Anatomy & Physiology of Animals

oVERVIEW

INSTRUCTOR:

UNIT:Performance of Technical Skills Related to Animal Science and Technology

LESSON: Anatomy and Physiology of Animals

IMS REFERENCE: IMS #8392

Lesson Plan

LESSON OBJECTIVES

The student will be able to:

  • describe the external anatomy of animals;
  • discuss the skeletal and muscular systems of animals;
  • explain the circulatory and respiratory systems of animals;
  • discuss the digestive and urinary systems of animals; and
  • describe the nervous and endocrine systems of animals.
TOols & equipment
  • Computer(s) with internet access
Key Terms
Adiposetissue
Aerobic
anaerobic
antagonist
antibodies
appendages
antigens
autonomic
Cellulose
complement
creatinine / defecation
diaphragm
diffusion
effectororgan
emulsify
endocrine
endoskeleton
enzymes
epiphysis
Piglottis
epithelial tissue / exhalation
exocrine
exoskeleton
glucose
hormones
humerus
hydrolyze
inhalation
larynx
metabolic wastes
monosaccharides
organ systems / pathogen
peristalsis
platelet
regurgitate
remasticate
sternum
synthesize
tendons
vasculated
volatile fatty acids
Z-line

TEACHING MATERIALS AND RESOURCES

  • IMS #8392
  • Class Notes for IMS #8392
  • Lesson Test for IMS #8392
  • PowerPoint Presentation for IMS #8392

TEACHING PROCEDURES

TEACHING PROCEDURES---Preparation, Presentation, Application, Evaluation

Preparation

Key Points / Methods
Link:
There is a great relationship between animal health and management, and the anatomy and physiology of animals. One must understand both to assist in selection, production, and reproduction.
Motivation:
List the organ systems to be discussed in this lesson in front of the class. Discuss the similarities and differences between animal organ systems and human organ systems.
Overview:
In this lesson, the students will:
  • describe the external anatomy of animals;
  • discuss the skeletal and muscular systems of animals;
  • explain the circulatory and respiratory systems of animals;
  • discuss the digestive and urinary systems of animals; and
  • describe the nervous and endocrine systems of animals.
/ Student Thought and Reflection
Teacher Led Discussion
Review of Objectives

Presentation

Key Points / Methods
INTRODUCTION
Knowledge of anatomy can aid in evaluating and selecting animals
Anatomy: study of form and structure
  • Gross anatomy: study of structures seen by naked eye
  • Microscopic anatomy: study of structures that require microscope to be seen
Physiology: functions of body and all parts, including cells, tissues, organs
Both divided into functions and integration of ten body organ systems:
  • Integumentary system (skin)
  • Skeletal system (bones)
  • Muscular system (muscles)
  • Circulatory system (heart and blood vessels)
  • Digestive system (stomach and intestines)
  • Nervous system (nerves)
  • Respiratory system (lungs and passageways)
  • Urinary system (kidneys and bladder)
  • Endocrine system (glands and hormones)
  • Reproductive system (organs involved in producing offspring)
integumentary system
Integumentary system: exterior covering essential for regulating body temperature, balancing water, protecting internal organ systems; consists of skin, skin appendages (hair, nails, horns, sebaceous glands, sweat glands)
Skin: essential organ for health; external barrier between internal organs and environment
  • Protective layer against disease, infection, sun, harmful elements
  • Two layers: epidermis and dermis
  • Epidermis: outer layer of skin; contains no blood cells; stratified epithelial tissue comprised of external layer of dead cells sitting on lower layer of living cells
  • Dermis: inner layer of skin; contains blood vessels, lymph vessels, nerves, glands, hair follicles, muscle fibers; deep layer of dense, irregular connective tissue
  • Modified extensions or structures of skin: hair, scales, hooves, feathers, claws, horns, nails
  • Coat coverings differ: hair (goats, horses, cattle, swine), wool (sheep), feathers (poultry); hair, wool, feathers composed of protein
  • Hair: essential for regulating body temperature; each follicle has small bundle of smooth muscle fibers that contract to pull hair perpendicular to skin (arrector pili muscles); contract involuntarily by nervous system in times of stress or cold
  • Glands: found in dermis; sweat glands, sebaceous glands
  • Sweat glands: release water to cool body when internal temperatures rise
  • Sebaceous glands: secrete oily substances to lubricate skin, hair
  • Mammary glands found in mammals
  • Sensory receptors: detect touch, pain, heat, cold
  • Merkel cells: respond to very light pressure
  • Free nerve endings
  • Meissner’s corpuscles: sensitive to touch; found in greater numbers in delicate areas
  • Paccinian corpuscles: detect pressure
Brahman cattle: originated in India; skin adapted to hot, dry, pest-ridden environments
  • Highly developed sweat glands
  • Less hair than Hereford, Angus, Limousin, Charolais
  • Body can release heat more effectively by sweating
  • Allows them to live in hot, humid environments
  • Oily secretion from sebaceous glands has strong odor, repels insects
skeletal system
Framework of body; provides structural support for all other organ systems
  • Made up of bones, connective tissues
  • Vertebraes have internal endoskeleton (domestic animals)
  • Insects: have exoskeleton
  • Essential function: protection of other organs; protects brain, ribs protect lungs, vertebrae protect spinal cord
  • Works in conjunction with muscles to allow body part movement
  • Individual bones are sites for blood formation, mineral storage
  • Made up of axial skeleton, appendicular skeleton
  • Axial skeleton: bones on midline of body; bones other than pelvis and limbs (skull, vertebrae, ribs, sternum)
  • Appendicular skeleton: bones coming off midline of body; limbs or appendages including forelegs, hindlegs, bones in pelvic region
  • Bones divided into four classes
  • Long bones: found in limbs; serve as supporting columns and levers for body
  • Flat bones: protect body’s organs; area of muscle attachment
  • Short bones: bones in knee and hock joint; diffuse concussion; diminish friction; change direction of tendons
  • Irregular bones: found in vertebral column
  • Bones made of organic and inorganic matter
  • Inorganic matter: tricalcium phosphate; gives bone rigidity, hardness
  • Organic matter: collagen; matrix of fibrous tissues and cells; give bone flexibility, resilience
  • Bone marrow: soft tissue in inner core of bone
  • Consists of yellow fat (yellow marrow)
  • Other portion comprised of red tissue (red marrow); responsible for blood cell, platelet information
  • Bone: living tissue that changes constantly; after maturity bones do not elongate any further, continue to turnover cells
  • Undergoes continuous deposition and resorption
  • Formed from cartilage that is laid down as embryo; process known as endochondral ossification
  • Osteoblasts become embedded in matrix of osteoid material; develop into osteocytes (mature bone cells)
  • Formation occurs as growth plates
  • primary ossification occurs at metaphyseal growth plate
  • secondary ossification occurs at epiphyseal growth plate; in center of epiphysis; growth plate is spherical
  • Connective tissue: connects other tissues together to give form, strength to organs; provide protection and leverage
  • Four types within skeletal system: ligaments, tendons, cartilage, fascia
  • Tendons connect muscle to bone, ligaments connect bone to bone
  • Three types of cartilage
  • Hyaline cartilage: found on ends of bones, acts as cushioning in joints
  • Elastic cartilage: makes up body parts such as ears
  • Fibrocartilage: provides cushioning between intervertebral discs
  • Fascia: located between skin and underlying muscle or bone; comprised of two layers: superficial fascia (attached to skin), deep fascia (cover muscle or bone)
  • Joints: articulations between bones
  • Fibrous
  • Cartilaginous
  • Synovial: allow greatest movement; referred to as true joints; gliding, flexion, extension, hypertension, rotation, adduction, abduction, circumduction
  • Joints can be movable (shoulder), partially movable (ribs), immovable (suture joints of skull)
muscular system
Works with skeletal system; allows movement of internal structures, limbs, body
Muscles are lean portion of carcass used for human consumption
Categorized by function and activation: skeletal, visceral, cardiac and/or voluntary, involuntary; can be by physiology (smooth, striated, unstriated)
Common classifications:
  • Skeletal: striated, voluntary muscles involved in movement of skeleton; intentionally controlled by animal
  • Smooth: (visceral) involuntary, unstriated; found in digestive organs, blood vessels of body; function automatically, can be controlled by animal
  • Cardiac: involuntary, striated muscle found within heart; no conscious control, can be regulated by autonomic nervous system; hormones epinephrine, norepinephrine stimulate autonomic nerves to control involuntary muscles, causing relaxation and contraction
Skeletal muscles:
  • Four groups
  • Flexors
  • Extensors
  • Abductors: i.e. biceps pull lower leg toward body
  • Adductors: i.e. tripceps move lower limb away from body
Antagonism: muscles working in pairs to contract and relax; biceps and triceps
Synergists: muscles that work together to perform movement; i.e. deltoid muscles in should work with bicep to move whole foreleg (arm)
  • Attach to two different bones; point of origin in on most stable, least movable bone; insertion point is on more moveable bone; i.e. pectoral muscles originate from sternum, insert on humerus
  • Made up of bundles of fibers that stretch from one tendon (connective tissue) to the other; bundles lie parallel to each other within muscle sheath making it appear striped (striated); each bundle consists of fibers (individual cells with multiple nuclei)
  • Myofibrils: bundles that make up individual muscle fibers
  • Sacomeres: enclose myofibrils; functional units of muscle extending from Z line to Z line; made up of thick filaments of myosin, thin filaments of actin
Muscle contraction
  • Occurs as result of sliding-filament action
  • Sarcomere contracts as result of actin and myosin filaments sliding over each other; fibers contract, causing bundles of fibers to contract; results in whole muscle contracting
  • Physiology of action is complex; energy for contraction comes from non-protein sources (adenosine, triphosphate (ATP), glycogen, body fats
  • If food intake is insufficient, energy may be taken from protein sources, resulting in weight loss
Fast-twitch muscle: fibers contract rapidly as break down glycogen in absence of oxygen (anaerobic); produce lactic acid causing muscle soreness
Slow-twitch muscle: convert fats to energy under aerobic conditions; cannot contract as quickly, do not produce lactic acid; continue to function for much longer periods
Quarter horses: more fast-twitch fibers
Thoroughbreds: ideal combination of slow and fast twitch fibers for middle distances
Arabians: slow-twitch fibers
CIRCULATORY SYSTEM
Distributes blood throughout body, removes waste, mounts immune responses to infections; assists regulating body temperature
Blood: provides organs, tissues, cells with oxygen, nutrients, gases, hormones, antibodies; removes carbon dioxide, metabolic wastes
Lymphatic system: responsible for draining fluid from body; defense mechanism against infection
System includes: heart, veins, capillaries, arteries, lymph vessels, lymph glands
Heart
  • Muscle with left and right side
  • Each side has atrium and ventricle
  • Atrium: receives blood from lungs or remainder of body
  • Ventricle: receives from atrium, pumps out of heart
  • Deoxygenated blood enters right atrium, passes through right atrioventricular (A.V.) valve, into right ventricle; then pumped through pulmonary artery to lungs
  • Oxygenated blood returns from lungs via pulmonary vein, enters left atrium; passes through left A.V. valve into left ventricle; pumped out of heart to remainder of body via aorta
Blood vessels: become smaller and smaller as they migrate away from heart
  • Arteries: divide into arterioles; carry oxygenated blood; pulmonary artery takes deoxygenated blood away from heart to lungs
  • Veins: divide into venules; carry blood back to hart; pulmonary vein carries oxygenated blood from lungs back to heart
  • Capillaries: smallest blood vessels; involved in transfer of oxygen, nutrients, gases to cells of body, removal of carbon dioxide gas, metablolic wastes out of cells; very thin membranes, components of blood can diffuse across membranes, enter cells
Two main systems: pulmonary, systemic
  • Pulmonary: delivers blood to and from lungs
  • Systemic: circulates blood throughout remainder of body
Portal Circulation systems: occurs when vein breaks into capillary bed, reforms into another vein
  • Renal (kidneys) portal system
  • Hepatic (liver) portal system
Blood
  • Red blood cells (erythrocytes): most numerous; contain hemoglobin
  • Hemoglobin: contains iron; responsible for carrying oxygen in blood
  • Red blood cells responsible for delivering oxygen to cells; involved in removing carbon dioxide
  • White blood cells (leukocytes): responsible for body’s immune response, defense against infections
  • Two types: granulocytes, agranulocytes; play roles in combating foreign bodies, bacteria, viruses, other infective agents
  • Platelets (thrombocytes)
  • Plasma: contains blood cells and platelets; yellowish liquid that is 90% water; carries most carbon dioxide
Lymphatic System
Part of, works with, circulatory system; comprised of lymph vessels, lymph nodes, lymph organs, areas of lymph tissue within intestinal wall
Organs include bone marrow, tonsils, thymus, spleen
Maintains internal fluid balance; important component of body’s immune system; certain amount of fluid leaks from blood vessels into intercellular space; 10-20% remains in tissue; lymph vessels remove this preventing tissue from filling up; returns fluid to blood stream via thoracid lymphatic ducts which open into veins in neck region
Lymph vessels
  • Thin-walled, blind-ended
  • Originate in body tissues
  • Take lymph towards heart
  • Lymph is moved by lymphokinetic actions: movement of muscles and organs and changes in thoracic, abdominal pressures
  • Have multiple valves, prevent back-flow of lymph
  • Lymph nodes: located throughout body along lymph vessels; filter lymph, act as barrier against infection by harboring lymphocytes, monocytes, plasma cells
Infection
  • Non-specific response: acts against general infections, first line of defense; mounted by phagocytic white blood cells and compound known as complement; includes process of inflammation
  • Phagocytic white blood cells: include neurophils, monocytes; found in blood and lymph vessels; ingest variety of bacteria on contact
  • Complement: made up of proteins which cause foreign cells to lyse or burst before destroying them; coat surface of bacterial cells, attract phagocytes to ingest them
  • Inflammation: occurs at site where foreign body or pathogen has invaded skin or another protective barrier such as epithelial lining of respiratory, digestive tracts; foreign cell may be virus, bacteria, protein, fungi, non-living substance such as a toxin or drug; enter body and circulate in blood and lymph systems; signs are swelling, redness, heat, pain
  • Specific response: involves immune mechanisms that target foreign bodies or pathogens
  • Mounted by immune system against particular pathogenic cells
  • Antibodies: formed from lymphocytes; bind to specific antigens surface of pathogenic cells; can inactivate or destroy cells; only react with particular antigens
Immune system
  • Ability to remember particular infections; capable of producing antibodies to combat that pathogen in the future, assuming immune system functioning normally, animal healthy
  • Infected second time, immune response will be quicker, more effective than response to original infection
  • Vaccine stimulates production of antibodies for particular pathogen without causing disease or infection; done by giving animal dead vaccine or modified live vaccine; exposes animal to what appears to be live pathogen, immune system generates antibodies
digestive system
Breaks down various nutrients found in feeds into molecules used by cells of the body; made up of mouth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, anus
Stages: biting, chewing, swallowing, mixing of food, digestion, absorption of nutrients, excretion of wastes
Digestion: chemical breakdown of complex food into simple nutrients, then into smaller particles, ultimately into molecules that are small enough to pass across wall of the intestines.
Absorption: passage of molecules across intestinal wall into blood or lymph system
Herbivores: animals such as cattle, sheep, horses, rabbits that depend entirely on plants for food
Carnivores: species that depend entirely on flesh of other animals for food
Omnivores: swine, poultry, humans; consume both flesh and plants
Different species of animals have digestive tracts adapted to most efficient use of feed they consume
Food must be digested (broken down chemically) into molecules before it can enter blood stream of an animal, be used by its cells; food that is eaten by animals can be broken down into carbohydrates, proteins, lipids, vitamins, minerals
Carbohydrates, proteins, lipids: broken down further into respective chemical building blocks
Polysaccharides: chemical building blocks of carbohydrates; made up of multiple monosaccharides; most common is starch; others include cellulose, hemicellulose, glycogen
Starch: made up of multiple glucose molecules
Glucose: is a monosaccharide
Enzymes that hydrolyze polysaccharides are named after the specific polysaccharide that they breakdown; starch broken down by amylase, cellulose broken down by cellulose, sucrose by sucrase
Protein: broken up into amino acids by enzymes called proteases and peptidases
Amino acids: hundreds exist; most animals have essential number of amino acids; proteins are synthesized from specific pattern of essential amino acids; if not present in diet, not able to synthesize protein for metabolic functions; will not be able to produce muscle tissue, hair, milk, new cells, other components of body
Proteases: break down large protein molecules
Peptidases: break down small protein molecules
Lipids (fats) fall into three categories: triglycerides (most common), phospholipids, waxes; triglycerides made up of glycerol molecule and three fatty acid molecules
Lipases: enzymes that break down triglycerides
Animals can be divided into three groups by digestive systems: ruminants, monogastrics, hindgut fermenters; distinct differences occur in anatomies; many similarities occur, especially in physiological functions of digestion
Ruminants: have four stomachs; cattle, goats, deer
  • Four stomachs: rumen, reticulum, abomasums, omasum
  • Rumen: largest chamber, contains millions of microbes including bacteria, fungi, protozoa; microbes digest food as it enters, releases nutrients used by animal
Monogastric: single glandular stomach; swine, poultry