lecture 5 and 6 Flashcards
what do cell junctions do
stick cells together - tight or loose, connected to fibres that make up the cytoskeleton
what do specialised junctions do
speed up the transfer of material between cells
what are tight junctions
seal two cells together, liquid cannot move e.g. skin
what are desmosomes
join cells but have a gap (flexible)
where is epithelial tissue found
surfaces exposed to internal fluids or environment, cover body surfaces and line body cavities e.g. lymph
where is cuboidal epithelium found
lines kidney tubules and ovary surfaces
where is columnar epithelium found
GIT - microvilli lines the surface to help absorption
where is squamous epithelium found
lines blood vessels/air sacs
what is the basement membrane
joins the epithelium to the underlying connective tissue
what is the outer skin layer made of
stratified squamous keratinised epithelium (strength)
what do glands do
secrete chemical products
what do exocrine glands do
secrete products into ducts or tubes - produce mucus, saliva or oils
what do endocrine glands do
secrete hormones into body fluids
what does connective tissue do
binds tissues and have roles in protecting, strengthening, supporting, binding tissues and fat storage
does connective tissue touch each other
generally not in contact, separated by matrix (non-connective) e.g. elastin/collagen fibres which are reticulated
what do fibroblasts do
secrete collagen and elastin fibres - modified polysaccharides
example of something made from CT
the umbilical chord - needs flexibility and strength as it needs to protect vascular connection
5 types of CT
fibrous tissue, cartilage, bone, adipose tissue and blood
what is fibrous tissue made of and where is it found
- made of fibroblasts and the secretions
- found in dense tissues such as tendons and ligaments
what is hyaline cartilage made of and where is it found
its white and found in the nose and ear - elastic present but more in ear than nose
what is fibrocartilage made of and where is it found
has collagen fibres and is found in as pads between load bearing joints e.g. knee
what is bone made out of
matrix of collagen and protein fibres with deposited calcium salts, has strength and rigidity with some flexibility
what is adipose tissue
protection and energy storage, found under the skin for insulation
FATTY TISSUE
role of blood
transports nutrients and gases, regulates temp/pH/salt and has a role in fighting infection
3 substances of blood
- RBC: transport oxygen using haemoglobin
- WBC: fight infection with antibodies or by phagocytosing pathogens
- platelets: cell fragments important in blood clotting
what does muscular tissue do
move parts of body by contraction and relaxation
how do muscles work
filaments of protein (actin and myosin) slide past each other
3 types of muscles
skeletal, cardiac and smooth
characteristics of skeletal muscle
- attached to skeleton by CT (tendon), under voluntary control
- cells with multiple nuclei
- striations (arrangement of actin and myosin)
characteristics of smooth muscle
- lines the digestive system, arteries and uterus and involuntary
- long tapered cells, single nuclei, forms walls of hollow internal organs (stomach)
- moves food with contractions (peristalsis)
characteristics of cardiac muscle
- found in the heart, communication channels ensure muscle cells contract in unison
- branching striated cells with single cells
- end of every cell = intercalated disk which synchronises contraptions and generates heart beat
what are loose junctions
have gaps (gap junctions) - channels
what does nervous tissue do
relays information about conditions in and outside the body
what is nervous tissue made of
neurons and neuroglial cells
what are neurons composed of
cell body (nucleus and cytoplasm, dendrites conduct information, axons conduct nervous impulses away)
what are neuroglia cells composed of
oligodendrocytes, astrocytes, microglial
what do oligodendrocytes do
synthesise myeline sheath around axons which help insulate
what do astrocytes do
supply nutrient and secrete nerve growth factors
what do microglial do
phagocytose cell debris
what is homeostasis
the interactions of internal systems to maintain stable conditions within the body
homeostasis flow chart
stimulus - receptor - regulator - effector - response
muscular system
maintains posture, moves body, generates metabolic heat
skeletal system
supports/protects, acts as attachment points for muscles, stores calcium/phosphorus, site of RBC production
nervous system
detects stimuli (external and internal), controls/coordinates responses, integrates/regulates activities of organs, memory and learning
cardiovascular system
transports nutrients/gases, removes wastes, stabilises temp/pH
digestive system
injects food/water, breaks down food mechanically and chemically, absorbs products of digestion, eliminates indigestible food residues
endocrine system
controls body functions using hormones, integrates with nervous system to control activity
reproductive system
females - produce eggs and forms protective environment for development of new individual
male - produces sperm, transfers to male
lymphatic system
stores WBC, collects excessive tissue fluids, absorbs fat from digestive system
excretory/urinary system
maintains composition and volume of blood, excretes excess fluids, removes wastes from blood and excretes these
