The Animal Body Tour. Levels of structure Cells Tissues: Cells combined in distinct ways into...

The Animal Body Tour

Levels of structure• Cells

• Tissues: Cells combined in distinct ways into layers. Specialization (division of labor)

• Organs: Made of more than one kind of tissue. Perform common function.

• Organ systems: Several organs combine to perform major body function.

Levels of structure• Example, circulatory system

Levels of structure• 11 organ systems

Tissue types (4)• 1) Epithelial tissue

– Covers outer and inner ____________ of body– Cells tightly joined together (no blood vessels in

intercellular spaces: materials must diffuse in and out)

– Two major types: covering and lining, and glandular

Tissue types• 1) Epithelial tissue types (covering and lining)

– Simple epithelial (1 cell layer). Further subdivided based on cell shape

• Squamous (flattened)

• Cuboidal (cube shaped)

• Columnar (rectangular)

Tissue types• 1) Epithelial tissue types (covering and lining)

– Stratified epithelial (multiple cell layers). Further subdivided by cell shape

• Ex., squamous (flattened)

– Pseudostratified epithelial (one cell layer but looks like 2 because __________ not all in same position)

• Ex., pseudostratified columnar (rectangular)

Tissue types• 1) Epithelial tissue

– Glandular (secretes materials) epithelial tissue• Exocrine glands: connected to epithelium surface by

duct (Ex., sweat glands, salivary glands)

• Endocrine glands: not connected to epithelium surface (Ex., adrenal gland of kidney). Secretions called hormones, enter blood and stay within body

Tissue types• Epithelial tissue functions:

– Protection: invasion, dehydration, physical injury, etc.– Secretion of chemicals: ex., digestive tract

• Note: usually with great regenerative ability– Ex., stomach lining replaced every ______ days

Tissue types• 2) Connective tissue

– Used to bind and support all other tissues– Other special functions too– Composed of cells and matrix (extracellular

material)

• Two types: – Connective tissue proper – Special connective tissues

Tissue types• Connective tissue proper

– 1) Loose connective tissue• Matrix often contains: collagen (strong protein

fibers), elastin (elastic protein fibers)


– 1) Loose connective tissue• Cells include: ______________ (cells that secrete

matrix), mast cells (make histamine: blood vessel dilator), macrophages (phagocytic cells), adipose cells (contain a fat droplet)

Adipose Loose connective


– 2) Dense connective tissue• Collagen fibers tightly packed (very strong)

• Ex, tendons and ligaments

Tissue types• Special connective tissues: cartilage

– Matrix: collagen fibers in parallel arrays and glycoproteins

Tissue types• Special connective tissues: cartilage

– Chondrocytes: living cartilage cells. Live in chambers (lacunae). Note lack of blood vessels: diffusion supplies cells with materials (slow process!)

Tissue types• Special connective tissues: bone

– Matrix hardened with calcium phosphate salts– No __________ occurs through bone matrix. Blood

vessels present in central canals

Tissue types• Special connective tissues: bone

– Cells called osteocytes, located in chambers (lacunae)– Osteocytes connect with cellular processes through

canalaliculi

Tissue types• Special connective tissues: blood

– Blood is connective tissue, with fluid matrix (plasma)– Erythrocytes (red blood cells): carry oxygen and

carbon dioxide– Leukocytes (white blood cells): ___________ cells– Thrombocytes (platelets): fragments of bone marrow

cells

Tissue types• Connective tissue functions:

– Connect parts (tendons connect muscle to bone)– Support body (skeleton)– Protection (cranium around brain)– Circulate materials (blood).

Tissue types• 3) Muscle tissue

– Most abundant _________ in humans– Basic structure: bundles of myofibrils, composed of

protein filaments (actin and myosin).

Tissue types• 3) Muscle tissue types:

– Skeletal (striated) muscle: multinucleated, produce voluntary movements


– Cardiac (also striated): single nucleus, have intercalated discs (heart muscle)


– Smooth muscle: no striations. Usually not under voluntary control

Tissue types• Functions:

– Movement (of body, fluids within body, etc.)

Tissue types• 4) Nerve tissue

– Transmits electrochemical impulses– Neuron (name of cell type)– Dendrite (process: brings impulse to cell body)– Axon (process: carries impulse from cell body)


– Neuroglia: support cells– Often associate with axons, form sheath

(_________ sheath)– Note Nodes of Ranvier (gaps in sheath).

Tissue types• 2 nerve networks:

– Peripheral Nervous System (PNS): perceives environment and communicates to body

– Central Nervous System (CNS): processes information and coordinates activities

Tissue types• 4) Nerve tissue:

Types of neurons– Sensory (receive

information: send to CNS)

– Motor (stimulate muscles/glands)

– Association (integrate information and connect to other neurons)


– Nerves: bundles of ___________– Ganglion (plural: ganglia): collection of neuron

cell bodies


– Functions: Send electrical signals to convey information, make things happen in body, etc.

Integumentary System

Integumentary System• Human skin: largest organ of body (2 square

yards, 16% of body weight)• Distribution: “Rule of _____s”

Note: diagram %s are foronly one side of body

Integumentary System• Many functions in animals:

– Protection. Forms boundary of individual, barrier to external dangers and valuable internal materials

– Sensing. Can gather information about environment: temperature, pressure, light, damage to integument

– Communication. Since visible to others, can send signals with skin color or structures (hairs, scales, feathers)

– Regulate body temperature. Can be used to gain/lose energy. Integument structures (hairs, scales, feathers) can provide ____________

Integumentary System• Many functions in animals:

– Excretion: Sweat contains water, urea (nitrogenous waste material), salts. These eliminated during sweating

Integumentary System• Skin layers

– Epidermis– Dermis

Integumentary System• Human skin layers: Epidermis

– Upper boundary: Stratum corneum. Dead cells that provide protective layer. Shed as skin scales or flakes


– You will shed about 40 lbs. of skin scales during your lifetime

– Good news for dust mites (Phylum Arthropoda, Class Arachnida, Order Acari)!


– Lower boundary: Stratum germinativum (basal cells). Living cells doing rapid _________. Daughter cells fill with keratin (tough water resistant protein: also found in hair, fingernails, hooves, claws), flatten and die


– Contains melanocytes: cells that produce melanin and transfer it to other skin cells. Darken skin color in response to UV exposure (tanning)


– UV exposure increases skin cancer chances– Melanoma: ____________ that divides out of control– Recall ozone thinning problem

Integumentary System• Human skin layers: Dermis• Contains connective tissue, blood vessels,

nerve endings.

Integumentary System• Human skin also contains:

hairs– Follicle: invagination of skin

surface containing hair– Shaft: body of hair (mostly

protein: ____________)– Bulb: base from which hair

grows by cell division (each cell divides every 1-3 days!)

– Papilla: contains blood supply

Integumentary System• Human skin also contains:

hairs– Arrector pili muscle:

smooth muscle. Can change angle of hair

Integumentary System• Human skin also contains: exocrine glands

– Sweat glands: empty onto skin surface at sweat pore.

Integumentary System• Human skin also contains: exocrine glands

– Sebaceous glands: associated with hair follicle, secrete oil to lubricate/protect skin and hair

Integumentary System• Human skin also contains: sense organs

– Free nerve endings: sense _____________– Hair follicle receptors: can sense movement of

hair


– Merkel cell, Meissner’s corpuscles, Pacinian corpuscles. Sense pressure/stretch of skin


– Temperature: End-bulb of Krause (cold), Organ of Ruffini (hot)

Integumentary System• Below the skin: Subcutaneous __________• Contains adipose tissue

– Stores energy, cushioning (soles of feet, palms of hands), provides insulation

Integumentary System• Nails: Special keratinized layer of cells

produced by fold of skin (nail root)

Fingernail magnified1000 X

Skin burns• First degree (epidermis), second degree

(epidermis), third degree (dermis)

Skeletal System

Skeletal System• Contains mostly connective tissue

– Bone– Cartilage– Tendons (connect bone to muscle)– Ligaments (connect one bone to another bone)

Bone• Living tissue. Contains nerves, blood vessels,

cells• Formed by cells called ___________, which

secrete collagen matrix in which Ca and P salts later deposited. These cells then called osteocytes.

• Usually forms by replacing cartilage in embryo and at ends of major bones as they grow (endochondral bones)

• Some bones formed directly from dense connective tissue (intramembranous bones)

Bone• Structure

– Periosteum: connective tissue sheath

Bone• Structure

– Compact bone (along shafts of long bones)• hollow inner core with yellow marrow

Bone• Structure– Compact bone

• Bone laid down in layers called lamellae in an _______ or Haversian system

Bone• Structure– Compact bone

• Haversian systems: structural unit that surrounds internal marrow cavity or spongy bone. Haversian Canal contains blood vessels and nerves

• Volkmann’s canals: connect adjacent Haversian canals

Bone• Structure– Spongy bone

• Mainly at outer ends of long bones• Cavities contain red marrow• All areas of bones start as spongy bone, some

become compact bone as they develop

Bone• Structure

– Marrow (in bone spaces)• Red marrow: stores fat, makes _______ cells

(red and white) by rapid mitotic divisions• Yellow marrow: stores fat only

Bone• Long bones grow in length in areas toward ends

at ____________ plates• Cartilage there grows, chondrocytes die,

osteoblasts move in and secrete bone. Process stops by age 20.

Bones• 206 bones in human body

Bones• In lab: use rat skeleton (240 bones total). Need to

know names of bones and groups shown in manual. DO BEFORE COMING TO LAB!

Cartilage• Generally, firm but flexible connective tissue• Cells called chondrocytes• Contains collagen and elastin fibers in matrix

Cartilage• 4 types:

– 1) Hyaline cartilage. Flexible, translucent. High in ___________ fibers (tough and strong)

– Ex, rings in trachea (windpipe). Seen in lab rat– Ex, found between bones in many joints (cushions

bone). Knee joint (articular cartilage).

Cartilage• 4 types

– 2) Elastic cartilage. High in __________ fibers. Flexible. Ex, outer ear

– 3) Fibrocartilage. High in collagen, not translucent. Very tough. Used to cushion some joints (vertebrae)

– 4) Calcified cartilage. Has some calcium deposits, but not as much as bone. Ex, Chondrichthyes (cartilagenous fishes)

Elastic cartilage

Tendons• Connect bones to adjacent

muscles. All major muscles attached to skeleton this way.

• Ex, muscles that work fingers are in lower arm. Attach to fingers by tendons that you can see on the back of your hand

Ligaments• Hold adjacent bones together. Can determine how

bones move (ex, knee joint)• Tend to stretch in one direction

Ligaments/Tendons• Similar, in that little to no ________ supply

present• So, very slow to heal if damaged. Also, scar

tissue that does form is not very strong• However, easily replaced by transplants

(from cadavers or other living humans)

Joints• Also called articulations. Where one bone meets another.• 3 types:• 1) Immovable joints. __________ tissue joints bones. Ex,

sutures in skull

Joints• Also called articulations. Where one bone meets another.• 2) Slightly movable joints. Bones bridged by cartilage.

Ex, intervertebral discs in backbone. Allow some movement, cushion vertebrae.

Joints• 3) Freely movable joints (synovial joints).

– Bone tipped with layer of ____________– End encased in synovial capsule: Fluid-filled membrane

bag. Ex, finger as hinge-like joint (movement in one direction). Hip joint as ball and socket joint (rotating movement possible).

The Animal Body Tour. Levels of structure Cells Tissues: Cells combined in distinct ways into...

Documents

Transcript of The Animal Body Tour. Levels of structure Cells Tissues: Cells combined in distinct ways into...