Flashcards in Anatomy Deck (328):
Blood, blood vessels, and the heart make up what body system?
What serves as the pump for the cardiovascular system?
What is primary function of the equine cardiovascular system?
To deliver oxygen from the lungs to the individual tissues of the body
What additional function does the cardiovascular system provide?
It also provides nutrients absorbed from the digestive tract to the tissues
Proper function of the cardiovascular system depends on what?
Maintaining adequate circulation
How many chambers are in the heart?
In the horse, what flows through a series of vessels known as the vascular system?
The cardiac muscle is composted of what three major types of muscle?
Arterial, ventricular, specialized excitatory and conductive muscle fibers
Where are substances carried in the blood exchanged with the cells of the body?
At the capillaries
What is blood composed of?
Erythrocytes, leukocytes, and platelets
What are erythrocytes?
Red blood cells
What are leukocytes?
White blood cells
What type of blood cells carry oxygen?
Red blood cells
What is the iron-containing protein in red blood cells?
The celluar elements of blood are suspected in a liquid known as what?
What are blood vessels?
The series of tubes through which the blood flows
Blood flowing away from the heart passes through what?
Arteries, arterioles, capillaries and venules
Blood is returned to the heart through what?
What is the main arterial source in the hind leg?
The femoral artery
What is stroke volume?
The amount of blood pumped by the ventricle with each heart beat
What is the measure of how much blood the heart can pump per minute?
How is cardiac output determined?
It is the product of heart rate times stroke volume
What two sources are available to supply the extra quantity of blood required by exercising muscles?
Increased cardiac output and redistribution of blood away from less active tissue
If an adult horse weighs 1,000 pounds, how many liters of blood would the body contain?
What is the result of a thick throatlatch when a horse flexes at the poll?
Breathing and blood flow may be restricted
Because horses eat fibrous feeds and are monogastric, they are classified as what?
What are the two main functions of the mouth?
1) To masticate food 2) To wet it with saliva
What system regulates the horse's salivary glands?
The nervous system
Name the 3 pairs of glands that produce saliva
1) Parotid glands 2) Sublingual glands 3) Submaxillary glands
What are the three salivary glands in a horse?
Parotid, submaxillary, and the sublingual
What are the accissory organs that aid in digestion?
Teeth, salivary glands, liver, and pancreas
What is the cartilage trap that serves to prevent food from entering the larynx when swallowing?
How long is the esophagus in a mature horse?
50-60 inches long
True or False? Distention of a horse's stomach can be so severe that it will rupture before vomiting occurs.
Where is the horses' gall bladder located?
The horse does not have a gall bladder
Where are red blood cells stored when the horse is not exercising?
In the spleen
The mouth, esophagus, stomach, and small intestine all make up what part of the digestive system?
How long is the small intestine?
Where is the primary site of protien digestion?
The small intestine
Where in the horse's body are soluble carbohydrates digested to simple sugars?
The small intestine
How long does food remain in the horse's stomach before it starts passing into the small intestine?
Approximately 15 minutes
What organs are in the horse's hindgut?
Cecum, large colon, small colon, rectum
About how long is the large intestine of a horse?
How long is the cecum?
How long is the large colon?
10-12 feet and holds 86 quarts
How long is the small colon?
10-12 feet and holds 16 quarts
Name 5 of the eight main parts of the large intestine?
1) Cecum 2) Right ventral colon 3) Left venral colon 4) Left dorsal colon 5) Right dorsal colon 6) Transverse colon 7) Small colon 8) Rectum
What group of vitamins is synthesized by bacteria within the large intestines of the horse?
How long does it take for food to pass through the cecum and large intestine?
What organ removes lactic acid from the body?
How much fecal matter will a mature horse generally poduce in a 24 hour period?
True or False? On average, horses produce more fecal coliforms per day than dogs, sheep, and cattle?
What group of glands in the horse secretes hormones in the blood or lymph system?
What are hormones?
Chemicals produces by various tissues that travel through the circulatory system to produce an effect on one or more organs
What is the study of hormones and their effects called?
What body system exercises long range control over all other body systems?
The endocrine system
What is the hypothalamus?
Located deep within the tissues of the mid-brain, it is responsible for sending and interpreting messages from many sources and coordinating their signals to produce the desired effect
Where is the pituitary gland located?
At the base of the brain
Where is lutinizing hormone produced
What hormone is produced by the thyroid gland if the blood calcium level is too high?
What is one process that allows a horse to cool its body?
Sweat glands are located over the horse's entire body with the exception of what parts?
Equine sweat is hypertonic. What does that mean?
That the sweat contains a signifigant amount of salts, primarily sodium and potassium
How much of reduction in body weight can occur in a 500kg horse after an endurance ride?
What is micturition?
Approximately how much urine will a horse void in a 24hr period?
If a horse experiences "renal failure," what part of the body is not functioning properly?
What is the most important part of a horse? If you don't have this, then you don't have a horse?
What is one well known quotation in the horse world about hoofs?
No foot, no horse
Describe a healthy hoof.
The hoof should be hard, with a slick, shiny and slightly waxy appearance. I should be free of grown or fever rings. the coronary band should not be dry and leathery but should contain enough moisture to feel and appear slighly resilient.
True or False? Grass is considered to be nature's hoof conditioner.
False. Water is nature's hoof conditioner
Name the parts of the exterior hoof?
Sole, frog, white line, hoof wall, periople, bar, heel, bulb, cleft of frog, commissure
What is between the periople and the white line?
What percentage of the hoof wall is water?
What percentage of the sole is water?
What percentage of the frog is water?
Which part of the hoof is the most elastic and which is the least elastic?
Frog is the most elastic and the wall is the least elastic
What has a spiral, columnar structure that helps resist compression and flexion?
Why are the sensitive structures of the horses' feet called sensitive?
Because they contain so many blood vessels and nerve endings that any injury to them causes pain and bleeding.
Which parts of the hoof do not contain blood vessels and nerves?
What is the primary funtion of the sole?
The outer surface of the hoof wall is covered by the periople and stratum tectorium. What is the function of the stratum tectorium?
It helps protect the hoof wall from moisture evaporation
What part of the hoof bears the weight of the horse?
The hoof wall
What part of the horse's foot provides traction and absorbs shock?
What is the groove along either side of the frog called?
True or False? The hoof wall is the thickest at the toe and the thinnest at the quarters.
What separates the hoof wall from the sole?
What is the term for the distance between successive imprints of the same foot?
In one month's time how much will the hoof wall grow on an adult horse?
What is the term for the elastic portion of the coronary band?
What supplies blood to the sensitive structures of the foot?
The functional balance of the horse's hoof has 3 dimensions around X,Y, Z axis. The movements of the foot are given names corresponding to those of an airplane in flight. What are these movements called?
Roll, Yaw, and Pitch
The normal ideal hoof supports the primary weight of the horse on which part?
The hoof wall
Is the hoof wall thicker at the quarters or the toe?
Which is more keratinized and harder the wall at the toe or at the quarters?
What condition may develop when there is no frog pressure or contact with the ground?
Which structures of the horse's hoof are classified as elastic structures?
Lateral cartilages, digital cushion, and the coronary cushion
What is a wedge-shaped structure with a fibro-fatty composition that is very elastic and has very few blood vessels and nerves?
The digital cushion
What are lateral cartilages?
Wing-like structures attached to the sides of the coffin bone
What is the elastic portion of the coronary band called?
What are the shunts or alternate pathways that exist between the arteries and the veins, by-passing the capillaries called?
Arterio venous anastomoses or AVAs
What are venus plexuses?
they lie within the foot and are made up of and extensive network of veins that when compressed force the blood up the leg and back to the heart.
The sensitive structures of the foot are supplied with blood by what?
What would a stronger-than-usual pulse in the foot indicate?
That inflammation is present
What is the treatment for sole bruises?
seated out shoe, frog pressure shoe pad
What is the white line disease?
An infection in the hoof wall of hoof digestion fungi
True or False? Vitamin A is needed for growth and development of normal hoofs.
What do the hoof tubules look like?
They have a spiral columnar structure that helps them resist compression and flexion
What are the six physiological systems that affect performance?
Cardiovascular, respiratory, muscular, biomechanics and conformation, hematology, and nutrition.
What is the single most important characteristic in equine selection and why is it so important?
Balance- it forms the basis of movement, length of stride, and ultimately and performance
What are the most sensitive areas to touch on a horse and why?
The eyes, ears, and nose because the horse's survival depends on seeing, hearing and breathing
What mathematical equation can be used to estimate a horse's weight?
What is the term used to indicate that a horse may have a structural problem or deviation which may have only limited affect on the horse's ability to perform?
What does it generally mean when a horse has excessive white around their eyes?
Nervous and flighty
Name three different vocal sounds or voice communication made by the horse.
Neigh, whinny, nicker, snort, squeal
At what age is a horse considered mature?
Five Years old
What is a togavirade?
A small lipid and protein enveloped ribonucleic acid particle
What is the oily waxy secretion that coats the horse's hair, protects it from overwetting and increases its insulating ability?
On a weight basis, the horse's body consists of what percent minerals?
The body of the horse is made up of many systems. Which system includes the brain, spinal cord, associated nerves, and special senses?
The nervous system
What are the signs of old age in the horse?
1) Drooping of lower lip 2) Lowered or sway back 3) Deep hollows above the eyes 4) Appearance of gray hairs
During an examination which mucous membranes are typically examined?
Inner eyelids, Inside of nostrils, Inner lips and gums, Vulva of mare
What appearance should normal healthy mucous membranes have?
Bright and moist and have a clean, pink color
How should you check for capillary refill time?
Press thumb against upper gum for a couple of seconds. Upon release of thumb pressure, the area should appear white but immediately return to the normal color within approximately 2 seconds.
What comprises the largest tissue mass in the horse's body?
True of False? Muscle is an extremely adaptable tissue
What are the three catergories of muscles?
Smooth, cardiac, and skeletal
Name the body systems where smooth muscles can be found?
Digestive, respiratory, circulatory, and urogenital
In regard to muscles, what are the two main classifications of fibers?
Slow-contracting and fast-contracting
What attaches muscles to bones?
What are the three basic types of muscle fiber?
Type I, HA, HB
Which type of muscle fibers are slow-contracting fibers?
Type I fibers
What happens to the oxygen need of tissues when exercising?
it dramatically increases
Muscles that work together to accomplish movement are called what?
Muscles that work against each other are called what?
What attaches the foreleg to the horse's body?
Muscles and ligamentous material
What is muscle hyperplasia?
Increase in the number of muscle fibers
What is muscle hypertrophy?
An increase in the diameter of individual muscle fibers
What are intercostal muscles?
Muscles located in between ribs that are involved in inspiration
What are the bundles of smooth muscle fibers located in the dermis that attach to the hair follicle and the surface of the skin in such a manner that their contraction causes an erection for the hair?
What molecule is used to produce muscular activity?
What does ATP stand for?
What two fundamental reactions resnthesize ATP?
Oxidative phosphorylation and glycolysis
What is glycosis?
Breaks down glucose or glycogen into lactic acid
What is glycogen?
A form of stored fuel for exercise of high intensity and relatively short duration
What is oxidative phosphorylation?
It breaks down carbohydrates, fats and protein into energy with the involvement of oxygen.
What are fatty acids?
Fuel sources used during low intensity and long duration exercise
What is lactic acid?
A by-product of anaerobic glycolysis which causes fatigue in the muscles
What accumulates in the muscles and is believed to cause muscle soreness and stiffness 24-48 hours after an intense exercise bout?
What is the anaerobic threshold?
The point in exercise at which lactase begins to accumulate in the muscle and spills over into the blood stream
A reaction that does not use oxygen is considered what?
A reaction that uses oxygen is what?
True or False? Protein is an important energy source for contracting muscles, but is not an important structural component for muscle tissue.
What is the muscular part of the hind leg directly above the hock?
What is the main role of the hindquarters?
To provide the force for propulsion
True or False? The horse has no muscle below the knee or hock.
How many muscles control each ear so that they turn in almost any direction?
True or False? Muscle is an extremely adaptable tissue.
What is myofibril?
One of the slender threads of muscle fiber composed of numerous myofilaments
What are myosin and actin filaments?
Large polymerized protein molecules that are responsible for muscle contraction
The dark bands containing myosin filaments are called what?
The light bands containing only actin filaments are called what?
What is the portion of myofibril that lies between two successive Z-lines called?
What is the basic contractile unit of skeletal muscle?
What is the sacrotubular system in skeletal muscle composed of?
Sacroplasmic reticulum and the tubular system
The end of the nerve fiber contains a highly specialized structure where droplets of chemical neuro-transmitters are stored called what?
The end plate
What are three common characteristics of the "ideal" head?
Short, well set ears, large bold eyes, short distance from eye to muzzle, large nostrils, and refined muzzle with a shallow mouth
What is the junction between head and neck from ear to ear?
What is the depth of the throat latch?
Usually equal to one-half the length of the head
What is the ideal ratio of the top to bottom of the horse's neck?
True or False? The distance from poll to muzzle is double the distance from eye to eye?
What is the ideal slope of the shoulder?
The withers, back, loin, and croup are what of the horse?
Where is the pivotal point of the horse's back?
The high point of the horse's back, located at the top of the vertebrae, between the shoulder blades, where the neck meets the back, is referred to as what?
What are the semi-horny structures located above the knees and on the lower portion of the hocks on the medial side of the leg?
Are the chestnuts above or below the horse's knee?
What is the function of the respiratory system?
To exchange oxygen and carbon dioxide between the animal and its enviroment
What is the passageway to the respiratory system?
When oxygen is taken in for use by the tissues and the carbon dioxide which is produced by these tissues is released it is referred to as what?
What occurs during normal inspiration?
The diaphragm and the intercostal muscles expand the chest, which causes th eexpansion of the lung and allow air to flow in
What is respiratory frequency?
The number of breaths taken per minute
The amount of air inspired or expired during a normal breath is often referred to as what?
True or False? Tidal volume is the amount of air inspired and expired in a normal breath.
What is minute volume?
The product of tidal volume and respiratory frequency
What is the term for the total amount of air expired or inspired in a minute?
During normal inspiration, what forms a smooth passage for air flow into the trachea?
The pharynx and the soft palate
What functions as a barrier to food entering the trachea?
The pharynx, soft palate and larynx
What houses the vocal cords and is sometimes referred to as the voice box?
How many liters of oxygen does the horse's body need per minute?
90 liters of oxygen per minute
What are intercostal muscles?
Muscles that are located in between the ribs that are involved in inspiration
What percentage of oxygen does air contain?
What does the bronchial tree consist of ?
Large ducts that divide into smaller and smaller passageways in the lungs
Where do the alveolar ducts terminate?
What are the alveoli?
The functional units of the lung where gas exchange usually occurs
What is arterial hypoxemia?
The lowering of oxygen saturation of the arterial blood
How many bones make up the horse's skeleton?
On a weight basis, the horse's body consists of what percent minerals?
What are the 4 classifications of bones?
1) Long 2) Short 3) Flat 4) Irregular
What determines balance?
the skeletal structure
What word is used to express the height of a horse?
Hands and inches
What is the minimum height of a mature horse?
14 hands or 56 inches
The skeleton contains approximately what percent of the total body calcium?
What is the cranial cavity?
I encloses and protects the brain and supports many sense organs.
The bony framework of the head consists of how many bones?
What is the orbital cavity?
The bony socket that surrounds and protects the eye
What is the largest bone in the head of the horse?
What two bones are fused to form the forearm?
Radius and Ulna
Name the internal bones of the horse's leg from the cannon bone down.
Sesamoid, short pastern bone, long pastern bone, navicular bone, coffin bone
What portion of the anatomy is composed of seven or eight carpal bones arranged in two rows?
The knee or carpus
What joints are located below the knee joint?
Fetlock, pastern, coffin joint
What joint is composed of the femur and the acetabulum?
What is attached by a muscular sling that supports the thorax and reduces concussion?
Scapula or shoulder blade
How is the scapula attached to the vertebral column?
By a muscular sling
Does a sloping shoulder or straight shoulder make for a smoother riding horse?
A sloping shoulder
The layer within the joint capsule is sealed by a delicate layer of synovial membrane and is lubricated by a secretion called what?
What is side bone?
Ossification or calcification of the lateral cartilages
Which bone is larger: the tibia or fibula?
What structures hold bones together?
What attaches the splint bones to the cannon bones?
Which bones function chiefly as levers and aid in support of weight and locomotion?
The horse's forelimbs bear what percentage of its weight?
Why are there more injuries and unsoundness in the horse's front of limbs?
Since 65% of the horse's body weight is carried by the forelimbs, they are subject to the most stress and strain.
How many joints are there in the front leg of the horse?
How is the hind leg attached to the spine?
With a bone to bone connection
What is the hardest working joint in the horse's body?
The tarsal joint is commonly called what?
How many bones are in the tarsus or hock of the horse?
Name the major bone of the leg between the stifle and the hock.
How many ribs does a horse have?
36 or 18 pairs
The first 8 pairs of the 18 pairs of ribs are called what?
What are true ribs?
Ribs that are attached to the sternum by means of cartilage
What is the largest joint in the horse?
The stifle joint
How many joints are in the hind leg?
Where would you find coccygeal vertebrae of the spinal column?
Tail or caudal
How many bones are located in the horse's foot?
What are the 3 bones of the foot?
Coffin, Navicular, Short pastern bones
What is integument?
the skin and hair that covers the horse's body and forms the boundary between the animal and it environment.
A horse begins to grow a longer hair coat during the fall due to what?
Decreased day length
Which event stimulates hair growth of the horse: temperature or shortening of daylight?
What are the two types of body hair?
The dense undercoat and the less prevalent long "guard" hairs
Hair covers most of the skin area on the horse except where?
Underneath the tail, around the genitals, and on the inside of the thighs
Where are the sebaceous glands located?
Same places as the hair follicles
What types of vision do horses have?
Binocular and monocular
What type of vision allows a horse to see areas on each side of its body?
What type of vision does a horse use for viewing objects closer than 4 feet?
The entire spatial area from which the complete visual image of an eye is formed is known as
Field of vision
What is the fluid that lubricates the eye?
What are the black nodules that are found on the upper part and lower margins of the pupils so they are on the iris?
Corpora nigra or granula iridica
What is the cornea?
The transparent portion of the front of the eyeball
When examinging a horse what are three of the vital signs that should be checked?
Pulse, temperature, respiration, capillary refill time, mucous membranes, skin pliability
What factor can cause variations in the TPR of an individual horse?
Time of day, Age and sex, Ambient temperature, wind and precipitation, Level and intensity of activity, Disease state
What is the average temperature of a horse?
Should a horse's temperature be higher at 7 am or 5pm?
What is the normal body temperature for an adult horse?
What is the normal pulse rate for a horse?
45-60 beats per minute
How is the heart rate measured?
By the number of time the heart beats in a given time
What is the heart rate of an adult horse at rest?
25-45 beats per minute
What is the maximum hear rate of the horse?
220-250 beats per minute
What is the pulse rate of a horse with heat exhaustion?
50-100 beats per minute
What is the body temperature of a horse with heat exhaustion?
Which should be lower, the pulse rate or the respiration rate?
Respiration rate should be lower
If the respiration rate is higher than the pulse rate it is known as what?
What are two linings of the hoof wall?
periople and stratum tectorium
What does gingival refer to?
the gums of the mouth
What is the name for the muscle separating the thoracic cavity from the abdominal cavity?
What artery supplies blood to the brain, head, and face?
What regulates sugar levels in the blood?
Where would you find the deep flexor tendon?
Running down the back of the cannon bone and pastors into the hoof where it runs underneath the Navicular bone and attaches to the Coffin bone
What is the smallest blood vessel and what does it do?
Capillaries; connect the arteries and the veins
What is a quarter crack and how do you fix it?
A vertical crack in the hoof in the quarter section, can be fixed by special shoeing, a clinch or special graving of the hoof
Where are the canine teeth located?
The interdental space on the male horse
What is the name for the 2 glands in front of the kidneys?
What is anal atresia?
Blocked anus; foal born with no anal opening, hence no anal opening, hence no products of digestion may pass; surgical correction is rarely beneficial
What are the turbinate bones?
Bones in the nasal passage that filter and warm the air that is inhaled
Where are the fecal balls formed?
What does the thyroid regulate?
Controls metabolic rate and produces thyroxin
What is a disadvantage to a thick neck?
Less flexible, more weight on the front end
What is another name for the first and second phalanges?
Long and short pastern bones
Define wry tail.
A tail that is carried to one side rather than being held straight
Junction between two or more bones; joints
What is the artery that supplies blood to the eye?
What is gonitis?
Inflammation of the stifle joint
What is a knocked down hip and why is it undesirable?
When one hip is lower than the other because of the fracture of the point of the hip on one side; undesirable because they develop lameness and have a hitching gait
What is a term for the thickening and hardening of the skin due to friction?
What is the name for spinal and brain fluid?
What is the term for being low in the withers with heavy shoulder muscling; having very little bone definition at the withers?
What is the dental star?
A star shape or circle like structure near the center of the wearing surface of the permanent incisors; used in judging age
What artery supplies blood to the intestines?
The 3rd, 4th, and 5th thoracic vertebrae make up what part of the horse?
What is the painful swelling of the knee joint called?
What is the channel between the middle ear and nasopharynx that allows adjustment of the pressure of air int he cavity to equal the outside air pressure?
What is the name for the disk shaped bone that forms the ridge at the back of the knee?
Accessory carpal bone
What is the name for the disease of the small bone of the horse's foot?
What is the infundibulum?
The funnel-shaped membrane that traps the egg when it is released from the follicle of the ovary
What are the melanocytes?
Cells that are responsible for the production of melanin
How do incisors change as the horse gets older?
They slant forward and outward more, and become triangular shaped
What does light reflect off of in the eye?
What is the congenital defect where the roof of the horse's mouth is split and allows food to regurgitate into the nose?
What is the purpose of the laminae?
To connect the hoof wall to the coffin bone
What does the term cathammed mean?
Having long and relatively thin thighs and legs
What is the first vertebrae and what does it do?
Atlas; permits flexion and extension of the head and neck
What is the name for wave like muscles contractions that move food esophagus and along the muscular walls of the intestine?
What is intestinal flora?
Bacteria and other micro-organisms normally residing in the intestines
What does vesicular refer to?
Fluid filled sac
Beneath the skin
What are the two chambers that blood is pumped out of the heart?
What is the fermentation vat?
What is carpitis?
Painful swelling of the knee
What vein is involved in a blood spavin?
What is the term for shrinking of the shoulder muscle?
What is the term for a fluid filled sac that is situated in places where there is friction?
What are two things the lymph system does?
Collects fluid from between the cells and returns the to the bloodstream; helps to fight infection and maintaining fluid balance in the body
Why is a thick neck and throat latch undesirable?
It lacks suppleness, balance, and mobility
What is periosteum?
Membrane covering the bones
What is gastric lipase?
An enzyme that helps digest fats into constituent fatty acids and glycerol
What muscle contracts the lenses of the eye?
Give one purpose of the fallopian tubes?
Conduct the ova from the ovary to the uterus and are the cite of fertilization
What is a green osselet?
Inflammation of the joint capsule of the fetlock joint
What is a substance secreted by the stomach to activate pepsin and break down protein?
What is deglutition?
The act of swallowing
What is the endocardium?
the tough membrane that lines the four chambers of the heart
What is the purpose of bile?
To assist in the digestion of fats and neutralize the acidic digesta from the stomach
What is the large bone in the thigh?
What is the carpus valgus?
Deformity of the knee when the cannon bone points away front he mid-line when viewed the fronts bow legged
What is a corn?
A bruise to the soft tissue underlying the horny sole of the foot that manifests itself in a reddish discoloration of the sole immediately below the affected area; can cause serious lameness
What are tactile hairs?
The hairs on the outside of the horse that helps the horse to distinguish between good an bad feed