VT 111 Lec. 1 Intro/Directional Terms

Anatomy

Form and structure

Physiology

Function of the body and its parts

Microscopic Anatomy

Anatomy observed with the assistance of a microscope

Macroscopic Anatomy

Anatomy that can be seen with the unaided eye; also called gross anatomy

Pattern of Structural Hierarchy

Atoms

Molecules

Cells

Tissues

Organs

Organ systems

Organism

11 Body Systems of Animals

• Skeletal

• Integumentary

• Nervous

• Urinary/excretory

• Endocrine

• Reproductive

• Cardiovascular

• Respiratory

• Digestive

• Muscular

• Sensory

• Lymphatic (not really a system)

Homeostasis

A state of dynamic equilibrium maintained in the body by feedback and regulatory processes in response to internal and external changes.

Components of a Homeostatic System

• Sensor: (AKA control center) detects change

• Variable: The parameter being controlled by the system (temperature, chemical concentration, etc.)

• Effector: the structure that changes the variable

Life Functions of the Animal Body

• Maintaining boundaries

• Movement

• Detect and respond to environmental change (stimuli)

• Take in and digest food

• Metabolism

• Excretion

• Growth

• Reproduction

Maintaining Boundaries

● Plasma (cell) membrane protects the inside of the cell from the outside

● Maintain membrane integrity (hydrophobic nature as well as cholesterol stabilizes the membrane)

● Maintain and support the integument (skin) as a barrier

Movement

●All activities promoted by the muscle system: Propulsion, etc.

●Manipulating of the environment: digging, etc.

●Skeletal system provides a system of levers

●Propelling digesta through the G.I. tract

Detect & Respond to Environmental Change (Stimuli)

●Detection is the responsibility of the nervous system

●Elaborate system of sensors are present: Special senses, as well as baroreceptors, chemoreceptors, thermoreceptors, etc.

●Animal must be able to respond to changes to maintain homeostasis: Increase or decrease blood pressure, temperature, glucose, etc.

Take in & Digest Food

●Ingest food, prehend (grab) food

●Secretion of digestive enzymes

●Absorption of nutrients across the gut wall

Metabolism

• The orderly set of chemical reactions that occur within cells

• Break down of complex substances

• Usage of small substances as building blocks for larger structures

• Usage of nutrients and oxygen to convert energy/ATP

• Metabolic processes are regulated by hormones

• Metabolic products are transported in the blood

Excretion

• Elimination of solid and aqueous waste from the body

• Production of carbon dioxide (CO2)

• Regulation of pH

• Osmoregulation - maintaining salt regulation (electrolytes) in the body

Growth

• Increase in the number of cells

• Increase in body size

• For growth to occur:

  Anabolic rate > Catabolic rate

Reproduction

• Can be at the cellular level:

  • Reproducing daughter cells for growth or repair (mitosis)

• Can be at the organismal level:

  • Reproduction of whole new organisms (sexual reproduction via fertilization of gametes created via meiosis)

• Two basic animal strategies:

  • Many offspring produced, few survive, little parental investment in survival

  • Few offspring produced, higher survival rate, considerable parental investment in survival

Importance of Anatomical Terminology

Have the same meaning regardless of the orientation of the animal or the position of the observer; eliminates confusion

Body Planes

Sagittal Plane

plane from cranial-caudal, separates body into unequal L/R halves

Median Plane

similar to sagittal except through the exact midline of the body

Transverse Plane

plane across the body, separates into cranial and caudal halves

Dorsal Plane (aka, coronal or frontal):

Dorsal (aka, coronal or frontal): separates into dorsal and ventral halves

Directional Terms for Animals

Anterior

Toward the head

Posterior

Toward the tail

Cranial

Towards the head

Caudal

Toward the tail

Dorsal

Toward the back

Ventral

Toward the belly

Medial

Toward the midline

Lateral

Toward the side; away from the midline

Superficial

toward the surface of the body or a body part (external)

Deep

toward the center of the body (internal)

Rostral

Toward the nose

Directional Terminology Pertaining to Limbs

Proximal

toward the beginning attachment point on a limb

Distal

away from the beginning attachment point on a limb

Palmar

the caudal surface of the forelimb from the carpus down

Plantar

the caudal surface of the hindlimb from the tarsus (hock) down

Dorsal (limbs)

toward the top of an animal

Cranial (limbs)

the “front” surface of a limb proximal to the carpus or tarsus

Caudal (limb)

toward the tail (or “back” surface of a limb

Axial

refers to the central axis of the body

Appendicular

refers to the appendages and their associated girdles (pelvic, pectoral)

Regional Terminology

Axillary

Armpits of the animal

Brachial

Upper arm

Buccal

Cheek

Carpal

“Wrist” area of an animal

Cervical

Neck region

Cranial

Head

Digital

Toes

Femoral

Thigh

Flank

The part of the side between the ribs and the hip; the side of a quadruped

Hock

Ankle

Inguinal

Area where thigh meets the trunk

Nasal

Nose; rostrum

Oral

Mouth

Orbital

Eye area

Occipital

Back of head

Patellar

Knee

Sternal

Breast bone area; ventral thorax

Stifle

Knee

Tarsal

Ankle

Thoracic

Chest

Umbilical

Navel

Withers

Dorsal in between shoulder blades

Body Cavities

• Dorsal:

  • Cranial cavity

  • Spinal cavity

    ONLY

• Ventral:

  • Cranial

    • Thoracic: heart, lungs

  • Caudal

    • Abdominopelvic

Serous Membranes

• Lungs (Thoracic cavity)

  • Lined by pleura

    • Layers over organs: Visceral layer = visceral pleura

    • Layers lining cavity:

      Parietal layer = parietal pleura

• Fluid in between layers

• Abdomen (Abominopelvic cavity)

  • Lined by peritoneum

    • Layer over organs: Visceral layer = visceral peritoneum

    • Layer lining the cavity: Parietal layer = parietal peritoneum

• Heart (Thoracic cavity)

  • Lined by the pericardium

    • Layer over organs: Visceral layer = visceral pericardium

    • Layer lining the cavity: Parietal layer = parietal pericardium

Serous Membranes

covers walls and organs in the thoracic

and abdominopelvic cavities.

Parietal Layer

line the walls of the body cavity

Visceral layer

covers the organs (the viscera).

Serous Space/Fluid

Between the parietal and visceral layers.

3 Serous Membranes

1. Pleura - Serous Membrane that surrounds the lungs. One for each lung.

2. Pericardium - Serous Membrane that surrounds the heart.

3. Peritoneum - Serous membrane that surrounds several organs in the abdominopelvic cavity.