4.2 The small size of cells relates to the need to exchange materials across the plasma membrane  Cell size must –be large enough to house DNA, proteins, and structures needed to survive and reproduce, but –remain small enough for a SA:volume ratio that will allow for adequate exchange with the environment. © 2012 Pearson Education, Inc.

Figure 4.2A Total volume Total surface area Surface-to- volume ratio 2 54 units 2 27 units units 2 6

20.3 Tissues are groups of cells with a common structure and function  Tissues –are an integrated group of similar cells that perform a common function and –combine to form organs.  Animals have four main categories of tissues: 1.epithelial tissue, 2.connective tissue, 3.muscle tissue, and 4.nervous tissue. © 2012 Pearson Education, Inc.

Extracellular Matrix in Animals  Animal cells synthesize and secrete an elaborate ECM –Composed of sugar-protein polymers –helps hold cells together in tissues and –protects and supports the plasma membrane. © 2012 Pearson Education, Inc.

EXTRACELLULAR FLUID CYTOPLASM Microfilaments of cytoskelton Plasma membrane Integrin Connecting glycoprotein Glycoprotein complex with long polysaccharide Collagen fiber ECM is glue that holds animal cells together!!

4.20 Cell junctions are found in animal tissues  Allow adjacent cells to communicate, interact, and adhere together. –Tight junctions prevent leakage of extracellular fluid across a layer of epithelial cells. –Anchoring junctions fasten cells together into sheets. –Gap junctions are channels that allow molecules to flow between cells. © 2012 Pearson Education, Inc. Animation: Tight Junctions Animation: Gap Junctions Animation: Desmosomes

Figure 4.20 Tight junctions prevent fluid from moving between cells Tight junction Anchoring junction Gap junction Plasma membranes of adjacent cells Extracellular matrix

4.21 Cell walls enclose and support plant cells  Cell wall –protects and provides skeletal support that helps keep the plant upright against gravity and –is primarily composed of cellulose.  Plant cells have cell junctions called plasmodesmata that serve in communication between cells. © 2012 Pearson Education, Inc.

Figure 4.21 Vacuole Plant cell walls Plasmodesmata Cytoplasm Primary cell wall Secondary cell wall Plasma membrane

20.3 Tissues are groups of cells with a common structure and function –Tissues combine to form organs. Epithelial tissue covers the body and lines its organs and cavities. Connective tissue binds and supports other tissues. Muscle tissue functions in movement. Nervous tissue forms a communication network. Sheets of closely packed cells Sparse cells in extra- cellular matrix Long cells (fibers) with contractile proteins Neurons with branching extensions; supporting cells Columnar epithelium Loose connective tissueSkeletal muscle Neuron Example Structure Function

Figure 20.4 Stratified squamous epithelium Pseudostratified ciliated columnar epithelium Simple columnar epithelium Simple cuboidal epithelium Simple squamous epithelium Basal lamina Underlying tissue Apical surface of epithelium Cell nuclei Epithelial tissue covers the body and lines its organs and cavities

Figure 20.5 Cell nucleus Collagen fiber Elastic fibers Loose connective tissue (under the skin) Cell nucleus Collagen fibers Fibrous connective tissue (forming a tendon) Fat droplets Adipose tissue White blood cells Red blood cell Plasma Blood Central canal Matrix Bone Bone- forming cells Cartilage- forming cells Matrix Cartilage (at the end of a bone)

Figure 20.6 Unit of muscle contraction Muscle fiber (cell) Nuclei Skeletal muscle Muscle fiber Nucleus Junction between two cells Cardiac muscle Muscle fiber Smooth muscle Nucleus

Figure 20.7 Dendrites Cell body Axon

Organs are made up of tissues  Each tissue performs specific functions.  The small intestine –is lined by a columnar epithelium, –includes connective tissues that contain blood vessels, and –has two layers of smooth muscle that help propel food. © 2012 Pearson Education, Inc. Small intestine Lumen Epithelial tissue (columnar epithelium) Connective tissue Smooth muscle tissue (two layers) Connective tissue Epithelial tissue

Figure 20.10_L Blood vessels Heart Circulatory system Respiratory system Nasal cavity Pharynx Larynx Trachea Bronchus Lung Bone Cartilage Skeletal system Muscular system Skeletal muscles Integumentary system Hair Skin Nails Urinary system Digestive system Urinary bladder Small intestine Large intestine Kidney Ureter Urethra Mouth Esophagus Liver Stomach Anus

Figure 20.10_R Endocrine system Thymus Adrenal gland Pancreas Testis (male) Hypothalamus Pituitary gland Thyroid gland Parathyroid gland Ovary (female) Lymphatic and immune systems Lymph nodes Appendix Bone marrow Thymus Spleen Lymphatic vessels Reproductive system Female Oviduct Ovary Uterus Vagina Male Seminal vesicles Prostate gland Vas deferens Penis Urethra Testis Nervous system Brain Sense organ (ear) Spinal cord Nerves

EXTERNAL ENVIRONMENT Mouth Food CO 2 O2O2 ANIMAL Digestive system Respiratory system Circulatory system Urinary system Heart Interstitial fluid Body cells Intestine Anus Unabsorbed matter (feces) Metabolic waste products (urine) Nutrients B l o o d respiratory system exchanges gases between the external environment and blood. digestive system acquires food and eliminates wastes excretory system eliminates metabolic waste circulatory system - distributes gases, nutrients, and wastes throughout the body - exchanges materials between blood and body cells through the interstitial fluid Every organism must exchange energy and nutrients/wastes with surroundings

Terminal bud Shoot system Root system Leaf Blade Petiole Axillary bud Stem Taproot Flower Node Internode Epidermal cell Root hair Root hairs  Plants have 3 Organ Systems: –Roots –Water and nutrient absorption; storage –Shoots (stems) –Support, structure, storage –Leaves –Photosynthesis; gas exchange (O2 / CO2)

Dermal tissue system Ground tissue system Vascular tissue system Key Sheath Stoma Guard cells Vein Phloem Xylem Eudicot leaf Cuticle Upper epidermis Lower epidermis Mesophyll Dermal = protective covering Ground = photosynthetic cells, storage, filler Vascular = transport xylem: water from roots to leaves phloem: leaves to roots Dermal = protective covering Ground = photosynthetic cells, storage, filler Vascular = transport xylem: water from roots to leaves phloem: leaves to roots