Transcript Anatomy Powerpoint

Functional
Anatomy
Equine Science II
Four Basic Surfaces
1.
2.
3.
4.
Dorsal refers to the upper surfaces of
the animal
Ventral refers to the lower or
abdominal area
Anterior or cranial refers to the head
or front
Caudal or posterior refers to the tail
or rear
Dorsal
Anterior
Caudal
Ventral
Nine Body Systems
1.
2.
Skeletal System- includes
bone and cartilage that give
the body shape and protect
internal organs
Muscular system- provides
movement both externally and
internally
3.
4.
Digestive System- converts feed into
a form that can be used by the body
for maintenance, growth and
reproduction
Urinary System- maintains water and
mineral balance while holding and
excreting wastes when needed
5.
6.
Respiratory System- takes in oxygen
and delivers it to the tissues and cells
and picks up carbon dioxide from the
tissues and cells to deliver to the
environment.
Circulatory System- distributes blood
throughout the body
7.
Nervous Systemsupplies the body with
information about its
internal and external
environment through
electrical impulses
between the brain,
spinal cord, and other
parts of the body.
8.
9.
Reproductive System- contains the
organs necessary for the creation of
new organisms.
Endocrine System- produces
hormones that influence vital
functions.
Two Divisions of
Skeletal System and
Articulations
1.
The axial skeleton consists of the
bones in the trunk area which
includes the skull, spine (vertebral
column), ribs and breastbone (chest
cavity), pelvis and tail
a. Bones of the skull are flat or irregular in
shape and form the framework for the
brain, mouth, eyes and nasal cavities.
b.
c.
The vertebral column consists of
a flexible column of small bones
(vertebrae) that form the basis of
the skeleton
Hip bones are two large flat
bones attached to the spine and
sacrum that form the pelvis or
pelvic girdle and cavity
d.
The ribs and breast
bone (sternum) along
with the thoracic
vertebrae form the
chest cavity.
2.
Appendicular skeleton consists of the
forelegs and hind legs that are used
for locomotion, grooming and to
some extent for defense and feeding
a. The forelimbs have no skeletal
attachments to the axial skeleton or
trunk, but are connected by muscles.
b. The hind limbs are attached to the
pelvis at the hip joint
3.
Articulations or joints are the union of
two or more bones or cartilages held
together by ligaments, tendons, or a
tough fibrous capsule.
a. Joints are classified by their structure
and movability.
b. Freely movable joints have a joint cavity
between the two surfaces, the bones
are covered with a smooth cartilage and
the bones are held by ligaments
Muscular System
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red, lean meat
compose about 50% of the
equine’s total body weight
stimulated to contract or
change shape by nerve
impulses from the brain
send nerve impulses back to
the brain indicating the
degree of contraction so that
movement is smooth
Three Basic Muscle
Types
1.
Smooth muscles are
involuntary muscles.
a. Sometimes called visceral
muscle
b. Found in the digestive system
and in the uterus of females
c. Capable of prolonged activity
without fatigue
2.
Cardiac muscles in involuntary
striated muscle
a. Found only in the heart
b. Contractions of the cardiac muscle
require no nerve stimulus
c. Contractions are rhythmic and require
no conscious control
3.
Striated or skeletal muscles are
usually attached to bones of the
skeletal system either directly or by
tendons and act voluntarily.
a. Bones serve as levers and the muscles
move the body voluntarily under the
direct control of the will
b. Skeletal muscles are usually arranged
in opposite sets so that one set of
muscles bends the limb (flexor muscle)
and the other set straightens it
(extensor muscle)
c. Voluntary muscles become fatigued and
need rest after a short period of time.
3.
Tendons eliminate undue friction to
allow muscles to act more freely
a. The tendon sheath is a synovial sac
through which a tendon passes and
which provides synovia to lubricate the
surrounded tendon.
b.
The tendon bursa does the same
thing as the sheath except the
tendon does not pass through it. The
tendon bursa is a synovial sac
interposed between the tendon and
the surface over which it comes in
contact which lubricates and
cushions the tendon.
c.
Both are found
mainly near joints
Digestive System
1.
The parts of the
digestive system
work together to
convert feed into a
form that can be
used by the body
for maintenance,
growth and
reproduction.
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Parts include:
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Mouth
Pharynx
Esophagus
Stomach
Intestines
Anus
Associated Organs
– Liver, teeth pancreas
and salivary glands
A.
Rate of feed passage through the
stomach (30 minutes to 2 hours) and
small intestine is very rapid so that
any feed not digested and absorbed
in the small intestine passes on to
the cecum and colon within 24 hours.
B.
Grinding or chopping
decreased feed size which
increases the rate of passage
but decreases the absorption
of nutrients by the equine
C.
It is easy to overwhelm the digestive
capacity of the equine’s stomach and
small intestine with large amounts of
concentrates, which if pass through to
the cecum, become fermented and
produce gas or lactic acid causing
colic or founder
2.
3.
The mouth extends from the lips to
the pharynx. It is bounded on the
sides by the cheeks, above by the
hard palate and below by the tongue.
The pharynx is the muscular
somewhat funnel shaped tube from
the back part of the mouth to the
esophagus. It directs food and serves
as an air passage.
4.
The esophagus extends from
the pharynx down the left side
of the neck through the
thoracic cavity and diaphragm
to the stomach at an angle
which makes regurgitation
impossible.
5.
6.
The stomach is a U-shaped muscular
sac at the front of the abdominal
cavity close to the diaphragm and
makes up less than 10% of the total
digestive capacity for an adult
equine.
The small intestine is a tube about 2”
in diameter and is the site of most
nutrient absorption but makes only
30% of the total digestive capacity.
7.
The large intestine consist of the
cecum, large colon, small colon, rectum
and anus.
a. The cecum and colon make up 65% of the
digestive system capacity and are greatly
enlarged to allow bacteria time to break
down the large quantities of cellulose from
plant material.
b. The small colon extends from the large
colon to the rectum and is the place
where the balls of dung are formed. The
contents are solid as most of the
moisture in the food is reabsorbed in
this part of the large intestine.
Urinary System
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The urinary system is made up of the
kidneys, ureters, bladder and urethra
which filter the blood and dispose of
waste products
– All the blood in the body passes though
the two kidneys more than 400 times per
day and is filtered of nitrogenous wastes
each time
– The kidneys are from 6-7 inches
long, 4-6 inches wide about 2
inches thick and are located on
each side of the backbone at
about the 18th rib
– Millions of tiny nephrons in the outer
cortex of the kidneys filter about 200
gallons of liquid per day, rejecting blood
cell and proteins but permitting fluid, salts
and other chemical waste to pass through
them
– The kidneys return about 198 gallons of the
200 gallons to the bloodstream, including
salts, sugars and most of the fluids
– The two gallons of waste fluid, urine is
collected in the inner portion of the kidney,
the renal pelvis and drained drop by drop
through the ureters to the bladder.
Respiratory System
1.
The respiratory system takes in
oxygen and delivers it to tissue and
cells and removes carbon dioxide
from those same tissues and cells.
– The lungs are the essential organ of
respiration
– Air is taken into the lungs where oxygen
is removed by diffusion into the blood
2.
Supporting parts of the
respiratory systems carry air to
and from the lungs and include
the nasal cavity, pharynx, larynx,
trachea and bronchi
– The pharynx is common to both the
digestive and respiratory systems
– The larynx serves as the voice box,
allowing equine to make sounds such as
neighing, whinnying, nickering and
regulates the amount of air passing into
or out of the lungs.
– The trachea is a long tube connecting the
larynx with the lungs and branches into
bronchi in each lung containing minute air
sacs called alveoli where the gaseous
exchange of carbon dioxide takes place
between the circulating blood and air.
Circulatory System
1.
The circulatory
system distributes
blood throughout
the body to
nourish each cell
with food
substance and
oxygen while
removing waste
products
The parts of the circulatory system
include the:
2.
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Heart- A muscular organ of about 7-8
pounds in ordinary sized equine that is
the main pump of the circulatory system
that creates blood flow
• Arteries- Vessels with rather thick
elastic walls that carry blood from the
heart to the tissues of the body.
• Veins Vessels that carry blood from the
tissues back to the heart
Capillaries connect the arteries
carrying blood cells and the veins
carrying blood away from the cells
3.
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It is through the walls of the capillaries
that the exchange of food and oxygen
for waste products takes place
Capillaries are microscopic in size
Blood is the red alkaline fluid tissue
that is the regulator of the body. It is
composed of blood plasma and red
and white blood cells
4.
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White blood cells are the active agents
in fighting disease germs in the body
Red blood cells originate in the bone
marrow, liver and spleen and carry
oxygen from the lungs and carbon
dioxide from the tissues
5.
Lymph is the fluid that
assists in carrying food from
the digestive tract to the
tissues and waste products
back to the bloodstream
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Lymph vessels are ducts that transport
lymph and lymph nodes or lymphatics,
are gland-like bodies found in the
lymphatic vessels that act as filters.
The vessels converge to form on large
ducts that lies parallel to the aorta, the
main artery from the heart and empties
into one of the large veins near the
heart.
Nervous System
1.
2.
The nervous system is a complex system
that uses electrical-chemical changes to
send impulses to and from the brain or
spinal cord, nerve fibers and sensory
receptors.
The nervous system is the communication
system of the body made up of the brain,
spinal cord, ganglia (secondary nerve
center along the spinal cord) and nerves.
The nervous system has two main
portions
3.
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The autonomic or automatic nervous
system is directed by the brain stem
to control respiration, digestion and
major organs like the heart
automatically.
The central nervous system is
directed by the brain to control the
conscious or voluntary actions of the
body like movement.
Endocrine System
1.
2.
Consists of ductless glands
producing internal secretions called
hormones that control and promote
homeostasis (balance) between
physiologic functions
Hormones regulate bodily reactions
by slowing or speeding the rate of
organ functions
The pituitary and hypothalamus work
together to coordinate the endocrine
and nervous system
3.
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The hypothalamus is the center of the
autonomic nervous system
The hypothalamus releases hormones that
regulate the pituitary
Some hormones and glands:
4.
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Hypothalamus: ADH (vasopressin)
is the trauma hormone, oxytocin
controls lactation and reproductive
phases of the mare.
• Pituitary:
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FSH stimulates the ovaries of the mare and
sperm production in the male,
LH stimulates secretion of estrogen in the
mare and testosterone in the male,
LTH (prolactin) promotes lactation once the
mammary system has been primed by
estrogen and progesterone,
TSH stimulates the thyroid gland to release
thyroxin that regulates body metabolism
• Pancreas: insulin
regulates glucose
metabolism.
Reproductive System
Stallion
1.
2.
Testicles- Primary sex organ
used to produce sperm and
the male hormone
testosterone
The seminal vesicles,
prostrate gland and bulbo
uretral gland are accessory
sex glands that furnish fluid
secretions for the semen.
3.
4.
5.
The epididymis carries sperm from
the testes to the Vas deferens and
provides a place for storage and
maturation of sperm
The Vas deferens transports mature
sperm from the epididymis to the
urethra
The urethra takes sperm from the
Vas deferens to the end of the male
genitalia
The penis deposits the sperm into
the female reproductive tract.
6.
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Stallions can ejaculate from 60-300
milliliters of sperm with up to about 10
billion live spermatozoa per ejaculate
A sperm cell may live in a mare’s
reproductive tract for 24-48 hours.
Sperm travel to the mare’s Fallopian
tubes in as short a time as 15-18
minutes but normally requite 2-6 hours
Mare
1.
2.
The ovaries produce eggs and secrete the
hormone estrogen that causes heat (estrus) and
stimulates the production of other hormones to
condition the reproductive tract
The Fallopian tubes connect the ovaries to the
uterus and are the normal site of fertilization of
the egg by the sperm
3.
4.
The uterus consists of the body,
cervix and two horns. It is in one
of the two horns that the egg
normally develops after
fertilization
The vagina receives the sperm
during mating and serves as the
birth canal
5.
6.
The uterus is prone to infections due
to its elongated shape
The mare’s reproductive system has
an unusual placenta arrangement
and inefficient cervical closure that
may hinder full-term pregnancy.
Functional Muscle
Groups
Flexors: Bend the limb
1.
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Decrease the angle of a joint
Examples: Teres major in the front leg
and Iliacus in the hind leg
Extensors: Straighten the limb
2.
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Increase the angle of a joint
Examples: Brachiocephalicus of the
front leg and Gluteus medius of the hind
leg
Abductors
3.
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Move a limb away from the center plane of
the equine
The abductor of the front leg is the deltoid
Adductors
4.
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Pull a limb toward the center plane of the
equine
Adductors of the front legs are the pectoral
muscles
Terminology of
Movement
1.
2.
3.
A gait is an equine’s way of going or
moving its legs during movement
A beat refers to the time a foot or two
feet simultaneously hit the ground.
A step is the distance between the
imprints of the two front legs or the
two hind legs
4.
5.
6.
7.
A stride is the distance between
successive imprints of the same foot
Directness, also called trueness is
the line in which the foot is carried
forward during the stride.
Spring is the manner in which weight
settles back on the supporting leg at
the completion of the stride.
Balance refers to the ability of the
equine to coordinate action, go
composed and in form
Components of a Stride
A stride has two phases
1.
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Stride stance is the weight
bearing phase
Stride suspension or swing
is the non-weight bearing
phase
The speed of a horse is
affected by:
2.
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Length of stride, rapidity or
frequency of stride and overlap
time
Overlap time is the time on the
ground versus the time off the
ground
Natural Gaits
(no training)
Walk is a slow, even, four-beat gait
1.
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The sequence of hoof-beats is first – left
hind, next, left fore, then- right hind, and
finally – right fore
Both feet on one side strike the ground
before the feet on the opposite side
strike the ground
Walk
Trot is a two-beat gait where the
diagonal fore and hind legs act
together
2.
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A period of suspension when all four
feet are off the ground occurs between
each beat
There are different styles of trotting:
road horse trot is fast-stepping, hackney
trot and heavy harness trot are highstepping forms of trotting
Trot
Canter or lope is a three beat
collected gait where the equine
carries more weight on its haunches
or rear quarter
3.
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Sequence of hoof-beats for canter is
first – right rear hoof, next- left rear and
right front striking the ground at the
same time and last- left front hoof.
Canter is performed in slow, animated,
rhythm.
Canter
Gallop or run is a fast, four-beat gait
4.
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Sequence of hoof-beats is first- one
hind foot, next- the other hind foot, thenthe diagonal forefoot followed by the
remaining forefoot
A period of suspension follows the four
beats.
Racehorses use the gallop or run gait
Other Gaits
1.
2.
Pace is a two-beat, lateral gait used
for speed with the fore and hind legs
on the same side moving together.
The gait has a rolling motion.
Slow gait or stepping pace is a show
gait that uses a lateral, four beat gait
where the front foot on the right is
followed by the hind foot on the right
3.
Rack (sometimes called the single foot) is
an even, fast four-beat lateral gait that is
hard on the equine’s forelegs due to
increased amount of concussion from the
excessive leg movement. Rack is easy
on the rider
4.
5.
Running walk is the fast walk of a
Tennessee walking horse where the
horse travels with a gliding motions
as a result of extending its hind leg
forward to overstep the forefoot
print.
Back is actually trotting in reverse
Gait Defects
1.
2.
3.
May interfere or cause injury to the equine
Forging is the striking of the toe of the hind
foot against the sole of the forefoot.
Interfering is when the foot of the striding
leg strikes the supporting leg and usually
occurs between the supporting front leg a
striding front leg or between a supporting
hind leg and a striding hind leg
4.
5.
Winding is twisting the front leg around
in front of the supporting leg as each
stride is taken and is common with
wide-chested horses
Other gait defects include scalping,
speedy-cutting, cross-firing, pointing,
swelling, trappy, pounding and rolling
Center of Gravity,
Conformation and Gaits
1.
2.
Most commonly located in the middle of
the rib cage just caudal to the line
separating the cranial and middle thirds of
the body
Because the center of gravity is located
more cranially, the forelimbs bear 60-65%
of the equine’s weight resulting in more
stress and lameness in the forelimbs
3.
Conformation for structure of
the horse can be generalized
to say that basically an
equine that stands straight is
likely to move straight and
true.