AP Biology 3/8/13 Chp.40: An Introduction to Animal Structure and Function

Diverse Forms, Common Challenges All organisms need to perform certain functions: Gas exchange with environment Obtain and digest food Eliminate Waste LE 40-3 Diffusion Mouth Two cell layers Single cell Gastrovascular cavity

Structure and Function…. Similar structures have evolved multiple times to deal with similar functions Ex: Convergent evolution in swimming animals

….Anatomy and Physiology Anatomy: structure Physiology: function LE 40-4 Digestive system Circulatory Excretory Interstitial fluid Cells Nutrients Heart Animal body Respiratory Blood CO2 Food Mouth External environment O2 50 µm A microscopic view of the lung reveals that it is much more spongelike than balloonlike. This construction provides an expansive wet surface for gas exchange with the environment (SEM). 10 µm Inside a kidney is a mass of microscopic tubules that exchange chemicals with blood flowing through a web of tiny vessels called capillaries (SEM). The lining of the small intestine, a digestive organ, is elaborated with fingerlike projections that expand the surface area for nutrient absorption (cross-section, SEM). Unabsorbed matter (feces) Metabolic waste products (urine) Anus 0.5 cm

Animal Anatomy and Physiology Most animals are composed of specialized cells organized into tissues that have different functions Tissues make up organs, which together make up organ systems Different tissues have different structures that are suited to their functions Tissues are classified into four main categories: epithelial, connective, muscle, and nervous

Organ systems Organ: organization of tissues Digestive-food processing Circulatory-internal distribution Respiratory-gas exchange Immune/Lymphatic-defense Excretory-waste disposal; osmoregulation Endocrine-coordination of body activities Reproductive-reproduction Nervous-detection of stimuli Integumentary-protection Skeletal-support; protection Muscular-movement; locomotion Organ: organization of tissues Mesentaries: suspension of organs (connective tissue) Thoracic cavity (lungs and heart) Abdominal cavity (intestines) Diaphragm (respiration) Organ systems…... (See Table 40.1)

Bioenergetics the flow of energy through an animal, limits behavior, growth, and reproduction

Internal regulation Homeostasis: “steady state” or internal balance Interstitial fluid: internal fluid environment of vertebrates; exchanges nutrients and wastes Homeostasis: “steady state” or internal balance

Regulation Negative feedback: change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation; i.e., body temperature Positive feedback: physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change; i.e., uterine contractions at childbirth

Homeostatic Regulation of cellular fluid

Metabolism: sum of all energy-requiring biochemical reactions Catabolic processes of cellular respiration (breaking down) Calorie; kilocalorie/C Basal Metabolic Rate (BMR): minimal rate powering basic functions of life (endotherms) Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms)

This photograph shows a ghost crab in a respirometer This photograph shows a ghost crab in a respirometer. Temperature is held constant in the chamber, with air of known O2 concentration flowing through. The crab’s metabolic rate is calculated from the difference between the amount of O2 entering and the amount of O2 leaving the respirometer. This crab is on a treadmill, running at a constant speed as measurements are made. Similarly, the metabolic rate of a man fitted with a breathing apparatus is being monitored while he exercises on a stationary bike.

Endotherms: bodies warmed by metabolic heat Ectotherms: bodies warmed by environment Examples: (In general) Endotherms – Birds, mammals Ectotherms – Fish, reptiles, amphibians Vs. Homeotherm – constant body temp Poikilotherm – variable body temp

800,000 Endotherms 340,000 Annual energy expenditure (kcal/yr) Basal (standard) metabolism Reproduction Temperature regulation Growth Activity 60-kg female human from temperate climate 4-kg male Adélie penguin from Antarctica (brooding) 4,000 0.025-kg female deer mouse from temperate North America 4-kg female python from Australia 8,000 Ectotherm Total annual energy expenditures. The slices of the pie charts indicate energy expenditures for various functions. Energy expenditures per unit mass (kcal/kg•day). Comparing the daily energy expenditures per kg of body weight for the four animals reinforces two important concepts of bioenergetics. First, a small animal, such as a mouse, has a much greater energy demand per kg than does a large animal of the same taxonomic class, such as a human (both mammals). Second, note again that an ectotherm, such as a python, requires much less energy per kg than does an endotherm of equivalent size, such as a penguin. Energy expenditure per unit mass (kcal/kg•day) 438 233 36.5 5.5 Python Human Deer mouse Adélie penguin

Homework  due Monday Chp.40 Guided Reading: Animal Structure & Function

Did not use…

Tissues: groups of cells with a common structure and function (4 types) 1- Epithelial: outside of body and lines organs and cavities; held together by tight junctions

Tight Junctions – impermeable to water

Epithelial Tissues basement membrane: dense mat of extracellular matrix mucous membrane Simple: single layer of cells Stratified: multiple tiers of cells Cuboidal (like dice) Columnar (like bricks on end) Squamous (like floor tiles)

Connective Tissues Bind and support other tissues Scattered cells through matrix Matrix - non-living material for the nourishment of cells Fibers. Not all types of connective tissues are fibrous though. Examples are adipose tissue and blood. Adipose tissue gives "mechanical cushion" to our body. The matrix of blood is plasma.

Connective Tissues Loose connective tissue: binds epithelia to underlying tissue; holds organs Fibrous connective tissue: parallel bundles of cells Cartilage: collagen in a rubbery matrix (chondroitin); flexible support Bone: mineralized tissue by osteoblasts Blood: liquid plasma matrix; erythrocytes (RBC’s) carry O2; leukocytes (WBC’s) immunity

Nervous Tissue Senses stimuli and transmits signals from 1 part of the animal to another Neuron: functional unit that transmits impulses Dendrites: transmit impulses from tips to rest of neuron Axons: transmit impulses toward another neuron or effector

Muscle Tissues 4- Muscle: capable of contracting when stimulated by nerve impulses; myofibrils composed of proteins actin and myosin; 3 types: A- Skeletal: voluntary movement (striated) B- Cardiac: contractile wall of heart (branched striated) C- Smooth: involuntary activities (no striations)

Organs – Containing multiple tissues Lumen of stomach Mucosa: an epithelial layer that lines the lumen Submucosa: a matrix of connective tissue that contains blood vessels and nerves Muscularis: consists mainly of smooth muscle tissue Serosa: a thin layer of connective and epithelial tissue external to the muscularis 0.2 mm Organs – Containing multiple tissues