cells and tissues Flashcards
what are the 6 levels of structural organisation of the human body
- chemical
- cellular
- tissue
- organ
- system
- organism
description and examples of the structural levels
chem - building blocks eg. atoms join to form molecules
cellular - basic structural and functional units of body eg. cardiac muscle cells, nerve cells
tissue - group of cells work together to perform particular function (4 classes = epithelial, connective, muscle, nerve) eg. cardiac muscle
organ - structures w/ specific funtions made of 2 or more types of tissues eg. heart, stomach, skin, brain
system - related organs w/ common funtion eg. cardiovascular
organismal - all parts functioning together to constitute living organism
11 body systems are…
- INTEGUMENTARY
- MUSCULAR
- SKELETAL
- URINARY
- REPRODUCTIVE
- DIGESTIVE
- NERVOUS
- ENDOCRINE
- LYMPHATIC & IMMUNE
- CARDIOVASCULAR
- RESPIRATORY
integumentary systems components (organs) and functions
- CUTANEOUS MEM. (skin) epidermis and dermis - E = protects surface, deeper tissues, vit. D. D = feeds E, strength
- HAIR follicles & sebaceous glands - sensation, protection, lubrication, removes waste
- SWEAT GLANDS - thermor. breast tissue = modified sweat gland
- NAILS - stiffen & protect digits
- SENSORY RECEPTORS - sensation touch temp. pain etc
- HYPODERMIS - fat stores insulation
muscular system components and functions
• SKELETAL MUSCLES - skeletal movement, entrance & exit to D sys R sys U sys
- AXIAL MUSCLES - support & positioning of axial skele
- APPENDICULAR MUS - support & move brace limbs
- TENDONS AND APONEUROSES - translate contractile forces to tasks. T = muscles to bone. A - muscle to muscle connection
skeletal system components and functions
- BONES CARTILATE JOINTS - c = bone interfaces. types: hyaline (ribs) fibro-(disks)
- AXIAL skele - skull, cartilage, ligaments. protects brain & SC, sense organs. supports body weight (over lower limbs)
- APPENDICULAR - limbs and supporting bones & ligaments. internal support —> muscles can move axial skele
nervous system
- CNS - control centre short term control over other systems
- brain - complex integrative activities
- spinal cord - relay info to & from brain, less complex act. eg reflex arc
- special senses (CNS AND PNS except optic nerve - CNS) - sensory input to brain sight hearing smell taste equilibrium
- PNS - link CNS w other systems and sense organs
endocrine system
- PINEAL GLAND - brain, day & night systems
- HYPOTHALAMUS/PITUITARY - brain, control other endocrine glands, reg. growth, fluid balance
- THYROID + PARATHYROID GLANDS - throat, metabolic rate & calcium levels
- THYMUS - below thyroid, maturation of lymphocytes
- ADRENAL - top of kidneys. water & mineral balance, tissue metabolism, cardio and resp function (adrenaline)
- KIDNEYS - RBC production, calcium levels, BP up
- PANCREAS
- GONADS - sexual characteristics & reprod.
growth hormone effects
- pit. gland releases —> migrates to liver —> prod. of IGF —> bone muscle and skin
- too much as child = gigantism
- too much as adult = acromegaly - sharp features etc
lymphatic and immune system
- LYMPHATIC VESSELS - carry lymph fluid & lymphocytes from peripheral tissues to veins of CV sys (blood)
- LYMPHATIC FLUID - all extra fluid around cells + lipids from gut
- LYMPH NODES (incl. tonsils - back of throat) - monitor composition of lymph, engilf pathogens, immune response (B&T)
- SPLEEN - next to left side of stomach. immune resp, engulf pathogens, recycle RBC, monitors circulation blood cells
- THYMUS - development and maintenance of T cell lymphocytes
- lymph. sys. absorb excess interstitial fluid and transport (proteins and fluid) to CV sys
cardiovascular system
- HEART - maintains BP, propels blood
- BLOOD VESSELS - arteries = from heart to cap. cap = diffusion between blood and interstitial fliuds. veins = return blood from cap to heart
- BLOOD = transport of o2 ans co2, nutrients, hormones, removes waste, temp, acid base balance, defense against illness (immune cells)
respiratory system
- NASAL CAVITY & SINUSES - filter warm humidify air, smells
- PHARYNX - air to larynx
- LARYNX - protects opening to trachea, vocal chords
- TRACHEA - conducts air, cartilage keeps open
- BRONCHI - air from trach. to lungs
- LUNGS - air movement, gas exchange, acid base control
digestive system
- ORAL CAVITY - break up food w teeth tongue
- SALIVARY GLANDS - (acid base) buffer, lubricant, enzymes eg. amylase
- PHARYNX - solid and liquid to oes.
- OESOPHAGUS - food to stomach
- STOMACH - secrets acid enzymes hormones
- SMALL INTESTINE - digestive enzymes, buffers and hormones, absorbs nutrients
- LIVER - bile, reg. nutrients in blood
- GALLBLADDER - concentrates bile
- PANCREAS - dig. enzymes, buffers, endocrine cells
- LARGE INTESTINE & ANUS - water removal, waste storage & removal
urinary system
- KIDNEYS - form and concentrate urine, reg. pH and ions, blood vol and pressure
- URETERS - urine to bladder
- BLADDER - stores urine
- URETHRA - urine to exterior
EPO
- glycoprotein hormone produced by kidney
- signals for erythropoesis in bone marrow - production of RBC
- more hemocytoblasts (RBC stem cells) = RBC prod. —> blood carry more o2
reproductive system FEMALE
- OVARIES (gonad) - oocytes hormones
- UTERINE TUBES - delivery oocyte location of fertilisation
- UTERUS - embryonic development
- VAG & EXTERNAL GENITALS - lubrication, birth canal, sperm reception
- MAMMARY GLANDS - nutrition for newborn
reproductive system MALE
- TESTES (gonad) - hormones, sperm prod
- EPIDIDYMIS - s mature
- DUCTUS DEFERENS - s from epididi
- SEMINAL & PROSTATE GLANDS - seminal fluid
- URETHRA - s to exterior
- PENIS & SCROTUM - reprod. thermal, control testes
4 types of tissues are…
EPITHELIAL
CONNECTIVE
MUSCLE
NERVOUS
epithelial tissue
covers body surfaces
lines hollow organs tubes cavities ducts
forms glands
protection filtration secretion excretion absorption
connective tissue
cells in matrix of fibres and ground substance (inc. blood) - CT = ECM + cells
not on body surfaces, highly vascular (unlike epi. except cartilage avasc; tendons little blood supply), supplied by nerves (like epi. except cartilage)
protects, supports connects body organs
transport- distributes blood vessels to other tissues
stores energy (adipose tissue)
nervous tissue
conducting nerve cells and supportive neuroglia
detects changes and carries info through generating nerve impulses
5 typesof junctions are..
TIGHT ADHERENS DESMOSOMES HEMIDESMOSOMES GAP
tight junctions
strands of transmembrane proteins (claudin, occludin), more strands = tighter
prevent migration of proteins between apical & basal surfaces, prevent contents of organs leaking to blood
LOCATIONS - stomach, intestine, bladder
adherens junctions
belt desmosome/adhesion belt (plaque layer of proteins)
more basal than tj
cadherins spans gap - catenins link cadherin to actin (microfilament on plaque), crosses intercellular space & attaches to cadherin of adj. cell
prevent cell from separation during contraction
LOCATIONS - intestines,
desmosomes
plaque attaches to intermediate filaments - keratin
k spans from one side of desmosome to other - stability
cadherin link cell surface to keratin, span gap
resist shearing forces
LOCATIONS - cardiac muscle cells, epidermal cells, skin epithelium
hemidesmosomes
anchor epithelia to bm
plaque
INTEGRIN linker protein binds to LAMININ in bm and KERATIN in cytoplasm
gap junctions
direct connection between cells —> communication
6 connexINs —> 1 connexon / hemichannel —> 2 connexons = gap junction (hydrophillic channel)
ions, small mol. (~1kDa mol.) diff from one cystol to another. NOT large molecules eg. protein
LOCATIONS - mucles , nerves (impulses), heart, gastointestinal tract, uterus
cytoskeleton
MICROFILAMENTS (eg. actin) - bundles beneath cell mem. and cyt. , strength, alter cell shape, link cyt to mem, tie cells together, muscle contraction INTERMEDIATE FILAMENTS (eg keratin) - strength, move materials through cytoplasm
basement membrane (structure, function)
2 parts - basal lamina (secreted by epi. cells; collagen, laminin, glycoproteins), reticular lamina (secreted by fibroblasts in connective tissue;fibrous protiens - fibronectin, collagen)
epi cells avascular, exchange of nutrients and waste by diff through bm from ct vessels
physical barrier
supports epi
surface where epi cells migrate - growth and wound healing
arrangement and shape of covering and lining epithelia
ARRANGEMENT
- simple (single layer) secretion, absorption, filtration, diff, osms
- stratified (multiple layers) protection
- pseudostratified (looks like strat, not - nuclei diff places, not all reach apical but ALL reach bm) secretion
SHAPE
- squamous (flat thin) diffusion
- cuboidal secretion absorbtion
- transitional (strat epi from cuboidal to flat) allow stretching
- columnar (taller than wide, apical surfaces have cilia or mv) protection secretion absorption
simple squamous epi
FILT, DIFF, SECRETION (serous mem)
thin, flat, irregular, most delicate, central nucleus
MESOTHELIUM - lines serous mem (pericardial, pleural, pentoneal cavities)
ENDOTHELIUM - lines inside of <3, blood, lymphatic vessels
L: bowmans cap, cardio & lymph sys, eye, lungs, heart
simple cuboidal epi
SECRETION ABSORPTION
central nucleus
L: ovary, kidney tubules, thyroid, pancreas ducts, eye (post. retina; ant. lens)
simple columnar epi
NON C: SECRETION, ABSORPTION, LUBRICATION (goblet cells)
- mv —> high SA —> higher rate of absoption
- L: gastointestinal tract, ducts of glands, gallbladder
C: cilia beat —> movement of mucus/foreign objects/oocytes
- goblet cells
- L: bronchioles, fallopian tubes, brain ventricles, spinal chord
pseudostratified columnar
ciliated - SECRETION via goblet cells —> trap foreign particles —> cilia sweep away
n ciliated - ABSORPTION, PROTECTION no goblet cells
L: c = resp tract, nc = larger ducts of glands, epididymus, part of male urethra
stratified squamous
PROTECTION from ABRASION, WATER LOSS, UV RADIATION, FOREIGN INVASION (keratinised), MICROBES
bottom = cuboidal/columnar, top is squamous
apical cells dehydrated less metabolically active —> tough, hard —> die & sloughed off and replaces
KERATINISED = tough layer of k in apical surface + several layers deep - waterproof
N-K = moistened by mucus, organelles not replaced
L: K = skin, N-K = wet surfaces; lining of mouth, oesophagus, vag, covers tongue
stratified cuboidal epi
PROTECTION, limited s & a
rare
L: ducts of adult sweat glands, oesophageal glands, part of male urethra
stratified columnar epi
PROTECTION, SECRETION
basal layers irregular & short; only apical columnar
uncommon
L: urethra, oesophageal glands, eye, anus
transitional epi
ALLOW urinary organs to STRETCH, maintain lining while holding FLUID w/o rupturing
relaxed = strat cub - apical large round, stretched = strat squamous
L: hollow structures; urinary bladder, parts of ureters, urethra
exocrine glands vs endocrine glands (classification of glandular epithelia)
endocrine = secrete to blood via interstitial fluid (int —> diff to blood) FAR reaching effects exocrine = secrete to ducts —> empty on surface of covering & lining epi LOCAL/LIMITED effects
2 types of glandular epi
UNICELLULAR - goblet cells (exocrine) mucus on apical lining of epi
MULTICELLULAR:
categorised by - branched or unbranched ducts; shape of secretory portion of gland; relo between the two
types of ducts and secretory portion of multicellular glands
branched ducts = compound non branched ducts = simple s tubular = tubular s rounded = alveolar/acinar s tubular and rounded = tubuloacinar
types of multicellular glands (epi)
SIMPLE TUBULAR - intestinal glands
SIMPLE BRANCHED TUBULAR - gastric glands
SIMPLE COILED TUBULAR - meocrine sweat glands
SIMPLE ACINAR - urethra (M)
SIMPLE BRANCHED ACINAR - sebaceous glands
COMPOUND TUBULAR - mucus glands (mouth)
COMPOUND ACINAR - mammory glands
COMPOUND TUBULOACINAR - pancreas, salivary glands
(connective tissue) extracellullar matrix composed of (basic)
GS (ground substance) + F (3 major types of protein fibres secreted by cells in ecm - collagen, reticular, elastic)
ground subtance (ecm connective tissue) composed of.. (basic)
WATER
PROTEINS
POLYSACCHARIDES - glycosaminoglycans (GAGS*)
* long unbranched polysacc, repeating disacc unit - amino sugar, uronic sugar, highly polar and attract water
GAGS types and applications
trap water to make GS more jelly
SULPHATED - bind to core protein —> proteoglycan
N-S - hyaluronic acid joined to PGs, unusual as ns and no covalent bond to c protein
APPLICATIONS
• HA - viscous, slippery, bind cells together, lubricates joints, maintains shape of eyeball
• hyaluronidase - digest HA, prod by sperm, WBC, bacteria —> GS more liquid —> move more easily
• (GS) chondoitin sulphate - support & adhesive feats of cartilage, bone, skin, bv
• keratan s - bone, cartilage, cornea of eye
• dermatan s - skin, tendons, bv, heart valves
disease related to ECM decomp
periorbital ECM decomp & thyroid dis. = exopthalamus
decomp of gags —> influx of h2o —> more orbital contents behind eye (ecm in tissues) —> eyes forward
autoimmune overreaction of goitre = swollen thyroid gland
AI action on firbroblasts in ecm of eye
common in younger women
3 types of connective tissue protein fibres in ecm
collagen (thick)- strong & flexible resist pulling forces, feat. vary in diff tissues, 25% of body (most abundant protein), parallell bundles. L: bone, cart., tendons, ligaments
reticular - fine bundles of c + glycop coating (= more protein than sugar), made by fibroblasts, strength + support, thinner branches in tissue, networks in v & tissues (esp. adipose, nerve, smooth muscle), bm
elastic - thinner than c, fibrous network, elastin (p) + surrounded by fibrillin (glycop) —> strength, stability, stretch 150% w/o breaking. L: bv, lungs, skin
defect in elastic fibres gives rise to..
MARFAN syndrome
dom. mutation in gene in cms 15 (code for fibrillin)
body prod. Transforming GF beta (TGFb) - doesnt bind normally to fibrillin to keep tgfb inactive —> growth
tall, ling limbed, chest deformed, medical vigilance for bp, weak <3 valves, arterial walls
1/20,000 live births
two main types of cells in connective tissue
FIBROBLASTS - wide distribution in CT; migratory. secrete components of ECM (f + gs)
ADIPOSE (fat cells) - under skin, around organs. store fat (triglycerides)
other cells in connective tissue
- macrophages - phagocytes; fixed (dust cells in lungs, kupffer in liver, langerhans skin) and wandering in CT (sites of infection/inflammation/injury)
- plasma cells - from B-lymphocyte, prod. antibodies. gut, lungs, salivary glands, lymph nodes, spleen
- mast - prod histamine —> dialate vessels. next to bv
- leucocytes - WBC. migrate from blood
embyronic connective tissue
MESENCHYME - gives rise to other all other CT. CT cells (mesenchymal cells) in semi-fluid GS (containing reticular fibres)
MUCOUS - widely scattered fibroblasts embedded in jelly-like GS, supports umbilical cord
lose connective tissue (3 types)
LOSE = many cells, few fibres
AREOLAR (most common) - 3 types of fibres - c, r, e, widely distributed around almost every structure. STRENGTH, ELASTICITY, SUPPORT
ADIPOSE - adipocyte dominant, found w/ aerolar CT, white = energy storage, brown = heat prod. buttocks, flanks, abdomen, eye. INSULATION, ENERGY SOURCE, TEMP. COMTROL
RETICULAR - thin interlacing network of reticular fibres & r cells. stroma or liver, spleen, lympg nodes; RL of BM; around bv and muscles. FORMS STROMA, BINDS smooth mucle to tissue cells, FILTERS & REMOVES worn out bc in speen & microbes in lymph nodes
dense connective tissue (3 types)
DENSE = more fibres, fewer cells
REGULAR - tendons, ligaments, aponeuroses. reg. arranged collagen w/ rows of fibroblasts in between. shiny white, collagen fibres not living. SLOW HEALING, ATTACHMENT BETWEEN STRUCTURES, WITHSTANDS TENSION
IRREGULAR - collagen irregular arrangement w/ few fibroblasts. sheets beneath skin (fasciae), periosteum of bone, joint capsules, mem capsules around kidneys liver testes lymph nodes, heart valves. TENSILE STRENGTH IN MANY DIRECTIONS
ELASTIC - elastic fibres w/ fibroblasts in between, yellowish. lung tissue, elastic arteries, tachea, bronchial tubes, vocal chords. STRETCHING, STRONG
cartilage structure and funtion
dense network of collagen and elastic fibres embedded in chondroitin sulphate
no nerves or blood supply in ECM
strength = collagen; resilience = chondroitin sulphate
chondrocytes (cells of mature cartilage) singly or in groups within lacunae (spaces) ECM
perichondrium (dense irreg. tissue - bv, nerves ) covers cartilage surface
resist tension, compression, shear —> support
precursor to bone
cartilage 3 types
HYALINE - relatively weak resiliet gel, fibres present but not obvious. most abundant; end of long bones, anterior ribs, nose, trachea, bronchi. FLEXIBILIY, SUPPORT, MOVEMENT
FIBROCARTILAGE - chondorcytes w/ clearly visible bundles of collagen fibres, no perichondrium. intervertebral discs, menisci (pads) of knees. SUPPORT, JOINING STRUCTURES TOGETHER, strongest type
ELASTIC - chondrocytes in threadlike network of elastic fibres, preichon. present. ear, lid on larynx (epiglottis), auditoru tubes. STRENGTH, ELASTICITY, MAINTAIN SHAPE
bone tissue (2 types)
BONE = organs composed of several CT types incl. bone tissue
COMPACT - outer layer, forms shaft of long bones, aka cortical bone. made up of rod shaped units - osteons/haversian syst. PROTECTION, SUPPORT, stores calcium and phosphorus
SPONGY - NO osteons, stores triglycerides (yellow marrow), PROD RBC (red marrow)
bone cell types
OSTEOGENIC - mesenchymal stem cells develop —> lay collagen —> trapped —> turn into
OSTEOBLASTS - bone forming cells. more collagen, mineralisation process
OSTEOCYTES - MATURE bone cells from osteoblasts trapped within ECM. maintain bone tissue, exhcange of nutrients and waste, gap junctions
OSTEOCLASTS - large multinucleated cells, formed from fusion of blood monocytes, break down bone, remodel new bone
structure of osteons (haversian systems)
- lamellae - concentric rings of mineral salts (hardness, eg. Ca hydroxide, Ca phosphate —> hydroxyapatite) and collagen (tensile strength).
- lacunae - small spaces between lamellae contain osteocytes
- canaliculi - “minute canals” (EC fluid, process of osteocytes) provide routes for O2 nutrients waste to osteocytes
- central haversian canal - bv, lymph, nerves
liquid connective tissue blood
blood plasma = ECM
formed elements = red cells white cells platelets
formed elements -
erythrocytes transport O2 and CO2
platelets (from megakaryocites in red marrow) for clotting
leukocytes:
neutrophils, monocytes (macrophages) = phagolcytic engulf bacteria
basophils (mobile), mast cells (immature circulate; mature fixed in tissue) = release (eg histamine) that intensity inflammatiry reaction
eosinophils = parasitic worms and allergic response
lymphocytes = immune response
muscle tissue basic structure/function
elongated cells (muscle fibre; myocyte), use energy from hydrolysis of ATP –> generate force. Contraction –> maintain posture, heat, movement
skeletal muscle tissue (basic not striation detail)
striated
contraction = voluntary (except posture spine)
cylindrical fibres
smallest = stapedius (1.25mm) stabilises smallest bones in ear, prevents hyperacusis (bells palsy; sound perception wrong –> loud –> muscle not functioning) transforms noise to auditory sys. vibrations
longest = sartorius (<60cm hip to knee). hip flexor, abductee, lateral rotator.
multinucleate - peripheral nuclei to side
striations in skeletal muscle tissue
myofibrils in sarcoplasm of mf –> striations.
myofilaments (actin & myosin) arranged into sarcomeres - functional unit of myofibril
A band = all filaments, dark
I band = only actin (thin)
H zone = only myosin (thick)
Z discs = centre of I band, made up of actinin protein - link filaments of adj. sarcomeres
M line = middle of sarcomere - holds thick fil. together
Titin = links Z to M –> tension in i
skeletal muscle structure (outside to in)
epimysium = surround whole muscle eg hamstring
perimysium = around fascicles (group of muscle cells. move as units)
endomysium = around muscle fibres (layer for cap./nerves)
sarcolemma = plasma mem
sarcoplasm = cytoplasm
actin myosin etc
cardiac muscle
striated involuntary branched single central nucleus fibres join end-end through intercalated discs (contain gap junctions - communication; desmosomes - adhesion during contraction)
smooth muscle
walls of hollow - intestines, bv walls (constrict)
no striations
involuntary
single central nuclei
short small spindle shaped, thickest in middle, bundles of actin & myosin.
actin attached to dense bodies (actinin - similar to Z)
intermediate fil. n-contractile, attached to dense bodies
contraction = tension –> IF (n-c) –> cell twists, contracts about stable “rods” –> changes diameter of hollow organs (contract = thick, bulging)
nervous tissue (basic + function)
CNS = brain, spinal cord (inc. optic nerve)
PNS = all nervous tissue outside CNS
- sensory/afferent division = intro TO cns
- motor/efferent division = info FROM CNS to ORGANS (muscles, glands)
perception, behaviour, memory
voluntary + involuntary movements
1. sensory - detect internal/internal stimuli –> cns
2. integrative - analysis & storing of info
3. motor - stim. effectors through PNS
neurons
cell body, short branched dendrites convey nerve impulses - input
axon = carries nerve impulse away from neuron –> other neuron/tissue
don’t divide
high metabolic rate (rapid death w/o O2)
types of neurons
MULTIPOLAR 2< dendrites single axon most common in CNS motor neurons some of longest BIPOLAR 1 dendritic process (branch at tip but NOT cell body) cell body between axon & dendrite 1 axon special senses (sigh smell hearing) relay info from receptor to neuron rare, small UNIPOLAR continuous dendrite & axon cell body to side very long like CNS motor nerves most CNS sensory ANAXONIC undistinguishable axon and dentrite rare brain and special sense organs
neuroglia (nervous tissue)
cns & pns 50% of cns - "glue" smaller than neurons but more numerous no AP but communicate still divide in mature nervous sys. PHYSICAL STRUCTURE of nt, REPAIR, PHAGOCYTOSIS, NUTRIENT supply for neurons, reg. INTERSTITIAL fluid in nt
types of cns neuroglia
ASTROCYTES
star shaped, most numerous, largest. syncytium network
support (microfilaments), repair (scar)
communication via gliotransmitters
maintain enviro - reg. ions
maintain blood brain barrier via endothelium - wrap around vessels & influence permeability
OLIGODENDROCYTES
myelin sheath (protein lipid layers)
faster AP
can myelinate 1< cells axon
MICROGLIA
phagocytic, active neuroglia look more plump; inactive small
EPENDYMAL
prod. cerebrospinal fluid; located where CSF is (mechanic buffer; move n&w)
lines CSF filled ventricles in brain & central canal of spinal cord
simple cuboidal w/cilia & microvilli (sample CSF composition)
types of PNS neuroglia
SCHWANN CELLS pns version of oligodendrocyte --> myelin sheath around axon OR support for non myelinated axons; multiple axons same time for support (single axon for myelination) SATELLITE CELLS pns version of astrocytes surround neuron cell bodies. SUPPORT, FLUID EXCHANGE
