Objectives Be able to give an example of the hierarchy of body plans from cells to body systems Name the structure and function of the different tissues: epithelial, connective, muscle and nervous

Overview of body systems

Hierarchical Organization of Body Plans Tissues make up organs, which together make up organ systems Most animals are composed of specialized cells organized into tissues that have different functions

Tissue Structure and Function Different tissues have different structures that are suited to their functions Tissues are classified into four main categories: epithelial, connective, muscle, and nervous

Epithelial Tissue Epithelial tissue covers the outside of the body and lines the organs and cavities within the body shape cuboidal (like dice) columnar (like bricks on end) squamous (like floor tiles) The arrangement simple (single cell layer) stratified (multiple tiers of cells) pseudostratified (a single layer of cells of varying length)

Epithelial Tissue Cuboidal epithelium Simple columnar epithelium Fig. 40-5a Epithelial Tissue Cuboidal epithelium Simple columnar epithelium Pseudostratified ciliated columnar epithelium Stratified squamous epithelium Figure 40.5 Structure and function in animal tissues Simple squamous epithelium

Connective Tissue - binds and supports other tissues six major types of connective tissue: Loose connective tissue: binds epithelia to underlying tissues and holds organs in place Cartilage: strong and flexible support material Fibrous connective tissue: found in tendons, which attach muscles to bones, and ligaments, which connect bones at joints Adipose tissue: fat cells Blood: blood cells and plasma Bone: your skeleton

Connective Tissue connective tissue fiber (all made of protein) Collagenous fibers provide strength and flexibility Elastic fibers stretch and snap back to their original length Reticular fibers join connective tissue to adjacent tissues Connective tissue cells Fibroblasts: secrete the protein of extracellular fibers Macrophages: involved in the immune system

Connective Tissue Loose connective tissue Cartilage Fibrous connective Fig. 40-5c Connective Tissue Collagenous fiber Loose connective tissue Chondrocytes Cartilage 120 µm 100 µm Elastic fiber Chondroitin sulfate Nuclei Fat droplets Fibrous connective tissue Adipose tissue 30 µm 150 µm Figure 40.5 Structure and function in animal tissues Osteon White blood cells Bone Blood 700 µm 55 µm Central canal Plasma Red blood cells

Muscle Tissue Muscle tissue consists of long cells called muscle fibers, which contract in response to nerve signals Three types: Skeletal muscle: or striated muscle, is responsible for voluntary movement Smooth muscle:responsible for involuntary body activities Cardiac muscle: responsible for contraction of the heart Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Muscle Tissue Skeletal muscle Cardiac muscle Smooth muscle Multiple Fig. 40-5j Muscle Tissue Multiple nuclei Muscle fiber Sarcomere Skeletal muscle Nucleus 100 µm Intercalated disk 50 µm Cardiac muscle Figure 40.5 Structure and function in animal tissues Smooth muscle Nucleus Muscle fibers 25 µm

Nervous Tissue Nervous tissue senses stimuli and transmits signals throughout the animal Nervous tissue contains: Neurons, or nerve cells, that transmit nerve impulses Glial cells, or glia, that help nourish, insulate, and replenish neurons Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fill out the tissue identification chart

Name the cell Simple Cuboidal Epithelium

Simple Cuboidal Secretion and absorption Found on the surface of ovaries, the lining of nephrons, the walls of the renal tubules (kidney), and parts of the eye and thyroid.

Name the cells Striated (skeletal) muscle cells

Striated muscle cell For movement Ex. Found in biceps, triceps,

Nerve cells Send signals to and from your brain and spinal cord Found throughout your body, but are most concentrated in your brain and spinal cord

Name the cell Blood cells

Blood cells Include red blood cells and white blood cells Found in blood vessels

Objective What are some adaptations that help organisms exchange nutrients, waste and gasses with the environment How do animals maintain homeostasis, especially in terms of heat (include in your answer how feedback mechanisms work) What are the two main adaptations to satisfy energy requirements and what are the pros and cons of each.

Exchange with the environment Must exchange Nutrients Waste Gasses What advantage would single celled organisms have and how do larger organisms deal with this?

It’s all about surface area

Homeostasis – Steady state Regulator– controls an environmental variable Ex. Endothermic organism Conformer – conforms to its environment EX. Ectothermic organism

Homeostasis: It is all about feedback loops Negative feedback loops - have a set point, and senses the deviation from the set point and then sends out a response Ex. Sweat Positive feedbacks do not normally contribute to homeostasis Ex. Child birth

In Humans Hypothalamus is responsible for sensing and responding to body temperatures Note: the same blood vessel supplies blood to hypothalamus and ear – that is why we can use an ear thermometer

Homeostasis: Thermoregulation – regulation of body termperature Using the Environment Behavioral responses – such as moving to different areas that are cold or hot Using Physiology Insulation Adjusting metabolic heat production (shivering) Circulatory adaptations

What are some ways organisms exchange heat with their environment? Hint: one way is conduction: By directly transferring heat (ex. Reptile sitting on a hot rock.)

Mexican Jumping Beans These are a good example of behavioral responses

Thermoregulation using Physiology Thermogenesis – heat production in the body either my muscle movement or metabolic activity producing more heat than ATP Shivering

Thermoregulation using physiology: Evaporative cooling Sweating Panting in birds and other mammals (dogs)

Thermoregulation using physiology: Insulation Trap the heat Ex. Blubber in whales or fluffed up feathers in birds

Thermoregulation using physiology: Circulatory adaptations Problem: Ducks feet need circulation, but the cold water will make the venus blood cold which will chill the body. Countercurrent exchange to the rescue!!!

Energy budgets

When would an environment favor ectothermy? What about endothermy? Endothermy – can live in more variable environments, but cannot live where food is scarce. Ectothermy – few can live in below-freezing weather (Must live in fairly stable climates), but could live where food is scarce.