse with a variety of molecules and break them down.
They are also used to digest foreign cells (phagocytes).
134
What separates the nucleus from the cytoplasm?
The nuclear membrane
135
How do substances move in and out of the nucleus?
Through nuclear pores
136
What is the cytoskeleton?
A network of protein filaments that extend through the cytosol.
137
List 3 things that the cytoskeleton does.
1. Provides physical support and shape to the cell.
2. Helps cells generate movement
3. Assists in cell division.
138
What is the cytoskeleton made of?
Protein filaments (microtubules and microfilaments)
139
How many types of cell reproduction are there?
Two, mitosis (cell replication) and meiosis (production of sex cells).
140
Which type of cell reproduction describes 1 division creating 2 identical daughter cells?
Mitosis
141
Which type of cell reproduction is used for growth and repair?
Mitosis
142
List 3 types of cells in the body that cannot undergo mitosis.
1. Brain cells
2. Muscle cells
3. Eggs
We are born with a set number of all of the above cells.
143
Do skeletal muscle cells get bigger in size or number?
Size. Skeletal muscle cells cannot replicate. We get what we are born with, in terms of number.
144
How often does the outer layer of our skin (the epidermis) replace itself via mitosis?
Every 40 days
145
How often is our superficial lining / mucosa of the stomach and intestines regenerated?
Stomach every 3-5 days
| Intestines every 5 - 7 days
146
How often do our tastebuds regenerate?
Every 10 days
147
Why does chemotherapy often affect tastebuds, the skin, and the stomach and intestinal lining?
Because chemotherapy targets cells that undergo rapid mitosis, which these cells naturally do.
148
What is meiosis?
The process through which gametes are formed.
149
Which form of cell reproduction produces 4 haploid cells through 2 divisions?
Meiosis
150
Define diploid and haploid
```
Diploid = cells with 46 chromosomes (somatic cells)
Haploid = cells with 23 chromosomes (gametes)
```
151
What type of cell is either male or female?
Gametes (sex cells)
Sperm = male
Ovum / eggs = female
152
Why does meiosis produce non-identical cells?
To produce genetic variability
153
What causes the production of non-identical cells in meiosis?
The overlapping of chromosomes throughout the process.
154
What does 'fertilisation' describe?
The fusion of a male and female gamete
155
What is a zygote?
A zygote is A DIPLOID CELL which has 2 copies of each chromosome (23 pairs) - 1 from each parent.
156
At what point in a pregnancy does an embryo become a foetus?
After 8 weeks
157
What is an embryo? At what stage of pregnancy is the baby called an embryo?
An embryo is essentially the first, very basic moulding of what the baby will become.
The baby is called an embryo in the first 8 weeks of pregnancy. After that it is called a foetus.
158
Describe a cell 'mutation'.
A mutation is a change in the genetic information (DNA sequence). A mix-up of the amino acid base A, C, T & G.
159
How many genes are there in an entire genetic sequence?
About 20,000
160
What are mutagenic agents?
Substances / things that can cause cell mutation. i.e, smoking, radiation, chemotherapy
161
What is protein synthesis?
The process whereby we manufacture proteins inside a cell. Where cells use the DNA code as a template for the synthesis of a specific protein.
162
Protein synthesis includes 2 phases. What are are they?
Transcription and Translation
163
Describe the transcription phase of protein synthesis.
Transcription is where a copy of one gene is made into mRNA.
This then travels out of the nucleus and into a ribosome.
164
Describe the translation phase of protein synthesis.
Translation is where a ribosome reads the 'code' from transcribed mRNA and produces a chain of amino acids to form the required protein.
165
Transport of molecules across cell membranes is essential to life. Name the 2 main types of movement/transport of substances.
Passive and active transport
166
What dictates whether passive or active transport is required for transporting certain molecules across a cell membrane?
The concentration gradient dictates whether passive or active transport is required.
167
What is active transport?
Moving of a substance against the concentration gradient (from low to high concentration)
N.B think of actively pushing a trolley up a hill analogy. It requires energy.
168
Describe passive transport
Moving of a substance WITH the concentration gradient (from high to low concentration).
N.B think of passively pushing a trolley down a hill analogy. It does NOT require energy.
169
List the 3 types of passive transport.
1. Diffusion (Gases)
2. Osmosis (Water)
3. Facilitated diffusion (large molecules i.e, glucose, and charged particles/ions)
170
What type of passive transport is used to get ions (charged particles) in and out of cells?
Facilitated diffusion.
| Transmembrane proteins help us move ions in and out of cells.
171
What type of passive transport is used to move large molecules such as glucose in and out of cells?
Facilitated diffusion (with the help of transmembrane proteins)
172
What type of proteins are involved in facilitated diffusion (passive transport)?
Transmembrane proteins
173
Describe 'active transport'.
The movement of substances from an area of low to high concentration (up the concentration gradient).
Active transport requires energy (ATP)
174
What are the 3 main types/methods of active transport?
1. Pumps
2. Endocytosis
3. Exocytosis
175
In which body system would you find active transport occurring via the sodium potassium pump?
The nervous system. It's what helps us to separate a charge around our nerve cells.
176
Give an example of a pump used in active transport
1. Proton (hydrogen) pump (in the stomach)
| 2. Sodium potassium pump (nervous system)
177
What is the difference between exocytosis and endocytosis?
Endocytosis is the engulfing of particles INTO a cell.
| Exocytosis is the removal of waste OUT of a cell
178
Endocytosis is a form of active transport that involves either phagocytosis or pinocytosis, but what is the difference between these?
```
Phagocytosis = 'cell eating' (solids)
Pinocytosis = 'cell drinking' (liquids)
```
