Animal Structure and Function

An Introduction to Animal Structure and Function : An Introduction to Animal Structure and Function

Tissues : Tissues Tissues are groups of cells with a common structure and function They work together! 4 major types of tissues Epithelial Connective Nervous Muscle

Epithelial Tissue : Epithelial Tissue Epithelial tissue covers the outside of the body (ie. skin) and lines organs and cavities within the body Tightly packed together…why??

Connective Tissue : Connective Tissue Connective tissue functions mainly to bind and support other tissues Few cells, scattered throughout an extracellular matrix Examples: Adipose tissue (fat droplets) pads and insulates the body Fibrous connective tissue Tendons Attach muscles to bones Ligaments Join bones together at joints Bones Blood

Connective Tissue : Connective Tissue

Cartilage : Cartilage

Nervous Tissue : Nervous Tissue Nervous tissue senses stimuli and transmits signals from one part of an animal to another The neuron is a specialized nerve cell that transmits nerve impulses We’ll talk about this more when we get to the nervous system

Muscle Tissue : Muscle Tissue Muscle tissue is the most abundant tissue in most animals Muscle cells contain large numbers of microfilaments within the cytoplasm made up of actin and myosin – contractile proteins

Muscle Tissue : Muscle Tissue There are 3 major types of muscle tissue: 1) Skeletal muscle - responsible for the voluntary movements of the body - examples: hamstring, biceps 2) Cardiac muscle - forms the contractile wall of the heart 3) Smooth Muscle - “involuntary” muscles - found in the walls of the digestive tract, bladder, arteries, and other internal organs

Muscle Tissue : Muscle Tissue

Organs & Organ Systems : Organs & Organ Systems In almost all animals, tissues are organized into organs Examples: Organs, then, are organized into organ systems Examples: ***Every organism is a living whole greater than the sum of its parts***

Metabolic Rate : Metabolic Rate All organisms exchange energy with the environment – it’s a characteristic of life! An organism’s metabolic rate is the amount of energy (ie. Calories) it needs to maintain basic life functions Basal metabolic rate (BMR) is the number of kilocalories we “burn” lying motionless Daily Average: Male: 1600 – 1800 kcal Female: 1300 – 1500 kcal

Homeostasis : Homeostasis Homeostasis = “steady state” Keeping constant (or relatively constant) conditions in an animal’s internal environment, even when the external environment changes 37C body temperature, 7.4pH of blood The interstitial fluid (ISF), which fills the spaces between our cells, is primarily responsible for our ability to maintain homeostatic conditions

Homeostatic Control Systems : Homeostatic Control Systems Every homeostatic control system has 3 major components: 1. Receptor - detects a change in some variable of the animal’s internal environment 2. Control Center - processes information it receives from the receptor and directs an appropriate response by the effector 3. Effector - performs the appropriate response dictated by the control center

Positive and Negative Feedback : Positive and Negative Feedback Negative Feedback A change in the variable being monitored triggers a response that counteracts the initial fluctuation Most common feedback mechanism in animals Example: Temperature drops in house, thermostat recognizes this, turns heater on Positive Feedback Involves a change in some variable that triggers mechanisms that amplify rather than reverse the change “You did a great job on #8. Keep at it!” Contractions during childbirth

Negative Feedback : Negative Feedback

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