Animal form and function
- An animal's size and shape are fundamental aspects of form that significantly affect the way an animal interacts with its environment.
- Physical laws limit the range of animal forms.
Exchange with environment
- Exchange occurs as substances dissolve in an aqueous medium move across the plasma membrane of each cell.
- The amount of material that must be exchanged to sustain life is proportional to volume.
- Every cell need to have access to a suitable aqueous environment, either inside or outside of the animal's body.
Exchange with environment in larger animals
- Every cell must be bathed in fluid and have access to oxygen, nutrients and other resources.
- The surfaces of exchange lie within the body, protecting delicate exchange tissues from abrasion of dehydratation and allowing for streamlined body contours.
- Intestitial Fluid: the fluid filling the spaces between cells in an animal.
- Exchange between intestitial fluid and circulatory fluid enables cells to obtain nutrients and get rid of wastes.
Tissue Structure and Function
Epithelial, Connective, Muscle and Nervous.
- Covers the outside of the body and lines organs and cavities within the body.
- Epithelial cell shape: cuboidal (dice), columnar (bricks), or squamous (floor tiles).
- Arranged in: simple epithelium (single layer), stratified epithelium (multiple tier of cells), or pseudostratified epithelium (single layer varying in height).
- Cuboidal epithelium: kidney tubules, glands like thyroid and salivary.
- Simple columnar epithelium: intestines.
- Pseudostratified ciliated columnar epithelium: respiratory tract.
- Stratified squamous epithelium: skin, esophagus, anus, vagina.
- Simple squamous epithelium: blood vessels, lungs.
- Bind and support other tissues and hold organs together in the body.
- Types: loose connective tissue, cartilage, fibrous connective tissue, adipose tissue, blood, bone.
- Types of connective tissue: collagenous (provide strength and flexibility), elastic (easily stretched but resilent), reticular (joins tissues together).
- Contains Fibroblast (secrete protein for fibers) and Macrophages (engulf foreign particules and derbis).
- Resposible for all types of body movement.
- Types:skeletal, cardiac, and smooth.
- Skeletal muscle:for voluntary movements, longs cells called muscle fibers.
- Cardiac muscle:forms the contractile wall of heart, involuntary movement.
- Smooth muscle:in digestive tract, urinary bladder, arteries and internal organs, involuntary movement.
- The function is to sense stimuli and transmit signals in the form of nerve impulses.
- Contains neurons that transfer nerve impulses, glial cells that help nourish, insulate and replenish neurons.
Endocrine and Nervous system
Endocrine system: releases signaling molecules (hormones) into the bloodstream by endocrine cells that reach all locations in the body. Hormones may have an effect in a single location or in sites throughout the body. Hormones are slow acting but the effects are long-lasting. Good for gradual changes like growth and development, reproduction, metabolic processes and digestion.
Nervous system: each signal (nerve impulse) travels to a target cell along axons. Only neurons, muscle cells, endocrine cells and exocrine cells can receive signal. They can only travel thought a pathway. Transmition is very fast and last only a fraction of a second. Good for direct immediate and rapid responses to environment like movement and behavior.
Regulator vs Conformer
Regulator: uses internal control mechanisms to regulate internal change in the face of external fluctuation (river otter). Temperature of regulator is independet of the environment.
Conformer: it allows its internal condition to conform to external changes in the variable (largemouth bass). As the water warms or cools, so do the cells in the conformer.
Negative vs Positive feedback
Negative feedback: a response the reduces the stimulus like sweating when you are producing heat by exercise, sweat cools the body.
Positive feedback: triggers mechanisms that amplify rather than diminish the stimulus. During child birth, the mother's uterus stimulates the uterus to contract that causes greater pression until the baby is born.