histology Flashcards
histological features of adipose tissue
-“chicken wire appearance”
-large pale staining central vacuole contains fat droplet
-displaced adipocyte nuclei (off to the side)
histological features of areolar tissue
-loosely arranged collagen and elastic fibers
-interspersed fibrocytes
-many immune system cells with larger nuclei
locations of adipose tissue
breasts, buttocks, deep to the skin, padding around eyes and kidneys
locations of areolar tissue
-within and deep to the dermis of the skin
-covered by epithelial lining of digestive, respiratory and urinary tracts
-between muscles
-around joints
-around blood vessels and nerves
locations of dense regular tissue
-tendons (between skeletal muscle and skeleton)
-ligaments (between bones or stabilizing organs)
-covering skeletal muscles
-deep fascae
functions of dense regular tissue
stabilizes bones, provides attachment and conducts pull of muscles, reduces friction of muscles
histological features of dense regular tissue
-linear arrangement of fibroblast cells with flattened nuclei
-many closely packed collagen fibers
-wave-like arrangement of collagen fibers
location of hyaline cartilage
-between tips of ribs and bones of sternum
-covering articular surfaces of bones
-nasal septum
functions of hyaline cartilage
-provides stiff but flexible support
-reduces friction between bony surfaces
histological features of hyaline cartilage
-“hazy” appearing matrix
-mature chondrocytes lay in lacunae
location of elastic cartilage
-auricle of external ear
-epiglottis
functions of elastic cartilage
-tolerates distortion without damage and returns to original shape
histological features of elastic cartilage
-scant matrix with many dark staining elastic fibers
-chondrocytes lay in lacunae
locations of fibrocartilage
-pads within knee joint
-intervertebral discs
-pubic symphesis
functions of fibrocartilage
-resists compression
-prevents bone to bone contact
-limits movement
histological features of fibrocartilage
-lacunae arranged in clusters or alternate rows
-fibrous matrix with thick collagen fibers
histological features of skeletal muscle tissue
-single, long, multi-nucleated cells, arranged in parallel rows
-obvious striations
histological features of cardiac muscle tissue
-short branching chains of uni- or bi- nucleated cells
-striated
-intercalated discs
histological features of smooth muscle tissue
-single, uni-nucleated, spindle-shaped cells
-non-striated
histological feature of erythrocytes
- Anucleated (essentially no organelles)
- Stain deep pink, owing to protein hemoglobin (Hb)
- “Central pallor,” owing to biconcave disc shape
histological features of neutrophils
-multi-lobed nucleus
-presence of light-staining granules
histological features of eosinophils
-bi-lobed nucleus
-presence of red-staining granules
histological features of basophils
-purple-staining granules that obscure the nucleus
histological features of lymphocytes
-absence of granules
-large, spherical nucleus that takes up most of the cell
histological features of monocytes
-large cell
-lacks granules
-large kidney-shaped nucleus
layers of the artery/vein walls and what they’re composed of (from lumen to outside):
-tunica intima: epithelial tissue (endothelium)
-tunica media: smooth muscle
-tunica externa: dense irregular connective tissue
describe the tunica intima of an artery
-simple squamous epithelia on top of a thin layer of areolar connective tissue
-may appear as crenulated (tight) waves
describe the tunica media of an artery
Thick layer of smooth muscles with interspersed
elastic fibers (wave-like)
describe the Tunica Externa (Adventitia) of an artery
relatively thin layer of connective
tissue (mostly collagen fibers with elastic fibers)
describe the tunica media of a vein
thinner compared to companion
arteries
describe the tunica externa (adventitia) of a vein
may be thicker
than the tunica media
function of a neutrophil
Phagocytosis of foreign cells,
toxins, and viruses
○ Example: A bacterial infection
stimulates the bone marrow to
make more neutrophils
function of an eosinophil
Participate in allergic reactions and
digest parasites
function of a basophil
Granules contain histamine and
heparin.
○ Histamine → promotes vasodilation
and enhances inflammation
○ Heparin → promotes anticoagulation
histamine function
promotes vasodilation and enhances inflammation (in basophil granules)
heparin function
promotes anticoagulation (in basophil granules)
function of a lymphocyte
(B cells): Produce antibodies to
mount immune response against infected
cells
○ Well adapted for fighting a viral infection
function of a monocyte
Leave the bloodstream to
become resident macrophages in tissue;
Phagocytosis of debris, microbes and other
foreign substances
function of thrombocytes
(platelets). Participate in proper blood
clotting
The heart is located in
the _____ of the thoracic cavity
mediastinum
Two-thirds of the heart lies to the left of the…
midsternal line
The heart is covered by an outer covering called
the
pericardium
Pericardium
a double-walled sac
○ Parietal layer
—has both a serous and a
fibrous component.
○ Visceral layer hugs the heart tissue proper
and is known as the epicardium.
epicardium
visceral layer of the pericardium that hugs the heart tissue proper
What is the function of the
pericardium?
The pericardium secretes serous fluid.
The serous fluid reduces friction as the
heart beats within the pericardial cavity.
The coronary circulation
supplies the heart tissue with blood.
What vessels comprise the coronary
circulation?
Vessels that deliver oxygen rich blood to
the myocardium are the coronary
arteries.
Vessels that remove deoxygenated blood
from the heart muscle are the cardiac
veins.
Vessels that deliver oxygen rich blood to
the myocardium are the
coronary arteries.
Vessels that remove deoxygenated blood
from the heart muscle are the
cardiac veins.
From where do the coronary arteries
receive oxygenated blood?
The major arteries of the coronary
circulation arise directly from the aorta
Where does the deoxygenated blood go
after passing through the capillary beds of
the myocardium?
The deoxygenated blood enters the
coronary veins, pools in the coronary
sinus then empties into the right atrium.
What are the consequences of coronary
artery blockage?
Blockage leads to ischemia (substrate and
oxygen deprivation). Prolonged ischemia
can significantly damage heart tissue
resulting in myocardial infarction (heart
attack). The damage caused by the
infarction is not reversible due to the poor
regenerative capacity of cardiac muscle
tissue.
Has a large opening along the superior
aspect of the heart next to the right
auricle (posterior view)
Superior vena cava
Superior vena cava function
Brings deoxygenated blood from the
top half of the body to the right atrium
Inferior and slightly left to the superior
vena cava (posterior view)
inferior vena cava
Inferior vena cava function
● Drains into the right atrium
● Returns deoxygenated blood to the
heart from the lower tissues of the
body
Large and most anterior blood vessel
visible along the superior aspect of the
heart (anterior view)
Pulmonary trunk
pulmonary trunk pathway and function
● Originates at the R ventricle and
branches into the L & R pulmonary
arteries
● Carry deoxygenated blood away from the
heart to the lungs
Next to the left auricle
Pulmonary vein
pulmonary vein pathway and function
● Delivers oxygenated blood from the
lungs into the left atrium
● Four pulmonary veins
● Empty into the left atrium
Arising at the center of the superior
aspect of the heart (anterior view)
aorta
aorta pathway and function
Largest of the blood vessels
● Originates at the left ventricle and
carries oxygenated blood away from
the heart to the rest of the body
● Has three major branches
What are the major arteries that emerge
at the aortic arch?
The main branches of the aorta are the:
-brachiocephalic artery
-left common carotid artery
-and left subclavian artery
● Portion of ventricular myocardium
● Separate left and right ventricle
interventricular septum
Atrioventricular (AV) valves function, and name them
Separate the atria from the ventricles. Have cusps - flaps to prevent the backflow of blood from the ventricle to atrium.
Mitral/bicuspid valve (left) and tricuspid valve (right)
● Chordae tendineae
● Extend from the cusps of the AV valve
● Anchor them to the ventricle walls via
papillary muscles - projections of the
ventricular myocardium.
papillary muscles
projections of the ventricular myocardium that anchor the chordae tendineae to the ventricle walls
How does the left AV valve differ
structurally from the right AV valve?
The left AV valve has two cusps
(called the bicuspid or mitral valve)
● The right AV valve has three cusps
(called the tricuspid valve)
(LAB RAT)
pulmonary valve function
(semilunar) prevents
blood from flowing back into the
right ventricle from the pulmonary
trunk.
do semilunar valves have chordae tenineae? what are their names?
no! aortic valve and pulmonary valve
What are the two layers of the parietal pericardium?
Fibrous and serous pericardium
What is the most anterior great vessel? What is its function?
Pulmonary artery/pulmonary trunk; carry deoxygenated blood to the lungs
To what circuit does each ventricle correspond?
Right ventricle: pulmonary circulation; left ventricle: systemic circulation
What is the structural difference between AV and
semilunar valves?
Semilunar valves lack chordae tendineae (rather, have pocket-like cusps)
What are the three main branches of the aorta?
Brachiocephalic artery; L common carotid artery; L
subclavian artery
What are the 3 layers of the heart wall,
from superficial to deep?
Epicardium, myocardium, endocardium
- Low R-R intervals
- Slow heart rate
Symptoms
* Fatigue
* Lightheadedness
Bradychardia (less than 60 bpm)
- short R-R intervals
- Fast heart rate
Symptoms
* Fatigue
* Lightheadedness
Tachycardia (greater than 100 bpm)
- long p-r interval
- Delay in atrial to
ventricular
depolarization
Symptoms
* Typically
asymptomatic
first degree heart block
- dropped qrs
- Not all atrial
depolarizations lead
to ventricular
depolarization
Symptoms
* Dizziness
second degree heart block
- no relation between p and qrs and t waves
Description - Disconnect between
atrial and ventricular
depolarization
Symptoms
* Dizziness – needs
immediate emergency
attention
complete heart block
- no discernable waves
- No coordinated
electrical rhythm
Symptoms
* Unconsciousness
ventricular fibrillation
histological features of ureter:
-star-shaped lumen
-3 layers (adventitia, muscularis, lamina propria)
-mucosa lined by transitional epithelium
what are the three layers of the ureter from superficial to deep?
adventitia, muscularis, lamina propria
histological features of the bladder:
- Mucosa lined by transitional epithelium
- Thick muscularis composed of 3 layers of smooth muscle (Detrusor muscle)
- Outer layer is a connective
tissue adventitia
epithelia of ureter lumen
transitional
epithelia of bladder lumen
transitional
epithelia of urethra lumen
transitional near bladder, then mostly pseudostratified columnar, then stratified squamous near external urethral orifice
histological features of the urethra:
- Branching lumen
- Mucosa lined by variable
epithelia:
o Transitional epithelium near bladder
o Mostly pseudostratified columnar epithelium
(both males and females)
o Stratified squamous epithelium near external
urethral orifice - Thick lamina propria
supporting the mucosa - Muscularis of smooth muscle
- Adventitia of connective
tissue
histological features of renal cortex
-presence of renal corpuscles and renal tubules
-renal tubules lines w simple cuboidal epithelium
histological features of renal corpuscle
● Outer envelope of simple squamous epithelium called Bowman’s (glomerular)capsule
○ Surrounds a Bowman’s (glomerular) space
● Cluster of varied cells suspended in Bowman’s space is the glomerulus
○ Endothelial cells of the glomerulus
are simple squamous epithelia
○ Endothelial cells are mostly
masked by darker staining oval
nuclei of mesangial cells and
podocytes
● urinary pole of the glomerulus is the
site where the capsular space of the
renal corpuscle gives rise to the
proximal tubule
histological features of the renal medulla
Collection of renal tubules in the
absence of renal corpuscles (glomeruli)
● Loops of Henle and collecting ducts
● Renal tubules lined by simple cuboidal
or simple squamous
● May appear round, oval or
elongated in shape depending on
sectional plane
histological features of the ureter
● Star-shaped lumen
● Mucosa (inner most layer) lined by
transitional epithelium ○ Epithelium sits atop a sparse and paler staining lamina propria of
areolar connective tissue
● Muscularis (middle layer) of smooth
muscle
● Adventitia (outer layer) of pale
-staining
connective tissue ○ Interspersed fat, blood vessels,
and nerves
histological features of the bladder
Mucosa lined by transitional epithelium
○ Epithelium sits atop a thick and
paler staining lamina propria of
areolar connective tissue
● Thick muscularis composed of smooth
muscle
○ Called the detrusor muscle
histological features of the urethra
● Branching lumen
● Mucosa lined by a variety of epithelia depending on the distance from the bladder:
○ Transitional epithelia close to the
bladder ( proximal urethra)
○ Pseudostratified columnar at the
midpoint
○ Stratified squamous near the urethral
orifice
● Three mucosa layers
○ Epithelia sits atop a thick, lighter
staining lamina propria of areolar
connective tissue
○ Muscularis (middle layer) of circular
and longitudinal smooth muscle
○ Adventitia (outer layer) of pale-staining connective tissue
Interspersed fat, blood vessels, and
nerves
histological features of the kidney
Bean-shaped, two variable staining
regions, pale-staining capsule
histological features of salivary glands:
- Collection of secretory cells, adipose tissue
and ducts - Variable staining secretory cells arranged as acini
(clusters)
o Mucus acini
o Serous acini - Ducts lined by simple cuboidal epithelium
what type of muscle is pharynx?
skeletal (voluntary swallowing)
what type of muscle is esophagus?
smooth (involuntary peristalsis)
histology of the esophagus
- Star-shaped lumen
- Mucosa─ contains stratified
squamous epithelium - Submucosa─ composed of
areolar connective tissue;
contains mucus glands - Muscularis externa─
composed of circular and
longitudinal smooth muscle - Adventitia─ composed of
connective tissue
name the specialized cells in the gastric pits of the stomach mucosa:
parietal cells, chief cells, mucous neck cells, and enteroendocrine cells
parietal cells secrete
HCl and intrinsic
factor
chief cells secrete
Inactive enzyme pepsinogen
mucous neck cells secrete
thin mucous
enteroendocrine cells secrete
Serotonin, histamine,
somatostatin and
gastrin
how does epithelia change at the cardiac sphincter?
changes from stratified squamous in esophagus to simple columnar in stomach
histological features of the stomach
simple columnar epithelium at lumen, gastric pits, and gastric glands
histological features of the SI
circular folds and villi, and intestinal crypts in the mucosal layer, and lumen lined by simple columnar epithelia with goblet cells (produce mucus)
histological features of the duodenum
presence of light-staining brunner’s glands (submucosal duodenal glands) that produce alkaline mucus
histological feature of the ileum
dark staining peyer’s patches: lymphatic tissue that protects from pathogens near the ileocecal valve
site of appendix:
cecum
colon parts
ascending (right side), transverse, descending (left side), sigmoid colon (then into rectum)
histological features of the large intestine (colon)
crypts of lieberkuhn; circular and longitudinal muscle layer
