Exam 1 (Nervous, Endocrine, Homeostasis, Infection and Technology) Flashcards
1
Q
Types of hormones with examples
A
Steroid - estrogen, testosterone etc
Protein - insulin, glucagon, ADH etc
Amine - epinephrine etc
2
Q
Describe different types of hormones
A
Steroid
* Lipid Soluble
* bind to transport proteins, enabling them to travel in the bloodstream
* slow to take effect, long lasting
Protein and Amine
* water soluble
* unable to diffuse across cell membrane
* quick to act, shorter lasting
3
Q
Endocrine vs Exocrine
A
Endocrine - secretes into the extracellular fluid that surround the cels that make up the gland
Exocrine - secretes into a duct that carries the secretion to the body surface or to a cavity
4
Q
Relationship between hypothalamus and pituitary gland
A
- Hypothalamus controls the secretions of hormones through the pituitary
- hypothalamus secretes releasing or inhibiting factors through blood vessels to the anterior lobe
- Hypothalamus produces some hormones which are passed along the nerve fibres to the posterior lobe of the pituitary gland
- Hypothalamus joins the pituitary by the INFUNDIBULUM
5
Q
Anterior vs Posterior
A
Anterior
* controlled by the releasing and inhibiting factors
* has no nerves connecting it to the hypothalamus, rather connected by a large network of blood vessels in the infundibulum
* FSH, TSH, LH, GH, PRL, ACTH
Posterior
* connected to the hypothalamus by nerve fibres that pass through the infundibulum
* does secrete hormones also stores and produces hormones
* ocytocin, ADH
6
Q
What glands secrete hormones and their target cells and effects (Posterior, Anterior, Pineal, Thyroid, Parathyroid, Thymus, Adrenal cortex, Adrenal medulla, pancreas, testes, ovaries)
A
refer to table on onenote
7
Q
Stucture of a neuron
A
- Cell Body - contains nucleus - responsible for controlling the functioning of the cell
- Dendrites - Short extensions - carry impulses into cell body
- Axon - carries nerve impulses away from the cell body
- Myelin sheath - insulates, protects and speeds up the movement of impulses along the axon
- Schwann Cell - forms the myelin sheath only within the PNS
- Node of Ranvier - facilitates the rapid transmission of nerve impulses
- Neurilemma - outermost coil of Schwann cells
8
Q
Neurons classified by function
A
- Sensory - carry messages from receptors in the sense organs, or in the skin, to the central nervous system
- Motor - carry messages from the CNS to effectors
- Interneurons - link between the sensory and motor neuron
9
Q
Neurons by structure
A
See OneNote
10
Q
Define nerve impluse
A
- the message that travels along a nerve fibre
- transmission of a nerve implulse triggers an action potential in the adjacent membrane
- Impulse conducts along unmyelinated fibres through salatory conduction (jumping conduction - jumps from one NOR to another)
11
Q
transmission of a nerve impulse
A
- Polarisation
○ At a resting, potential the membrane is polarised
○ inside of the cell and has a net negative charge and the outside of the cell has a net positive charge.
○ A Na/K pump allows these ions to move across the membrane: sodium into the cell and potassium out - Depolarization
○ the sudden increase in membrane potential
○ This occurs if the level of stimulation exceeds 15mV
○ Once they are open, more sodium ions move into the cell. this makes the intracellular fluid less negative, increasing the potential difference
○ If the stimulus is strong enough to increase the potential to -55mV then voltage-gated sodium channels open
○ This produces a movement of sodium ions into the cells
○ The size of the response is not related to the strength of the stimulus, this is also known as the all or none response3) Repolarization
○ The sodium channels close, which stops the influx of sodium ions
○ At the same time, voltage-gated potassium channels open, increasing the flow of potassium ions out of the cell
○ This makes the inside of the membrane more negative than the outside and decreases the membrane potential
○ The membrane is repolarized
○ The potassium channels remain open longer than what is needed, this results in the membrane potential dropping lower than the resting membrane potential, and the membrane is hyperpolarized
○ This process is called hyperpolarization
4) Refractory Period
○ Once the sodium channels have opened they quickly become inactivated
○ Thus being unresponsive to stimulus
○ Therefore, for a brief period after being stimulated, the membrane will not undergo another action potential
12
Q
Transmission across a synapse
A
- Nerve impulse reaches the axon terminal, it activates voltage gated calcium ion channels
- As there is a higher concentration of calcium ions in the extracellular fluid, they flow into the cell at the pre-synaptic axon terminal
- This causes synaptic vesicles to fuse with the membrane, releasing special chemicals called neurotransmitters by exocytosis
- The neurotransmitters diffuse across the gap and attach to receptors on the membrane of the next neuron
- This stimulates ligand-gated protein channels to open, which allows the influx of sodium ions an initiates an action potential
13
Q
Central Nervous System Protection
A
- Bone - cranium and vertebral canal
- Meninges - duramater, arachnoidmater and pia mater
- CSF - clear watery fluid
14
Q
Describe the layers of the meninges
A
○ Dura mater - outermost layer, tough and fibrous, texture and thickness similar to rubber glove
○ Arachnoid mater - loose mesh of fibres - resembles web
Pia mater - inner layer, delicate - contains many blood vessels and sticks closely to the surface of the brain and spinal cord
15
Q
What are the three main functions of the CSF
A
- Protection - acts as a shock absorber
2. Support - brain floats inside it
3. Transport - CSF is formed from the blood, and circulates around and through the CNS before eventually re-entering the blood capillaries. During its circulation it takes nutrients to cells of the brain and spinal cord
16
Q
Describe the different parts of the brain
A
Cerebrum - responsible for thinking, reasoning, learning, memory and sense of responsibility. Has a large surface area due to its folded structure.
Medulla oblongata - joins the brain to the spinal chord
Cerebellum - part of the brain behind and below the cerebrum; concerned with coordination of movement
Corpus callosum - bundle of nerve fibres that links the two cerebral hemispheres
17
Q
Divisions of the PNS
A
- Afferent
- Efferent ->1. Somatic 2. Autonomic -> Sympathetic & Parasympathetic
18
Q
Effect of the Sympathetic and Parasympathetic on the heart, lungs, stomach, intestines, liver, iris of the eye, sweat glands, salivary glands, adrenal medulla.
A
see onenote
19
Q
Postive VS Negative Feedback
A
Positive feedback response adds to the stimulus increasing the response. Examples include childbirth and blood clotting
Whereas, Negative feedback response eliminates or reduces the stimulus . Examples include increase in body temperature etc
20
Q
Define Homeostasis
A
Homeostasis refers to the maintenance of relatively constant internal environment independent of the changing external environment.
21
Q
Describe a feedback system
A
Stimulus - Change in environment
Receptor - Detects change in environment and sends this message to modulator
Modulator - Receive message and initiates response
Effector - Carries out response
Response - what is caused by the effector
Feedback - Environment back to normal
22
Q
What are the organs involved in the regulation of BS
A
Liver - stores glucose
Pancreas - A cells and B cells secrete hormones
Adrenal Glands - Secretion of Cortisol
23
Q
Increase in blood glucose
A
S - Increase in blood glucose
R - Carotid Chemoreceptors detect increase in BG
M - Hypothalamus receives and initiates response through the effectors
E - Pancrease secretes Insulin through Beta Cells
- Liver converts glucose into glycogen for storage through glycogenesis
R - Insulin promotes glycogenesis in the liver
- liver keeps glucose out of the blood for storage
F - Decrease in blood glucose
24
Q
Decrease in BG
A
S - Decrease in BG
R - Carotid chemoreceptors in heart detect increase in BG
M - Hypothalamus receives message and activates the liver, pancreas, and adrenal glands
E
- Pancreas secretes Glucagon from Alpha Cells
- Liver converts glycogen into glucose through glycogenolysis
- adrenal glands secrete cortisol
R
- Glucagon initiates glycogenolysis
- Liver releases glucose into the blood
- Cortisol regulates carbohydrate metabolism by ensuring enough energy is provided
F - Increase in BG
25
Genesis, Neo and lysis meanings
Genesis - Creation
Neo - New
Lysis - Breakdown
26
Organs involved in thermoregulation
Skin - Vaso, sweating, radiation, evaporation
Muscles - movement
Adrenal medulla - secretion of hormones
27
Increase in body temperature
S - Increase in BT
R - Peripheral thermoreceptors in skin
M - Hypothalamus
E
- Skin sweats
- Vasodilation of skin arterioles
- Decrease in metabolic rate
- Behavioural Response
R
- Vasodilation causes increase in blood flow through the skin due to the higher SA - causing heat loss through convection
- Sweating causes evaporation
- decreased metabolic rate causes a decrease in heat production
F - Decrease in BT
28
Decrease in BT
S - Decrease in BT
R - Peripheral thermoreceptors in skin
M - Hypothalamus
E
- Skeletal muslces shiver
- vasoconstriction
- adrenal medulla secretes adrenaline & noradrenaline
- pituitary releases TSH - releases thyroxine
- Behavioural Response
R
- Shivering produces heat by movement
- vasoconstriction causes a reduction in heat loss
- adrenaline and noradrenaline increase metabolic rate causing greater heat production
- thyroxine also increases metabolic rate
F - Increase in BT
29
Hot, Perfect, Cold
Greater than 42 = heat stroke
Greater than 45 = death
Perfect = 36.8C
Lower than 33 = hypothermia
Lower than 31 = Death
30
Define heat stroke and hypothermia
Heatstroke - the failure of a person's temperature regulating mechanisms when exposed to excessive heat
Hypothermia - temperature drops below the level required to maintain normal body functions
31
Neurons by structure and function
Function:
1. Sensory - takes messages from sensory organs to CNS
2. Motor - takes messages from CNS to effectors
3. Interneurons - Connects sensory and motor neurons
Structure:
1. Unipolar -
2. Multipolar -
3. Pseudounipolar -
4. Bipolar -
32
Water contents of the body
2/3 In the intracellular fluid
1/3 in the extracellular fluid
1/4 of extracellular fluid is PLASMA
3/4 of extracellular fluid is interstitial fluid
33
Organs involved in bodily fluids
Kidney - Main site of reabsorption and excretion
Adrenal gland - secretes key hormones
Posterior lobe of pituitary - secretes hormones
34
Increase in water concentration
S - Increase in water concentration
R - Osmoreceptors in thirst centre of hypothalamus detect decrease in osmotic concentration and increase in plasma volume
M - Thirst centre
E
- Kidney begins with excretion
- Adrenal gland secretes aldosterone
R
- Kidney excretes larger volumes of water at a faster rate
- aldosterone maintains sodium levels of the body
F - Decrease in water concentration
35
Decrease in water concentration
S - decrease in water concentration
R - osmoreceptors detect decrease in plasma volume and increase in osmotic concentration
M - Thirst centre
E
- Posterior lobe of pituitary gland secretes ADH
- thirst centre initiates thirst response
R
- ADH increase permeability of the DCT and collecting ducts of the nephron, meaning more water is reabsorbed into the blood stream
- Thirst response causes the person to drink water
F - increase in water concentration
36
Define osmotic concentration and pressure
Osmotic concentration - the concentration of solutes - how much water is in a cell
Osmotic pressure - the tendency of a solution to take in a solvent - trying to keep all the tea in a teabag
37
Too much or TOO little water
Too little = Dehydration
Dehydration causes;
- severe thirst
- low BP
- dizziness
- headache
Too Much = Water intoxication
Water intoxication causes;
- lightheadedness
- vomiting
- collapse
- headache
- excessive urination
38
Organs involved in gas concentrations
Diaphragm, intercostal muscles, lungs
39
Increase in CO2 concentration
aS - Increase in CO2 concentration
R - Chemoreceptors in the carotid bodies and the respiratoryc centre
M - Respiratory centre in the medulla oblongata
E - Diaghragm and intermuscle have an increased rate and depth of breathing
R - More CO2 is excreted and O2 is intaken
F - Decrease in CO2 Concentration
40
Decrease in CO2
S - Decrease in Co2
R - Chemoreceptors in the carotid body and respiratory centre
M - respiratory centre in the medulla oblongata
E - Intercostal muscles and diaphragm
R - decreased rate and depth of breathing
F - Increase in Co2
41
Types of receptors
* Thermoreceptors - respond to heat and cold
* Osmoreceptors - respond to changes in osmotic pressure
* touch receptors - found on skin
* Pain receptors (nociceptors) - respond to damage to tissue
* Chemos
42
Describe reflexes
Reflex refers to a rapid automatic response to a change in the external and internal environment. All have the following four properties:
1. stimulus is required to trigger a reflex
2. reflex is involuntary
3. reflex is rapid
4. reflex is stereotyped - occurs same way each time
43
Describe the reflex arc
1. Receptor
2. Relay to CNS through sensory neurons
3. Integrations interneurons
4. Motor neurons relay to effector
5. response
44
Learnt reflexes
Reflexes that are learnt through constant repetition.
E.g include slamming brakes while driving, maintaining balance while riding a bike
45
Define pathogens
Pathogens are disease-causing microorganisms, namely viruses and bacteria. They are transmitted through direct and indirect contact, transfer by body fluids and disease specific vectors
46
What are the body's external defence mechanisms against pathogens
* skin - acts as a physical barrier
* Digestive tract - stomach acids and enzymes help kill pathogens
* Urogenital tract - urine flow and acidic pH help flush out pathogens
* Respiratory system - Mucus, cilia, and coughing relexing help trap and expel pathogens
* Eye and ear - tears and earwax contain antibodies and enzymes
47
What is a non-specific immune response
It is non-specific so it responds in the same way to all germs
e.g inflammation - helps isolate and eliminate pathogens, as well as initiate tissue repair
48
Specific immune response
- They are specific and not generalized
- There are two broad cases
1. Antibody mediated immunity
2. Cell Mediated immunity
49
Explain antibody mediated immunity ****
- Antigen presenting cells recognise, engulf and digest pathogens displaying the antigen on their surface
- antigen presenting cells reach lymphoid tissue and present the antigen to lymphocytes
- Helper T cells are stimulated by antigen presenting cells which release cytokines
- Specific B cells are stimulated and undergo rapid cell division
- Most new B cells develop into plasma cells which produce antibodies and release them into blood and lymph
- Antibodies combine with the antigen and inactivate or destroy it
- Some of new B cells form memory cells
50
****Explain cell mediated immunity
- Antigen presenting cells recognise, engulf and difest pathogens displaying the antigen
- Antigen presenting cells reach lymphoid tissue and present the antigen to lymphocytes
- Helpher T cells are stimulated by antigen presenting cells which release cytokines
- Specific T lymphocytes are stimulated to under go rapid cell division
- Most new T cells develop into killer T cells or helper T cells which migrate to site of infection
- Killer T Cells destroy antigen, helper T cells promote phagocytosis by macrophages
- Some T cells form memory cells
51
Treatments and preventions of pathogen induced infections include
* antivirals - target specific steps in the viral life cycle to inhibit viral replication
* antibiotics - used to treat bacterial infections by targeting and killing bacteria or inhibiting their growth
* vaccines - stimulate the immune system to produce a specific immune response againsty pathogens, providing immunity.
52
Immunity
* Passive and Active
* Herd immunity
* Immunizatin
53
Compare the endocrine and nervous systems
Speed of action - Nervous System responses are rapid, whereas Endocrine are slower
Duration of action - Nervous system short lived while endocrine system are longer lasting can persist for days
Nature and transmission of the message - nervous uses electrical signals (nerve impulses) and chemical signals (hormones)
Specificity of message - Nervous system signals are highly specific whereas Endocrine are more generalized, affecting target cells
54
Bacteria vs Virus
Bacteria - non pathogen prokaryote, no nucleus, decomposition of organic material and cycling of the elements
Virus - contain either rna or dna, non living, reproduced by infecting a living organism and induces cells with its RNA/DNA
55
Types of bacteria
Bacilii - flagella, rod shaped
Cocci - spherical cells
Spirilla - twisted cells
Vibrio - comma shaped
56
Internal non specific defences include
Phagocytosis
1. phagocyte moves to bacterium
2. phagocyte changes shape so it encloses bacterium
3. lysosomes contain destructive enzymes that are released and destroy bacterium
4. Enzymes are released and destroy bacterium
5. Harmless particles are released from phagocyte
57
Fever
- elevation of body temperature
- due to pyrogens that are released by white blood cell during inflammatory response and act on hypothalamus
- interleukin-1 is produced by activated macrophages and dendritic and epithelial cells
58
Types of T cells
1. Killer T cells - migrate to infection and secretes a chemical destroying antigent
2. Helper T cells - binds to antigen on antigen presenting cells which secretes cytokine
3. Suppressor T cells release substances that inhibit T and C cell activity slowing immune response
59
Scientific process
Independent - explanatory variable
Dependent - response variable
Control - stuff we control
Ethics - no risk of harm, voluntary participation, informed consent, confidentiality
Graph - explanatory on x - response on y
60
Similarites and Differences between Cell Mediated and Antigen Mediated
Antigen Mediated
* Humoral
* Antibodies involved
* controls extracellular pathogens
* B-cells (major role)
Cell Mediated
* Cellular
* controls intracellular pathogens
* T-Cells (major role)
61
Disruptions to homeostasis (Type 1)
* immune system destoyes islets of langerhans
* no production of insulin
* needs to administer insulin
62
Disruptions to homeostasis (Type 2)
* Develops due to a poor lifestyle, cells in the body stop responding to insulin
* no cure - can be managed through a careful diet, exercise etc
63
Disruptions to homeostasis (hyperthyroidism)
* too much thyroxine
* enlargement of thyroid
* removal of thyroid
* can cause graves disease
64
Distruptions to homeostasis (hypothyroidism)
* too little thyroxine
* enlargement of thyroid due to lack of iodine in diet
* treatments include - increased iodine in diet
* hashimotos disease
65
Behavioural distruptions to homeostasis
Drugs
Excessive exercise
Eating habits
66
Describe live attenuated vaccines
* (live and attending)
* A live attenuated vaccine is a type of vaccine that contains weakened or "attenuated" forms of the disease-causing virus or bacteria. These vaccines are created by modifying the disease-causing microorganism so that it is less harmful or virulent.
67
Describe inactivated vaccines
An inactivated vaccine is a type of vaccine that contains killed or inactivated forms of the disease-causing virus or bacteria. These vaccines are created by treating the microorganism with chemicals, heat, or radiation to render them incapable of causing disease.
When an inactivated vaccine is administered to a person, it prompts their immune system to recognize and respond to the killed microorganism. The immune system then mounts a defense by producing antibodies and memory cells to provide protection against future
68
describe toxoid vaccines
Toxoid vaccines are vaccines that use weakened or inactivated toxins produced by bacteria or other microorganisms. These vaccines stimulate the immune system to produce antibodies that can neutralize the harmful effects of the actual toxin, protecting against the associated disease.
69
describe sub-unit vaccines
Subunit vaccines are vaccines that contain only specific parts or "subunits" of the disease-causing microorganism, such as proteins or sugars. These vaccines stimulate the immune system to recognize and mount a targeted immune response against those specific subunits, providing protection against the disease without introducing the whole microorganism.
70
why are synthetic hormones developed
71
what are synthetic hormones
72
what is gene therapy used to treat
73
Define recombinant DNA and how it has been developed
74
What is recombinant DNA used to produce
75
what are mutations in genes and chromosomes a result of
* errors in dna replication
* errors in cell division
* mutagens
76
Describe errors in DNA replication
* During DNA Replication errors can occur resulting in wrong DNA being made this is caused by
1. Substituition - wrong base pairs lining up
2. Deletions - bases can be deleted
3. Insertion - duplicated or extra DNA can be added
4. Frameshifts - Incomplete DNA code - DNA is unreadable
* these erros can be passed onto new cells (gline or somatic)
* Cancer, cystic fibrosis, sickle cell anaemia
77
Describe errors in Cell division
* Occur during Meiosis
* Majority of which occuring during the first stage of Meiosis especially when:
- Homologous chromosomes lineup
- crossing over
* during these, sections can be put in the wrong order, or added to the wrong chromosomes
* whole chromosomes can also be added or deleted
* the gametes produced have either faulty chromosomes or an incorrect number of chromosomes
* Down syndrome, Turners Syndromem
78
Describe mutagens
* Mutagens are agents that are known to increase the likelyhood of mutations - known mutagens are mustard gas, radiation
* Mutages cause mutations as they:
- Resemble proteins and become incorporated into DNA
- Triggfer DNA replication errors
- Cause DNA to break
- Block DNA replication or damage structure
* Cells affected by mutagens will replicate with damaged DNA
* Can cause somatic, germline, gene & chromosomal mutations
79
Describe the changes in allele frequency caused by mutations
* Mutations refers to a change that occurs in our DNA sequence that leads to a new characterisitc.
* Mutations can occur in somatic and germline forms, arising from erros in DNA replication, errors in Cell division and Mutagens.
* Two types: Gene and Chromosomal
* Mutations can create new more favourable adaptations which can be passed on to the next generations
80
Describe the changes in allele frequency caused by random genetic drift
* RGD is randon and non selective, occurs due to chance
* the effect is stronger on smaller populations
* rare allele has a greater change of becoming more frequent in small populations.
* Bottleneck: drastic reduction in population, surviving individuals breed, thus, alleles are passed on
* Founder effect: Small group migrates establishing new community, the new founding community has different characterisitics that are not typical of the original populations
81
describe changes in allele frequency caused by gene flow between adjoining groups
Barries to gene flow influence the allele frequency
Geographical barriers alike deserts, mountains, oceann
sociocultural barriers include religion, language and culture
82
how do genetic diseases in particular populations illustrate the effects of different factors on the dynamic gene pool (Tay-sachs)
Tay-Sachs
* Carrier are resistant to tuberculosis
* population: Ashkenazi Jew
* Cause: Missing enzyme essential for fat metabolism
* Symptons: build up of fatty substances, mental and physical disabilities.
* inheritance: recessive trait/passed from two carrier parrents
* Effect on Gene Pool:
* Carrier couples choose not to reproduce
* heterozygous individuals are resisitant to tuberculosis
83
What factors in an environment create a selective advantage on specific phenotypes to enhance survival and reproduction
Variation
Struggle
Selection
84
describe inherited variation
Inherited variation refers to the genetic differences passed down from one generation to the next. Large gene pools with a variety of genes creates variation. Variation must be present in individuals.
85
Isolation and differential selection
Differential selection: Individuals that have a particular phenotype that is suited for the environment survived and passes on favoured genes to offspring. Over time desirable phenotypes will be more prevalent and can lead to speciation.
86
Explain how those mechanisms produce significant changes to gene pools to an extent that speciation occurs
Speciation occurs when a combination of variation, isolation, struggle and selection are present.
Variation - wide variety of genes
Isolation - barriers to gene flow
Struggle - Overproduction of offspring with limited resources
Selection : individuals with suitable genes survive, passing it onto next generation.
Speciation: A new species forms when they are no longer able to reproduce with others
87
Sickle Cell
* Population : african/italian/indian
* Cause: muation of gene responsible for RBC
* Symptoms: RBC have sickle-shape, reduces SA of RBC
* Inheritance: recessive trait
* Effect on gene pool
* individuals homozygous for condition usually die early
* heterozygous have sickle cell trait
88
Thalassemia
* Population: Mediteranian sea/greek/italian
* Cause: mutation of gene responsible for RBC. Haemoglobin production
* Symptoms: Defects in formation of haemoglobin. Fewer functioning RBC
* Inheritance: Recessive trait
* Effects on gene pool:
* more mutations in RBC formation increases severity of disease
* individuals affected with mild thalassemia only have 1-2 mutations
* more mutations = higher mortality rate
* resitant to malaria
89
describe gene mutations
Gene mutation:
* a change to a sinlge gene loci, occuring during DNA replications
* Changes to nucleotides:
* Subsitution: silent (no effect), missence (little), nonsense (proteins wont be made)
* Insertion : results in a frame shift
* Deletion (framshift)
* Albinism
90
Chromosomal mutations
* Changes occur to all or part of a chromosome
* can cause severe deformity
* Insertion: extra base pairs added
* Duplication: section of DNA is replication
* Deletion: dna is lost of removed
* Translocations: one segment attaches to another chormosome
* Inversions: broken segment is reversed and reinserted into a chromosome
* Non-disjunction - Chromosome is missing
* Down syndrome
91
Read a phylogenetic tree
check onenote
92
Why is the fossil record incomplete
93
**describe relative and absolute dating techniques**
94
Describe K/AR dating and C dating
95
describe statigraphy and index fossils
96
How are humans different to great apes
97
Describe the differing tool cultures
