Animal Form and Function Chapter 40 Animal Form and Function

Tissues: groups of cells with a common structure and function - Tissues: groups of cells with a common structure and function - 4 general categories: epithelial, connective, muscle, nervous

1) Epithelial Covers surfaces and lines organs and cavities Sometimes specialized for absorption or secretion; mucous secretions lubricates digestive and respiratory systems Types: Simple: single layer of cells Stratified: multiple tiers of cells Cuboidal (like dice) Columnar (like bricks on end) Squamous (like floor tiles)

2) Connective Bind and support other tissues (suspend organs in place) Made of scattered cells in a matrix

Connective Loose connective tissue: binds epithelia to underlying tissue; holds organs (aka body’s binding and packing tissue), made of: 1-Fibroblasts- secretes extracellular proteins 2-Macrophages- amoeboid WBC’s; Adipose tissue (specialized type of loose)- fat storage; insulation

Types of Connective Tissue 1) Fibrous connective tissue: parallel bundles of cells 1-Tendons- muscles to bones 2-Ligaments- bones to bones; joints 2) Cartilage: collagen in a rubbery matrix; strong but flexible support 3) Bone: dense network made of collagen and mineral deposits

Types of Connective Tissue, cont. Blood: fluid matrix with different types of blood cells suspended Loose connective tissue – binds epithelia to underlying tissue Adipose tissues: contains fat cells; pads and insulates

3) Muscle Able to contract when stimulated by nerve impulses; myofibrils composed of proteins actin and myosin; 3 types: A- Skeletal: powers voluntary movement (striated) B- Cardiac: contractile wall of heart (branched striated fibers) C- Smooth: involuntary activities (no striations), found around intestines and blood vessels

4) Nervous (you can add these details to #2) Senses stimuli and transmits signals from one part of the animal to another

Organ systems ORGAN SYSTEMS Digestive - food processing Circulatory - internal distribution of materials Respiratory - gas exchange Immune/Lymphatic - defense Excretory - waste disposal; osmoregulation Endocrine - coordination of body activities Reproductive - reproduction Nervous - detection of stimuli, coordination of body activities Integumentary - protection Skeletal - support; protection Muscular - movement; locomotion

Internal regulation Interstitial fluid: internal fluid environment of vertebrates; exchanges nutrients and wastes Homeostasis: “steady state” or internal balance Maintained by homeostatic control system: 1) Receptor detects changes in some variable of animal’s internal environment 2) Control center processes info from receptor and 3) directs response by effector

Negative Feedback Negative feedback: change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation Example: body temperature

Positive Feedback Positive feedback: A change in some variable triggers mechanisms that amplify the change (rather than reverse it) Example: uterine contractions at childbirth

Energy and Molecular Uses for Food

Energy Needs Basal Metabolic Rate (BMR): minimal rate powering basic functions of life Larger organisms use less energy per kilogram

Metabolism: sum of all energy-requiring biochemical reactions Endotherms: bodies warmed by heat generated by metabolism Many are able to maintain high and stable internal temp regardless of surroundings Ex: mammals, birds (BMR 1300-1800 kcal/day) Ectotherms: bodies warmed by environment (smaller energy expenditures) Low metabolic rate doesn’t generate enough heat to effect body temp Ex: fish, amphibians, lizards, snakes (BMR 60)