Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ESA 1 - RJS > TOB > Flashcards

TOB Flashcards

1
Q

What is the meaning of the term tissue?

A

A collection of cells specialised to perform a particular function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an organ?

A

An aggregation of tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the different types of tissue classification?

A

Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is histology important?

A

It is the gold standard of diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the relationship between milli-, micro- and nanometers?

A 
m = 1000mm = 1^9nm
Millimetre = 10^-3m
Nanometer = 10^-9m
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How big is a normal cell?

A

10-20 micrometers (1 micrometer = 10^-6m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How big is a red blood cell?

A

7.2 micrometers (1 micrometer = 10^-6m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the common biopsy techniques?

A 
Smear - cervix or buccal cavity
Curettage - endometrial lining of uterus
Needle - brain, breast, liver, kidney, muscle
Direct incision - skin, mouth, larynx
Endoscopic - lung, intesting, bladder
Transvascular - heart, liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a biopsy?

A

The removal of a small piece of tissue from an organ or part of the body for microscopic examination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why does tissue need to be fixed and state which fixtures are commonly used?

A

Preserve cellular structure, no autolysis or putrefaction

Glutaraldehyde, formaldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the common stains and what do they stain?

A

Haematoxylin - stains acidic components purple/blue (e.g. RNA, DNA)
Eosin - stains basic components pink (e.g. cytoplasmic proteins, extracellular fibres)
Periodic Acid-Schiff (PAS) - stains carbohydrates and glycoproteins magenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define epitheila

A

Sheets of contigous cells, of varied embryonic origin, that cover the external surface of the body and line internal surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the different types of epithelia?

A

Simple squamous, cuboidal & columnar
Pseudostratified
Stratified squamous, cuboidal, columnar and transitional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the basement membrane?

A

Thin, flexible, acellular layer that lies between epithelial and subtending connective tissue to which the epithelial cells adhere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give an example of where simple squamous epithelia are located and their functions?
Little bears play ball - little grey active bears

A

Squamous - Lining of vessels (Endothelium), linings of body cavities (pericardium, pleura, peritoneum), pulmonary alveoli, bowman’s capsule (kidney)
Functions: Lubrication, active transport, barrier, gas exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Give an example of where simple cuboidal epithelia are located and their functions?
The secret’s out kid - her majesty’s secret army boys

A

Thyroid follicles, small ducts of exocrine, kidney tubles, ovary surface
Function: Hormone synthesis, storage and mobilisation, absorption and secretion, barrier/covering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Give an example of where simple columnar epithelia are located and their function?
Slog us - and surrender to love

A

Stomach, small and large intestine, gallbladder, large duct exocrine glands, oviducts, uterus
Function: Absorption, secretion, lubrication, transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Give an example of where stratified squamous epithelia are located and their functions?
4 P’s

A

Keratinised - Skin
Functions: Protection against abrasion, prevents water loss, prevents invasion of microbes, protects against UV rays
Non-keratinised - Mouth, larynx, anal canal, corneal surface, vagina
Functions: Protect against abrasion, reduce water loss but remains moist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Give an example of where stratified cuboidal epithelia are located and their functions?
Weights stacked up at gym

A

Sweat glands

Function: protection, secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Give an example of where stratified transitional epithelia are located and their functions?

A

Bladder, ureters, renal calyces

Function: protection, distensibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Give an example of where stratified columnar epithelia are located and their functions?

A

Conjuctiva

Function: protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Give an example of where pseudostratified epithelia are located and their functions?
Tiny naughty bears are terrible - caps

A

Nasal cavity, trachea, bronchi, auditory tube, tympanic cavity
Function: protection, secretion, cilia-mediated transport of particles trapped in mucus, absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the rate of renewal for the skin and the small intestine?

A

Skin - 28 days

Small intestine - 4-6 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Define a gland

A

An epithelial cell or collection of cells specialised for secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How can glands be classified?

A

By destination of secretion
By structure of gland
By nature of secretion
By method of discharge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the difference between an endocrine and exocrine gland?

A

Endocrine - ductless glands which secrete into bloodstream

Exocrine - glands with ducts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the difference structure classifications of glands?

A

Unicellular/multicellular
Acinar/tubular
Coiled/branched

and

Simple gland (single duct)
Compound gland (branched ducts)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe the two types of secretions

A

Mucous - contain mucus, rich in mucins (highly glycosylated polypeptides)
Serous - secretions (often enzymes) are water, free of mucus. Stain pink in H&E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe the different methods of secretion

A

Merocrine - Exocytosis
Apocrine - Non-membrane dound structure approaches cell surface and pushes it up making a think layer of membrane and cytoplasm surround it, then pinches off
Holocrine - Disintegration of cell, releases contents, discharge of whole cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe the process of exocytosis

A

Proteins and lipids are packaged into vesicles within the RER.
Travel through the Golgi, cis-medial-trans, where modifications occur.
Secreted either through regulated or constitutive pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe the glycocalyx and how destruction affects its function

A

Glycocaylx is the extracellular glycoprotein on epithelial and other kinds of cells.
Branching sugars on it offer complex shapes for specific interactions
Destruction alters:
1. Adhersion to substrates and neighbouring cells
2. Mobility of cells
3. Communication with neighbouring cells
4. Contact inhibition of movement and division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the different controls of secretion? (4)

A

Nervous
Endocrine
Neuroendocrine
Negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where are mucous membranes found?

A

Line certain internal tubes which are open to the exterior

e.g. alimentary tract, respiratory tract, urinary tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the layers of a mucous membrane?

A

Epithelium
Lamina propria
In alimentary tract muscularis mucosae
This is all known as the mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Where are serous membrane found?

A

They are thin, two part membranes which line certain closed body cavities
e.g. peritoneum, pleural sacs, pericardial sacs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does a serous membrane consist of?

A

Simple squamous epithelium (mesothelium), visceral serosa and parietal serosa
Thin layer of connective tissue (attaches epithelium to adjacent tissues)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the layers of the gut? (4)

A

Musoca (epithelium, lamina propria, muscularis mucosa)
Submucosa - connective tissue containing glands, arteries, veins and nerves
Muscularis externa - 2 layers, longitudinal & circular
Serosa - peritoneum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the layers of the oesophagus? (4)

A

Mucosa (epithelium, lamina propria, muscularis mucosa)
Submucosa - containing mucous secreting glands
Muscularis externa - 2 layers, longitudinal & circular
Adventitia - connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the layers of the stomach? (3)

What does the stomach contain that is unique?

A

Mucosa (epithelium, lamina propria, muscularis mucosa)
Submucosa
Muscularis externa - 3 layers, obilque, circular, longitudinal
Contains rugae (folds of gastric mucosa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What does the jejunum have that is unique?

A

Contains plicase circulares - circular folds of mucosa and submucosa projecting into gut lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does the large intestine have that is unique?

A

Crypts of Lieberkuhn (gland in the epithelial lining)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are the layers of the trachea? (4)

A

Mucosa - epithelium, lamina propria
Submucosa - containing seromucosa glands
Hyaline cartilage - calcifies with age
Adventitia - connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are the layers of bronchus (3), bronchiole and alveoli?

A

Bronchus:
Mucosa - epithelium, smooth muscle lamina propria
Submusoca - contains glands
Cartilage

Bronchiole does not have cartilage or submucosa
Alveoli do not have submucosa or muscle - they are covered in a network of elastic fibres and capiliaries (epithelium, basement membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are the layers of the ureter? (2)

A

Mucosa - epithelium, fibroelastic lamina propria

Muscularis externa - circular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the layers of the bladder wall? (2)

A

Mucosa - epithelium, smooth muscle in lamina propria

Muscularis externa - 3 interwoven layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are the layers of the urethra? (3)

A

Mucosa - epithelium, lamina propria
Muscularis externa - 2 layers, longitudinal and circular
Adventitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How does a transmission electron microscope work?

A

Heated filament (electron source) is passed through specimen onto fluorescent screen (condenser lends, objective lens and projector lens required)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Define the limit of resolution

A

The minimum distance at which two objects can be distinguished

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Why are electron microscopes capable of finer resolution than light microscopes?

A

Limit of resolution proportional to wavelength
Resolution improves as wavelength decreases
Electron wavelength = 0.004nm
Light wavelength = 400nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Describe the following components of a cell’s ultrastructure:
Plasma membrane, glycocalyx, nucleus, nuceolus, nuclear envelope, SER, RER, ribosomes, Golgi, secretory vesicles, lysosomes, peroxisomes, mitochondria, cytoskeleton

A

Plasma membrane - bilipid membrane, amphipathic, impermeable barrier to water-soluble molecules, contains proteins
Glycocalyx - polysaccharide side chains on outside of the plasma membrane
RER & SER - site of protein synthesis
Ribosomes -
Golgi - modification, packaging and sorting of proteins synthesised on RER (cis-trans)
Secretory vesicles - contain proteins for secretion extracellularly
Lysosomes - synthesised by golgi and contain many hydrolytic enzymes - fuse with material requiring digestion
Peroxisomes - Detoxify molecules including alcohol phenols, formic acid and formaldehyde
Mitochondrial - contain folds called cristae, generate ATP by oxidative phosphorylation, contain their own genetic information and can divide (inherited maternally)
Cytoskeleton - contains microfilaments of actin, epithelia cells contain intermediate filaments, Microtubules are hollow cylinders found in structures that are moved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is a connective tissue?

A

Forms a continuum throughout the body, linking together muscle, nerve and epithelial tissue. Also provides support in metabolic and physiological ways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are the function of connective tissues? (CADDIS)

A
  1. Provide cushion between tissues and organs
  2. Attach muscle to bone, and bone to bone
  3. Provide a medium for diffusion of nutrients and wastes
  4. Defend against infection
  5. Aid in injury repair
  6. Provide substance and form to body and organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the components of connective tissue?

A
  1. Cells

2. Extracellular matrix: ground substance (hyaluronate proteoglycan aggregates), fibres (collagen, reticular, elastic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

In terms of connective tissue which cell lines are derived from mesenchyme cells (embryonic connective tissue)

A 
Chondroblasts (cartilage)
Lipoblasts (fat)
Fibroblasts (ligament, tendons, capsules, general supporting tissues)
Osteoblasts (bone)
Myoblasts (skeletal muscle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is reticulin and where is it found?

A

Fibre present in connective tissue - type 3 collagen

Lymph node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How can connective tissue be classed?

A

Loose
Dense: regular & irregular
Specialised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are elastic fibres made from?

A

Elastin make up elastic fibres but are surrounded by microfilbrils called fibrillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is the composition of loose irregular connective tissue?

A

Wispy collagen (non-branching) and many fibroblasts
Branching elastic fibres
Mast cells
e.g. lamina propria between crypts of lieberkuhn, submucosa of colon, areolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the composition of dense irregular connective tissue?

A

Densely packed collagen in irregular arrangement (resists forces in multiple directions), fewer fibroblasts, some elastic fibres
e.g. dermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the composition of dense regular connective tissue?

A

Collagen bundles that lie in parallel, densely packed
Rows of elongated flattened fibroblasts lie between
e.g. Tendons, ligaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the function of fibroblasts?

A

Synthesise and secrete both ground substance and fibres that lie within the ground substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the function of macrophage?

A

Derived from blood monocytes which move into loose connective tissue, especially during local inflammation.
Phagocytic - degrade foreign organisms and cell debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the function of mast cell?

A

Found near blood vessels Contain granules of heparin, histamine, substances that attract eosinophils, neutrophils - secretion results in immediate hypersensitivity reactions, allergy and anaphylaxis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What are specialise connective tissue?

A

Adipose tissue, blood, cartilage, bone, lymphatic tissue, heamopoietic tissue

65
Q

What are the layers of the epidermis?

A

Stratum corneum
Granular layer
Prickle cell layer
Basal layer

66
Q

How does the epidermis proliferate?

A

Keratinocyte mitosis occurs at basal layer
Upward movement to form prickle layer where terminal differentiation begins and kerationcytes lose ability to divide, joined by desmosomes (intercellular junctions)
In granular layer keratinocytes lose plasma membrane and begin differentiating into corneocytes
Stratum corneum contains flattened corneocytes (barrier)

67
Q

What do keratinocytes synthesise and what is it’s function?

A

Keratins - strengthen epidermis

68
Q

What other cells are present in the epidermis?

A

Melanoctyes - produce melanin (pigment of skin), occur at intervals along basal layer
Langerhans cells - mediate immune reactions, scattered throughout prickle cell layer, presented antigens to T lymphocytes

69
Q

Describe the structure of the dermis

A

Tough, fibrous, vascular layer

Contains collagens, type 1, elastin, fibroblasts, blood vessels, lymphatic vessels, mast cells, nerves

70
Q

What are the skin appendages?

A

Hair follicles
Sebaceous glands
Sweat glands - exocrine, apocrine
Nails

71
Q

What are the main functions of skin?

A

Barrier function
Sensation
Thermoregulation - thermoregulatory exocrine sweating
Psychosexual communication

72
Q

What is the composition of cartilage?

A

Extracellular matrix produced and maintained by chrondrocytes, composed of hyaluronate proteoglycans aggregate and type 2 collagen

73
Q

What are the three major types are cartilage

A

Hyaline
Elastic
Fibrocartilage

74
Q

What is the composition of hyaline cartilage? Give an example of where it is found

A

Matrix: Proteoglycans, hyaluronic acid and type 2 collagen
Chondrocytes lie in lacuna (small clusters called isogenous groups)
Covered by perochondrium containing fibroblast-like cells which can develop into chrondrocytes
Calcifies with age
Location: Articulating surfaces (no pericondrium), joints, rib cage, nose, trachea, bronchi, larynx, epiphyseal growth plate

75
Q

What is the composition of elastic cartilage? Give an example of where it is found

A

Proteoglycans, hyaluronic acid, type 2 collagen and many elastic fibres - gives elasticity
Locations: pinna, external meatus, epiglottis, eustachian tube

76
Q

What is the composition of fibrocartilage? Give an example of where it is found

A

Combination of dense regular connective tissue and hyaline cartilage
Type 1 collagen plus proteoglycans, hyaluronic acid and type 2 collagen
No surrounding perichondrium
Cells often seen in rows
Locations: intervertebral discs, articular discs of sternoclavicular & temporomandibular joints, menisci of knee

77
Q

What is the difference between appositional and interstitial growth of cartilage?

A

Appositional - grows from periphery (fibroblast-like cells give rise to new chondroblasts)
Interstitial growth - Deposition of matrix by isogenous groups of chondrocytes

78
Q

What is the function of Haversian and Volkmann’s canals?

A

Carry blood vessels, lymph vessels and nerves
Haversians run vertically
Volkmann’s run horizontally

79
Q

What is the difference between immature and mature bone?

A

Immature bone has osteocytes with are fairly randomly arranged
Mature bone has osteocytes arranged in concentric lamellae of osteons

80
Q

What is the structure of spongy (cancellous) bone?

A

Trabeculae - spaces for bone marrow
Osteocytes lie in-between lamellae
No Haversians or Volkmann’s

81
Q

Explain the function of osteoblasts and osteoclasts

A

Osteoblasts - deposit new bone

Osteoclasts - resorbing bone to remodel (cuts a tunnel through bone)

82
Q

What is endochondral ossification?

A

Replacement of pre-existing hyaline carrilage template by bone

83
Q

Describe the steps in endochondral ossification

A
  1. Collar pf periosteal (compact) bone appears in shaft (embryo 6-8 weeks)
  2. Central cartilage calcifies, nutrient artery penetrates - primary ossification centre formed (fetus 8-12 weeks)
  3. Medulla becomes cancellous bone (middle/shaft), cartilage forms epiphyseal growth plates, epiphyses develop secondary centres of ossification (postnatal)
  4. Epiphyses ossify and growth places continue to move apart (prepubertal)
  5. Epiphyseal growth plates replaced by bone, hyaline articular cartilage persists (mature)
84
Q

Describe intramembranous ossification

A

Condensations of mesenchymal tissue to form flat bones

85
Q

Describe the effects that growth hormone has on growth of bone

A

Growth hormone
Before puberty - excess causes gigantism, insufficient causes pituitary dwarfism
Adult - excess causes acromegaly

86
Q

Describe the effects that sex hormones has on growth of bone

A

Sex hormones influence development of ossification centres
Give rise to pubertal growth spurt, premature closure of epiphyses
Deficiency can cause tall stature - epiphyseal pleats persist

87
Q

What is the role of vitamin D in bone?

A

Increases calcium absorption by the small bowel

Promotes mineralisation of bone

88
Q

What are the three types of muscle?

A

Striated muscle - skeletal & cardiac

Non-striated muscle - smooth

89
Q

What are the two types of skeletal muscle fibres?

A

Red - Smaller, myoglobin rich, numerous mitochondria, slow/repetitive contraction, slow to fatigue, fewer neuromuscular junctions
White - opposite

90
Q

Describe skeletal muscle structure

A

Epimysium surrounds muscle
Fascicles make up muscle - surrounded by permysium
Fascicles made up from fibres - surrounded by endomysium
Fibres made up from myofibrils - surrounded by sarcolemma
Myofibrils made up from sarcomere

91
Q

Describe the structure of sarcomere

A 
ZIAHM
Z disc - actin filaments join
I band - actin filaments where myosin does not overlap
A band - where myosin lie
H band - area between actin filaments
M line - central C protein
92
Q

Explain how calcium causes contraction

A

Calcium binds to C subunit of troponin which causes a conformation change moving tropomyosin away from actin binding sites - allowing myosin heads to bind to actin

93
Q

Explain the sliding of actin during contraction

A
  1. ATP binds to myosin head causing it to uncouple from actin filament
  2. Hydrolysis of ATP to ADP causes bending of head
  3. Release of Pi and ADP causes power stroke
94
Q

Explain how muscles are innervated

A
  1. Action potential causes release of acetylcholine into synaptic cleft of neuromuscular junction causing local depolarisation
  2. Voltage-gated Na+ channel open
  3. General depolarisation spreads over sarcolemma and down T tubules
  4. Voltage sensor proteins of T tubule membrane change conformation
  5. Gated Ca2+ channels open and Ca2+ enters sarcoplasm
  6. Ca2+ binds to TnC subunit of troponin
95
Q

What is the difference between cardiac muscle and skeletal muscle?

A

Centrally placed nuclei
Intercalulated discs - where Z bands meet
Branching
T tubules lie in register with Z bands and is a diad rather than triad
Unable to regenerate - lays down scar tissue

96
Q

Describe the composition of Purkinje fibres

A

Abundant glycogen
Sparse myofilaments
Extensive gap junction sites
Connect sinoatrial note to atrivoventricular node

97
Q

Describe features of smooth muscle

A 
Spindle-shaped
Central nucleus
No striation, sarcomeres or t-tubules
Contaction still relies on actin-myosin interactions (criss-crossed along spindle)
Contraction is slower, more sustained
98
Q

What are the meninges of the brain and spinal cord? (DAP)

A
  1. Dura mater
  2. Arachnoid mater
  3. Pia Mater (innermost)
99
Q

What does leptomeninges refer to?

A

The arachnoid mater and pia mater when taken together - cerebrospinal fluid flows within the leptomeninges

100
Q

Describe the structure of a nerve?

A

Epineurium surrounds the nerve in which there are nerve fascicles
Perineurium lines nerve fascicles which contain a collection of axons
Endoneurium surrounds an axon

101
Q

What is a neurone?

A

A specialised functional unit of the nervous system

Includes cell body (with extending dendrites) and axon

102
Q

What is the function of dendrites?

A

Increase surface area of the cell body

Some can develop further appendages called spines - They are associated with learning experiences

103
Q

Describe the componens of an axon

A

Myelin sheath - Schwann cell wrapped around - increases action potential speed
Node of Ranvier - where there is no myelination
Axonal terminal

104
Q

How do neurones communicate? What is the difference between excitatory and inhibitory signals?

A

Submicroscopic gaps called synapses through neurotransmitters
Excitatory - depolarisation
Inhibitory - hyperpolarisation

105
Q

What are the functional classes of neurones?

A

Sensory neurones
Motor neurones
Interneurones

106
Q

What pathways relays information from the body to the brain?

A

Afferent - sensory neurones

107
Q

What pathways relays information from the brain to the body?

A

Efferent - motor neurones

108
Q

What are the divisions of the ANS?

A

Sympathetic - rest and digest - short preganglionic (terminates in paravertebral sympathetic chain), long postganglionic
Parasympathetic - fight/flight - long preganglionic, short postganglionic

109
Q

What are the neurotransmitters?

A

Acetylcholine and noradrenaline

110
Q

What the the ANS?

A

Autonomic nervous system - part of the Peripheral nervous system (outside the brain)

111
Q

Communication between pre- and post-ganglionic sympathetic and parasympathetic neurones is…?

A

Cholinergic (involves acetylcholine) via nicotinic receptors - parasympathetic
Or
Noradrenergic (noraldreanline)

112
Q

What is the life of a RBC?

A

120 days

113
Q

What is the life of a platelet?

A

10 days

114
Q

What is the function of bone marrow?

A

Produce RBCs, platelets, WBCs from progenitor stem cells

115
Q

What are the functions of RBCs?

A 
Deliver oxygen
Carry haemoglobin
Maintain haemoglobin in its reduced state
Maintain osmotic equilibrium
Generate ATP
116
Q

Describe how RBCs structure facilitates its function

A

Biconcave flexible disc facilitates passage through the microcirculation (capillaries)

117
Q

What are the two main metabolic pathways within RBCs?

A

Embden Meyerhof Pathway - glucose metabolised to lactate (ATP generated)
Hexose monophosphate pathway - glucose-6-phosphate metabolised (generates NADPH)

118
Q

How is erythropoiesis controlled?

A

Reduced O2 pressure detected in interstitial peritubular cells in kidney
Increased produced of erythropoietin
Stimulates maturation and release of RBCs from bone marrow
Haemoglobin rises
O2 pressure rises
Erythropoietin production falls (negative feedback)

119
Q

How are RBCs catabolised?

A

RBCs brown down in the spleen to release heam group which is broken down until bilirubin
Bilirubin transported to liver which travels down bile duct into large intestine

120
Q

How are platelets produced?

A

Megakaryocytes produce platelets - they bud off from the cytoplasm - controlled by thrombopoietin

121
Q

What are the functions of the platelet?

A

Adhersion to connective tissue
Aggregation with other platelets
Phospholipid membrane to facilitate clotting (glycoprotein receptors for clotting factor and platelet adhersion)

122
Q

What is the function of neutrophils? What do they release?

A

Phagocytosis - first arrival in inflammatory response
Once granules are used up they die
Chemokines - attacts more phagocytes

123
Q

What is the function of monocytes?

A

Mature into macrophages in tissues

124
Q

What is the function of eosinophils?

A

Degranulating cells - release heparin, histimine

Involved in allergy and asthma

125
Q

Which cells undergo degranulation?

A

Mast cells, eosinophils, basophils

126
Q

What is the function of basophil?

A

Degranulation cell - releases histimine and heparin

127
Q

What are the features innate immune system?

A 
Inbulit immunity to resist infection 
Present from birth
Non-specific
No memory
Involved in the triggering and amplification of adaptive immune response
128
Q

What is adaptive immunity?

A

Immunity established to adapt to infection
Learnt by experience
Pathogen specific
Has memory

129
Q

What is the function of the lymphocyte?

A

Adaptive immune response (T & B lymphocytes)

Recognise non-self antigens and generate a specific response to eliminate foreign antigen

130
Q

Which cells are phagocytes?

A

Macrophages and neutrophils

131
Q

Describe the role of epithelial cells in first line of defence to pathogens

A 
Mechanical, selectively permeable barrier
Produce natural antibodies
Produce cytokines
Motile cilia
Rapidly renewable
132
Q

What is the complement system?

A

Marks pathogens for destruction by covalently binding to their surface - activated by sugars on surface of antigen

133
Q

What are the cells of the adaptive immune response? And what do they do?

A

T helper cells (CD4) - release cytokines which activate cytotoxic T cells & increase activity of phagocytes
Cytotoxic T cells (CD8) - cell-mediated immunity (no cytokines secreted), they secrete interferon
B lymphocytes - receptors can be secreted into intercellular space (immunoglobin or antibody), binds on surface of pathogen, stimulates innate immune system

134
Q

Describe the general scheme of immune response

A

Pathogens break epithelial barrier
Activated epithelial cells release cytokines
Inflammatory mediators promote endothelium (capillary) to become permeabilised allowing cell and fluid migration (antibodies and complement)
Opsonisation (binding of antibody) to pathogen
Attracting phagocytes for phagocytosis

135
Q

What are the cells involved in innate immunity?

A 
Monocytes - macrophages
Neutrophil
Eosinophil
Basophil
Mast cell
Natural killer cells
136
Q

Describe the adaptive immune response

A

Clonal selection - recognition of receptor needed by naive T & B lymphocytes
Clonal expansion - mitotic division (daughter cells)
Elimination of antigen
T & B cell apoptosis
Seeding of memory

137
Q

What is opsonisation?

A

The coating of a microorganism by antibodies or complement to render it recognisable as foreign by phagocytes - enhancing phagocytosis

138
Q

What are the antigen receptors expressed on lymphocytes?

A

B cell = surface immunoglobulin (membrane-bound antibody)
T cell = T cell antigen receptor (distinct molecule, not membrane-bound)
Each expresses a single antigen receptor specificity

139
Q

What are the three main ways which antibodies protect the host from infection?

A

Neutralisation - prevents bacterial adherence
Opsonisation - promotes phagocytosis
Complement activation - enhances opsonisation and lyses some bacteria

140
Q

What is a pathogen?

A

Microbes that cause human disease

141
Q

What is an infection?

A

Presence and multiplication in a host of a causal organism in abnormal circumstances and with an associated host reaction

142
Q

Describe the gram stain procedure

A

Crystal violet is added
Iodine is added
Decolourisation with alcohol/acetone
Counter staining with safranin

143
Q

How does gram staining work?

A

Crystal violet and iodine are absorbed into cell and form and purple complex
During deolourisation:
Gram -ve loses outer lipopolysaccharide membrane and purple complex is washed away - counter stain then used
Gram +ve becomes dehydrated trapping purple complex

144
Q

What is the difference between gram +ve and -ve bacteria?

A

Gram +ve has a thick layer of peptidoglycan

Gram -ve has a thin layer of peptidoglycan with an outer lipopolysaccharide membrane

145
Q

Which type of bacteria cannot be seen using gram stain? What stain is used?

A

Mycobacteria - acid-fast

146
Q

Which groups of bacteria are gram +ve?

A

Staphylococcus
Streptococcus
Clostridium

147
Q

Which groups of bacteria are gram -ve?

A 
Everything not staph, strept or clostridium
Neisseria
Salmonella
Helicobacter
Pseudomonas
Bacteroides
148
Q

Which viruses have DNA and an envelope?

A

Hepatitis B, herpes viruses, smallpox

149
Q

Which viruses have DNA and no envelope?

A

Papillomaviruses (warts, cervical cancer)

150
Q

Which viruses have RNA and an envelope?

A

Rubella, HIV, ortho- & para- myxoviruses (measles, mumps)

151
Q

Which viruses have RNA and no envelope?

A

Picomaviruses (polio, hepatitis A, colds)

152
Q

What does Koch-henle postulates?

A

Identification of particular microbe as causing disease

  1. Isolate organism from every case
  2. Propagate the organism in pure culture in vitro
  3. Reproduce disease by injecting the organism into a suitable recipient
  4. Re-isolate the organism
153
Q

What are the components in the transmission of infection?

A

Reservoir - immediate source - mode of transport - susceptible host

154
Q

Describe the pre-ganglionic and postganglionic neurones in the parasympathetic nervous system

A

Long pre-ganglionic neurone - synapses locally to effector

Short post-ganglionic neurone - synapses at effector

155
Q

In terms of infection, what is R0?

A

The basic reproductive rate of an infection after introduction into a susceptible population
R0 >1 - infection propagates
R0 <1 - infection dies out

156
Q

What are the stages of fracture repair?

A
  1. Haematoma formation - blood clot forms in which granulation tissue
  2. Fibrocartilaginous callus formation - Fibrocartilaginous callus replaces procallus of granulation tissue (bone trabeculae is developing in callus)
  3. Boney callus formation - Endochondral & intramembranous ossification gives rise to a bony callus of spongy bone
  4. Bone remodelling - cancellous bone replaced by compact bone
157
Q

Describe the pre-ganglionic and postganglionic neurones in the sympathetic nervous system

A

Short pre-ganglionic neurone - synapses in spinal column

Long post-ganglionic neurone - synapses at effector

158
Q

What is interferon?

A

Interferon is released by cells that have become infected - prevents further cells from becoming infected & switches off cellular machinery necessary for viral replication

ESA 1 - RJS (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions