AA22 ANIMAL SCIENCE IIANATOMY & PHYSIOLOGYEssential Standard 3.00: Understand anatomy and physiology of animals.

Objective 3.01: Classify anatomy of body systems.

Objective 3.02: Summarize pysiology of body systems.

Body System Structure

A. Organisms begin as a single cell created from the fertilized ovum.

B. As cells divide and grow they differentiate into various tissues and serve various functions in the body.

C. There are essentially 5 tissues found in the body:1. Muscle- contractile tissue that allows for movement of the

animal.2. Connective- holds various tissues together such as bone.3. Nerve- tissue that transmits information to various parts

of the body. 4. Epithelial- tissue that covers other tissue such as skin. 5. Fluid- liquid type tissue such as blood.

D. The tissues work together to form the organs that sustain life and serve various functions.

E. Each body system will have a variety of the different tissues with each depending on the other to function normally.

Skeletal System Anatomy

A. Functions- protect vital body organs and give form or shape to body.

B. Major parts include bones, cartilage, teeth and joints.

C. Kinds of Bone- based on the different structure of the bone.

1. Cancellous Bone- also known as spongy bone. Soft bone tissue filled with holes that are surrounded by hard bone. Typically found at the end of long bones.

2. Compact Bone- consists of a structure known as the Haversian system. This system is a hard, protective layer of bone tissue that surrounds bone marrow.

D. Types of Bone- classified based on the shape or structure of the bone.

1. Long- long cylindrical shaped bones that support the body. Example: femur.

2. Short- cube shaped bones. Example: carpus/knee.

3. Flat- long, wide bones that protect vital organs. Example: scapula.

4. Pnuematic- contains sinuses (spaces) that come into contact with atmosphere. Example: face bones.

5. Irregular- various shapes that protect and support the nervous system. Example: vertebrae.

6. Sesamoid- flat and round shaped bones. Located along tendons. Example: patella.

E. Components to the Skeletal System1. Axial Skeleton- bones that are on or

close to the midline of the animal. Major bones of the axial skeleton:

i. Vertebral Column- includes 5 sections. a. Cervical vertebrae- section closest to the skull. b. Thoracic vertebrae.c. Lumbar vertebrae.d. Sacral vertebrae.e. Coccygeal vertebrae- tail section.

ii. Ribs.iii. Sternum- breastbone. iv. Skull.

2. Appendicular Skeleton- bones that project from midline of the animal.

i. Pectoral Limb- front limb of the animal. Major bones of pectoral limb:a. Scapula- shoulder blade.b. Humerus- arm. c. Radius and ulna- forearm.d. Carpals- knees of the forelimb. e. Metacarpals- feet/hoof. f. Phalanges- toes.

ii. PelvicLimb- hind limb of the animal. Major bones of pelvic limb:a. Femur- upper leg bone.b. Tibia and fibula- lower leg bones. c. Tarsals- hocks.d. Metatarsals- feet/hoof. e. Phalanges- toes.

Skeletal System Physiology

A. Formation of Bone1. Embryo skeletal development begins

as cartilage. 2. Cartilage is tough yet flexible and

elastic connective tissue.3. As the mammal develops, most

cartilage is replaced as bone tissue. Remaining cartilage is found in joints or other specialized structures.

4. Bone Compositioni. 26% minerals- calcium compounds.ii. 50% water.iii. 4% fat. iv. 20% protein.

5. Transformation of cartilage to bone occurs when specialized cells called osteocytes break down the cartilage and replace it with bone tissue.

B. Bone tissue contains blood, lymph vessels and nerve fibers that continue to grow and repair themselves over the life of the animal.

C. Bone tissue requires adequate nutrition to function properly.

Muscular System Anatomy

A. Functions- provide movement, form and generate heat for animals. Also important in the support of life through the digestive and respiratory systems.

B. Lean portion of the carcass of meat animals used for human food.

C. Classes of Muscles1. Voluntary- under control of the animals will.2. Involuntary- not under control of the animals

will.

D. Types of Muscle1. Striated- voluntary and involuntary muscles that

are attached to the skeleton by tendons. i. Also known as skeletal muscle. ii. Most meat consumed by humans is striated muscle

tissue. iii. Makes up majority of muscle tissue in body.

2. Smooth- involuntary muscle found in internal organs and blood vessels.

i. Acts more slowly than other muscle types. ii. Can react to stimuli other than nerve endings such as

chemicals and/or hormones.

3. Cardiac- involuntary muscle found in the heart.

Muscular System Physiology

A. Striated Muscle- contains dark bands that cross each muscle fiber.

1. Exist in bundles that are enclosed in connective tissue called the perimysium.

2. Each perimysium contains cylindrical shaped muscle fibers called sarcoplasm.

3. Each fiber is contained in a sheath known as the sarcolemma.

4. Muscle is covered by a sheath of connective tissue called the epimysium.

5. Myofibrils are the components of the muscle fiber.

6. Myofilaments are found in the myofibril.

7. Nerve endings are located on every muscle fibril.

8. Muscle contracts when stimulated by an impulse from the nerve.

9. Energy for muscle contraction comes from ATP (adenosine triphosphate).

10. The muscle contraction process generates heat for the body.

B. Smooth Muscle- activated by the autonomic nervous system.

1. Do not contain the myofibrils or dark bands found in skeletal muscle.

2. The cellular structure of smooth muscle is smaller and more spindle shaped as compared to striated muscle.

3. Myofibrils are replaced by bundles of thick filaments.

C. Cardiac Muscle- functions similar to striated muscle except fibers are interconnected.

Respiratory System Anatomy

A. Functions- provide oxygen to tissues and removal of carbon dioxide, control temperature and voice production (“talking-” squealing, mooing, etc.)

B. Major Organs Include1. Nostrils- draw in air. 2. Nasal cavity- air is warmed and moistened

while dust particles are filtered out. Also responsible for smell.

3. Pharynx- site where air and food passages are joined and split into respective parts.

4. Larynx- cartilage structures that contain vocal cords.

5. Trachea- tube that connects larynx to bronchi.

6. Bronchi- two branch shaped structures that connect trachea to each lung.

7. Bronchioles- smaller branches inside lungs. 8. Alveoli-thin microscopic sacs located at the

terminal end to respiratory system. Location of actual carbon dioxide and oxygen exchange.

9. Lungs- large lobed organs that contain parts essential for oxygen exchange. Spongy, pinkish colored organ located between the front legs of the animal and extends to the abdominal area.

10. Diaphragm- large muscle separating the chest from the abdomen and aids in the respiration process.

Respiratory System PhysiologyA. Animal breathes by using

diaphragm and rib muscles to enlarge the chest cavity.

B. Air enters the body through the mouth and nasal cavity.

C. Passes through pharynx and larynx. 1. Larynx contains vocal cords. 2. As air passes over the vocal cords,

sound is produced by the animal.

D. Air continues down through trachea, bronchi, and bronchioles to clusters of air sacs called alveoli in the lungs.

E. Alveoli are surrounded by minute blood vessels called capillaries.

F. The capillaries pick up oxygen through the thin walls of the alveoli.

G. The oxygen goes into the bloodstream and locks onto red blood cells in the bloodstream.

H. The heart pumps the oxygen rich red blood cells to other tissues throughout the body.

I. The bloodstream then picks up carbon dioxide from tissues, carries it to the alveoli where the gas is again exchanged and excreted through the trachea into the atmosphere.

Circulatory System Anatomy

A. Functions- supply body tissues with nourishment, collect waste materials from body tissues, transports hormones and cells of the immune system.

B. Major Organs/Parts Include1. Heart- major involuntary muscle that

pumps blood throughout the circulatory system. Large reddish colored organ located just behind the shoulder on the left side of the animal.

2. Arteries- small tube-like structures that carry blood from the heart to organs and tissues throughout the body.

3. Veins- small tube-like structures that carry blood to the heart from organs and tissues.

4. Capillaries- vessels that exchange nutrients, oxygen, carbon dioxide, waste products, etc. from the arteries and/or veins.

5. Lymphatic System- works with circulatory system to carry lymph fluid from vessels and glands to the capillaries that feed into the circulatory system.

Circulatory System Physiology A. The heart is the major circulatory

system organ and pumps blood throughout the animal’s body.

B. Blood flow through the heart: 1. Contractions of the heart begin in the

atria and proceed to the ventricles.2. The contraction and relaxation of the

heart forces blood to move through the circulatory system.

3. Mammals have four chambers:i. Left and right ventricles- in the lower part of

the heart.ii. Left and right atria- in the upper part of the

heart.

4. Valves between the atria and ventricles keep blood flow moving in one direction.

5. Blood enters the right atrium through:i. Cranial/Superior/Anterior vena cava-head

area.ii. Caudal/Inferior/Posterior vena cava-lower

body.

6. This blood is low in oxygen and high in carbon dioxide (deoxygenated blood)

7. Contraction of the right ventricle forces the blood into the pulmonary artery that carries the deoxygenated blood to the lungs.

8. Gas exchange takes place in the lungs and then the blood is sent back to the heart through the pulmonary veins.

9. Pulmonary veins enter the left atrium of the heart.

10. Then the left atrium contracts and forces blood into the left ventricle.

11. Then goes to the aorta that carries oxygenated blood to the body.

Student Assignment

Instructions: Use the lines provided in your guided

notes to take notes during the “Blood Flow through the Human Heart” module.

You should take notes from each slide of the module.

Bulleting information is recommended! Website link: http://

www.sumanasinc.com/webcontent/animations/content/human_heart.html

C. Blood1. Material that circulates throughout the body

through veins and arteries. 2. Major Functions Include

i. Transport nutrients from digestive system to various body tissues.

ii. Transport oxygen from the lungs to various body tissues.

iii. Transport waste products.iv. Helps regulate body temperature. v. Transport hormones.vi. Help protect body against disease and organisms by

transporting immune cells.

Nervous System Anatomy

A. Functions- coordinate the physical movement of the body, respond to hearing, sight, smell, taste, and touch and react to internal and external stimuli.

B. Major Parts/Organs Include1. Central Nervous System- functions to coordinate

and control body activities. Includes the brain and spinal cord.

2. Peripheral Nervous System- includes all the nerves that send messages to and from the central nervous system. Two basic types of nerves:

i. Somatic Nerves- voluntary process of relaying information between skin, skeletal muscles and the central nervous system. Reflexes are also somatic nerves, but are controlled involuntarily.

ii. Autonomic Nerves- involuntary process of relaying information from central nervous system to organs.

Nervous System Physiology

A. Neurons are cells that conduct impulses in the nervous system.

B. Neurons control different parts of the reaction to stimuli based on their type and function:

1. Sensory Neurons- carry impulses from internal and external stimuli to the brain and spinal cord.

2. Interneurons- processes the impulses received from sensory neurons inside of the brain and spinal cord.

3. Motor Neurons- carry the impulses away from the brain and spinal cord.

C. Stimuli Response Example1. Receptors in the skin identify touch or

other stimuli.2. Sensory neurons carry stimuli message

to the brain and spinal cord. 3. The interneurons in the brain process

the “message” and determine a response.

4. Motor neurons transmit a response reaction to the stimulated tissue.

Endocrine System Anatomy

A. Function- works with the nervous system to control internal body functions. Affects and controls growth, reproductive functions (heat, lactation, birth, etc.), shape of the animal’s body, feed efficiency and adaptation to environment. Hormones are primary substance involved in function of endocrine system.

B. Major Organs/Parts Include 1. Pituitary Gland- major gland of the endocrine

system. Secretes hormones that regulate the other hormones involved in the endocrine system.

2. Ovaries- secrete hormones such as estrogen and progesterone that are involved in the estrus cycle, gestation and parturition.

3. Testicles- secrete hormones such as testosterone that are involved in the production of sperm, sex drive and development of male body characteristics.

4. Thyroid Gland- secretes the hormone thyroxin that stimulates growth and metabolism.

5. Hypothalamus- secretes hormones involved in the reproductive cycle.

6. Adrenal Glands- secrete hormones such as adrenaline that respond to stress.

Endocrine System Physiology

A. Hormones in the animal’s body control various body functions such as growth, reproductive functions, feed efficiency, etc.

B. Hormones- chemical substances that affect glands and organs in the body.

C. Glands- cells or groups of cells that secrete fluids.

D. Hormones are passed into the bloodstream as the blood passes through various glands in the animal’s body.

E. The hormones then travel to the “target” organ in the body which stimulates a response. Example: estrogen stimulates heat behavior “response.”

Urinary System Anatomy

A. Functions- filter fluid and remove waste.

B. Major Organs/Parts Include1. Kidneys- blood passes through and waste products

and water are removed. Urine is the combination of this liquid and waste products.

2. Ureters- the liquid (urine) from the kidneys travel through tube-like structures called ureters to the bladder.

3. Bladder- stores urine. 4. Urethra- tube-like structure that excretes the urine

waste.

C. Poultry do not have a bladder or urethra. The ureters are directly connected to the cloaca where solid and liquid wastes are excreted.

Urinary System Physiology

A. Blood in the animal’s body passes through the kidneys. Waste products are removed and water is collected to form liquid waste (urine).

B. The urine containing the waste products travels through the ureters to the bladder.

C. Urine is stored in the bladder until it is full.

D. The urethra then excretes the urine.