lecture 4 Flashcards
what do mucous membranes line
internal tubes which open to the exterior.
i.e. the alimentary tract
the respiratory tract
the urinary tract
what is the mucous membrane made of
in resp and urinary: lumen, epithilium then lamino propria
urinary; lumen, epithilium, lamina propria, muscularis mucosae
SEROUS MEMBRANES description
thin, two-part membranes which line certain
closed body cavities
They envelop the viscera
what do serous membranes line
They line the peritoneum–> abdominal organs.
the pleural sacs –> lungs.
the pericardial sac –> heart.
serosae secrete a lubricating fluid which promotes friction-free movement of the structures they surround
what is the serous membrane made of
simple squamous epithelium –>secretes a watery lubricating fluid.
connective tissue–>attaches epithelium totissues (also carries blood vessels and nerves).
describe parietal and visceral serosa
parietal is outer, lubricating fluid, visceral is inner layer
describe the alimentary canal
oesophagus, stomach, small intestine: duodenum, jejunum, ileum, colon, rectum
how many layers does gut wall have
the mucosa (innermost) the submucosa external muscle layers (muscularis externae) the serosa (outermost).
what is mucosa made of
Muscularis mucosae
Lamina propria (Aggregations of lymphocytes found)
Epithelium
describe submucosa
connective tissue with glands, arteries, veins and nerve
describe muscularis externa
Outer longitudinal layer
Inner circular layer
successive peristaltic waves to move luminal contents along the gut
layers in oesophagus
lumen, mucosa, sub mucosa, muscularis externa, Adventitia – thin outermost layer of connective tissue
epithilium in oesophagus
stratified squamous non-keratinized as it withstands abrasion
describe stomach layers
R = rugae, folds of gastric mucosa forming longitudinal
ridges in empty stomach
M = gastric mucosa (secretes acid, digestive enzymes, and gastrin
MM = muscularis mucosae
SM = submucosa
ME = muscularis externa (3 layers of smooth muscle in stomach; oblique, circular and longitudinal)
describe jejunum
M = jejunal mucosa ( simple columnar epithelium + lamina propria + MM made of inner circular and outer-longitudinal SM = submucosa ME = muscularis externa
Plicae circulares
circular folds of mucosa and submucosa project into gut lumen
colon description (large intestine)
Mucosa; lymphoid tissue, numerous cypts of lieberkuhn
submucosa
Muscularis externa
parts of the respiratory tract
conducting portion: nasal cavity, nasopharynx, oropharynx, larynx, trachea, bronchi, bronchioles, Respiratory portion: bronchioles, aveoli
trachea tissues
E= Epithelium; LP = Lamina propria;
SM = Submucosa with seromucous glands
C shaped cartilage ring
a bronchus tissue
epithilia: pseudo stratified ciliated
smooth muscle
glands in submucosa
cartilage
alveoli tissue
ciliated columnar/ cuboidal and smooth muscle
types of alveoli
Type I cells (squamous) cover 90% of surface area
and permit gas exchange with capillaries
Type II cells (cuboidal) cover 10% of surface area and produce surfactant.
Gas exchange occurs across blood-air barrier.
urinary tract
kidney, ureter, bladder, urethra
tissue of ureter
Transitional epithelium
fibroelastic lamina propria
circular muscularis externa
bladder wall tissue
TE = transitional epithelium. SM = smooth muscle in lamina propria.. ME = muscularis externa (3 interwoven layers).
function of bladder epithilium
Impermeability to urine conferred by thick plasma membrane & intercellular tight junctions.
distention
size of male and female urethra
20cm, 3/4cm
