module 2

Question 1

whats a plasma membrane

Answer 1

Thins and flexible boundary between intercellular fluid and extracellular fluid.

Question 2

what does selectively permeable mean

Answer 2

a membrane that allows certain substances to pass while restricting the movement of others.

Question 3

whats a plasma membrane composed of

Answer 3

phospholipids
integral proteins
peripheral proteins

Question 4

whats phospholipid and whats repelled or not by it

Answer 4

hydrophilic phosphate head and hydrophobic fatty acid tails Lipid soluble substances= water insoluble substance, not repelled by the lipid core of plasma membrane.
Lipid insoles substance=water soluble substance, repelled by the lipid core of plasma membrane

Question 5

whats integral proteins

Answer 5

embedded within the lipid bilayer and span entire membrane. Act as carriers or channels for transport of substances that cannot pass through the membrane.

Question 6

whats peripheral proteins

Answer 6

not embedded in the bilayer, attached closely to integral proteins. Act as cell membrane support.

Question 7

whats passive transport

Answer 7

• requires no energy
  substances move down a concentration gradient.
  Eg simple and facilitated diffusion and Osmosis.

Question 8

whats activity transport

Answer 8

• requires energy (ATP)
• substance move up concentration gradient.
  eg. Active transport.

Question 9

whats simple diffusion and examples of molecules

Answer 9

movement of substances down a concentration gradient. Lipid soluble substances. eg. Oxygen, carbon dioxide, fats, steroid hormones and alcohol.

Question 10

whats facilitated diffusion and examples of molecules

Answer 10

movement of substances down a concentration gradient using a carrier or channel protein. Lipid insoluble or large substances. eg. Glucose using carrier proteins.

Question 11

whats osmosis and examples of molecules

Answer 11

the movement of water through a selectively permeable membrane from a low solute concentration to high solute concentration.

Question 12

whats tonicity

Answer 12

the ability of a solution to affect the shape of a cell by altering the cells internal water volume.

Question 13

whats an isotonic solution

Answer 13

has same concentration as the cell: cause no change in cell shape or volume. Maintain homeostasis of cell.

Question 14

whats a hypertonic solution

Answer 14

has a higher concentration of solutes than the cell(lower amount of water than cell): causes cells in a hypertonic solution to lose water and therefor shrink.

Question 15

whats a hypotonic solution

Answer 15

has lower concentration of solutes than the cell(higher amount of water than cell): causes cell to gain water and swell, cells can burst or lyse.

Question 16

whats active transport

Answer 16

movement of substance from an area of low solute concentration to high solute concentration, requires ATP, uses carrier proteins.
Eg. Sodium potassium ATPase pump, moves potassium inside against gradient etc.

Question 17

whats potential energy

Answer 17

energy that is stored ready to be released and used to do work. Eg when magnets are kept apart there is potential energy.
ions are atoms that have an overall electric charge.

Question 18

whats resting membrane potential(membrane potential)

Answer 18

potential energy that exists across the plasma membrane resulting from separating oppositely charged ions of A RESTING CELL.

Question 19

how is resting membrane potential generated

Answer 19

by difference in sodium and potassium ion concentrations between the ECF and ICF.

Question 20

whats the concentration of sodium and potassium ion in and outside the cell

Answer 20

ECF: higher concentration of sodium ions compared to ICF (overall positive)
ICF: higher concentration of potassium ions compared to ECF (overl negative).

Question 21

how is resting membrane potential maintained

Answer 21

by active transport of ions using carrier proteins.

- interior of plasma membrane is slightly negative, outside is slightly positive

Question 22

functions of the cytoplasm

Answer 22

cellular material between plasma membrane and the nucleus.

Question 23

function of nucleus

Answer 23

control centre, contains deoxyribonucleic acid. All mature cells contain a nucleus except for red blood cells which eject the nucleus beefier entering the blood stream and there for can not reproduce.

Question 24

function of ribosomes

Answer 24

ite of protein synthesis.
Two types;
free ribosomes: floating in cytosol- produce proteins for use inside cell.
Membrane bound ribosomes: attach to endoplasmic reticulum- proteins for export.

Question 25

function of rough Er

Answer 25

contains ribosomes, proteins produced are modified to a 3 dimensional shape and packaged into vesicles. Vesicles sent to Golgi apparatus. Liver cells have larger amount of rough ER as they produce lots of protein.

Question 26

function of smooth er

Answer 26

no ribosomes attached, synthesis of lipids, cholesterol and steroid based hormones, involved in detoxification and storing of calcium ions. Important for muscle cells in muscle contraction. Also testes would have large amounts for steroid based hormones.

Question 27

function of Golgi apparatus

Answer 27

consists of stacks of flattened sacs. Functions include; modify, concentrate and packages proteins and lipids, form vesicles and distributes them. Large numbers in cells that secrete protein eg. Salivary glands and pancreas.

Question 28

function of mitochondria

Answer 28

function in cellular respiration, releases energy in the form of ATP. Highly active cell skeletal muscle cell high demand of energy= high number of mitochondria in the cell.

Question 29

function of lysosomes

Answer 29

contains digestive enzymes called lysosomal enzymes. Function of the enzymes dispose of invading bacteria and debris, recycle molecules that have been broken down. Eg white blood cell (macrophages) have high numbers of lysosomes.

Question 30

function of cytoskeleton

Answer 30

act as cells bones, muscle and ligaments. Structural support, directional movement through the cell and movement of the cell.

Question 31

three types of cytoskeletons and function

Answer 31

Microfilaments- thinnest of cytoskeleton. Made up of protein called actin that contracts for the for cell movement. Physical support, resists cell compression and overall shape of the cell. Muscle cells. Intermediate filaments- middle size, involving resisting pulling forces on cell. Tough protein fibres, high tensile strength. Microbtubules- largest of cytoskeleton, maintain cell shape and distribution of cellular organisms.

Question 32

whats the four major types of tissues

Answer 32

muscle tissues epithelial tissue connective tissue nervous tissues

Question 33

what are muscle tissue

Answer 33

composed of muscle cells that contain proteins specialised for contraction allowing movement.

Question 34

three types of muscle tissue

Answer 34

skeletal muscles cardiac muscles smooth muscles

Question 35

what are skeletal muscles

Answer 35

voluntary( under conscious control) muscles composed of muscle cells packaged in connective tissue sheets that attach to bone, muscle or skin. When skeletal muscles contract it causes body movements.

Question 36

what are cardiac muscles

Answer 36

only found in the heart and contract involuntary to help move blood through the body.

Question 37

what are smooth muscles

Answer 37

found in the walls of hallow organs and blood vessels. These are involuntary. Contract to squeeze substances through these organs by alternately contracting and relaxing.

Question 38

whats epithelial tissue

Answer 38

forms the lining, covering and glandular tissue of the body. Any surface exposed to external environment is covered by epithelium forming the outer layer of skin and lines internal body cavities and organs.

Question 39

layers of epithelial tissue

Answer 39

Named by the layers of cells, thinest epithelia is most absorbent, secretion and filtration. Eg found in wall of air sacks of lungs. Stratified(thick) epithermia impotent for protection found of the surface of skin.

Question 40

functions of epithelial tissue

Answer 40

Protection- protects underlying tissues from abraision, dehydration and damage. Proveded by a continuous sheet of epithelial cells preventing any unwanted movement of substances across the tissue. Eg bacteria on the outside of skin cannot gain entry to body. Secretion- epithelial tissue can be modified into glandular tissue that secrete hormones, sweat, mucus and digestive juices. Absorption- Epithelial can include carrier protein on the plasma membrane to regulate absorption of material. Eg absorbing nutrients from digestive trace into the bloodstream. Excretion- sweat glands excrete nitrogenous waste. Filtration- epithelial tissue makes up filtration membrane of kidneys and filters blood to remove waste products that are excreted in urine. Sensory reception- provides a source of information about the environment to the CNS.

Question 41

whats connective tissue

Answer 41

the most diverse tissue type.

Question 42

whats the four main types of connective tissue

Answer 42

connective tissue proper cartilage blood

Question 43

whats connective tissue proper tissue

Answer 43

divided into lose and dense based on amount of fibres found in the ECM. Lose serves as a resivor for slats and water. Dense has a high tensile strength and forms tendons to attach muscles to bone. CT proper includes adipose tissue which contains adipocytes which store fats and acts as shock absorbers and insulator.

Question 44

whats cartliage

Answer 44

contains 3 types; healne, elastic and fibro cartilage. It does not contain blood vessels and lack nerves and if injured heals very slowly.

Question 45

whats blood

Answer 45

develops from the same embryonic tissue as other CT types.

Question 46

functions of connective tissue

Answer 46

Bind- connecting muscles to bones, bones to bones, muscle to muscle and epithelial tissue to the underlying tissue. Support- CT proper, cartilage and bone can withstand tension from many directions and proveds structural support. Protection- bones and adipose tissue provide protection for underlying soft tissues or organs. Insulate- adipose tissues insulates against heat loss to external environment. Transport- blood transports respiratory gases, nutrients, waste and other substances throughout the body.

Question 47

whats the two layers of skin

Answer 47

epidermis | dermis

Question 48

whats epidermis

Answer 48

-outer later: -is avascular (lacks blood vessels) dynamic steady state, cells constantly dying and being shed from surface with dead cells being replaced with new cells which originate from stem cells. Epidermis is replaced every 25-45 days. Cells move from deepest layer of epidermis to top layer, they flatten, produce large amounts of Keratin(waterproof protein) and eventually die.

Question 49

layers of epidermis

Answer 49

Deepest strata called Stratum Basle( where stem cells are found): Most superficial layer called Stratum Corneum: dead keratinised flattened cells, eg. Dandruff. Is a protective barrier from abrasion, dehydration and penetration.

Question 50

whats dermis

Answer 50

-deep supporting layer of connective tissue: -cells including fibroblasts that produce collagen and elastic fibres providing strength and flexibility, and macrophages. contains; blood vessels, nerves and sensory receptors, glands and hair follicles. Blood and oxygen diffuses into the epidermis.

Question 51

how does the skin have blood supply

Answer 51

-capillary network in hypodermis, capillary loops projecting through the dermis, amount of blood regulated by constricting of pre capillary sphincters. Eg. Temperature control.

Question 52

skin nerve supply

Answer 52

dense network of nerves. Controls; blood flow, glandular secretion and collecting sensory information.

Question 53

functions of the skin

Answer 53

``` protection sensations metabolic function blood reservior excretion temperature regulation ```

Question 54

how does the skin protect

Answer 54

skin protects underlying tissues from damage. CHEMICAL BARRIER: PHYSICAL/MECHANICAL BARRIER BIOLOGICAL BARRIER

Question 55

how is skin a chemical barrier

Answer 55

- Low pH secretions (acid mantle) prevents bacteria from multiplying. - Defensins (natural antibiotic) secreted by skin cells to kill bacteria. - melanin protects DNA from UV damage.

Question 56

how is skin a physical/mechanical barrier

Answer 56

-Keratin and oily secretions block most water and water soluble substances from leaving or entering the body. some penetration of skin by lipid soluble substances eg nitroglycerine, medicine patch on skin.

Question 57

how is skin a biological barrier

Answer 57

-macrophages engulf viruses and bacteria that penetrate the epidermis.

Question 58

how is skin function sensation

Answer 58

``` skin has 3 types of receptors pain receptors (nociceptors) Temperature receptors (thermoreceptors) Touch, press and vibration receptor (mechanoreceptors) ```

Question 59

how is skin metabolic function

Answer 59

synthesis of vitamin D.

Question 60

how is skin blood reservoir

Answer 60

can hold up to 5% of body blood volume

Question 61

how does skin excretion

Answer 61

nitrogenous wastes and salt are excreted in sweat.

Question 62

how does skin regulate temperature

Answer 62

hermoreceptors tell CNS in terms of skin temperature. When you have a fever the Brian changes the receptors. Thermoregulatory centre. Temperature goes up making fight pathogen and prevent from multiplying.

Question 63

how does skin age

Answer 63

When ageing skin becomes thin, stem cells produce less number of cells, but abrasion remains same pass. Less cologne and elastin results in wrinkles.

Question 64

what protects skin from sun

Answer 64

Melanin produced by melanocytes, sits on top of skin and form a pigment shelf for DNA. Provents Melintons. Sun nights melanin makes skin warm and when exposed to uv. Doesn’t increase until 10 days, why people get burnt at start of summer.

Question 65

whats another name for skin

Answer 65

Cutaneous membrane

Question 66

whats the first stage of tissue repair

Answer 66

Inflammation and formation of blood clot damaged blood vessels release inflammatory chemicals Plasma fluid released to area Macrophages Clotting proteins, minimises blood loss, hold would together to prevent invasion of more pathogens Clot surface dries to form a scab

Question 67

whats the second stage if tissue repair

Answer 67

Formation of granulation tissue: -blood clot is replaced by granulation tissue capillaries: restore blood supply with oxygen and nutrients Fibroblast: produce collagen fibers that bridge gap Macrophages Surface stem cells multiply and replace skin under scab

Question 68

whats the third stage of tissue repair

Answer 68

Regeneration and fibrosis: - if stem cells present divide and grow under scab to replace and regenerate skin=scab falls off - collagen fibres mature and contract= forming scar tissue.

Question 69

skin damage due to burns

Answer 69

may lead to tissue damage, denatured proteins and cell death. Loss of skin function Immediate threat results from fluid loss= dehydration, electrolyte imbalance then renal shutdown and circulatory shock. Infection via bacteria etc.

Question 70

whats the burn classification

Answer 70

1st degree= epidermis 2nd degree=epidermis and part of dermis 3rd degree= entire thickness of skin, needs to be replaced by skin graft, no epidermis stem cells left.

Question 71

which cation is the cell membrane more permeable to

Answer 71

potassium

Question 72

what voltage exists across the membrane of a resting neutron

Answer 72

-70

Question 73

what occurs natural across the membrane

Answer 73

2 sodium in cell | 3 potassium out cell

Question 74

what does the sodium potassium atpase pump due to maintain resting potential

Answer 74

3 sodium out cell | 2 potassium in cell

Question 75

whats the function of new cappillaries in skin repair

Answer 75

restore blood supply bring oxygen/nutrients

Question 76

whats the function of fibroblasts in skin repair

Answer 76

produce collagen (bridge the gap)

Question 77

whats the role of macrophages in. skin repair

Answer 77

destroy bacteria

Question 78

what needs to be present for epidermis to regenerate itself and where are they found

Answer 78

epidermal stem cells found in stratum basal

Question 79

what happens to tissue that is repair by fibros

Answer 79

does not have same function, is scar tissue

Question 80

why are serious burn life threatening

Answer 80

dehydration electrolyte imbalance circulatory shock reneal shutdown, kidney failure.