Histology- From Exam 3 to final Flashcards
Why should you not inject drugs into legs of birds?
This is because drugs will be diverted through kidney immediately befoer your drug has had a chance to work. Normally pectoral system is ideal
What is an issue with coelomic epithelium, pronephric or mesonephric epithelium in lower vertebrates?
less efficient
What are the large pink structures indicated with the arrow?
Thyroid follicle ( Hormones are here bound to extracellular pool of protien)
What is the trophic hormones of the pars distalis?
GH, Prolactin, LH, FSH, ACTH
Why is the urinary system important?
Without urinary system their are very limited ways to get rid of wastes.
What is some histological / anatomical differences of reptiles? (Chelonians)
- Have urinary bladder
- Tortoises can collect and reabsorb water ( like a canteen)
- Turtles reabsorb Na + helps with flotation
Why is the urethra surrounded by the external striated muscle sphincter? What kind of muscle is it?
Voiding must be voluntary. Skeletal muscle.
What are the 5 layers of the cornea?
Anterior epithelium
Basement Membrane
Substantia propria ( corneal stroma)
Posterior limiting (descements) membrane
Posterior epithelium ( corneal endothelium)
What is the job of the neurophypophysis?
The site for hormone storage and release. (site of hormone secreting neurons are located in hypothalamus) ( NO SYNTHESIS HERE)
What kind of arteries are found in the glomerulus?
Afferent & efferent arteries
What is a negative feedback mechanism?
Products of stimulated cell inhibit further hormone secretion.
What is paracrine signaling?
Substance is released by cells and affects cells within short distance.
What maintains the ventral portion of the middle ear?
tympanic bulla
What is a common site of hyperplasia/ neoplasia in older horses ( and sometimes dogs)?
adenohypophysis
What is the role of PTH?
Increases blood calcium concentration
This causes bone to activate osteoclasts, intestines to absorb calcuim, and kidneys to block reabsorption of phosphorus and enhance reabsorption of calcium
What can you find in the visceral layer of the bowmans capsule?
Podocytes
What kind of cells are found between glomerular capillaries? What do they do?
Mesangial cells. They are phagocytic
What cell type is found within the thick capsules of the kidney?
mesothelial
What is the arrow pointing to in this image of thyroid gland?
C cells
What is the function of the adrenal medulla?
synthesize catecholamines (epinephrine [adrenaline], norepinephrine [noradrenaline], and dopamine.
What stimulates erythropoetin production in the kidneys?
Decreased oxygen saturation
What kind of glands ( not specific types, just overall) are found in the endocrine system?
Ductless Glands
What are the zones labeled by the numbers in this image?
- ) Zona Glomerulosa
- ) Zona Fasciculate
- ) Zona Reticularis
What is the function of the aqueous humor?
Formed by non-pigmented cells of the ciliary processes
• Nourishes cornea (glucose)
• Maintains intraocular pressure and therefore some of
the ocular shape
- CONSTANT DRAINAGE required
- GLAUCOMA – increase in intraocular pressure
What is gout?
build up of uric acid in tissues. Uric crystals build up and damage not only kidneys but other tissues. Can be caused by dehydration.
What is the tapetum lucidum?
- light reflecting layer that can be of either cellular or fibrous type. This layer is absent in swine and in humans. This light reflecting layer is believe to increase light perception under conditions of poor illumination (superior night vision)
- present in nocturnal animals, especially carnivores, and in some deep sea animals.
What are some histological/ anatomical differences in Bird urinary systems?
Kidney: Cortical (Reptilian)
- Smaller Glomerulus (dense mesangium)
- No loop of henlee
Medullary: Mammalian
- Larger glomerulus with loop of henry
NO RENAL PELVIS
SPINAL NERVES RUN THROUGH KIDNEY
Ureter: Pesudostratified columnar cilliated epithelium
NO URINARY BLADDER (Urodeum in cloaca)
What is cranial nerve 8?
vestibulochoclear nerve
Why is the presence of spinal nerves in the kidneys of birds important clinically?
Kidney disease can cause pressure on nerves and cause issues walking/ paralysis
What are the cells in this image?
Chief cells
Parathyroid gland cells are arranged….
in dense cords/ nests around abundant capillaries
What are hematological indicators of kidney function?
BUN and Creatnine
What hormones does the Adenohypophysis release:?
TSH - Stimulates thyroid to release thyroid hormone (ie. T3, T4)
PRL- acts on mammary glands to stimulate milk production
FSH/ LH : Acts on gonads to stimulated development of gametes.
GH- acts on all body tissue (especially connective tissue) to stimulate growth
ACTH - Acts on adrenal cortex to produce corticosteroids (ie. cortisol)
What is the normal cortex medulla ratio ?
1:1(2):1
What is the function of the ear?
- Collect auditory stimuli
- Transduce the mechanical stimuli
- Transmit nerve impulses to CNS
What is some histological / physical differences of amphibians?
Histological:
- Glomerular line rather than cortex vs medulla
- Hematopoietic tissue in kidney
Physiological:
Nitrogen excreted as:
- Ammonia (aquatic stages/species)
- Urea (terrestrial stages/species)
- Uric acid (arboricoral species – tree frogs)
- Unable to concentrate urine
Plasma= urine (USG not helpful)
Frogs have urinary bladders. Will also void immediately when being lifted.
What is the cell indicated by the black line in this photo?
Ganglion cell (looks like a neuron)
What is this black arrow pointing at?
Residual Rathkes pouch
What is the renal pelvis and what does it become?
Pseudostratified columnar to transitional epithelium
- Becomes the ureter (1 per kidney)
What is this epithelium? Where is it?
Transitional
What is this arrow pointing at?
Parathyroid gland sitting on top of thyroid gland
What are the three tunics of the eye? What can you find in each?
Fiberous tunic (sclera/ cornea)
vascular tunic ( iris, cilliary body, choroid)
Retina (pigmented layer, neural layer)
What cells of adenohypophysis are considered basophils?
- ACTH, TSH, FSH, LH
- Basophilic granules in cytoplasm.
Pars intermedia and pars tuberalis are composed mostly of basophils
What are the different poles of the glomerulus?
Urinary pole: More urine is accumulated in this area
Vascular pole: Area where the cells of the glomerulus meet the surrounding cells.
What is the black line indicating in this image?
Chromaffin cells
What type of cells are present in the thyroid?
Follicular cells ( produce T3/T4 and secretion stimulated by TSH)
Parafollicular cells ( C cells ) which produce calcitonin
What is an indication you are looking at a feline kidney?
Abundant adipose tissue
What are the layers of the urethra?
Mucosa: Transitional epithelium to stratified squamous to skin. Lamina propria
Adventitia: loose connective tissue
Surrounded by external striated muscle sphincter.
What are the layers of the ureter?
Mucosa (transitional epithelium)
- LP often very thin, mucus glands in first bit of ureter in horses
Muscularis (muscular layer)
- smooth muscle (inner longitudinal, middle circular, outer longitudinal (not as distinct)
Adventitia
- Loose connective tissue sometimes with adipocytes.
What is the order from least toxic to most toxic of the product of breaking down nitrogen?
- ) Urea
- ) Uric Acid
- ) Ammonia
What is the brown color caused by in this image?
Uroplakins
What are these arrows pointing at ?
Tubules filled with uric acid (BIRDS CAN DIE FROM GOUT)
What does Renin do? What is the result?
Renin- Cleaves angiotensinogen to result in angiotensin. This will increase blood pressure.
What is the difference between a distal convoluted tubule and a proximal convoluted tubule in the kidneys?
Proximal convoluted has a brush border (microvilli)
Distal Convoluted tubules do not have a brush border
What are hormones?
Chemical messengers produced by endocrine cells and deliver to target cells.
How much hormone is stored within the thyroid follicle?
several weeks worth
What are the arrows pointing at?
A.) Cortex
B.) Medulla
What is important about kidney tissue in amphibians?
Kidney is more important than bone marrow. Their is hematopoietic tissue in kidney.
What is inflammation of the cornea called?
Keratitis
What is the name of epithelium which invaginates into capillaries?
Bowmans capsule
What is some histological / anatomical differences of reptiles? (Snakes)
- Males Sexual segment of kidney
protien + lipid secretion= copulatory plug
regresses with castration (androgen dependent)
- no urinary bladder
What is included in the renal corpuscle?
Glomerulus + Bowman’s capsule + extras
What does the proximal convoluted tubule reabsorb?
- Water
- Protiens
- Electrolytes
** RICH IN FAT IN CATS***
*** LONGER THAN DISTAL CONVOLUTED TUBULES ***
What is produced in the zon fasciculata? What stimulates it?
Production of mineralocorticoids hormones (Aldosterone), which maintain sodium and
potassium levels in extracellular body fluid. Stimulated by ACTH
What do collecting ducts become? What happens at the papilla?
Collecting ducts become papillary ducts. These ducts open onto renal pelvis at the papilla.
- Simple to pseudostratified columnar epithelium