Animal Organization & Homeostasis Benjamin Dong Jack Szymanski Joseph Tang

Tissue BEN Tissue: a group of specialized cells. 4 major types: Epithelial tissue Connective Tissue Muscular Tissue Nervous Tissue

1. Epithelial Tissue tightly packed cells that form a continuous layer BEN 1. Epithelial Tissue tightly packed cells that form a continuous layer layers cover surfaces and line body cavities. Basement membrane is like the ground where you build a building Connected by tight junction protiens – like our stomach connects the cells preventing anything from passing Adhesion junction – like our skin….allows stretching And gap junction that allows movement.

Types of Epithelium BEN Glandular- an epithelium that secretes a product (sweat glands/endocrine glands) Stratified- layer on layer (esophagus) Squamous – flattened cells (lining blood vessels) Cuboidal – cube shaped cells (lining the kidney) Columnar – rectangular pillars (small intestine)

2. Connective Tissue BEN 3 Types of Fibers: White collagen: contain collagen; are flexible and strong. Reticular: thin and branched Elastic: as its name suggests

Fibrous Tissues BEN have fibroblasts (fancy term for fiber) loose connective tissue supports internal organs adipose holds the fat in dense connective tissue packs fibers together (e.g. tendons and ligaments)

Supportive Connective Tissue BEN Supportive Connective Tissue Cartilage: No blood supply and heals slowly. Hyaline: nose Elastic: outer ear Fibercartilage: withstand pressure Bone: compact and spongy (e.g. bone marrow makes blood)

Fluid Connective Tissue BEN Fluid Connective Tissue Blood Red Blood Cells (RBC) White Blood Cells (WBC) Platelets Lymph

3. Muscular Tissue Skeletal: voluntary muscles (e.g. biceps) BEN 3. Muscular Tissue Skeletal: voluntary muscles (e.g. biceps) Smooth: involuntary muscles (e.g. stomach) Cardiac: involuntary muscles in the heart

Organs Organ: combination of two or more tissues JACK Organ: combination of two or more tissues e.g. kidney: contains epithelial/connective tissues  elimination of waste from blood

Organ Systems Organ System: multiple organs working in cohesion JACK Organ Systems Organ System: multiple organs working in cohesion functions: waste removal gas exchange body coordination offspring production

Body Cavities JACK Body cavities: empty spaces in body where internal organs are located 2 vertebrate cavities: dorsal cavity ventral cavity.

Integumentary System JACK Integumentary system: Skin Derivative organs and structures. Universal function (all animals): Protect internal organs from: Physical trauma Pathogens Regulate body temperature Specific functions (some animals): gas exchange insulation flight water containment

JACK Regions of Skin 2 Regions: Dermis Epidermis. subcutaneous layer

Epidermis (Outer Layer) JACK Epidermis (Outer Layer) Stratified squamous epithelium 2 Types: Thin: contains hair follicles, oil glands Thick: present on palms of the hands and soles of feet. Derived from basal cells in skin Pushed out toward the surface as the surface skin cells are shed. Keratin: protein that hardens skin Melanocytes: special cells that produce melanin (skin tone)

Dermis (Inner Layer) JACK Dense network of connective tissue Below the epidermis Contains: Collagen/elastic fibers: Prevents tearing of skin Allows flexibility Sensory receptors (respond to external stimuli)

JACK Subcutaneous Layer Between the dermis and the rest of the body (i.e. Hypodermis) Technically not part of the skin Loose connective tissues and adipose tissue (insulation)

Accessory Structures JACK Nails: highly compressed, high keratin cells Oil glands: secret sebum  protect skin/hair follicles Sweat glands: excrete water/minerals  cool body. Hair follicles: hair is rooted here (hair = dead hardened epithelial cells)

4. Nervous Tissue JOSEPH Neuron: primary signal transmitter cell Neuroglia: provides support for neurons

JOSEPH NEURON 3 Parts: Dendrites: conducts signal to cell body Axon: conduction of impulses from body Cell Body: contains the regular cell organelles Function: transmission of nerve signals throughout body (from brain/spinal cord) Cannot divide

NEUROGLIA JOSEPH Concentrated in brain Functions: Can divide Nourishment of neurons (hormone glial) Brain function Phagocytosis of debris Can divide

JOSEPH Homeostasis The ability of an organism to maintain a constant internal environment Includes: regulating temperature/chemical composition e.g. warm-blooded (homeothermic) v. cold-blooded (poikilothermic) Controlled by nervous system

Examples of Homeostasis JOSEPH Examples of Homeostasis Digestive  provision of nutrients Respiratory  provision of oxygen/removal of carbon dioxide Kidneys  removal of excess salts that affect the pH of blood

Positive/Negative Feedback JOSEPH Positive/Negative Feedback Negative feedback: Step 1: abnormality in conditions activates sensor Step 2: abnormality corrected by control center  deactivates sensor Positive feedback: Step 1: change in condition activates sensor Step 2: change exacerbated by control center

fin Sources: THE ALMIGHTY TEXTBOOK + Google/Bing Images