Final Flashcards
What is external respiration
Occurs in the lungs
What is internal respiration
Occurs in peripheral tissue
What are secondary functions of the respiratory system
Voice production, body temperature, regulation, acid base balance regulation, and sense of smell
What is phonation
Voice production that begins in the larynx (voice box) and the vocal cords stretches across lumen of the larynx, vibrates as air passes over them, and produces basic sound of animal’s voice
How is body temperature regulated by the respiratory system
Involves many body systems utilizing superficial blood vessels lining the nasal passages
How does panting affect temperature regulation
It increases evaporation of fluids to cool circulating blood
How does the respiratory system balance acid-base
It influences the amount of CO2 in the blood by the rate of breathing to maintain a normal blood pH of 7.4 (7.35-7.45)
What are the structures in the URT
Nose, nasal passages, sinuses, pharynx, larynx, and trachea
What are the nares
External openings of the respiratory tube that contains nasal passages btw the nares and pharynx
What is the nasal septum
The midline of the nose
What are the turbinates (nasal conchae)
Divide each nasal passages into 3 main passageways such as the ventral nasal meatus, middle nasal meatus, and dorsal nasal meatus
What type of tissue lines the nasal passages and why
Pseudostratified columnar epithelium, cilia, mucus, and blood vessels the modified epithelium aids in filtering inhaled air and the cilia beat up mucus to be coughed up or swallowed
What are the main functions of the nasal passages
Condition inhaled air by warming, humidifying, and filtering the air to reduce trauma and inflammation in the LRT
What are sinuses
Ciliated outpouchings of the nasal passages that are named for the skull bones that house them such as the frontal and maxillary
What is the pharynx
The throat is the common passageway for respiratory and digestive systems that is divided at rostral end by the soft palate and opens at the caudal end into the esophagus and larynx
What is the nasopharynx
The respiratory rostral end of the pharynx that is above the soft palate
What is the oropharynx
The digestive rostral end of the pharynx that is below the soft palate
What is the larynx
Connects the pharynx w/ the trachea, is supported by the hyoid bone, and is made of cartilage segments epiglottis, arytenoid cartilages (2), thyroid cartilage, and cricoid cartilage
What is the role of the epiglottis
Covers the larynx opening when swallowing
Where do the vocal cords attach to
The arytenoid cartilages
What is the role of muscles attached to the cartilages of the larynx
To adjust tension in the cords changing pitch
What are false vocal cords in non ruminants
Second set of CT bands also known as the vestibular folds
What are the functions of the larynx
Part of the upper airway, voice production, prevention of inhalation of foreign matter, and control of airflow to and from the lungs
What is the roaring horse or larpar
Abnormal laxity of one or both sides of the larynx
What is the trachea
Short wide tube of fibrous tissue and smooth muscle held open by cartilage rings that extends from the larynx into thorax at base of heart where it is then referred to as the tracheal bifurcation
What is the purpose of the trachea’s C-shaped rings
To prevent collapse during inhalation
What are the structures of the LRT
Bronchial tree broken up into the bronchi, bronchioles, and alveolar ducts and the alveoli
What are the bronchi
The 2 main stems that are covered in smooth muscle
How does the ANS control the diameter of the bronchi
By adjusting the muscle fibers in their walls causing either bronchodilation or bronchoconstriction
What does spasms of bronchoconstriction result in
Asthma
What are the alveoli
Tiny thin walled sacs surrounded by capillaries, their sacs are lined w/ a thin layer of fluid that contains surfactant, and this is where external respiration takes place in alveoli
What is surfactant
Lowers the surface tension at the air/liquid interface and prevents alveolar collapses at the end of respiration
What is the alveolar membrane or the gas/blood barrier
The walls of the alveolus that has simple squamous epithelium, goes to its basement membrane, goes to the walls of the capillaries consisting of the endothelium, to its basement membrane
How is each lung lobe attached to each other
By its root and pulmonary ligament
What are characteristics of a normal lung
Elastic, contains considerable amount of air, light in weight, floats in water, soft & spongy, crepitates when squeezed, and pale pink in color
How are lobes distinguished externally and internally
Externally by visible grooves and clefts and internally by major branches of bronchi
What is the basic lung pattern across most species
3 lobes in the left lung (cranial, middle, and caudal) and 4 lobes in the right lung (cranial, middle, caudal, and accessory)
What lung lobes are missing in horses
The medial lung lobes
What is the hilus
Small well defined area on medial side where air, blood, lymph, and nerves enter/leave the lung
What is the pleura
Thin glistening serous membrane arranged in 2 sacs w/ a space btw them (mediastinal space)
What is parietal pleura line
The mediastinum and the walls of the thorax
What intrapleural space
The space btw the parietal and visceral pleura
Why does the intrapleural space contain a small amount of serous fluid
To allow frictionless motion of the lungs
What is the thorax bounded by
The thoracic vertebrae, ribs, intercostal muscles, and sternum
What are the main contents of the thorax
Lungs, heart, large blood vessels, nerves, trachea, esophagus, lymphatic vessels, and lymph nodes
What is the mediastinum
Portion of the thorax btw the lungs
What is contained in the mediastinum
Heart, trachea, esophagus, blood vessels, nerves, and lymphatic structures
What is the cranial mediastinum
Part of the mediastinum cranial to the heart
What is the middle mediastinum
Part of the mediastinum containing the heart
What is the caudal mediastinum
Part of the mediastinum caudal to the heart
What is the diaphragm
Thin sheet of skeletal muscle that forms the caudal boundary of the thorax and acts as a respiratory muscle
What are the functions of the negative intrathoracic pressure
Provides a partial vacuum pulling the lungs tightly out against the thoracic wall, allows the lungs to follow movements of the thoracic wall/diaphragm, and aids in return of blood to the heart
How is inspiration an active process
Muscles cause thoracic cavity to enlarge increasing the volume leading to a drop in pressure drawing air in
Why does air flow in the lungs during inspiration
Because pressure w/in the lungs becomes lower than the atmospheric pressure
Why does air flow out of the lungs during expiration
Because the intrapulmonic pressure exceeds the atmospheric pressure at the time
What is respiratory frequency
Number of respiratory cycles per minute
What can affect the respiratory frequency
Body size, age, exercise, excitement, environmental temperatures, pregnancy, degree of filling of the digestive tract, and state of health
What happens when expansion of the lungs are restricted
Adequate ventilation is maintained by increased frequency
What is tidal volume
Volume of air inspired and expired in one breath
What is minute volume
Volume of air inspired and expired in one minute
What is residual volume
Volume of air remaining in the lungs after full exhalation
What is hemoglobin
The principle component for oxygenation in RBCs it is composed of 4 heme groups combined w/ one molecule of globin, each heme group contains an iron atom that combines w/ 1 oxygen molecule
What things affect the oxygen carrying capacity of an erythrocyte
Change in pH (decrease), change in CO2 concentration (increase), change in blood temperature (increases), nitrate poisoning, and carbon monoxide poisoning
What does exchange of gases depend on
Ventilation, diffusion, and blood flow in pulmonary vessels
How does nitrate poisoning affect the oxygen carrying capacity of an RBC or Hb
The heme is oxidized to its ferric state so it can’t carry O2 and is referred to as methemoglobin
How does carbon monoxide poisoning affect the oxygen carrying capacity of an RBC or Hb
Carboxyhemoglobin is formed because CO occupies the site normally occupied by oxygen and Hb has a much greater affinity for CO than for O2
What is partial pressure
Pressure of each individual gas
What part of the brain controls breathing
Medulla oblongata
How is the mechanical control system for breathing controlled
Thru stretch receptors in the lungs
What is the mechanical process of breathing
Nerve impulses sent to the respiratory center indicate when lungs inflate to certain point, muscle contractions that produce inspiration are stopped, muscle contractions to produce expiration are initiated, another set of nerve impulses is sent when the lungs deflate to a certain point, and expiration is stopped beginning the process of inspiration again
What is the chemical control system of breathing
When the system affects breathing pattern when something in the body is out of balance this is monitored by chemical receptors in the carotid artery, aorta, and brain stem that monitor CO2 content, pH, and O2 content
What does slight hypoxia trigger
The respiratory center to increase rate and depth of breathing
What does severe hypoxia trigger
Neurons of respiratory system becomes so depressed that impulses cannot be sent to respiratory muscles and can cause breathing to decrease or stop completely
What are metabolic waste products
Potentially harmful substances to the body that must be eliminated
What are routes for waste product elimination
Respiratory system (CO2 and water vapor), sweat glands (water, salts, and urea), digestive system (bile salts and pigments), and urinary system (urea, salts, water, and other soluble waste products)
What is the urinary system
Single most important route for removal of waste products removing nearly all soluble waste from the blood, transports soluble waste out of the body, and the major route for elimination of excess water
What are the parts of the urinary system
Kidneys, ureters, urinary bladder, and urethra
What are the functions of the kidneys
Maintenance of homeostasis through blood filtration, reabsorption, and secretion, fluid balance regulation w/ ADH and aldosterone, acid base balance regulation, production of hormones such as erythropoietin and prostaglandins, and BP regulation
What are the kidneys surrounded by
Perirenal fat
What is the renal pelvis
Pelvis receives urine from ducts and transmits urine to the ureters and is expanded at the proximal end of the ureters
What are the kidneys incapsuled in
A fibrous connective tissue
What is the renal cortex
The outer layer of the kidney parenchyma beneath the capsule
What is the renal medulla
The inner layer of the kidney parenchyma projecting into the renal pelvis w/ one or more papillae that contains collecting ducts and nephric loops
What is the renal papilla
The apices of the renal pyramids (kidney lobule)
What is the calyx
Funnel shaped to direct urine into the renal pelvis
What is a nephron
The basic functional unit of the kidney the number of these varies w/ the size of the animal that is composed of the renal corpuscle, proximal convoluted tubule (PCT), loop of henle, and distal convoluted tubule (DCT)
What is the renal corpuscle
Located in the renal cortex it is a dilated origin of a renal tubule w/ a tuft of capillaries that contains a glomerulus surrounded by the Bowman’s capsule
What is the function of the glomerulus
Filters blood in first stage of urine production forming the glomerular filtrate about 20% of substances are reabsorbed here
What is the proximal convoluted tubule
The continuation of capsular space of Bowman’s capsule where the glomerular filtrate is now called the tubular filtrate, it is lined w/ cuboidal cells, concentrate and excrete waste products from the blood into the tubular lumen
Why is the PCT lined w/ cuboidal cells
Because most substances are reabsorbed here including 85% of the salt and water, 80% of the bicarb, glucose, and AA
What is the loop of henle
A continuation from PCT, descends in the medulla, makes a U-turn, and heads back into cortex, the ascending wall becomes thicker again, and contains the most concentrated urine w/ the highest concentration at the lowest end of the loop
What is the distal convoluted tubule (DCT)
The continuation of ascending loop of Henle that empty into the collecting ducts in the renal pelvis, is the primary site of ADH action, and regulates the potassium and acid base balance
How does the SNS alter kidney function
It can stimulate vasoconstriction of renal vessels to temporarily decrease urine making
How does the renal artery change as it enters the hilus
Subdivides to become series of afferent glomerular arterioles
How are peritubular capillaries organized in the kidney
They run down w/ the nephron collection down to the loop of Henle where oxygen transfers to cells of nephron
At what level does tubular reabsorption and tubular secretion occur at
At the peritubular capillaries
What are the mechanisms of renal action
Filtration of the blood, reabsorption of useful substances back into the bloodstream from urine, and secretion of waste products
Where is the blood filtrated
Occurs in renal corpuscle
How is the blood filtered in the nephron
High BP in the glomerular capillaries forces some plasma into the capsular space of Bowman’s capsule forming the glomerular filtration rate (GFR) that depends on the rate of blood flow to kidney
What does the kidney reabsorb from urine
Useful substances such as Na, K, Ca, Mg, glucose, AA, Cl, bicarbonate, and H2O are absorbed from the tubules of the nephron to the peritubular capillaries
What is secreted in the DCT
Waste products such as H, K, and ammonia are eliminated along w/ some medications
How is the urine volume regulated
It is determined by the amount of water contained in tubular filtrate when it reaches the renal pelvis that is controlled by actions of ADH and aldosterone
What happens if ADH is absent
Polyuria occurs resulting in diabetes insipidus
What is the purpose of ADH
Increasing the reabsorption of water from the DCT and collecting ducts so low osmotic pressure of dilute blood inhibits the release of ADH from the pituitary gland and high osmotic pressure stimulates the release of ADH
What other drugs or stress chemicals stimulate the release of ADH
Acetylcholine, nicotine, adrenaline, and barbiturates
What is the purpose of aldosterone
Increases the reabsorption of water due to active reabsorption of Na in DCT and collecting ducts stimulating the cells to reabsorb Na
How is water retained in the nephron under normal conditions
80% is retained in the PCT, 5% is reabsorbed in the loop of Henle, and 15% is influenced by ADH or aldosterone
What are the steps of the kidneys maintaining BP
RAAS system responds when blood pressure falls, renin is released and splits enzyme angiotensin, increased amounts of Na and water reabsorbed back into bloodstream causing an increase in blood volume, and as blood volume increases so does BP
What are the ureters
Tubes that are a continuation of the renal pelvis that exits the kidney at the hilus and then connect to the urinary bladder that
What is the trigone
Arrangement of openings of ureters into the bladder and opening from bladder into the urethra
What are the 3 layers of the kidney
Outer fibrous layer, middle muscular layer that propels urine by peristalsis, and inner epithelial layer that allows ureters to stretch when urine passes thru
Why do the ureters enter the bladder at an oblique angle
So the openings collapse when the bladder is full to prevent backup of urine into the ureters
What are ectopic ureters
Ureter that terminates some place other than the urinary bladder resulting in urinary incontinence
What is the bladder
Stores urine as it is produced releasing urine periodically from the body it is composed of a muscular sac (apex) and neck (trigone)
What is the detrusor muscle
Smooth muscle that is the sac of the bladder that contracts to expel urine
What provides voluntary control over the urination process
The circular sphincter that is around the neck of the bladder
What is urination
Micturition/uresis is the expulsion of urine from the urinary bladder into the urethra for elimination from the bladder
What are the 3 steps of urination
Urine accumulation, detrusor muscle contraction, and sphincter muscle control
What type of receptors are in the bladder
Stretch receptors signal when it is full
What happens when the involuntary bladder muscles contract
After the spinal reflex is activated the motor impulse is sent to detrusor muscle contracting the smooth muscle in the bladder wall if the animal is not potty trained this is when the bladder empties
What happens when the voluntary bladder muscles are being stimulated
Voluntary control of sphincter around the neck of the bladder offers temporary control of urination, the fuller the bladder the more pressure on the sphincter muscle, eventually the sphincter muscle relaxes, and urine is released
What is the urethra
Continuation of the neck of the bladder that carries urine from the bladder runs thru the pelvic canal and to the external environment
What are characteristics of female urethras
Shorter and straighter, opens on floor of vestibule of the vulva, lined w/ transitional epithelium allowing it to expand, and strictly a urinary function
What are characteristics of the male urethra
Longer and curved, runs along the ventral aspect of the penis, lined w/ transitional epithelium allowing it to expand, and has both urinary and reproductive functions
What are things that can cause urinary incontinence
Hormone responsive, polyps or tumors, ectopic ureters, uroliths, and spinal injury
What is a blocked cat
When the urethral outflow is obstructed due to urolith or mucus lodge in the urethra
Where does spermatogenesis occur
In the seminiferous tubules of the testes
Where are androgens produced
In the Cells of Leydig of the seminiferous tubules
What is the band of CT that attaches the testes to the scrotum
Gubernaculum
What are the 2 layers of CT that surround the testes and spermatic cord
The visceral vaginal tunic (proper vaginal tunic) and parietal vaginal tunic (common vaginal tunic)
What is the tunica albuginea
Fibrous connective tissue capsule that encloses each testis divided into tiny lobules by the septa
What is the rete testis
Connects the seminiferous tubules w/ the ductus deferens
What is the sertoli cells
Support developing spermatids and shield from body’s immune system
What are the 2 portions of the male urethra
The pelvic and penile
What is the purpose of accessory reproductive glands
To produce an alkaline fluid to help counteract acidity of female reproductive tract this fluid is filled w/ electrolytes, fructose, and prostaglandins
What are the 3 accessory reproductive glands
Seminal vesicles, prostate gland, and bulbourethral glands
What is the only species that does not have bulbourethral glands
Dogs
What does the penis comprise
Muscle, erectile tissue, connective tissue, a large blood supply, and many sensory nerve endings
What are the 3 main parts of the penis
Roots, body, and glans
What are the roots of the penis
2 bands of crura that attach the penis to the brim of the pelvis
What is the body of the penis
Corpus cavernosum contains 2 bundles of erectile tissue w/ sinuses that engorge w/ blood and the corpus spongiosum
What is the glans
Distal end of the penis w/ numerous sensory nerves
What is the prepuce
Sheath of skin that encloses the penis when it is not erect
What is phimosis
Stricture of the preputial orifice
What is the paraphimosis
Protrusion of the penis through a constricted preputial orifice and the inability to retract it
What is the sigmoid flexure
Present in bulls, bucks, rams, and boars where the erection results from straightening the S shape of non erect penis
What pulls the penis back into the prepuce after erection in the sigmoid flexure species
The retractor penis muscle
What is the suspensory ligament
Attaches the ovary to the retroperitoneum
What is the mesosalphinx
Supports the oviduct
What is the round ligament
Attaches the uterine horn to the inguinal ring
What is the corpus luteum
Temporary endocrine gland from ovulated follicle
What is a primary follicle
Immature oocyte surrounded by single layer of flattened follicular cells
What forms around a growing follicle and why
Glycoprotein zona pellucida layer to protect during fertilization by preventing polyspermy, protects blastocyst, and prevents premature implantation
When is the antrum formed
During the growing follicle phase
What forms around the zona pellucida in a mature follicle
Corona radiata it supplies proteins to the ovum
What is the corona radiata surrounded by
The cumulus oophorus
What species are induced ovulators
Cats, rabbits, and ferrets
What is follicular atresia
When a follicle does not fully develop this can occur at any stage of development
What catches the ova
Fimbriae in the infundibulum
What are the 3 layers of the uterus
Endometrium, myometrium, and perimetrium
What type of suture is used w/ uterine prolapse
Buhner
