Unit 1 AOS 2 Flashcards
System Functions (116 cards)
1
Q
Vascular Plants
A
Most multicellular plants, and have specialised conducting systems
2
Q
Meristematic tissue
A
Type of plant tissue made of cells that can undergo cell division and continue dividing for the rest of the plants life
3
Q
Permanent Tissue
A
Type of plant tissue made of specialised cells that can’t divide
4
Q
Vascular Plant Conducting Systems
A
2 conducting systems
- Above Ground Shoot System
- Below Ground Root System
5
Q
Transportation systems in vascular plants
A
2 transport systems
- Xylem tissue
- Phloem tissue
6
Q
Absorption of liquid in plants
A
- Water enters root cells via osmosis
- Water moves across cells the the cortex to xylem
7
Q
Pathways of water and nutrient absorption in roots
A
2 pathways
- Extracellular Pathway
- Cytoplasmic pathway
8
Q
Xylem tissue
A
Contains 2 types of water conducting cells, moves water from roots to the rest of plants, transpiration pulls water upwards
9
Q
Types of water controlling cells
A
Tracheids and Vessels, both have thick cell walls, lose live contents, meaning they aren’t living
10
Q
Extracellular pathway
A
Water diffuses into the roots in the gaps between the cells
11
Q
Cytoplasmic pathways
A
Mineral ions are passively diffused into the cytoplasm of the next cell or are taken up by active transport in root hair cells
12
Q
Transpiration
A
The passing out of unused water into the atmosphere. It occurs in leaves through air space in mesophyll tissue and is stomata
13
Q
Guard cells
A
Guard stomata, when less water in the cell, stomata close, when more water, stomata opens
14
Q
Stomata
A
Pores in epidermal tissues surrounded by 2 guard cells
15
Q
Water movement in plants
A
Water is pulled upwards from transpiration and pressure in roots pushes it. Water column doesn’t break from adhesion and cohesion
16
Q
Adhesion
A
Water creeps up plant cells by connecting to other substances eg. lignin
17
Q
Cohesion
A
Water molecules staying together during movement
18
Q
Translocation
A
Process of transporting sugars and inorganic materials
19
Q
Phloem
A
Composed of sieve tubes and other cells, process of moving sugars and other organic material
20
Q
Sieve tubes
A
No nucleus but is living, sieve cells form rows of elongated cells, forming sieve plates and perforated cell walls, companion tubes are closely associated
21
Q
Tissues
A
Formed by cells of similar types or a single type acting to perform a specific function.
22
Q
4 types of recognised tissue
A
- Epithelial
- Muscle
- Connective
- Nervous
23
Q
Epithelial tissue
A
Covers internal and external surfaces
24
Q
Muscle tissue
A
Contracts and enables movement
25
Connective tissue
Provides structure and support as well as energy and transportation
26
Nervous tissue
Made up of neurons, important for connectivity and control
27
Organ
Group of different types of tissues grouped together to form discrete systems that carry out specific functions
28
System
Group of organs that co-operate to carry out a specific function sustaining life
29
Mechanical digestion
Breaks food into smaller pieces but doesn't alter the chemical formation
30
Chemical digestion
Breaks down food into simpler substances to be absorbed
31
Components of the digestive system
2 components
- Alimentary Canal
- Accessory Organs
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Alimentary canal
The gastrointestinal tracht composed of organs that food moves through
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Digestive system
Aimed to obtain nutrients from ingested food through either chemical or mechanical digestion
34
Accessory organs
Organs that release enzymes into the alimentary canal
35
Enzymes
Protein molecules that speed up chemical reactions and are sensitive to pH and temperature.
36
Types of enzymes
3 types
- Amylases
- Proteases
- Lipases
37
Lipases
Enzyme that breaks down fats and oils into fatty acids
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Amylases
Enzyme that breaks down carbs into sugars
39
Proteases
Enzyme that breaks down proteins into amino acids
40
Gut flora
Bacteria and archaea in the large intestine
41
The mouth
Tongue and teeth responsible for mechanical digestion (chewing) and saliva mixes with food with amylase digesting starch.
42
Bolus
The product of chewed up food from the stomach that is ready to move down the oesophagus
43
The Oesophagus
A smooth tube that pushes bolus to stomach via peristaltic waves aka peristalsis.
44
The Stomach
Muscular organ that is surrounded in mucus, secretes hydrochloric acid and churns food, mixing bolus with pepsin resulting in chyme.
45
Pepsin
A protease that chemically digests protein. It has a pH of 1.5 which is quite acidic
46
Small Intestine
Surrounded in villi which are covered in microvilli that increase surface area for absorption. Intestinal juices with mucus and enzymes help digest and absorb chyme.
47
Parts of the small intestine
3 parts
- Duodenum (about 25cm long)
- Jejunum (about 2.5m long)
- Ileum (about 3m long)
48
The liver
An accessory organ that filters blood from the intestine, detoxifies chemicals, metabolises drugs, and secrets bile produced in the gall bladder to the duodenum.
49
The Gall Bladder
An accessory organ that concentrates bile
50
Bile
A yellow-green-brown substance that neutralises chyme as well as emulsifying lipids mechanically to increase their surface area to assist digestion.
51
The Pancreas
An accessory organ that secretes pancreatic juices that contain enzymes, bicarbonate ions to the duodenum to neutralise the pH of foods.
52
Large Intestine
Absorbs water and produces vitamins B and K as well as containing 700 species of bacteria and archaea
53
The Rectum and Anus
Stores remainder of waste material. When full the urge to defecate occurs via anus
54
Hormones
Molecules produced by endocrine glands
55
Hydrophilic hormones
Doesn't diffuse through the cell membrane, receptors on outside of cell membrane
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Hydrophobic hormones
Easily diffuse across cell membrane, receptors in nucleus or cytosol.
57
Metabolism
Chemical reactions in cells
58
Endocrine system
A system of glands that transports chemical messages around the body
59
Purposes of hormones
Regulate the metabolism, growth, electrolytes, glucose, and sexual development
60
Purpose of the Thyroid Gland
To regulate metabolic processes, growth and development
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Hormones produced by Thyroid Gland
T4 (Thyroxine), T3 (Triiodothyronine) and Calcitonin
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Purpose of the Hypothalamus
To coordinate body functions and maintain homeostasis
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Purpose of the Pancreas
To control blood glucose levels by releasing glucagon and insulin
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The Excretory System
The excretory system removes waste as well as regulating water and ion concentration
65
Excretory System organs
- Kidneys
- Ureters
- Urinary bladder
- Urethra
66
Purpose of the Kidneys
To filter blood, reabsorb, secrete ions and excrete urea
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Nephrons
The smallest part of the kidney that still filters, reabsorbs, secretes and excretes
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Parts of the Nephrons
- Bowmans capsule
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collection tube
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Bowmans capsule
Collection of fluid and waste from glomerulurs. Blood is filtered here.
70
Proximal Convoluted Tubule
Glucose, Ions, Amino Acids are reabsorbed via active transport. Water reabsorbed via osmosis.
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Loop of Henle
Water exits to be reabsorbed via osmosis. If water needs to be retained, water exits via active transports.
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Distal Convoluted Tube
Fine tunes filtrate composition. Might reabsorb water and ions. May secrete ions and toxins
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Collecting Tube
More fine tuning. Might reabsorb more water. Secretes water
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Bladder
Urine enters bladder via ureter, before being excreted via the urethra.
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Homeostasis
The process of maintaining a stable internal environment
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Stimulus Response Model
Stimulus - Receptor - Modulator - Effector - Response - Negative Feedback
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Stimulus
Any internal or external change
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Receptor
Something that detects the change
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Modulator
Processes the info and determines the response
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Effector
Something that brings about the response
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Response
The desired effect
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Core body temperature
The internal temperature in organs and tissues. For humans the core body temperature 36-39°C
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Constant Temperature
The balance between loss of heat and gain of heat
84
Thermoregulation
Regulation of Body temperature
- Occurs from homeostatic regulation.
- Results in core body temperature to rise and fall.
- Response begins from the hypothalamus
85
Heat production & conservation
- Vasoconstriction
- Rise in metabolic rate
- Shivering
- Hairs rise
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Heat loss
- Vasodilation
- Decrease in metabolic rates
- Sweating
- Hairs lower
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Effectors + Response when it's too cold
Skeletal muscle cells - Shivering
Blood vessels in skin - arterioles shrink
Cerebral Cortex - Behaviour change
Arrector Pilli muscles -hairs stand up
Cells - metabolic rate increases
Brown fat - burning of triglycerides
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Effectors + response when it's too hot
Sweat glands - sweat
Blood vessels in skin - arteries expand
Cerebral Cortex - Behaviour change
Arrector Pilli muscles - hairs flatten
Cells - decrease metabolic rate
89
Hyperglycaemia
- Too much glucose in blood
- Leads to damage to nerves, kidneys, and retina blood vessel damage
- Can cause foot ulcers
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Hypoglycaemia
- Not enough glucose in blood
- Can cause clumsiness, confusion, coma, brain damage, or death
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Glucose
- Primary cellular energy
- Broken down via cellular respiration producing carbon dioxide and water
92
Insulin
- Produced from pancreas
- Reduces glucose
- Causes liver to turn glucose to glycagon
- Causes skeletal muscles take up glucose & turn glucose to glycogen
- Causes adipose cells to initiate greater glucose uptake
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Glucagon
- Produced by pancreas
- Causes liver to turn glycogen to glucose
- Causes cells to break down and release fatty acids as an energy source
94
Rise in Glucose stimulus response model
Stimulus - rise in blood glucose
Receptor - beta cells in pancreas
Modulator - Pancreas which secretes insulin
Effector - muscles, liver and tissues
Response - decrease in blood glucose
95
Osmolality
Concentration of dissolved solutes. indicator of water levels. If blood plasma osmolality is too high, water level is too low and vice versa
96
Decrease in Blood Glucose stimulus response model
Stimulus - decrease in blood glucose
Response - alpha cells of pancreas
Modulator - Pancreas secretes glycogen
Effector - liver and cells
Response - Increase in blood glucose
97
Hypotonic solution
Low solute concentration in a liquid
98
Hypertonic
High solute concentration in a liquid
99
Osmoreceptors
Specialised nerve that detects osmolality changes
100
Presence of Water
In intracellular fluid, cytosol, blood plasma
101
Greater water intake than output
- Toxic ion and waste increase
- Disruption of nerve and muscle function
- Cell shrinkage
- Confusion and seizures
102
Greater water output than input
- Overhydration
- Cells swell
- Legs, feet and brain swell
- Confusion, headache and drowsiness
103
Osmoregulation
- Regulation of body fluid
- Regulates water and electrolyte (potassium and sodium) balance
104
Regulating water balance
- Controls volume of body fluids excreted and initiates thirst
- Controls osmolality of body fluids by regulating water sodium balance
105
Organs in osmoregulation
Brain and Kidneys
106
Role of Brain in osmoregulation
- Osmoreceptors located in hypothalamus
- Osmoreceptors signal pituitary gland to release ADH
- Another part of the brain stimulates thirst
107
Antidiuretic Hormone (ADH)
- Release from posterior pituitary gland
- Travels via blood
- Mainly connects to kidney cells
- Facilitates water reabsorption
- More ADH = less amount of concentrated pee
- Less ADH = more amounts of diluted pee
108
Role of Kidneys in osmoregulation
- Regulates volume & osmolality of body fluid
- Less blood plasma osmolality, kidneys produce more dilute pee
- More blood plasma osmolality, kidneys produce more amounts of concentrated pee
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Responses triggered by ADH - water decrease
Stimulus - water decrease, osmolality increase
Response - osmoreceptors
Modulator - hypothalamus
Effector - kidney
Response - release in water reabsorption
111
Responses triggered by ADH - water increase
Stimulus - water increase, osmolality decrease
Response - osmoreceptors
Modulator - hypothalamus
Effector - kidney
Response - decrease in water reabsorption
112
Reasons for homeostatic malfunctions
- Genetics
- Ageing
- Poor diet
- Exposure to harmful substances
- Insufficient exercise
113
Homeostatic malfunctions
Causes imbalance and an over or under supply of balance in a cell
114
3 groups of endocrine system diseases
- Hypersecretion of hormones
- Hyposecretion of hormones
- Cancers
115
Hyperthermia
- Brought about by fever or hot temperatures or long periods of excessive exercise
- Non-fever hyperthermia can lead to heat exhaustion which can lead to heat stroke which is fatal
116
Type 1 diabetes
- Autoimmune, immune system destroys beta cells in pancreas that produce insulin
- Treatment involves insulin injections
- Failure in glucose regulation
- Can damage to kidneys, nerves, blood vessels, ketoacidosis and death
117
Hyperthyroidism
- Overproduction of thyroxine (T4)
- Impacts ability to thermoregulate
- T4 regulates metabolic rates
- Negative feedback loop bypassed
- Can cause anxiety, excessive sweating, increased heart rate, sleeping difficulty, bulging eyes, enlarged thyroid
- Commonly caused by Graves disease, hyperthyroidism meds and increased iodine consumption
- Treatment involves surgery to remove part of thyroid or antithyroid meds.
