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Question 1

Four types of tissue

Answer 1

Neural, connective, muscle, epithelial

Question 2

Three types of connective tissue

Answer 2

Connective tissue proper
Fluid connective tissue
Supportive connective tissue

Question 3

Functions of epithelial tissue

Answer 3

Provides sensation
Physical protection
Produces secretions
Controls permeability

Question 4

Types of cell junctions

Answer 4

Gap junctions) connected by cannexons, allows movement of ions and small molecules
Tight junctions) prevents movement of water and solutes between cells, protects basal surface in digestive tract
Desmosome) allows stretch, usually in skin. Linking of cells by CAMs and proteoglycans to the cytoskeleton

Question 5

How to maintain the integrity of the epithelia

Answer 5

Connections between cells) tight junctions, gap junctions, desmosome
Attachment to the basement membrane) hemidesmosomes
Maintenance and repair of the epithelium) division of stem cells at basement membrane to offer protection

Question 6

8 Types of epithelium and features

Answer 6

Simple squamous) diffusion. Lines body cavities and heart/ blood vessels. Alveoli
Stratified squamous) protection. In skin
Simple cuboidal) secretion and absorption. In salivary glands
Stratified cuboidal) rare, involved in protection, secretion and absorption. Lines some ducts of sweat glands.
Transitional) tolerates repeated cycles of stretching and recoiling. In urinary bladder. Appearance changes from cuboidal to squamous when stretched.
Simple columnar) absorption, protection, secretion. Has microvilli to increase SA. Generally in digestive tract
Pseudistratifued columnar) protection, secretion, absorption. looks stratified but all cells actually attach to basement membrane, has cilia. respiratory epithelium
Stratified columnar) rare, protection, in eyelids.

Question 7

Two components of connective tissues

Answer 7

Extracellular part) ground substance and protein fibres

Cellular part) specialised cells

Question 8

3 roles of connective tissue

Answer 8

Connection) supports and surrounds other tissues
Protection) protects and insulates internal organs
Storage) energy reserves

Question 9

Types of cells in connective tissue proper

Answer 9

Fibrocytes) secretary’s protein and hyaluronon
Fibroblasts) maintain fibres, produce collagen
Adipocytes) fat cells
Mesenchymal cells) divide when injury occurs and differentiate into other cells types
Others) macrophages, mast cells, lymphocytes, microphages

Question 10

Four types of membranes

Answer 10

Synovial) produces synovial fluid, protects articulating bone, lacks true epithelium
Serous) lines cavities but do not open to the outside, has visceral and parietal portion
Mucous) lines passageways, have external connections, moist epithelial surface
Cutaneous) skin, thick waterproof and dry

Question 11

Neuroglia of CNS and PNS

Answer 11

CNS)
astrocytes) regulates environment, maintains blood brain barrier, forms scar tissue
ependymal cells) produce, secrete and monitor cerebrospinal fluid
oligendrocytes) form myelin, insulate axons
microglia) clean cellular debris, waste products and pathogens

PNS
Schwann cells) produce myelin, insulate axons
Satellite cells) similar to astrocytes, regulate environment
Myelin

Question 12

What is the propagation of an action potential called on an unmyelinated neuron called?

Answer 12

Continuous propagation

Question 13

Two types of synapses

Answer 13

Electrical) cells are in direct physical contact at gap junctions. Action potential transmitted quickly and efficiently

Chemical) cells not in contact, uses neurotransmitters. Most common type

Question 14

Steps to neurotransmission

Answer 14

Action potential arrives at axon terminal
Voltage gated calcium channels open
Calcium ions released, increasing cellular calcium ion concentration
Synaptic vesicles fuse with membrane
Neurotransmitter released into cleft
Neurotransmitter diffuses to post synaptic terminal

Question 15

Excitory vs inhibitory neurotransmitters

Answer 15

Excitory) makes cell membrane potential more positive, depolarisation, promotes generation of action potentials
Eg ACh

Inhibitory) makes membrane potential more negative, hyper-polarisation, inhibits generation if an action potential
Eg GABA

Question 16

How do long bones form? (6 steps)

Answer 16

Endochondral ossification

1 Cartilage forms from stem cells
2 Cartilage grows due to bursting of cells in the centre, which causes a shift in PH and trigger calcification
3 Primary ossification centre forms, nutrient arteries penetrate the centre of cartilage and sponges bone forms since bone mineral matrix covers spongey bone
4 Medullary cavity forms when bone mineral is reshaped and reformed
5 Secondary ossification centre formed as blood vessels enter the epiphyses (around time of birth) Spongey bone is formed here, but no medullary cavity
6 Cartilage remains of ends of bones/ joints as articulate cartilage

Question 17

How do long bones get longer?

Answer 17

1 Cartilage grows on growth plate, on the epiphyseal side
2 Cartilage cells are destroyed and replaced by bone at the metaphysis
3 bone gets longer
4 bone stops growing when the growth plate becomes too thin, this leaves an epiphyseal line

Question 18

Growth of flat bones

Answer 18

Intramembranous Ossification

Bone grows directly from osteoblasts, no growth plate or cartilage formation involves
Fibroblasts differentiate into osteoblasts
Skull plates grow towards each other over time

Question 19

What is bone made up of?

Answer 19

10% organic collagen matrix
65% mineral (hydroxyapatite, insoluble salt of calcium and phosphorus)
25% water
Trace amounts of magnesium, sodium and bicarbonate

Question 20

4 Types of bone cells

Answer 20

Osteoblasts) bone forming cells, secrete type 1 collagen (make the collagen chains that form the new matrix), on surface of bone, control deposition of mineral, becomes osteocytes or undergo apoptosis
Osteoclasts) bone resorbing cells, large cells with many nuclei, umbrella shaped, secrete acids and enzymes that degrade bone, undergo apoptosis when finished
Osteocytes) born from osteoblasts that cipher stuck in matrix, maintains bone matrix, has canniculi, forms gap junctions w neighbouring cells, detects changes in environment
Bone lining cells) flat elongated cells, generally inactive, lines surfaces of inactive bone

Question 21

How does vitamin D help bone growth?

Answer 21

Promotes calcium and phosphorus absorption at the intestine
Regulates osteoblast and osteoclast function

Question 22

Structure of muscle from big to small components

Answer 22

Muscle (surrounded by epimysium)
Fascicle (surrounded by perimysium)
Fibre (surrounded by sarcolemma)
Myofibfil
Sarcomere

Question 23

Overview of muscle contraction

Answer 23

An action potential is the stimulus that arrives to the muscle
Calcium ions released from sarcoplasmic reticulum
Calcium ions bind to top onion on action filaments
Tropomyosin moves out the way, G actin binding sites becomes exposed
Myosin heads on thick filaments bind to G actin binding sites, Cross bridge formed
ATP on myelin head broken down into ADP and Pi
Power stroke occurs, head pivots and pulls filaments together
Creates a contraction, tension is produced
Another ATP attaches to myosin, cross bridge detaches
Myosin is reactivated

Question 24

Termination of a muscle contraction

Answer 24

ACh is broken down
No more generation of action potentials
Calcium ions are reabsorbed into sarcoplasmic reticulum
Active sites are covered, no more cross bridge formation
Contraction ends
Muscle relaxes to resting length

Question 25

Effect of exercise on bone

Answer 25

Exercise places compression on bone Osteocytes act as mechano-sensors that respond to intermittent pressure Fluid that surrounds osteocytes and canniculi is compressed and creates fluid shear stress Osteocytes produce nitric oxide Nitric oxide triggers production of a factor that causes osteoblasts to produce collagen and bone mineral Leads to increase bone mineral density

Question 26

What to hemopoetic stem cells differentiate into

Answer 26

Myeloid stem cells, gives rise to WBS, RBC, platelettes Lymphoid stem cells, gives rise to lymphocytes

Question 27

What hormone regulates RBC production?

Answer 27

Erythropoietin

Question 28

Types of blood cells

Answer 28

RBC (erythrocytes), high SA to V ratio, no nucleus or mitochondria, contains haemoglobin, discs bend to enter capillaries, biconcave discs WBC (leukocytes) nucleated, no haemoglobin, short lived, for inflammation and infection. Platelets (thrombocytes) no nucleus, replaced by spleen, disc shaped cell fragments, for clotting

Question 29

Hemostasis (clotting process)

Answer 29

Vascular phase) smooth muscle wall of vessel damaged, vascular spasm, platelets activated and release vasoconstrictors, response initiated by pain receptors Platelets phase) platelets form a plug, extend projections to each other, release clotting compounds Coagulation phase) clotting factors promote formation of prothrombinase, turns into thrombinase, forms thrombin. Thrombin converts fibrinogen into fibrin. Fibrin is meshwork around the plug to stabilise it. Needs calcium.

Question 30

Three layers of heart wall

Answer 30

Epicardium) visceral layer on heart Myocardium) cardiac muscle fibres that provides pumping action. Has high aerobic capacity, lots of mitochondria and glycogen deposits. Contains intercalated discs maintain structure and conduct action potentials. Endocardium) outer parietal lining

Question 31

2 types of cardiac muscle fibres

Answer 31

Autorhythmic fibres) initiate and conduct action potentials Contractile fibres) provide mechanical pumping action

Question 32

Components of the conducting system in order

Answer 32

Sinoatrial node (pacemaker) , spontaneously generates an action potential (depolarises 80-100 times per min) Atrioventricular node , stimulus spread across atria and reach AV node. Atria contract AV nodal delay allows time for atria to contract and fill the ventricles (spontaneously depolarises 40-60 times per min) Action potential spreads across: Atrioventricular bundle, Right and left branches, Perkinje fibres Action potential relayed across ventricles and ventricles contract.

Question 33

Cardiac action potential

Answer 33

Resting membrane potential is -90mV 1 Rapid depolarisation , voltage gated sodium channels open and influx of sodium ions until 30mV 2 plateau , sodium Chanel’s close rapidly and calcium channels open slowly for a long time. Calcium influx and sodium efflux, balances slow sodium outflow until 0mV 3. Calcium Chanel’s close, voltage gated slow potassium channels open. Potassium efflux until resting -90mV

Question 34

Factors effecting cardiac output

Answer 34

HR) hormones (adrenaline, noradrenaline) and autonomic innervation (cardiac centres) SV) EDV (preload, filling time, venous return) and ESV (preload, afterload, contractility)

Question 35

Blood vessels vs diameter, blood pressure, cross sectional area and velocity of blood flow

Answer 35

diameter, veins highest, arteries 2nd highest blood pressure , arteries highest, veins lowest cross sectional area , capillaries highest, bell curve velocity of blood flow , arteries highest, veins second highest

Question 36

Types of lung diseases

Answer 36

Obstructive - difficultly to expire Restrictive - difficulty to inspire

Question 37

Neural control of respiration Chemical control of respiration Voluntary control of respiration

Answer 37

Neural - involuntary establishment of basic breathing rhythm from medullary oblongata Dorsal respiratory group - inspiratory centre only, quiet and forced breathing Ventral respiratory group - inspiratory and expiratory centres, forced breathing only The neurons in the pons fine tune to adjust breathing rate and depth Chemical - detects changes in pH, PCO2 and PO2, exert secondary control over breathing Peripheral chemoreceptors - in aorta and carotid arteries, detect changes in plasma pH Central chemoreceptors - in medulla, detect changes in pH of cerebrospinal fluid Voluntary Cerebral cortex

Question 38

4 Types of receptors

Answer 38

Ion channels - allows movement of ions across membrane, usually associated with a activities that reply on transmission of action potentials Transmembrane receptors with linked enzymatic domains - usually associated with cancer. Ligands binds to receptors and linked enzymatic domain becomes activates and carries out a response. G protein coupled receptors - crosses the membrane, has seven different transmembrane domains. ligand binds to receptor and activates a G protein, initiates a response. Intracellular - in cytoplasm and nucleus, binds to DNA and prevent transcription/protein production

Question 39

Variation in cell structure depending on type of cell

Answer 39

Fibroblasts involved in forming connective tissue, they make collagen proteins so they need lots of RER, ribosomes and nucleoli Neurons involved in transmitting information from nervous system and need lots of microtubules to move material from axon terminal to cell body. They produce proteins so need lots of nucleoli. Macrophages fight disease and engulf bacteria so have lots of lysosomes Muscle cells need energy to move bone so have lots of mitochondria

Question 40

Cell life cycle

Answer 40

I - interphase G1 - growth and regular cell functions, duplication of organelles S - DNA replication G2 - protein synthesis M - mitosis and cytokinesis

Question 41

Types of active transport

Answer 41

Sodium potassium exchange pump , sodium and potassium ions move down their concentration gradients through leak channels Secondary active transport - important for absorption of glucose and amino acids in digestion Receptor mediated endocytosis Phagocytosis

Question 42

Regulation of gastric activity (3 phases)

Answer 42

Cephalic phase) sense, see, smell, taste food. Directed by CNS sends submucosal plexus via vagus nerve. Increase gastric secretions from gastric glands and increase motility. Gastric phase) undigested food arrives at stomach. Triggers stretch receptors and chemoreceptors. Increases enzyme and chemical secretions and increase motility. Intestinal phase) chyme enters duodenum. Controls rate of chyme existing stomach to maintain efficiency of small intestine. Increases intestinal secretions.

Question 43

Vomiting reflex

Answer 43

1 deep inspiration, glottis closes 2 diaphragm and abdominal muscles contract, stomach compressed 3 gastric contents forces through relaxed gastroeosophageal sphincter 4 oesophageal distends and forces contents back down to stomach via peristalsis 5 cycle repeats, retching 6 pressure increases in oesophagus, jaw thrusts out, pharynx sphincter opens, contents forced out

Question 44

Peristalsis vs segmentation

Answer 44

Both - smooth muscle contraction in digestive system Peristalsis is wave like contractions that propel the bolus forward. Circular muscles push forward and longitudinal muscles shorten the tract. Segmentation is non directional cycles of muscle contraction that churn and fragment the bolus to mix with intestinal secretions and expose greater surface area to mucosa.

Question 45

Secretory cells from gastric glands

Answer 45

Chief cells, pepsinogen and gastric lipase Parietal cells, HCl and intrinsic factor Mucous cells, mucous G cells, gastrin

Question 46

Physical and chemical factors that impact haemoglobin affinity to oxygen

Answer 46

pH) as pH increases, more oxygen is bound to hameglobin Temp) as temp increases, more oxygen is unloaded for, haemoglobin pOH) as pOH increases, the effect of pH is reduced, so more oxygen is unloaded rather than bound to haemoglobin

Question 47

Partial pressures of gases in the lungs and blood

Answer 47

Oxygen) 40mmHg in veins, 100mmHg in alveoli, 95mmHg in arteries Carbon dioxide) 46mmHg in veins, 40mmHg in alveoli, 40mmHg in arteries

Question 48

3 parts of respiratory membranes

Answer 48

1 squamous epithelial lining of alveoli 2 endothelial cells lining an adjacent capillary 3 fused basal laminae

Question 49

Hormones that increase BP

Answer 49

Adrenaline and noradrenaline Angiotensin II ADH

Question 50

How to calculate mean arterial pressure

Answer 50

Cardiac output x total peripheral resistance

Question 51

Hormonal control of food intake

Answer 51

Ghrelin - appetite stimulant, produce feeling of hunger by stimulating NPY Leptin - appetite suppressant, secreted by adipose tissue when fat stores increase. acts by inhibiting the appetite stimulant NPY Insulin and CCK - depress hunger, feelings of fullness when food is absorbed