Test 2 (Lectures 5-8) Flashcards
what is an animal with single true stomach
monogastric
examples ruminants
deer, moose, cows, sheep, goats
examples of monogastrics
horses, cats, dogs
ruminants have 4 stomachs what are they
- reticulum
- rumen
- omasum
- abomasum
5 digestive organs in order
- mouth
- esophagus
- stomach
- small intestine
- large intestine
the small intestine includes what 2 other organs
liver and pancreas
do carnivores have mouth enzymes to breakdown food
no
herbivore
plant eater
Carnivore
meat eater
Omnivore
both plants and meat eater
the start of food breakdown is what
Food is typically chewed
what are Herbivore teeth designed for
designed for grinding plant material
what are Carnivore teeth designed for
tearing and biting
what are Carnassial teeth
shearing and cutting flesh
what are Omnivore teeth designed for
- flat teeth at the back for grinding
- sharp teeth at the front for tearing and biting
carnivores genrally have what kind of teeth
a high number of highly curved teeth
herbivores genrally have what kind of teeth
have teeth with flat occlusal surfaces
Omnivores genrally have what kind of teeth
sharp and flat
the process of chewing is called
mastication
what enzymes aid in pre-digestion of food in the oral cavity
amylase
lipase
what does amylase aid in
breakdown of starch
which enzyme is present in carnivores
amylase
what is bovine
cow saliva
how much saliva do cows produce per day
25-50 gallons
when is lipase normally present orally
in animals on a high milk diet
what is the esophagus
Is a muscular tube connecting the oral cavity with the stomach
the esophagus is _____
multi-layered
the esophagus is made up muscles what do the two different muscles do
outer longitudinal muscles: shorten and contract
circular layer: constricts
peristalsis occurs in the esophagus what is it
coordinated effort of squeezing and stretching, simultaneously, results in rhythmic contraction
how long does it take for food to move from the mouth to the stomach
20-30 seconds
what controls the reflux
a sphincter muscle at the stomach end of the esophagus
ruminants esophagus operates how
bi-directionally
which is the smallest part of the stomach
reticulum
when smaller digesta or liquid particles enter the reticulum where do they move
to the omasum
when large particles enter the reticulum where do they move
into the rumen for further digestion
the reticulum traps specific things what are these specific things
- heavy dense object that the animal consumes (metal)
how many L does the reticulum hold?
19 L
which two stomachs are considered the same
the rumen and reticulum are considered one organ
reticulorumen
small muscular fold of tissue separating the rumen and reticulum
the structure of the rumen is what
a series of muscular sacks
the main purpose of the rumen is
fermentation
what does anaerobic mean
no oxygen
what gases are produced in the rumen
- carbon dioxide
- methane
- hydrogen sulfide
the rumen and reticulum combined make up how much volume of the stomach
84%
how many L does the rumen hold
150 L
what shape is the omasum
spherical
how does it connect to the reticulum
by a short tunnel
the omasum is made up of what
muscular folds
the omasum has muscular folds which do what
the surface area, which increases the area that absorbs nutrients from feed and water
the main 3 purposes of the omasum
- Breaks down food and conveys it into the abomasum
- Removes excess fatty acids and bicarbonate ions
how many Ls does the omasum hold
57 L
the abomasum is the _____ stomach
true
what does the abomasum produce?
- hydrochloric acid
- digestive enzymes
what is an example of a digestive enzyme and what does it do
- pepsin
- breaks down proteins
what does the abomasum receive and from what
- digestive enzymes secreted by the Pancras
the secretions form the Pancras into the abomasum do what
secretions help prepare proteins for absorption in the intestines
there are chief cells in the abomasum what do they do
secrete mucous to protect the abomasal wall from acid damage
how many L does the abomasum hold
26 L
B12 vitamens do what
- help with DNA production
- keep nerve cells healthy
B9 vitamens do what
- efficient use of iron
- make red blood cells
the monogastric stomach main function is to
Digestion of simple carbohydrates only
the monogatric stomach lining produces what 3 things
- mucous
- hydrochloric acid
- enzymes
all the energy gained from food goes where
released into the blood stream excluding the energy used to walk, drink etc
how long is the small intestine
2.5 times the length of the animals body
what happens in the small intestine
absorption of almost all nutrients into the blood occurs
in the small intestine what happens to the food
- exposed to enzymes and bile
- this converts the food to even smaller particles capable of being absorbed into the blood
what else does the small intestine absorb
- water
- electrolytes
- other molecules
3 parts of the small intestine
duodenum, jejunum and ileum
the duodenum is short or long
relatively short
what other 2 organs are attached to the duodenum
pancreas and gall bladder by the pancreas and gall bladder ducts
which is the longest part of the small intestine
the jejunum
what things are in the jejunum
finger-like projections called villi
after food contents have been through the jejunum what happens
contents of the jejunum empty into the ileum and from there pass into the large intestine
what do villi do
protrude inward into the food contents and provide a large surface area to absorb nutrients
what drug affects the small intestine
antibiotics
what can cause diarrhea
under-active small intestine rather than an over-active one
what compounds can affect intestinal activity
hormones
what is bile
a fluid
essential for digesting food in the
stomach and intestines
what does the bile duct do
transports bile from liver to the gall bladder and then into the small intestine
what is the gall bladder
storage receptacle for bile
how does the liver function
in the secretion of the bile
what does insulin do
Insulin allows glucose in bloodstream to leave and enter cells
what thing breaks down into glucose and then enters the blood stream
carbohydrates
the pancreas does what 2 things
- Produces insulin which regulates glucose in the body
- Produces digestive enzymes to help digest food
protease
breaks down protein
what is the protein called in dogs
trypsin
lipase
breaks down fat
amylase
breaks down carbohydrates
do humans have a cecum
NO
what is the cecum
secondary fermentation system
what are the four parts of the large intestine
cecum
colon
rectum
anal canal
what is the longest part of the large intestine
colon
3 parts of the colon
ascending, transverse and descending colon
main function of the colon
recover water from feces as needed to keep hydration levels consistent
secondary function of the colon
store fecal matter awaiting passage from the body
the rectum has 2 types of sphincter muscles
internal and external sphincter muscles
internal sphincter muscles are under ______ control
autonomic
external sphincter muscles are under ______ control
voluntary
what are structures external to the lungs are known as
upper respiratory tract
what are structures internal known as
lower respiratory tract
when do the respiratory and digestive tract come in contact
the back of the throat
upper resp tract consists of
nose mouth pharynx larynx trachea
where is air drawn into the lungs
through openings in the nose called nostrils
when is the sense of smell activated
As air passes over the back portion of the nose
what are the nasal passages seperated by
nasal septum
what happens in the nasal passages
warm, filter and humidify incoming air
where is the olfactory region located
in the back of the nasal cavity
the olfactory region has a mucous membrane which contains what
special nerves designed for smell
do dogs have sweat glands
No except for on their feet
how do dogs cool down?
by panting
how does panting cool a dog down
By breathing faster, warm air is exchanged from the body for the cooler outside air.
what specific things are found in the nasal cavity
Cilia and mucous
Cilia and mucous in the nasal cavity do what
trap and remove materials that otherwise might be inhaled
what are sinuses and where are they found
in various pouches in various skull bones within the nasal passage and they do the same thing as the Cilla
dogs have how many sinuses and what are they called
2
frontal and the maxillary
other sinus possibilities
sphenoidal and ethmoida
why do sinuses become irritated or swollen
infection, allergies, or cancerous conditions
swollen and irritated sinuses is a general condition referred to as
sinusitis
what meds can be used to treat sinusitis
antibiotics and deconges
where do the nasal passages lead into
pharynx
the pharynx is also called the ______
throat
the pharynx is also a part of the _______ system
digestive
what does the larynx contain
many segments of cartilage, connected by muscle
what is the larnyx held in pace by
the hyoid bone
how many cartilage components make up the larynx
varies between animal species
what is the most important cartilage component of the larynx
epiglottis
what happens when an animal swallows
the epiglottis is normally pulled back to cover the opening of the larynx
the larynx has 3 functions what are they
- makes sounds
- prevents materials from entering the lungs
- controls the flow of air into and out of the lungs
the trachea is a _____ and _____ tube
The trachea is a short, wide tube
what keeps the trachea open
hyaline cartilage rings
structure of the trachea
a tube of fibrous tissue and smooth muscle
what is the trachea’s lining similar to
that of the nasal passage
what helps with the removal of trapped materials
Cilia and mucous
how can you clear the trachea
by coughing
what tube like structure enters the lungs on either side
bronchi
where are the lungs located
located above the diaphragm
what is the diaphragm
a sheet of muscle separating the abdominal and thoracic cavity
another word for branches
bifurcates
the right and left bronchus divide into what
- bronchioles
- alveolar ducts
- group of alveoli
what is surfactant
a substance in the alveoli that promotes gas exchange by reducing surface area tension
what is the structure of the alveoli
small, thin-walled sac
what are the alveoli responsible for
for the exchange of respiratory gases
the respiratory gases are what
oxygen and carbon dioxide
what are the alveoli surrounded by
capillary bed of branches from the pulmonary arterioles and venules
what covers the various organs of the thorax and also lines the thoracic cavity
pleural membrane
the pleural membrane has 2 layers which are called what
visceral layer and the parietal layer
the space between the visceral layer and the parietal layer is filled with what
pleural lubricating fluid
what is the tidal volume
is the volume of air taken in and expelled during one respiratory cycle of breath
what is the minute volume
the volume of air taken in and expelled during one minute
how is gas exchange during respiration controlled
by the process of diffusion
what is the residual volume
the volume of air remaining in the lungs after a maximum expiration
how much oxygen and carbon dioxide is present in inhaled air
21% oxygen
0.03% carbon dioxide
The alveolar capillary bed contains what (levels)
relatively low levels of oxygen and much higher levels of carbon dioxide
how does oxygen typically diffuse
from alveolar air into the blood of the alveolar capillary bed
how does carbon dioxide typically diffuse
in the opposite direction of oxygen
where is the respiratory centre of the brain
located in the medullary oblongata
what does the respiratory centre of the brain do
control the respiratory muscles at a subconscious level
can the autonomic system (breathing) be overridden
yes consciously
how is normal breathing maintained
a mechanical control system with stretch receptors in the lungs
what is Agonal breathing
not enough oxygen from breathing to support the brain
what does Agonal breathing lead to
lends to unconsciousness
during Agonal breathing what is not happening
it is not actually oxygenation happening at all
what do Chemical receptors in blood vessels do
monitor physical and chemical blood constituents
what are chemical blood constituents
oxygen, carbon dioxide and blood pH
what happens after the chemical control system monitors these levels
signals the respiratory centre to modify the breathing process in an attempt to maintain homeostasis
what do senses allow the animal to do
to monitor what is happening both internally and externally
what are sense organs an extension of
central nervous system (CNS)
what do all senses contain
modified nerve endings called sensory receptors
what happens when the sensory receptors receive stimuli
nerve impulses are sent to the CNS
3 types of mechanical senses
- touching
- hearing
- balance
2 types of thermal senses
- hot
- cold
1 type of Electromagnetic senses
- vision
2 types of chemical sense
- Taste
- smell
visceral sensations are generally _____ and poorly ______
visceral sensations are generally vague and poorly localized
what kind of stimuli trigger visceral sensations
chemical or mechanical
why is the GI tract sensitive to pain
because of stretch receptors
which organs are less sensitive to pain
bladder and other hollow organs
the pleura and peritoneum have lots of what which can lead to what
sensory receptors which can lead to pleuritis or peritonitis being very painful
what is touch monitored by
receptors
2 types of receptors
superficial and central
what kind of receptors are found in the skin
superficial receptors
superficial receptors in the skin do what
generate nerve impulses when the external temperature is either too hot or too cold
what monitors the “core” body temperature and how
- Central temperature receptors
- by monitoring the temperature of the blood
where are the Central temperature receptors located and how do we get to them?
- hypothalamus
- obtained rectally
how is temperature control achieved (5)
- blood flow
- piloerection
- sweating
- shivering
- thyroid hormones
taste is also called what
Gustatory sense
what are the taste buds of the tongue called
papillae
where are the majority of last receptor located
on the sides of the taste buds
how do we pick out a taste (substances, triggers)
- Dissolved substances enter the taste buds and contact the sensory receptors
– this contact triggers a nerve impulse that travels to the brain where it is interpreted
where could other taste receptors be found
lining of the mouth and throat
which animals have greater developed olfactory senses
dogs and bear
nasal passages are more important in which species
animals over humans
where is the sense of smell localized
in two areas or patches of olfactory epithelium located dorsally in both nasal passages
what happens when odors dissolve in the mucus
they stimulate sensory areas on olfactory hairs, or cilia, and generate nerve impulses
what olfactory cells project into the mucus layers and cover the surface of the epithelium of the nasal area
Hair-like processes
how do we hear
Converts vibrations of air molecules into nerve impulses
what are the 3 functional areas associated with hearing
external, middle and inner ear
where the 3 parts of the ear found
within the temporal bones of the skull
what does the external ear do
Collects sound waves and vibrations
what makes up the external ear
- pinna
- external auditory canal
- tympanic membrane (eardrum)
what is the tympanic membrane made up of
a thin layer of connective tissue
what happens when sound waves hit the tympanic membrane
cause it to vibrate at the same frequency and transmit these vibrations to the middle ear
the pinna collects and funnel vibrations into
the external auditory canal called the vertical and horizontal ear canal
what is the vertical and horizontal ear canal
soft membrane-lined tube the ends at the tympanic membrane
what does the middle ear do
Amplifies and transmits vibrations
what links the tympanic membrane with the inner ear
Three small bones called ossicles
name of the 3 small bones
- malleus (hammer)
- incus (anvil)
- stapes (stirrup)
what do the ossicles do
act as a system of levers that transmit the sound wave vibrations from the tympanic membrane to the cochlea
where is the stirrup attached
to the membrane that covers the oval window of the cochlea
what does the inner ear do
Contains sensory receptors that convert vibrations to nerve impulses
where is the hearing portion of the inner ear contained
in a cavity of the temporal bone called the cochlea
what is the receptor organ of hearing filled with and what does it run along
- endolymph
- runs the length of the cochlea
receptor organ of hearing is also known as
the organ of corti
The receptor cells of hearing consist of what
hairs that also run the length of the organ of corti
when bending sensory hairs what happens
generate nerve impulses that in turn are sent to the brain
what does the eye contain to help detect images and generate visual nerve impulses
photoreceptors
what are the photoreceptors made up of
a single layer of cells
where are the photoreceptors located
in the retina at the back of the eyeball
3 layers of the eyeball
- outer fibrous
- middle vascular
- inner nervous
what does the outer fibrous do
admits light and gives shape and strength to the eye
what is the outer layer composed of
cornea and sclera
what is the cornea
a transparent window that admits light and contains collagen fibres
what doesn’t the cornea contain
blood vessels
what does the eye also contain
pain receptors
what is the
the largest component of the outer eye
what is the sclera
- the white of the eye
- is a dense fibrous connective tissue
5 parts of the female reproductive system
- Ovaries
- Uterus
- Vagina
- Vulva
- Mammary glands
where are ovaries suspended from
the top of the abdomen
what are the ovaries suspended by
a broad ligament called the suspensory ligament
what are oviducts
small tubes that extend from the ovaries to the uterine horns
the funnel-like structure, found at the end of the oviduct nearest the ovary is called what
the infundibulum
what does the infundibulum do
catches the egg (ovum) when it is released from the ovary
what shape is a cat uterus
Y shape
which part of the Y is longer
arms of the Y are longer
what are the arms of the Y and the stem of the Y called
arms: horns
stem: body
what do the uterine horns do?
extend from each ovary and join to form the body of the uterus
what happens when a female gets pregnant (fetuses)
the fetuses are arranged in a row in both horns
what is the very tip or base of the Y called
cervix
what are the walls of the uterus lined with
- vascular and glandular lining called mucosa
- smooth muscles
what is the muscular substance of the uterus called
myometrium
what is the inner lining of the uterus called
endometrium
what are mammary glands composed of
connective tissue
the connective tissue in the mammary glands does what
provide support and structure, blood vessels, lymphatic vessels and glandular tissue
what do mammary glands contain
small saclike glands that secrete and store milk
how does milk travel in the glands
Milk eventually travels through a duct system to empty into the teat
how many PAIRS of mammary glands does a cat have
4
what are the ovaries located behind
kidney’s
the cervix separates what
the uterus from the vagina
when is puberty/sexual maturity is reached
6 months in GENERAL
small breeds can get there first estrus cycle when
earlier than 6 months
large breeds can get there first estrus cycle when
18 month - 2 years of age
how often do dogs come into heat
2 times a years or once every 6 months
how long does heat last
2-3 weeks
what will happen first when a dog goes into heat
swelling or engorgement of the external vulva
what can happen with a breeding queen
Queens can be bred by more than one male during a heat period, resulting in kittens from the same litter with different sires.
gestation period for dogs and cats
63 days
cats are considered
induced ovulators
what does induced ovulators mean
the act of breeding stimulates or induces ovulation or the release of eggs from the ovaries
how many matings must occur in 24 hours in order for ovulation to occur
3-4 matings
when can a queen be bred
can be bred at any time during the active stage of estrus or heat
Estrus is usually ________
Estrus is usually seasonal
other factors (3) that effect Estrus
- # of daylight hours
- health of cat
- age
typical feline mating season
spring till autumn
polyestrous means what
more than one heat cycle in a year
can a cat have a litter in the winter or late fall
yes
how long does estrus last in cats
7-10 days
how often will estrus repeat until the cat gets pregnant
14 to 21
whelping
is the term for giving birth
queen
female unspayed cat
Tom
male unneutered cat
bitch
female unspayed dog
dog
male unneutered dog
male reproductive system (9)
- Penis
- 2 testicles
- scrotum
- prostate gland
- 2 bulbourethral glands
- epididymis
- ductus deferens
- spermatic cords
- the urethra
another name for bulbourethral glands
Cowper’s glands
another name for ductus deferens
vas deferens
what structure is found at the base of the penis
bulbus glandis
what is the bulbus glandis
a knot of tissue that surrounds the penis and becomes enlarged during erection
what does the bulbus glandis do
“knot” that locks them into a female during breeding
the erected knot is called what
“the tie”
how long does “the tie” last?
5 – 20 minutes
what can happen in neutered dogs when they
are excited.
the knot can get enlarged
what is an Ovariohysterectomy
Surgery removes the ovaries, fallopian tubes and uterus
is an Ovariohysterectomy a major surgery
YES
another name for an Orchidectomy
castration
Orchidectomy is _____ invasive than an Ovariohysterectomy
less
what is a cryptorchid male
one or both testicles are retained in the abdomen
in cat what is different about an Orchidectomy
Involves just a tiny incision right over the testicles
- minimal invasive and no sutures
what is Pyometra
Infection of the uterus
what is a Pyometra considered
serious and life threatening
why does a Pyometra happen
a result of hormonal changes and lack of breeding
what kind of dogs does a pyometra happen in
middle to older female dogs 2-8 weeks after last heat
pyometras can be what
open or closed
4 S + S of pyometra
- Anorexic
- Listless and depressed
- Vomiting
- Diarrhea
- Increased water consumption
- Increased body temperature
- Pus dripping from vulva (if open)
what is a vaginal prolapse
refers to a mass which protrudes from the vaginal area
what kind of animals can a vaginal prolapse affect
- all animals of any age typical in younger animals
is the prognosis for a prolapse good
yes but may secure again requiring surgery
if the prolapse is serious what can it prevent
normal urination
what is a prolapse similar to in nature
fluid-filled tissue called an edema
mammary tutors can be
Benign andmalignant
in which dogs do tumors of themammary glandsoccur fairly frequently in
unspayed female dogs
what can prevent mammary gland cancer/tumours
spaying before going into first heat
exocrine glands do what
secrete their products on to epithelial surfaces through tiny ducts
endocrine glands are _______ glands
ductless
endocrine glands do what
secrete tiny amounts of hormones directly into the bloodstream
hormones in general do what
circulate through body and produce effects when they find specific receptors
6 glands
- Hypothalamus
- Thyroid
- Parathyroid
- Adrenal glands
- Pancreas
- Gonads
the endocrine glands work together with the what to accomplish what
the endocrine glands work together with the nervous system to maintain homeostasis
the
Parathyroid gland is ______
very small
where is the Pituitary gland
in the brain
the Hypothalamus is a part of what
the brain
a nickname for the Hypothalamus might be
mission control
the Hypothalamus links what two things together
Links the conscious mind with the rest of the body
the Hypothalamus connects certain parts of the brain all together what are these parts
the cerebral cortex with lower brain centres and endocrine system
what does the Hypothalamus control (3)
- appetite
- body temp regulation
- wake-sleep cycle
6 primary hormones the Anterior Pituitary Gland produces
GH Prolactin TSH FSH LH ACTH
what does the GH hormone do
promotes bone and muscle growth and regulates the metabolism of CHO’s, fats and proteins
what does prolactin do
triggers and maintains lactation
what does TSH do
- stimulates the growth and development of the thyroid gland
- regulates the production of hormone from the thyroid gland
prolactin is only in ______
females
what does FSH do
- stimulates the growth and development of ovarian follicles
- stimulates the follicles to produce and secrete estrogen
what is the relation between LH and FSH
Generally as FSH decreases, LH increases
LH does what
completes follicle development
ACTH does what
– stimulates the growth and development of the cortex of the adrenal gland and its secretion of hormones
what is the Pituitary Gland connected to
hypothalamus gland
what is the size of the Pituitary Gland
Pea sized
2 parts of the Pituitary Gland are
Anterior (production) and posterior (storage) pituitary glands
does the Posterior Pituitary Gland produce hormones?
NO. just stores them
what does the Posterior Pituitary Gland do?
releases 2 hormones produced in the hypothalamus (ADH, oxytocin)
ADH affects what organ
kidney
what does ADH do
conserve water producing more concentrated urine
what does oxytocin do
- promoting uterine contractions at birth
- milk let-down during lactation
where are the thyroid glands
2 lobes located on either side of the larynx
what do the thyroid glands do?
- Produces two hormones that help regulate metabolic functions and calcitonin
what does calcitonin do
regulates blood calcium levels
what happens when the thyroid gland is stimulated from the anterior pituitary gland
it produces T3 and T4
what is Calcitonin also important for (4)
- blood clotting mechanisms
- secretion of milk
- muscle contraction
- maintenance and formation of bone tissue
what is the Calorigenic effect
impact of body’s energy expenditure
what does the thyroid hormone effect
- Regulates metabolic rate of all body’s cells
- Calorigenic effect
- maintain constant internal body temperature
what are thyroid hormones Necessary for
normal growth and development of CNS, muscles and bones in young animals
how do thyroid hormones affect metabolism
- synthesis of proteins
- encourages catabolism of lipids
- maintains homeostasis of blood glucose level
where and what are the parathyroid glands
Several small nodules located on or near the thyroid gland
what does PTH do
regulates blood calcium levels
what does an increase in PTH cause
force the kidneys and intestines to retain calcium as well as cause calcium to be released from bone supplies
PTH is the opposite of what
calcitonin
what are Epinephrine and norepinephrine involved in
the “fight or flight” response
what do Glucocorticoid hormones do
- increase BG levels
- decrease inflammation
- maintains blood pressure
- reduces stress
2 sex hör Mohnes
estrogen & androgens
what do Mineralocorticoid hormones do
- directs the kidney in controlling NA, K, and H ions
- controls acid/base balance and ultimately water
where are the adrenal glands located
near the cranial (top) end of the kidneys
what 2 parts make up the adrenal glands
- medulla
- cortex
medulla produces what
Epinephrine and Norepinephrine
cortex produces what
Glucocorticoids, Mineralocorticoids, Sex Hormones
the pancreas is a what kind of gland
endocrine and exocrine gland
what is the pancreas
Accessory digestive organ
how is it an exocrine gland
Produces enzymes that are released in the duodenum
how is it an endocrine gland
Produces hormones
why is insulin necessary
- the body to uses it as fuel
- prevents abnormally high blood glucose through absorption into cells
what does Glucagon do
increases blood glucose levels by stimulating cells in the liver to convert glucagon to glucose.
to hormones the pancreas produces
insulin
Glucagon
gonads are
Sex-cell producing organs
males have what kind of sex hormones
testosterone
females have what kind of sex hormones
estrogen and progesterone
what is Testosterone responsible for
development ofmale sexual characteristics
do females produce testosterone
yes in small amounts
6 things Testosterone regulates
- sex drive
- bone mass
- fat distribution
- muscle size and strength
- red blood cell production
how is progesterone produced
LH from pituitary gland causes the follicle to rupture and release ovum
progesterone does or does not impact behaviour
DOES
what does progesterone do
prepares the lower reproductive tract for breeding as well as mammary development
what produces the estrogen hormone
the follicles
Levels of hormones produced by the ovaries fluctuate in a _______ fashion
Levels of hormones produced by the ovaries fluctuate in a cyclical fashion
