introduction to animal structure and function ap biology
TRANSCRIPT
Introduction to Animal Structure and Function
AP BiologyAP Biology
Levels of Structural Organization
Cells Tissues
Organs Organ Systems
Four Principle Tissue Types
Epithelial tissueEpithelial tissue—covers and protects the body surface, lines body cavities, specializes in moving substances into and out of the blood
Connective tissueConnective tissue—supports the body and its parts, to connect and hold them together, and to transport substances through the body
Four Principle Tissue Types
Muscle tissueMuscle tissue—produces movement; specialized for contractility
Nervous tissueNervous tissue—specialized in communication between various parts of the body and in integration of their activities
Epithelial Tissue
Sheets of tightly packed cells Cells held together by tight junctions Functions as a protective barrier
Dermis Cells Keratinocyte - (90%) anchoring junctions Melanocyte - melanin blocks UV light, shields nucleus Langerhans cell - Macrophage
Epidermal Layers Deep layer
single layer of stem cells & melanocytes division produces keratinocytes keratinocytes - anchoring junctions cells have keratin - dense "waterproof" protein nuclei break down
Top layer approx. 25 layers of flat dead cells filled with keratin continuously shed
Simple Squamous Epithelium
Simple Cuboidal Epithelium—alveoli
Stratified Squamous Epithelium—lining of the mouth
Simple Columnar Epithelium—lining digestive tract/organs
Pseudostratified Columnar Epithelium—lining trachea and bronchi
cilia
Transitional Epithelium—lining urinary passages and bladder; allows for distension and evacuation
Connective Tissue Made of 3 kinds of protein fibers:
Collagenous fibers—made of collagen; nonelastic and do not tear easily when pulled lengthwise
Connective Tissue Made of 3 kinds of protein fibers:
Collagenous fibers Elastic fibers—long threads of elastin; lends tissue
resilence Reticular fibers—thin, branched fibers composed
of collagen and continuous with collagenous fibers; aids in joining connective tissue to adjacent tissues
Extracellular Matrix—ground substance that is composed of a web of fibers embedded in a uniform foundation that may be liquid, jellylike, or solid
Loose Connective Tissue
Holds organs in place and attaches epithelia to underlying tissues
Two types of cells: Fibroblasts—
secrete proteins of the extracellular fibers
Macrophages—phagocytic amoeboid cells that function in immune defenses
Has all 3 fiber types
Adipose tissue
Loose connective tissue specialized to store fat
Insulates the body and stores fuel molecules Each adipose cells has one large fat droplet
which varies in size as fats are stored or used
Fibrous Connective Tissue
Dense arrangement of collagenous fibers in parallel bundles
Found in tendons (attach muscles to bone) and ligaments (attach bone to bone)
Cartilage
Composed of collagenous fibers embedded in chondroitin sulfate
Chondrocytes secrete collagen and chondroitin sulfate (makes cartilage strong and flexible)
Cartilage makes up skeleton of vertebrate embryo—most gets replaced by bone except ears, nose, trachea, invertebral discs and ends of some bones
Growth Plate
Bone
Mineralized connective tissue Osteoblasts—bone forming
cells deposit collagen and calcium phosphate matrix which hardens to form hydroxyapetite
Consists of repeating Haversian systems
Right image:
1. Haversian Canal
2. Canaliculi
3. Lamellae
4. Lacunae
Blood Liquid extracellular matrix of plasma that
contains water, salts, and proteins Blood cells made in red bone marrow near ends
of long bones Cellular components:
Erythrocytes— red blood cells; transport oxygen
Blood
Leukocytes—white blood cells; immune defense
neutrophilseosinophils
basophil
Blood
Platelets—cell fragments; blood clotting
Nervous Tissue
Senses stimuli and transmits signals from one part of the animal to another
Neuron—specialized to conduct an impulse or bioelectric signal
Consists of:Cell bodyDendrites—conduct impulses to cell bodyAxons—transmit signals away
Muscle Tissue
Long, excitable cells capable of contraction Cell cytoplasm contains bundles of
microfilaments made of the contractile proteins, actin and myosin
Most abundant tissue in the body 3 types: skeletal, cardiac, and smooth
Muscle Tissue Skeletal
Attached to bones by tendons
Microfilaments aligned to form a banded (striated) pattern
Voluntary muscle movements
Muscle Tissue
CardiacForms the contractile walls of the heartEnds of cells joined by intercalated disks,
which relay contractile impulse between cells
Muscle Tissue
SmoothFound in walls of internal organs (digestive
tract, bladder) and arteriesSpindle-shaped cells contract slowly, but can
retain contracted conditions longer than skeletal muscle
Involuntary movements
Energy InputIngestion
Digestion(Hydrolysis)
Absorption
Catabolism(Cellular Respiration)
Energy stored(ATP)
Energy lost(heat)
Energy used(ATP)
Bioenergetics
Heterotrophs harvest chemical energy from the food they ingest
Metabolism Metabolic rate—total amount of energy an
animal uses per unit of time; usually measured in calories or kilocalories
Determined by measuring:Amount of oxygen used for an animal’s
cellular respirationAn animal’s heat loss per unit of time
Endotherms—generate own heat metabolically Exotherms—acquire heat from environment
Homeostasis--Regulating internal environment Dynamic state of equilibrium in which internal
conditions remain relatively stable; steady state Depends on feedback circuits
Receptor detects internal changeControl center processes info and directs to
effector to respondEffector provides the response
Homeostasis--Regulating internal environment Positive feedback—
enhances initial change in variable and response of effector
Negative feedback—stops or reduces the intensity of the original stimulus
Negative feedback in a thermostatic control