Unit II – Anatomy and Physiology
Course Outcome
 Identify
external and internal anatomy of domesticated
animals
 Discuss
basic physiology of domesticated animals
important to production
Introduction
Anatomy – is the study of the structure of a body and the
relation of its parts
- External and Internal
Physiology – deals with the function of living matter and
includes a number of subsidiary disciplines such as
behavior, biochemistry, and biophysics
Body Systems
Skeletal & muscular
 Cardiovascular
 Respiratory
 Nervous
 Digestive
 Reproductive
 Endocrine and body temperature regulations

Directional terms
External Anatomy
Cattle
Integumentary System
Functions:
 Physical protection: barrier against outside
 Prevention of dehydration
 Body temperature regulation
 Sensory information via cutaneous receptors
 Metabolic ions
 Excretion of wastes
Sweat gland - specialized structure
Eccrine – produces hypotonic
water secretion that derives
from intertitial fluids (water
with some dissolved salts,
lactic acid, and other wastes)
 Apocrine gland – located in
distinct part of the body.
Secretes watery fluid, fatty
acids and some protein. This
gland is affected by sex
steroids

Sebaceous gland
Also known as oil gland
 Present in mammals
 Sebaceous gland produces
“sebum”
 Sebum

◦ Acts as natural skin cream and
hair protector
◦ Prevents excessive evaporation
◦ Keep the skin soft
◦ Has bactericidal
Other Skin Glands

Submental gland in cats

Scent gland in goat
Other Skin Glands

Uropygial gland – oil gland

Hair
Appendages of Skin
Hoof or claw - It is the horny
covering of the distal end of the
digit.

Chestnut - horny mass
found in the medial aspect of
the forearm about halfway
between the carpus and the
elbow, and on the media
aspect of the hind leg just
below the hock of the horse.
Appendages of Skin
Ergot. A horny mass found in
all four legs, embedded in the
hair on the posterior aspect of
the fetlock joint.
. Horns - epidermal derivatives
bound together into a solid
mass by keratin. It is
supported for a variable
distance by the horn core or
process cornus, (which is a
bony outgrowth of the frontal
bones of the skull).
Appendages of Skin

Feathers – it helps protect
the body, maintain body
temperature in poultry and
allows bird to fly
Skeletal System
Functions
 Protection of vital organs
 Rigidity and form to the body
 Acts as levers
 Storage of minerals and lipids
 Site of blood formation
Classification of bone





Long bones
Short bones
Flat bones
Irregular bones
Sesamoid bones
Division of the body skeleton
Appendicular
Axial
Visceral
os rostri
 os cordis
 os penis

Muscular System
Functions
 Production of movement
 Maintaining posture
 Stabilizing joints
 Generating heat
Properties of muscle

Excitability
◦ Sometimes called irritability
Contractility
 Extensibility
 Elasticity

Classification of Muscle
Skeletal
Voluntary
Striated muscle
Cardiac
Involuntary
striated muscle
striated
muscle
smooth
Digestive System
Functions
 Ingestion
 Mastication
 Digestion and Absorption
 Excretion
Parts of Digestive System
Mouth

Tongue, lips, teeth and salivary
glands

Responsible for food breakdown
 Serves
as prehensile (grasping)
mechanism, defensive and offensive
Pharynx
o
Passage of food and air
Esophagus
o
Connects pharynx and
stomach
Stomach
A. Simple stomach
A. Cardia (entrance)
B. Fundus ( body)
C. Pylorus (terminal)
B. Compound Stomach
A. Rumen (paunch)
B. Reticulum (honeycomb)
C. Omasum (many flies)
D. Abomasum (true stomach)
Enzyme
Enzymes
Origin
Enzyme
Target nutrient
Salivary gland
Amylase
carbohydrates
Mouth
Lipase
Lipid
Stomach
Pepsin
Protein into peptide fragment or amino
acid
HCl*
Denaturation of protein
Destroy bacteria and virus
Activate pepsinogen into pensin
Gastric lipase
lipid
Bile*
Emulsify fats
Liver
Origin
Enzyme
Target nutrient
Pancreas
Trypsin
Protein and amino acid
Chymotrypsin
Protein and their aromatic amino
acid
Carboxypeptidase
Terminal amino acid group from
protein
Elastases
Protein elastin
Lipase
Triglycerides into FA and glycerol
Amylase
Starch and glycogen
Maltase
Maltose to glucose
Lactase
Lactose to glucose and galactose
Sucrase
Sucrose to glucose and fructose
Small Intestine
Origin
Enzyme
Target nutrient
Stomach of young ruminants
rennin
Causes milk to coagulate
Microorganism
Cellulose
Cellobiose
Soluble cellooligomers
Xylan
Arabinoxylan
Laminarin
Lichenin
Pectin
Polygalacturan
Cell wall
Small Intestine
Parts
Duodenum – Contains the
pancreas
Jejunum – Middle part
Ileum – Terminal Part
Large Intestine
Cecum – functional among
pseudo-ruminants
as site
of microbial digestion “cul de
sac”- colon
Rectum – terminal part of
intestine, organ of storage
of waste
Anus – end part of alimentary
tract
Accessory Gland of Digestive System
Pancreas – secretes insulin and
digestive enzyme
Liver – produces bile; largest
gland
Functions of Liver
1. Storage and formation of glycogen (animal
2. Secretion of bile
3. Detoxification of poisons
4. Breakdown of uric acid
5. Formation of urea
6. Desaturation of fatty acids
starch)
Urinary System

Extraction and removal of waste products from the blood
Kidneys – urine formation
• nephron is the unit of structure
and function of the kidney.
Ureters – conveys urine from
kidney to bladder
Urinary bladder (pantog) –
hollow muscular organ that
contains urine
Urethra –passageway of urine and
semen in male;solely urinary
function for female
Urine Formation
Secretion moves substances out of the blood and into
the collecting tubules where they mix with the water and
other wastes and are converted into urine.
Micturition – the term for the expulsion of urine from the
bladder
Male Reproductive System
Testis or testicles – primary organ of the male
-sperm cells production
-hormone production (testosterone produce in the Leydig
cells)
Scrotum – cutaneous sac serves as external covering of
testes. Temperature regulation (6-9 0C below body
temperature; cremaster and tunica dartos muscles for
thermoregulatory. Seminiferous tubules are found inside
the testes where spermatozoa are produced.
Duct System
Epididymis – (head, body and tail) as storage, concentrate,
site of sperm maturation
Vas deferens – found at the tail of epididymis,enlarges to
ampulla. Carries sperm from epididymis to urethra
Urethra – where spermatozoa and accessory fluids mixed,
with loop called sigmoid flexure (bull, boar, ram and
buck)
Penis –organ of copulation, ( glans, body and roots which is
attached to the pelvis)
Accessory Gland
Seminal vesicles – paired, hollow, absent in dogs, secretion
neutralizes urine residues ( ascorbic acid, citric acid,
seminal fructose, ergothionine)
Prostate – unpaired, more or less completely surrounds the
pelvic urethra. Produces alkaline that gives
characteristic odor to semen
Cowper’s gland or bulbo-urethral gland – small paired, on
either side of pelvic urethra. None in dogs, extremely
large in boars, secretes sialoprotein
Female Reproductive System
Ovaries – primary organ of
the female
 Produces ovo (egg cell),
 Female sex hormones
(estrogen and progestero)
Oviduct or Fallopian tube
 Tube extending from the
ovaries to uterus, with funnel
fimbriated membrane portion
near the ovary called
infundibulum;
 Serve as site of fertilization
Uterus
 site of implantation for fertilized egg; with body and horns;
 Types: bipartite, bicornuate, duplex, didelphic and simplex
Cervix
 neck of uterus;
 its opening called os uteri
closes when pregnant and not
in-heat
Vagina
 organ of copulation
Vulva
 external genital organ
Male Fowl Reproductive System
two testicles in bird are located inside the
abdominal cavity
 body temperature of fowl (about 104°F)
does not inhibit spermatogenesis as it
does in most mammals
 the quite small epididymis on the side of
each testicle provides limited storage
 thus, the vas deferens which lead from
the testicles to the cloaca are the main
storage site of sperm cells
 no accessory glands in the bird

Female Fowl Reproductive System
Ovary – left is functional
Oviduct
 Infundibulum
 Magnum – secretes egg
white
 Isthmus – secretes shell
membrane
Uterus – “ shell gland”
Vagina
Cloaca
Respiratory System
Function
 Gas exchange
 Regulation of blood pH
 Olfaction
 Filtration of inspired air
 Production of sound
 Elimination of some water and heat
Parts of Respiratory system
Nose
Pharynx
 Connects the nasal cavity and
mouth to larynx and
esophagus, respectively
 Also known as troat
Larynx
 Provide routing mechanism for
air and food
 Make sound (voice box)
Trachea and bronchi
 Also known as wind pipe
Lungs
 two elastic membranous sac,
whose general scheme is as
follows:
trachea, primary bronchi,
secondary bronchi, bronchioles,
alveolar sacs, alveolar ducts,
alveoli ( smallest subdivision)
Alveoli
 smallest subdivision of the air
passages and the true
respiratory structures where
the exchange of gases
between the bloodstream and
the inspired air takes place
The diaphragm
 is
a
musculomembranous
partition
that
completely
separates the thoracic from the
abdominal cavity. It is muscle
for respiration
Mechanism of Respiration
External Respiration
 movement of air into and out
of the lungs (breathing)
 the passage of oxygen from
the lungs to blood
 passage of carbon dioxide
from blood to the lungs
Breathing – includes inspiration
and expiration
Internal Respiration
 Cellular respiration
 Concerned with the utilization
of oxygen and production of
carbon dioxide by the cells
Types of Breathing
costal (thoracic) – (ribs)
 abdominal - diaphragmatic
 eupnea – normal
 dyspnea – difficult breathing
 apnea – absence of respiration
 hyperpnea –increase in depth of breathing
 polypnea – shallow rapid breathing

Cardiovascular System
Function
a. to transport the nutrients absorbed from the digestive tract to
the tissues
b. to carry oxygen from the lungs to the tissues and carbon
dioxide from the tissues to the lungs
c. transport hormones from one part of the body to another
d. help maintain the water equilibrium of the body
e. assist in keeping the normal temperature of the body
f. assist in overcoming diseases
The Heart
The heart is a cone-shaped
 hollow, muscular structure
located in the thorax
 The opposite end of the cone
is known as the apex
 It is contained in a serous sac
called the pericardium.

The Blood Vessels
Arteries
 tubular structures that carry blood away from the heart
(except pulmonary artery)
 walls of arteries tend to be thick and elastic
Veins
 larger in diameter than the arteries and they carry blood
towards the heart
 (except pulmonary vein)
Veins, Arteries and capillaries
Blood Circulation
The blood vascular system is further divided into four circulations:
a. the cardiac which involves the heart;
b. the pulmonary, which involves the lungs;
c. the systemic, which involves the general body area; and the
d. the portal, which involves the intestines and the liver
Pulse Rate

Pulse rate determines the rate, rhythm, and amplitude of
the heart and can be taken using our ears and fingers or
stethoscope or electrocardiogram (ECG)
Site for taking pulse rate
Horse - Submandibular artery
Cattle – Facial artery and coccygeal artery
Pig, goat/sheep, dogs and cats - femoral artery (thigh)
Terms associated with Pulse rate
a. Bradycardia – marked slowing of the heart
rate
b.Tachycardia - increased pulse rate
c. Arrythmia – no heart beat
Blood
Charateristics
 Sticky and Viscous (5x of water)
 Specific gravity is 1.06
 pH of 7.4
 Color
Bright red – with oxygen
Dark red – without oxygen
 Has distinct odor and salty
 6-8% of body weight
Cellular elements of blood
Red Blood cells (erythrocytes)
 non-nucleated biconcave discshaped cells specialized in the
transportation of oxygen
 Composed of water and
 hemoglobin
an
iron
containing pigment which is the
principal
oxygen
transport
medium
Abnormalities

Anemia – red blood cells are
reduced in number and or
hemoglobin content

Polycythemia – excessive
number of RBC are found in
the circulating blood
White Blood Cells (leucocytes)
 nucleated cells that is capable of
independent movement
Classification of WBC
A. Granulocytes – contains
granular material within their
cytoplasm
B. Agranulocytes – has very
little granular material in their
cytoplasm
Granulocytes
A.
Nuetrophils - these are highly
phagocytic and increase in
number during acute bacterial
infections
B.
Eosinophils – become
numerous during parasitism
C.
basophils – similar to mast
cell and are enhanced during
allergic reactions
Agranulocytes
monocytes – largest
leucocytes, involved in
phagocytosis and increased in
number during chronic
infection
B. lymphocytes – involved in
immune responses
A.
Abnormalities
Leucopenia - decrease in the number of white blood cells
Leucocytosis - increase in the number of white blood cells
Platelets (thrombocytes)
 cells responsible for blood
clotting
Abnormalities:
Thrombus – a clot that
remained fixed in the lumen
of the blood vessel
Embolus – a clot that
floats freely in the
bloodstream
Fluid Elements of Blood
Plasma
 Liquid part
 92 % is water
 Provides the medium of
exchange between the blood
vessels and the cells of the
body
Serum
 fluid that remains after the
blood has clotted
Nervous system
Function
 responsible for collecting information about what is
happening inside (internal environment), as well as outside
(external environment), the body
 It communicates with all parts of the body via electrical
signals
Components
Organization of Nervous System
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
Basic Units of Nervous System
Neuron
 highly specialized cells that
respond to stimuli and
produce an impulse and
transmit that information to
distance site
Supportive cells
 Cells responsible myelin sheat,
to provides nutrients and
phagocytic role
Neuron (Nerve Cell)
Function
 Receive, process and respond
to stimuli
 Consists of the cell body,
dendrite and axon
 Dendrite – conducts
impulses toward the body cell
 Axon (nerve fiber) conducts
impulses away from the body
cell
Synapse
The continuity from one neuron
to the next is provided by the
synapse. It is the point of
contact between the neurons.
Central Nervous system (CNS)
 Brain
and Spinal Cord
Division of Brain
 Forebrain
 Midbrain
 Hindbrain
Spinal Cord

Spinal cord - the direct continuation of the brain into the
vertebral canal Structurally, the cord is somewhat similar to
the brain, being surrounded by meninges
X. Anatomy of the Mammary Gland
a. Exterior of the udder
-Udder, skin gland not connected with abdominal cavity
-Udder contains large amount of secretory tissues and small
amount of connective tissue.
b. Supporting system
-median and lateral suspensory ligaments -fibrous elastic
connective tissue
Physiological Mechanism of Lactation

mammary glands are the distinguishing characteristics of all
mammals

classified as exocrine glands, modified skin glands secrete
milk for the nourishment of the young

these glands grow during pregnancy and start to secrete
milk after parturition
 Lactation
is the production of milk by the mammary
gland in mammals like cattle, sheep, swine, horse,
goats, buffaloes and rabbits
 Young mammals at first feed solely on milk from
their mothers
 milk produced for human consumption usually
comes from cow and goat, including buffalo/carabao
Secretion of milk
1. milk is made and secreted by the single layer of cells in the
alveoli
2. precursor for milk is the plasma from the blood where large
blood vessels can be seen in the udder
c. Duct and secretory
system
- teat
- teat cistern
- sphincter muscles
- gland cistern
- secretory tissue
alveolus - tiny structure
resembling a balloon, lined
with simple layer of
epithelial cells (active in
milk secretion)
 the number of alveoli is
highly correlated with the
production capacity.

THE ENDOCRINE SYSTEM

Endocrine gland – ductless, produces hormones travel in
the blood stream to affect distant target organs

Hormones – chemical substances secreted by the
endocrine glands
Anterior Pituitary Secretes number of hormones:
Growth
Follicle
or Somatotrophic Hormone (STH)
Stimulating Hormone (FSH)
Luteinizing
Hormone (LH)
Prolactin
Thyrotropic
Hormone (TTH)
Adrenocorticotrophic
Hormone (ACTH)
Posterior pituitary gland hormones:
-Antidiuretic Hormone (ADH)
-Oxytocin
Intermediate lobe
-melanophore hormones
Adrenal Glands hormones:
-Glucocorticoids
-Mineralocorticoids - aldosterone
-Adrenaline (epinephrine) or noradrenaline
(norepinephrine)
Thyroid gland hormones
 Thyroxine
 Calcitonin
Parathyroid gland hormone

parathormone
Pancreas (Lapay) hormones
 Insulin
 Glucagon
Hormones from the Testis
 Testosterone
Hormones from the Ovaries
 Estrogen (Ovarian follicles)
 Progesterone (corpus luteum)
 Relaxin
SENSORY SYSTEM

Special senses:
- eyes (sight)
- nose (smell)
- ears (hearing and balance)
- tongue (taste)