Anatomy Flashcards
Blood, blood vessels, and the heart make up what body system?
Cardiovascular
What serves as the pump for the cardiovascular system?
The Heart
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?
four
In the horse, what flows through a series of vessels known as the vascular system?
blood
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?
Hemoglobin
The celluar elements of blood are suspected in a liquid known as what?
Plasma
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?
Large veins
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?
Cardiac Output
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?
50 liters
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?
Nonruminant herbivores
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?
Epiglottis
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.
True
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?
Foregut
How long is the small intestine?
70 feet
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?
25 feet
How long is the cecum?
4 feet
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?
B Vitamins
How long does it take for food to pass through the cecum and large intestine?
36-72 hours
What organ removes lactic acid from the body?
The liver
How much fecal matter will a mature horse generally poduce in a 24 hour period?
28-40 pounds
True or False? On average, horses produce more fecal coliforms per day than dogs, sheep, and cattle?
False
What group of glands in the horse secretes hormones in the blood or lymph system?
Endocrine 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?
Endocrinology
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
Pituitary Gland
What hormone is produced by the thyroid gland if the blood calcium level is too high?
Calcitonin
What is one process that allows a horse to cool its body?
Sweating
Sweat glands are located over the horse’s entire body with the exception of what parts?
The legs
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?
25-50kg
What is micturition?
Urination
Approximately how much urine will a horse void in a 24hr period?
4-7 quarts
If a horse experiences “renal failure,” what part of the body is not functioning properly?
Kidneys
What is the most important part of a horse? If you don’t have this, then you don’t have a horse?
Feet, hooves
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?
Hoof wall
What percentage of the hoof wall is water?
25%
What percentage of the sole is water?
33%
What percentage of the frog is water?
50%
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?
Hoof tubules
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?
Hoof structures
What is the primary funtion of the sole?
Protection
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?
The Frog
What is the groove along either side of the frog called?
The sulci
True or False? The hoof wall is the thickest at the toe and the thinnest at the quarters.
True
What separates the hoof wall from the sole?
White Line
What is the term for the distance between successive imprints of the same foot?
Stride
In one month’s time how much will the hoof wall grow on an adult horse?
1/4-1/2 inch
What is the term for the elastic portion of the coronary band?
Coronary Cushion
What supplies blood to the sensitive structures of the foot?
Digital arteries
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?
The toe
Which is more keratinized and harder the wall at the toe or at the quarters?
The toe
What condition may develop when there is no frog pressure or contact with the ground?
Contracted Heels
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?
Coronary Cushion
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?
Digital Arteries
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.
True
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?
W= (HG)^2xBL
330
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?
Serviceably Sound
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?
Sebum
On a weight basis, the horse’s body consists of what percent minerals?
4%
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?
Muscles
True of False? Muscle is an extremely adaptable tissue
True
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?
Tendons
What are the three basic types of muscle fiber?
Type I, HA, HB