Bioscience Flashcards
(360 cards)
1
Q
Skins Function of Protection
A
Physical/Chemical Barrier
Eg. Melanin Protects from UV damage
2
Q
Skins Function of Protection (2)
A
Immunity : Immune cells in
- Epidermis (Langerhans Cells)
- Dermis (Macrophages)
3
Q
Skins Function of Sensation
A
Receptors detect pain, heat, pressure, vibration
4
Q
Skins Metabolic Function
A
Synthesis of Vitamin D
5
Q
Skins Function of Temperature Regulation
A
Sweat glands,
thermoreceptors,
dilation or construction of blood vessels
6
Q
What Skin Excretes
A
Urea
Ammonia
Uric Acid
Pheromones
7
Q
Epidermis Cell Types
A
Keratinocytes (90%)
Langerhans Cells : Immune Cells
Melanocytes : Produce Melanin
8
Q
Epidermis Sublayers
A
5 Sublayers : No blood vessels - able to shave
9
Q
Dermis Cell Types
A
Fibroblasts : Produce Collagen
Macrophages : Immune Cells
Mast Cells : Release histamine during allergies, inflammation
10
Q
Dermis Sublayers and what they contain
A
2 Sublayer Contain :
- Blood Vessels
- Lymph Vessels
- Sweat Glands
- Hairs
- Arrector Pili Muscles
- Sebaceous Glands
- Sensory Nerve Endings
11
Q
Hypodermis or Subcutaneous describe layers and what it contains
A
Deepest Layer
Contains : Collagen & Fat cells
12
Q
Role of Hypodermis or Subcutaneous
A
Conserve body’s heat ; protects body by acting as a shock absorber
13
Q
Directional Planes
A
Midsaggital Plane : 👁 | 👁
Coronal (Frontal Plane) : 🍑 | 🗣
Transverse Plane : 👕
➖
👖
14
Q
Superior (cranial)
A
Above; towards the head and upper part of a structure or body
15
Q
Inferior (caudal)
A
Below ; away from the head or towards the lower part of the structure or body
16
Q
Anterior (ventral)
A
In front of ; toward or at the front of the body
17
Q
Posterior (dorsal)
A
Behind ; toward or at the backside of the body
18
Q
Medial
A
On the inner side of ; toward or at the middle of the body
19
Q
Lateral
A
On the other side ; away from the midline of the body
20
Q
Intermediate
A
Between a more medial and a more lateral structure
21
Q
Proximal
A
Close to the origin or the point of attachment of a limb to the body trunk
22
Q
Distal
A
Further form the point of origin or point of attachment of a limb to the body trunk
23
Q
Superficial (external)
A
Toward or at the surface of the body
24
Q
Deep (internal)
A
Away from the surface of the body
25
Muscle Functions
- Movement
- Posture
- Stability of joints
- Generating Heat
26
Muscle Properties
- Get Excited
- Contract (shortens and thickens when stimulated)
- Extension (stretches without damage)
- Elasticity (returns to original shape)
- Adaptable
27
Skeletal System Functions
- Movement
- Support
- Protection
- Blood Cell Formation
- Storage of Mineral Eg. Calcium
28
Axial Skeleton
- Skull
- Sternum (breast bone)
- Ribs
- Spine (vertebral column)
29
Appendicular System
- Shoulder bones & Upper Limbs
| - Pelvis & Lower Limbs
30
Joints (articulations)
Weakest parts of the skeleton
Articulation : Where 2 bones come together
3 subtypes of joints
31
Fibrous Joints
Bones linked by fibrous material
- No or very limited movement
32
Cartilaginous Joints
The connection between the bones is made up of cartilage which acts as a shock absorber
Generally, limited amount of movement
33
Synovial Joints
There is a small space between the bones which contains synovial fluid
Highly Moveable
34
Number of bones in adult Skeleton
206 Bones
35
Spongy bone structure
Contains red bone marrow needed for blood cell production
36
Compact bone structure
Contains yellow bone marrow
37
Bone shape categories
- Long
- Short
- Flat
- Irregular
- Sesamoid
38
Example of long shaped bone
Femur
39
Example of short bone
Carpals
40
Example of flat bone
Sternum
41
Example of irregular bone
Vertebrae
42
Example of sesamoid bone
Patella
43
Functions of Joints
- Give skeleton mobility
| - Hold the skeleton together
44
Function of fibrous joints
Stability
45
Example of fibrous joints
Joints between the skull bones
46
Example of cartilaginous joints
In between the vertebrae of the spinal column
47
Most common joints in the human body
Synovial joints
48
Synovial joints all have
- A Capsule
- A Synovial Membrane
- Cartilage
49
A Capsule
Collagen structure surrounding the entire joint
50
Synovial Membrane
The inner layer of the capsule which secretes synovial fluid (a lubricating liquid)
51
Cartilage of synovial joints
Hyaline which pads the ends of the articulating bones
52
Subtypes of muscle
- Skeletal Muscle
- Cardiac Muscle
- Smooth Muscle
53
Skeletal muscle
- Cylindrical fibre
- Striated
- Voluntary
- Many nuclei
54
Function of Skeletal muscle
- Controls movement, position, heat production
55
Cardiac muscle
- Branched Fibre
- Striated
- Involuntary
- One Nucleus
56
Function of cardiac muscle
Pumps blood around the body
57
Smooth muscle
- Spindle Shaped fibre
- Not Striated
- Involuntary
- One Nucleus
58
Function of Smooth muscle
- Alters size of organs, blood vessels
| - Pushes substances through the ducts/tubes of the body
59
Matter definition
Anything that occupies space & has mass
Made up of molecules
60
Molecules
Composed of 1 or more smaller units called atoms
61
Atoms
Composed of protons, electrons & neutrons
At the core of each atoms is nucleus
62
Electrons
Negatively charged and surround the nucleus at a distance
63
Atomic number
Number of protons in the nucleus
64
Atomic weight (mass)
Number of protons & neutrons combined
65
Element
A chemical substance whose atoms are all of the same pure substances
66
4 elements make up 96% of the human body
- Oxygen
- Carbon
- Hydrogen
- Nitrogen
67
Trace elements (mineral salts)
- Calcium (Ca)
- Phosphorus (P)
- Potassium (K)
- Chlorine (Cl)
- Sodium (Na)
- Iron (Fe)
- Magnesium (Mg)
68
Compounds
When different types of atoms combine
69
Compound containing carbon
Organic Compounds ;
all other compounds are inorganic
70
An atom is inert / chemically unreactive if:
- The outer shell has the maximum number of electrons allowed
- Stable proportion of this maximum number
Eg. Helium
71
Atoms will come together to:
- Take electrons from another atom
- Give away it’s spare electrons
- Share Electrons
72
Covalent Bonds
Form when atoms share their electrons
- Strong & Stable bond
Eg. H20
73
Ionic Bonding
Form when electrons are transferred from one atom to another
Atoms stick together as carry opposite charge
- Weaker bonds
Eg. NaCl (table salt)
74
Ions
Atoms that have become charged as a result of the loss or gain of electrons
75
Cations
Positively charged ions
76
Anions
Negatively charged ions
77
Electrolytes
Molecules that form ions when dissolved in water
Eg. Na+ (sodium)
78
Molarity
1 mole per litre
79
A mole
Atomic weight in grams
80
An acid
Breaks apart into one or more hydrogen ions (H+) when dissolved in water
81
A base
Breaks apart into one or more hydroxide ions (OH-) ions when dissolved in water
82
Buffers
Resist changes in pH
- Responsible for keeping body pH stable
83
Excess acids and excess bases are excreted by the body by two organs
- Lungs
| - Kidneys
84
Carbohydrates
Sugar & Starches
Element Ratio :
1 Carbon : 2 Hydrogen : 1 Oxygen
85
Functions of carbohydrates
- Common readily available energy source
- Energy storage; glycogen in muscles
- Attach to external surface of cells to guide cell interaction
- Structural element of Nucleic acids RNA, DNA
- Make up some cell receptors
86
Groups of carbohydrates
- Monosaccharides
- Disaccharides
- Polysaccharides
87
Monosaccharides
Basic building blocks of carbohydrates
Eg. Glucose
88
Disaccharides
Two monosaccharides joined together
Eg. Sucrose
89
Polysaccharides
These are long chains of thousands of monosaccharides joined together m
Eg. Glycogen (storage form of glucose)
90
Glucose
Key fuel in the body and is main carbohydrate used by all cells
91
Hyperglycaemia
Blood sugars are too high
92
Hypoglycaemia
Blood sugars are too low
93
Lipids
Not soluble in water
Contain mainly carbon, hydrogen, with some phosphorus & nitrogen
94
Functions of lipids
- Insulation
- Protection of body organs
- Energy storage when glucose is in short supply
95
Lipid groups
- Fats (triglycerides)
- Fatty acids
- Phospholipids
- Steroids including cholesterol
- Fat-soluble vitamins - A, D, E, K
- Prostaglandins
96
Fats (triglycerides) structure
Single glycerol molecule and 3 fatty acids attached
97
Fats (triglycerides) Function
- Storage of chemical energy
- Excess carbohydrates, fat, protein stored as triglyceride
- Protects / insulates body organs
98
Fatty acids structure
Long chain of carbon atoms with hydrogen attached
99
Types of fatty acids
- Saturated fatty acids
- Monounsaturated fatty acids
- Polyunsaturated fatty acids
100
Saturated fatty acids
Single bonds between carbon atoms
Eg. Stearic acid, Animal fats
Usually solid at room temperature
101
Monounsaturated fatty acids
One double bond between carbon atoms
Eg. Olive oil
102
Polyunsaturated fatty acids
More than one double bond between carbon atoms
Eg. Omega 3 / 6/ 9 fatty acids
Sunflower oil
103
Phospholipids structure
Phosphate & glycerol attached to 2 fatty acids
Arranged in bilayers & forms cell membrane
104
Cholesterol structure
- Basic steroid molecule
- Found in cell membrane
- Can be converted into other steroids
105
HSE recommended total cholesterol level for healthy adults
Level below 5 mmol/L
106
Proteins structure
Contain carbon hydrogen, oxygen and nitrogen (some also contain sulphur, phosphorus)
Amino acids are building blocks of protein
107
How amino acids form protein
Joined together by dehydration synthesis and linked by peptide bonds to from proteins
108
Dipeptide
2 amino acids joined together
109
Tripeptide
3 amino acids joined together
110
Polypeptide
Many amino acids joined then folded & processed, producing the final protein
111
How many different amino acids
20 used in different combinations & quantities to produce many different proteins
112
Essential amino acids
9 that can’t be produced by the human body & need to be taken in as food.
113
Functions of protein
- Structural support : tendons, ligaments
- Speed up chemical reactions in body (enzymes)
- Muscle
- Antibodies (part of immune system)
- Hormones
- Haemoglobin
- Nitrogen balance
114
Enzymes
Proteins which speed up chemical reactions in the body without being changed themselves
Only involves in one type of reaction each
115
Nucleotides types
- Adenosine Triphosphate (ATP)
| - Nucleic Acids
116
Adenosine triphosphate (ATP)
- Made from ribose (sugar), adenine (base) & 3 phosphates
- Energy currency of the body, and is made in the mitochondria
117
Nucleic Acid
- Made from ribose or deoxyribose (sugar) & 1 phosphate
118
Nucleic acid bases
- Cytosine
- Guanine
- Adenine
- Thymine
- Uracil
119
How much water in adult human body
60% water ; approx 40 litres
120
Intracellular fluid
Fluid inside cells / cytosol
- 28 Litres
121
Extracellular fluid
All other fluid outside cells
- 12 Litres
122
Intercellular / interstitial fluid
Fluid in between cells
123
Plasma
Watery component of blood
124
Lymph
Watery fluid within lymphatic vessels
125
Types of movement of substances within body fluids
Passive Movement :
- Diffusion
- Osmosis
126
Homeostasis
Maintaining a constant internal environment
127
Negative feedback
Any movement away from the normal level is reversed (negated)
- Eg. Control of body temp
128
Positive feedback
Increasing response as long as the stimulus is present
- Eg. Labour during childbirth
129
What is a Cell
- Structural & Functional unit of all living organisms
| - Often called the “building block of life”
130
Unicellular organism
Bacteria
131
Multicellular organisms
Plants, animals & humans
132
Prokaryotic properties
- Genes not enclosed in nuclear membrane
- Cytoplasm have no other membrane bound organelles
- Really small cells
133
Prokaryotic Example
Bacteria
134
Eukaryotic properties
- Genes enclosed in a nuclear membrane
| - Cytoplasm contains other bound organelles
135
Interstitial space
Space between cells
136
Interstitial fluid Function
- Provides cells with nutrients
| - Provides a means of waste removal
137
Cell (plasma) membrane
- Surrounds the cytoplasm
- Separates & protects cell
- Membrane made up of phospholipids
- Hydrophilic = “water loving” head group
- Hydrophobic tail
- phospholipids naturally form a bilayer when added to water
- Dynamic (not rigid structures)
138
Embedded in the cell membrane
- Cholesterol : adds stability
| - Protein
139
Role of protein in cell membrane
- Can act as specific receptors
- Can regulate what is transported across the membrane. in & out of the cell
- Carbohydrates can attach to the proteins and “flag” the cell, identifying it as “self” and not a foreign invading cell
140
Passive transport
Substances move down concentration gradient, from high concentration to low concentration
141
Active transport
Energy is required to move substances against their concentration gradient; from low to high concentration
142
Osmosis
Movement of water across a semi-permeable membrane
143
Facilitated / carrier-mediated diffusion
Bonds to a specific carrier site; the carrier changes shape & deposits molecule on the other side
Eg. Glucose
144
Bulk transport across the cell membrane
Taken into the cell by ;
- Pinocytosis (small particle)
- Phagocytosis (large particle)
Eliminated from the cell by ;
- Exocytosis (rid cell of waste)
145
Cytoskeleton
Strands of protein involved in maintaining the structure of the cell
146
Microfilaments
- Structural support, maintaining the shape of the cell
147
Microtubules
These protein are like train tracks on which various molecules are transported, within the cell
148
Nucleus
- Contain chromosomes (genes)
| - Cell replication & protein synthesis begin here
149
Mitochondrion
- Power-plant of the cell because energy is generated here
- Aerobic respiration occurs in the mitochondrion which generates energy in the form of ATP
- Can self-replicate as they contain their own DNA
150
Lysosomes
- Contain digestive enzymes which breakdown / digests substances which are then either recycled or released from the cell
151
Digestive enzymes
- Lipases which digests lipids
- Carbohydrases which digest carbohydrates
- Proteases which digest proteins
- Nucleases which digest Nucleic acids
152
Ribosomes function
- Synthesise proteins within our cells (nucleus dictates what type of protein)
153
Ribosomes locations
- Floating freely in cytoplasm
- Binding to the nuclear envelope
- Binding to the endoplasmic reticulum
154
Endoplasmic reticulum types
Smooth & Rough
155
Smooth Endoplasmic reticulum functions
- Synthesis of lipids & steroid hormones
- Metabolism of carbohydrates
- Detoxification of some drugs
156
Rough endoplasmic reticulum functions
- Processes / modifies proteins & transports proteins to the cell membrane, some of which may be secreted from the cell
Eg. Enzymes & hormones
157
Golgi apparatus
- Further processes / refines & sorts proteins
- Vesicles from rough endoplasmic reticulum are transported to the Golgi apparatus where they are modified, sorted & shipped toward cell membrane
158
Infection
The growth of an organism within a host
159
Pathogen
Disease-causing organism
160
Virulence
The relative ability of an organism to cause disease : degree of pathogenicity
161
Commensal or human normal flora functions
- Prevent other bacteria from multiplying
- In the gut they aid digestion and produce essential vitamins
- Play a role in immunity against disease
162
Bacterial infection example
- Streptococcus (throat infection)
163
Fungal infection example
- Candida (yeast infection)
164
Viral infection example
- Human Immunodeficiency Virus (HIV)
165
Protozoa infection example
- Plasmodium Malaria (Malaria)
166
Parasitic infection example
- Worms (tapeworm)
167
Prions infection example
- Creutzfeldt-Jacob disease
168
How bacteria divide
- Binary Fission : divide in 2 equal parts
| - Fast multipliers (every 20 mins under favourable conditions)
169
Identifying bacteria
1) Specimens collected (blood, urine...)
2) Grow bacteria on special medium (agar)
3) Identify
170
Bacteria Shapes
1) Cocci : Round / Berry shape
2) Bacilli : Rod Shaped
3) Spirochete : Corkscrew / Twisted
171
Staining
- Gram stain most important staining reaction
1) A thin film of specimen is smeared on to a glass microscope slide and stained with mixture of violet & red dyes
2) Depending upon which dye is taken up, the bacterium will appear purple (Gram Positive) or pink (Gram- Negative)
172
Obligate aerobes
- Require oxygen to survive
Eg. Mycobacterium tuberculosis
173
Obligate Anaerobes
- Do not tolerate oxygen
Eg. Clostridium tetani = tetanus
174
Facultative anaerobes
- Can survive in the presence or absence of oxygen
Eg. Escherichia coli (enteric gut bacteria)
175
Fungi
- Study is called mycology
- Are composed of slender filaments called hyphae
- Eukaryotic cells
- Can be unicelular or multicellular
176
A mass of hyphae
- Mycelium
177
Fungal infections reproductions
- Reproduce sexually or asexually : produce spores
- Fungal infection can be chronic (grow slowly within or on host)
- Opportunistic (take over when host is immunosuppressed)
178
Systemic fungal infections
- Deep within the body, can affect many tissues & organs
Eg. Inhalation of a fungal spore may cause respiratory infection
179
Subcutaneous fungal infection
- Occur beneath the skin, usually acquired from puncture wounds
180
Viruses is made of
- Consists of Nucleic acid (DNA or RNA) wrapped in a protein coat (capsid)
181
Obligate intracellular parasites definition
- They can exist only at the expense of another organism
182
Viral infection process
1) Virus attached & enters cell
2) Virus Releases genetic material into host cell
3) Hijacks the host cells replication machinery to make more vital Nucleic acid & more protein coats
4) Assembled into new viruses which leave the cell & move on to infect other neighbouring cells
183
Bacterial infection - preventative methods
1) Sterilisation of utensils
2) Basic hygiene & cleanliness-hand washing
3) Wiping surfaces
4) Use of disposable gloves
5) Personal protective equipment
184
Antibiotics are :
- Bactericidal (kills bacteria)
| - Bacteristatic (inhibit growth of bacteria)
185
Action of antibiotics
- Prevent bacterial cell wall formation
Eg. penicillins
- Inhibit protein synthesis
Eg. Tetracyclines
- Enzyme inhibition
Eg. Sulphonamides
- Blocking DNA replication
Eg. Quinolones
186
Combating viral infections
- Difficult to treat viral infections as you may also affect host cells
- Antibiotics are no use
- Vaccines (attenuated or dead version of the virus used to prime the host immune system)
187
Prevent fusion of virus membrane with host thereby preventing entry
- Amantadine
188
Prevent Viral Replication
- Aciclovir : used against herpes & cold sores
| - Zidovudine (AZT) : used to protect child in utero from HIV from mother
189
Prevent viral proteins being made
- Proteases (break down proteins)
| Eg. Saquinavir
190
Prevent viral release from cell
- Oseltamivir for influenza
191
Skin Host Defence
- The skin is an inhospitable environment for many microbes :
1) Dry & Acidic
2) Sweat & sebum posses antimicrobial properties
3) Skin sheds regularly & keratin is a strong physical barrier
192
Oral cavity host defense
Normal flora : Ideal home for microbes : warm, moist & lots of nutrients
1) Saliva is antimicrobial
2) Ingestion and dislodgement of microbes by chewing and swallowing
193
Digestive tract normal flora
- Not many microorganisms found in stomach & duodenum due to low ph (acidic)
- Many commensal and mutualistic microbes in large intestine
- Vitamin K & some B vitamins are produced by bacteria in large intestine
194
Digestive tract host defense
- Shedding of intestinal membrane occurs periodically
| - Mucus prevents unwanted bacterial from attaching
195
Respiratory tract normal flora
- Nose & throat contain many microbes while lower respiratory tract is usually sterile (cilia & mucus)
- Mostly bacterial
196
Respiratory tract host defense
- Nasal secretions kill many microbes, movement of cilia removes many microorganisms, also sneezing & coughing
197
Urinary tract normal flora
- Lower urethra contains many microbes
198
Urinary tract host defense
- Mechanical flow of urine removed many microbes
| - Acidic pH and urea antimicrobial
199
Routes of entry
1) Inhalation : Inhaling organisms
2) Ingestion : Contaminated food / water
3) Inoculation : Damage to skin or mucus membrane
4) Congenital Transmission : Maternal or foetal transfer of pathogen
Eg. Rubella
200
Modes of spread
- Contact : Direct (via hands or sex) / Indirect (contaminated equipment or surface)
- Vectors eg. mosquitos
- Airborne eg sneezing
- Endogenous eg one body to another
- Contaminated food / water eg faecal-oral transmission
201
Disinfection :
- Making the object non-infective
- May still be microorganisms but much less
- Spores remain following disinfection
202
Sterilisation:
- Destruction of all living organisms
- A number of methods exist
1) Heat (dry & moist)
2) Radiation
3) Chemicals
203
Role of Nurse with infection
Aim: Prevent cross-infection rather than relying upon the ability to treat infection once it has occurred
1) Protect ourselves
2) Protect our colleagues
3) Protect patients/clients
204
Glycaemic index
- A scale that describes how fast a food is converted to glucose in the blood
205
Low GI foods
- “Drip feed” the body with energy over a longer period of time
Eg. Starches / Fibers
206
High GI foods
- Converted to an absorbable sugar quickly & provide rapid energy to the bloodstream & muscles
- Generates an insulin spike and may give rise to energy swing
- Good before sports
207
Starch
- Major plant storage form of glucose
208
Dietary fibre non starch polysaccharide properties
- Resistant to digestion by amylase
- Recommend intake of fibre a day is 20-30kg (currently average only 50%)
- Passes through bowel undigested, some fermented in bowel to short fatty acids
209
Dietary fibre non starch polysaccharide functions
Adds bulk of faeces decreases faeces transit time :
- Decreases risk of bowel problems like constipation or cancer
Helps control energy intake :
- Reduces eating speed
- Slows gastric emptying - feel full longer
- Low GI prevents peak of glucose and insulin
- Soluble types lower cholesterol levels
210
Anabolism
- Smaller substances give rise to bigger molecules-synthesis
211
Catabolism
- Substances are broken down into simpler ones; energy is released & used to make ATP
212
Order of preference for making ATP
1) Carbohydrates (especially glucose)
2) Fats (when inadequate carbs)
3) Proteins (conserved but broken down in starvation)
213
Metabolism of carbohydrates
1) Digestion : taken in by diet & catabolised into simple sugars in the gastrointestinal tract
2) Absorption: simple sugars are transported into bloodstream and transported around the body
3) Cells take glucose & catabolise further into ATP
4) Glucose + Oxygen 🔜 + ATP
214
Gluconeogenesis
- Making glucose from non carbohydrates
215
Intake of carbohydrates per day
- Should make up approx 55% of total caloric intake per day (only 10% sugars)
216
First class proteins
- A protein that contains essential amino acids in good quantities
1) Meat / Fish / Milk products
2) Peas / Beans
217
Second class proteins
- Are low in one or more essential amino acids
- If vegan / vegetarian need mutual supplementation
i. e Rice + Peas
218
Daily intake of protein
- 0.8 grams per kg of body weight
| - Average western diet 15% more protein than adequate needs
219
Protein Metabolism (Eating)
1) Digestion : taken in by diet & digested in gastrointestinal tract to amino acids
2) Absorption & Transport to cell as amino acids
3) Amino acids used to build other proteins needed
4) Cells can’t build their own proteins unless all need amino acids are present
5) When carbs & fats aren’t available amino acids used to make ATP
6) When amino acids metabolised amine part is removed and forms ammonia
7) Rest of amino acid is catabolised further in the mitochondrion to generate ATP
220
Protein Metabolism (Making Proteins)
1) Mainly occurs in liver
2) Synthesis of proteins from amino acids
3) Conversion/making of non essential amino acids
4) Breakdown of proteins
221
Protein Metabolism (Nitrogen)
1) Proteins are main source of nitrogen, deficiency leads to negative nitrogen balance
2) If protein are eaten in excess, nitrogen removed & nitrogenous wastes are excreted by the kidneys
3) Remainder is converted to fat for storage
222
Lipids definition
- Lipids are broadly defined as any fat-soluble (lipophilic), naturally- occurring molecules
223
Types of Lipids
1) Fats
2) Fatty Acids
3) Steroids
4) Phospholipids
224
Example of fats
- Monoglycerides, diglycerides & triglycerides
Function : Energy
225
Example of fatty acids
- Arachidonic acid
Function : Cell membrane structure & signalling
226
Example of steroids
- Cholesterol
Function : Cell membranes, give rise to some hormones
227
Example of phospholipids
- Leicitin
Function : Cell membranes
228
Main source of fats
1) Milk fats
2) Meat fats
3) Seeds(oils) & Nuts
4) Fish oils
5) Hidden fats
229
Functions of fats
1) 20-35% of our energy
2) Palatability
3) Satiation : delays emptying time of stomach
4) Transport & store fat soluble vitamins
5) Structural support of many organs Eg. eyes
6) Forms cholesterol & steroid hormones
7) Forms myelin sheath that insulates nerves
8) Insulates heat in the body
230
Lipid Metabolism
1) Lipids taken in by diet & digested in the gastrointestinal tract to fatty acids + glycerol
2) Absorbed from digestive tract to the blood and the lymph
3) Fatty Acids are broken down in the liver
4) Liver cells use fatty acids to make cholesterol,
Lipoproteins & release the remaining smaller fat molecules into the blood
5) Fat molecules & cholesterol are taken up & used by the cells of the body for membrane structure or for making steroid hormones
6) Fats molecules are used to make myelin sheaths in the nervous system
231
Fat Breakdown
For fats to be used for ATP
1) Broken down by the liver to acetic acid
2) Within mitochondria of liver cells:
Acetic acid 🔜 Carbon Dioxide + Water + ATP
3) When carbohydrates are low large amounts of fat are used to make ATP
(Ketosis happens in uncontrolled diabetes)
232
Cholesterol - Transportation
- Lipoproteins transport fat & cholesterol in the blood as they are not water-soluble
1) Low density lipoproteins (LDLs)
2) High density lipoproteins (HDLs)
233
Low density proteins
- “Bad” lipoproteins
- LDLs transport cholesterol & other lipids TO body cells
- Large amounts of LDLs are circulating, there is a high chance that fatty substances will be deposited on arterial walls causing atherosclerosis
234
High Density Lipoproteins
- “Good” lipoproteins
- HDLs transport cholesterol & other lipids from body cells to liver for disposal in bite salts
- Help in eliminating circulating cholesterol
235
Water soluble vitamins
- Vitamins B, C, Folic Acid
236
Vitamin A Source
1) Animal Sources Eg. Meat/Eggs/Dairy
2) Green leafy and intensely coloured fruits and vegetables Eg. Carrots
Belongs to the family of chemical compound known as retinoids
237
Vitamin A Functions
1) Eye Health
2) Skin Health
3) Bone Health
4) Hormone Synthesis
238
Vitamin A Deficiency
1) Night Blindness
2) Dry Scaly Skin
3) Inefficient functioning of immune system so prone to infection
239
Vitamin D Source
1) Cheese, eggs, butter, cereals & fish
| 2) Skin synthesises vitamin D when exposed to sunlight
240
Vitamin D Functions
- Promotes absorption & use of calcium & phosphorus for strong bones & teeth
241
Vitamin D Deficiency
1) Rickets : failure of growth & deformity of long bones (childhood disease)
2) Osteomalacia : a bone softening disorder in adults where there is muscle weakness & bone fragility
3) Osteoporosis: Fragile bones
242
Vitamin E Source
1) Vegetable oils
2) Egg yolk
3) Nuts
4) Sunflower seeds
5) Wheat germ
243
Vitamin E Functions
1) Antioxidant to prevent cell membrane damage
| 2) May reduce risk of heart disease, cancer, cataracts, age related macular degeneration
244
Vitamin E Deficiency
1) Premature or very low birth weight infants
| 2) Neurological problems due to poor nerve conduction
245
Vitamin K Source
1) Green leafy vegetables
| 2) Vegetable oils
246
Vitamin K Functions
1) Needed by liver to make clotting factors (prothrombin, factors VII, IX & X)
247
Vitamin K Deficiency
1) Defective blood clotting causing severe bleeding on injury
248
Vitamin B1 (thiamine) Source
1) Lean Meats & fish
2) Egg yolk
3) Yeast
4) Nuts
249
Vitamin B1 (thiamine) Functions
1) Helps the body convert carbs & fat into energy
| 2) Essential for normal growth, development & proper functioning of the heart, nervous system & digestive system
250
Vitamin B1 (thiamine) Deficiency
1) Leads to Beriberi :
- Altered nerve activity
- Symptoms may include weight loss, emotional disturbances, impaired sensory perception, weakness and pain in the limbs, and periods of irregular heartbeat
- Oedema of bodily tissues common
- May cause heart failure and death
251
Vitamin B2 Source
1) Lean Meat, Eggs
2) Green Vegetables
3) Milk, Cheese
252
Vitamin B2 Functions
1) Metabolising carbs, fats & proteins
2) Needed for enzymes in :
- Red blood formation
- Respiration
- Reproduction
253
Vitamin B2 Deficiency
1) Skin Rash
| 2) Eye Sensitivity to the sun
254
Vitamin Folic Acid (B9) Source
1) Dark green leafy vegetables
| 2) Citrus Fruits
255
Vitamin Folic Acid (B9) Functions
1) Production & maintenance of new cells
2) Key for periods of rapid cell divinos & growth such as infancy & pregnancy
3) DNA & RNA replication & red blood cell formation
256
Vitamin Folic Acid (B9) Deficiency
1) Leads to neural tube defects & malformations of the brain
2) Anaemia
257
Vitamin C Source
1) Fresh fruits & vegetables
258
Vitamin C Functions
1) Important antioxidant
2) Collagen synthesis
3) Enhances immune system
4) High doses may be carcinogenic
259
Vitamin C Deficiency
- Scurvy :
1) Easy bruising
2) Loose teeth
3) Superficial bleeding
4) Compromised immunity
260
Calcium Source
1) Milk, Cheese
2) Eggs
3) Green Vegetables
261
Calcium Functions
1) Bone & tooth formation
2) Blood coagulation
3) Nerve & Muscle activity
262
Calcium Deficiency
1) Stunted growth in children
| 2) Bone loss (osteoporosis) in adults
263
Potassium Source
1) Meat
2) Milk
3) Fruit & Vegetables
264
Potassium Functions
1) Fluid balance: electrolyte balance
| 2) Nerve & Muscle activity
265
Potassium Deficiency
1) Muscular Weakness
| 2) Cardiac arrest
266
Phosphorus Source
1) Cheese
| 2) Liver & kidney
267
Phosphorus Functions
1) Bones & tooth
2) Enzymes
3) DNA & RNA
268
Phosphorus Deficiency
1) Weakness
| 2) Demineralisation of bone
269
Sodium Source
1) Salt
| 2) Cured meats
270
Sodium Functions
1) Fluid balance
2) Muscle & nerve activity
3) Blood pressure
271
Sodium Deficiency
1) Muscle cramps
2) Reduced appetite
3) Weakness
272
Iron Source
1) Red meat
2) Egg yolk
3) Green Vegetables
273
Iron Functions
1) Haemoglobin in red blood cells
| 2) Enzymes
274
Iron Deficiency
1) Anaemia
2) Weakness
3) Infections
4) Fatigue
275
Gene Definition
Encodes a single protein & is the unit of inheritance
276
Describe Nucleic acid
- The genetic materials
| - 2 forms : DNA & RNA
277
DNA is made up of:
1) Sugar (deoxyribose)
2) Phosphate
3) 1 of 4 nucleotide bases
278
DNA Replication Steps
Before to cell division
1) DNA helix starts to unfold & unwind
2) Each strand acts as a template to produce new molecule
3) Continue until 2 new DNA strands form
4) Each new molecule has one “old” and one “new” DNA strand
279
RNA Function
Build complex proteins through transcription & translation
280
DNA & RNA differences
DNA :
1) Deoxyribose
2) Very Large
3) Double Helix
4) In nucleus
5) Double stranded
RNA:
1) Ribose
2) Small
3) Single strand
4) In nucleus & cytoplasm
5) hnRNA, mRNA, tRNA, rRNA
281
mRNA Function
Carry genetic instructions from the gene to the ribosomes in the cytoplasm
282
Transcription
Using DNA as a template, a piece of mRNA is made from the gene which will make a new protein
283
Translation
mRNA leaves the nucleus & travels to the ribosomes where the new protein is made.
Amino acids are added one by one to form a polypeptide
284
Mitosis Steps
1) Prophase : chromatin condenses into chromosomes, nuclear envelope disappears
2) Metaphase : Chromosomes align at equatorial plate
3) Anaphase : sister chromatids separate, centromeres divide
4) Telophase : Chromatin expands, cytoplasm divides
285
Locus Definition
Specific location of a gene on chromosome
286
Trait/Phenotype
Observable expression of a gene or collection of genes- the trait observed because of the genotype
287
Allele Definition
Alternative forms of a gene at a given locus m
288
Homozygous Definition
Both genes on both chromosomes are identical i.e. both alleles identical at a given locus
289
Heterozygous Definition
Both genes on both chromosomes are different I.e. alleles differ at a given locus
290
Genotype Definition
Genetic composition of individual- pair of alleles present in an individual
291
Autosomes Definition
The first 22 pairs of chromosomes
292
Structural Mutations
1) Inversion
2) Translocation
3) Duplication
4) Deletion
5) Insertion
293
Monosomy
One copy of a given chromosome
Eg. Turner’s syndrome
294
Trisomy
3 copies of a given chromosome
Eg, Down syndrome
295
Epigenetic Mechanisms
1) Development
2) Environmental chemicals
3) Drugs/Pharmaceuticals
4) Aging
5) Diet
296
DNA Methylation
Methyl group can tag DNA and activate or repress genes
297
Histones Definition
Histones are proteins around which DNA can wind for compaction and gene regulation
298
Male Reproductive System Function
Produces, stores & transports sperm outside the body
299
Male External Gentilalia
1) Penis
| 2) Scrotum
300
Male Essential Sex Organs
Gonads = Testes
301
Male Accessory Structures
1) Ducts
| 2) Glands
302
Penis Functions
1) Delivers sperm into the female reproductive tract & urine to the exterior
2) Expansion of blood sinuses under the influence of sexual excitation cause erection
303
Scrotum Functions
1) Out pouching of the abdomen that supports the testes via the spermatic cords
2) The production & survival of sperm required -3 degrees lower than body temperature
304
Spermatogenesis
In seminiferous tubules - sperm is made under the influence of Follicle Stimulating Hormone (FSH)
305
Testes Connective Tissue Functions
Supports seminiferous tubules
1) Sertoli Cells : Sperm cells mature here
2) Leydig Cells : Under the influence of Luteinizing Hormone (LH) these cells make testosterone
306
Duct System includes :
1) Epididymis
2) Vas deferens
3) Ejaculatory Duct
4) Urethra
307
Epididymis Function
Site for sperm maturation & storage
308
Vas Deferens Function
Stores sperm & propels them towards the urethra during ejaculation
309
Male Urethra Function
Carries urine & sperm but not at the same time
During ejaculation sphincter at the base of bladder constricts to prevent urine passing and sperm entering bladder
310
Seminal Vesicle Function
1) Secrete an alkaline, viscous fluid
2) 60% of the volume of semen
3) Fructose & nutrients give sperm with energy & viability
311
Prostate Gland Function
Secretes slightly acidic fluid that constitutes 15% of the semen volume & contributes to sperm mobility
312
Bulbourethral (Crowper’s) Glands Function
Secrete mucous (10%) for lubrication & neutralises acid
313
Semen (Seminal Fluid) Defintion
Mixture of sperm + secretions from glands that provide nutrients and fluid that sperm are transported
Neutralises acidity of male urethra & female vagina
314
Sperm Head
1) Contains DNA in the nucleus
| 2) Helmet-like structure called Acrosome releases enzymes to penetrate the layers around egg
315
Sperm Midpiece
Contains mitochondria which provide energy (ATP) and aid mobility
316
Sperm Tail
Contains filaments which propel the sperm
317
Female External Genitalia
1) Vulva
| 2) Mammary Glands
318
Female essential sex organs
Ovaries (gonads)
319
Female accessory structures
1) Fallopian tubes
2) Uterus
3) Vagina
320
Vulva Includes :
1) Mons pubis
2) Labia majora & minora
3) Clitoris
4) Vestibule
5) Vaginal & urethral orifices
6) Vestibule & Bartholin’s glands
321
Perineum Definition
Area between vaginal opening & anus, sometimes cut to assist childbirth (episiotomy)
322
Ovaries location
Upper pelvic cavity on sides of the uterus
323
Ovaries Function
1) Oogenesis : Produce eggs
| 2) Produce hormones oestrogen & progesterone
324
Uterine (fallopian) tubes
1) Transport the ova from the ovaries to the uterus
| 2) Where fertilisation occurs
325
Uterus (womb) functions
1) Transporting sperm
2) Menstruation
3) Implantation of fertilised ovum
4) Development of the foetus during pregnancy
5) Labour
326
Uterus consists of :
1) Outer perimetrium
2) Middle myometrium
3) Inner endometrium
327
Vagina Functions
1) Passageway for sperm & the menstrual flow
| 2) Receptacle for the penis during sexual intercourse & is the lower portion of the birth canal
328
Mammary glands Function
1) Lactation : secretion & ejection of milk
Secretion = Hormone Prolactin
Ejection = Hormone Oxytocin
329
Gonadotropin-releasing hormone (GnRH) Functions
1) Regulates Hormones
2) Released from Hypothalamus
3) Stimulates (FSH) & (LH) from anterior pituitary
330
Follicle Stimulating Hormone (FSH) Functions in Male & Female
Male- Drives spermatogenesis
Female- Development of ovum
331
Luteinising Hormone Function in Male & Female
Male- Hormone production (testosterone
Female- Hormone production (Oestrogen & Progesterone)
332
Follicular Phase Steps
1) FSH stimulates 20 follicles to grow & secrete oestrogen
2) One follicle outgrows others, secretion of FSH is decreased
3) Dominant follicle becomes Graafian (mature) follicle
4) Blister-like bulge develops in surface of ovary
5) Just before ovulation, small quantities of progesterone are produced
6) Oestrogen causes division of new cells to replace the shed endometrium and begins repair and thickens
333
Ovulation Steps
Day 14
1) Surge of LH causes rupture of mature Graafian Follicle and the release of the ovum
334
Luteal Phase Steps
14 days
1) Stimulated by LH, remnants from Graafian Follicle become the corpus luteum
2) Corpus Luteum secretes :
- Oestrogen
- Progesterone
- Relaxin
- Inhibin
3) If not fertilised corpus luteum degrades into corpus albicans and hormones oestrogen & progesterone drop and cycle begins again
4) If fertilised egg begins to divide & produces human chorionic gonadotropin
335
Pregnancy Steps
Gestation Period :
1) Fertilisation
2) Implantation
3) Embryonic Development
4) Foetal Development
5) Birth after 38 weeks
336
Name for 1st two months after fertilisation
Embryo
337
Name after 2 months after fertilisation until birth
Foetus
338
Name for first 42 days after birth
Neonate
339
Names after joining & division of egg
1) Zygote
2) Morula
3) Blastocyst
340
Teratogen
Something that causes developmental defects in the embryo
341
Location of the heart
1) In thoracic cavity
2) Slightly more to the left
3) Diaphragm separates thoracic cavity from abdominal cavity
342
Systemic Flow
Oxygenated flow to the organs of the body from the left size of the heart through the aorta
343
Pulmonary Flow
1) Deoxygenated blood flow to lungs by pulmonary artery
| 2) Oxygenated blood to the left side of heart to body by pulmonary veins
344
Hydrostatic Pressure
Blood pressure which tends to drive fluid out of the bloodstream at the arterial end of capillary
345
Osmotic Pressure of the blood
Where due plasma proteins in blood, it exerts a force that pull or holds onto water in the blood vessel at the venous end of the capillary
346
Lymphatic System Structure
1) Oneway system made up of blind ended tubes
2) Most vessels are like capillaries, thin endothelial layer only
3) Larger vessels have some muscle
347
Lymphatic System Function
1) Collect and return surplus interstitial fluid and plasma proteins to the blood
2) Defend the body against invading organisms by means of the immune system
3) Absorb lipids from the digestive tract
348
Upper Respiratory Tract Function
1) Air Passage
2) Cleaning of Air
3) Smell
349
Pharynx Functions
1) Movement, warming and humidifying air
2) Movement of food
3) Protection
4) Speech
350
Larynx Functions
1) Passage of Air
2) Sound and Speech
3) Warming and humidifying
351
Trachea Functions
1) Air Passage
2) Support
3) Protection
352
Pleura Layers
1) Parietal : outer layer - chest wall
2) Visceral : inner layer - lungs
3) Pleural cavity : space between two layers - small
353
Lower Respiratory Tract Function
1) Airways - Conduction
| 2) Alveoli - Gas exchange
354
Sympathetic Nerves
Stimulation causes
1) Relaxation of smooth muscle
2) Enlargement of airways
355
Parasympathetic Nerves
Vagus nerve
Stimulation causes :
1) Construction
3) Decrease in size of the airways
356
Squamous Epithelium Function
Facilitates easy diffusion of gases
357
Secretion of Surfactant Function
1) Reduces surface tension
| 2) Prevents drying of alveoli
358
Respiration Steps
1) Cycle of breathing : ventilation (expiration & inspiration)
2) Exchange of gases in lungs (external respiration)
3) Transport of gases in blood
4) Exchange of gases at tissues (internal respiration)
359
Inspiration at rest Steps
Active phase
1) Muscle contraction leads to expansion of lungs
2) Decrease in pressure in the lungs compared to the surrounding air
3) Air moves from high pressure area (air) to low pressure area (lungs)
360
Expiration at rest Steps
Passive Phase
1) Muscle relaxation leads to slight reduction in size of lungs compared to air
2) Air moves from high pressure (lungs) to low pressure (air)
