ZOOLONE Module 08-10 (Long Exam 2)

Integumentary System, Musculoskeletal System, Digestive System *Module 7 (Animal Form and Function) not part of set*

Integumentary System

organ system whose functions are:

- protects the underlying organs and tissues
- maintains body temperature
- synthesizes vitamin D3
- stores lipids
- detects touch, pressure, pain, and temperature
- excretes salt, water, and organic wastes
- protects body against infection

hypodermis

- aka subcutaneous layer
- thick layer of fat underneath the skin

epidermis

layer of skin:

- thinner
- protected by hair
- some areas thickened with keratin
- where the glands are embedded
- made up of stratified squamous keratinized epithelium

keratin

fibrous protein that constitute the nails, claws, hooves, hair, and feathers

Layers of the Epidermis

stratum:

corneum, lucidum, granulosum, spinosum, & basale/germinativum

stratum corneum

layer of the epidermis:

- outermost layer
- keratinized layer
- dry, dead layer that prevents skin from dehydration

stratum lucidum

layer of the epidermis:

- seen only in thick skin
- ex. palms, fingers, soles

stratum granulosum

layer of the epidermis:

- grainy in appearance
- due to generation of keratin

stratum spinosum

layer of the epidermis:

- thickest layer of epidermis
- spiny in appearance
- due to protruding cell processes that join cells via desmosomes

stratum basale

layer of the epidermis:

- aka stratum germinativum
- nearest to the dermis
- deepest layer
- mitosis of skin cells

Dermis

layer of skin:

- made up of connective tissues
- location of nerve endings, blood vessels, and hair follicles

Hair

characteristic of mammals:

- epidermal structure BUT lies in the dermis
- grows continuously
- rapid proliferation of cells in the follicle
- pushed upwards away from source of nourishment
- accumulate keratin then die
- stops at a certain length
- remains in the follicle until new growth pushes it out

Hair Growth Cycle

Anagen, Catagen, Telogen (ACT)

Anagen

stage in the hair growth cycle:

- growth phase
- nourishment of hair follicle via blood supply

Catagen

stage in the hair growth cycle:

- transition phase
- follicle detaches from nourishing blood supply

Telogen

stage in the hair growth cycle:

- resting phase
- without nourishment, hair dies and falls out

2 Types of hair in Mammals

Under hair & Guard hair

Under hair

type of hair:

- Dense and soft
- for insulation
- below guard hair

Guard hair

type of hair:

- course and longer
- protect against wearing
- provide coloration
- under water, they become wet and adhere to each other

3 Layers of Hair

Medulla, Cortex, Cuticle

Medulla

layer of hair:

- center of the hair

Cortex

layer of hair:

- with pigment granules that lie outside the medulla

cuticle

layer of hair:

outermost layer

arrector pili muscle

muscle in the dermis that causes the hair to "stand" thus causing chicken skin or goosebumps

Molting

- process of shedding hair or fur
- can happen periodically

Structural and Functional Adaptation

- types of adaptation that are present in fur having different patterns
- ex. spots, stripes, salt-and-pepper patterns conceal the animals
- camouflage for survival

Integumentary Derivatives

Vibrissae, Quills, Horns, Antlers, Glands

Vibrissae

example of an Integumentary Derivative:

- whiskers
- sensory hairs that provide a tactile sense to many mammals
- long in length for nocturnal and burrowing animals

quills

example of an Integumentary Derivative:

- effective and dangerous spiny armor
- porcupines, hedgehogs, and echidnas (sea urchins)
- NOT embedded in the skin

True Horns

example of an Integumentary Derivative:

- antelopes, sheep, cattle
- hollow sheath of keratinized epidermis that embraces a core of bone arising from the skull
- NOT shed and NOT branched, but continuously grow

Antler

example of an Integumentary Derivative:

- deer
- branched and composed of solid bone when mature
- velvet
- shed after breeding season

velvet

high vascular soft skin that covers the antlers during annual spring growth

Rhinoceros Horn

example of an Integumentary Derivative:

- Hair-like keratinized filaments arise from dermal papillae and are cemented together
- NOT attached to the skull

Glands in the Integumentary System

Sweat Gland
Scent Gland
Sebaceous Gland
Mammary Gland

Sweat Glands

example of an Integumentary Derivative:

- Tubular, highly coiled glands that occur over much of the body surface in most mammals
- absent in other vertebrates
- 2 types: eccrine & apocrine

eccrine gland

type of sweat gland:

- secrete watery fluid
- occur in hairless regions (foot pads)
- seen all around the body
- involved in heat regulation
- either reduced or absent in rodents, rabbits, and whale

apocrine glands

type of sweat gland:

- ALWAYS open to hair follicle
- larger, longer, more convoluted ducts
- secretory coil is in the dermis and extends deep into hypodermis
- glands may be present in dermis or hypodermis
- develop near puberty
- seen in ear canal, chest, underarm, scrotum
- secrete milky fluids (whitish or yellow)
- NOT involved in heat regulation
- correlated with the reproductive cycle

Scent Glands

example of an Integumentary Derivative:

- location and function vary greatly
- present in nearly all mammals
- for communication with members of the same species
- marking territorial boundaries
- warning or defense

Sebaceous Glands

example of an Integumentary Derivative:

- associated with hair follicles
- gland cells are secreted in their entirety & are continuously renewed by cell division
- cells become distended with fatty accumulation then die
- cells expelled as greasy mixture

sebum

- “polite fat”
- greasy mixture expelled by sebaceous glands
- does NOT turn rancid
- keeps hair pliable and glossy

Mammary Glands

example of an Integumentary Derivative:

- modified apocrine gland
- occur in ALL female mammals
- rudimentary form in all male mammals
- increase in size at maturity
- large during pregnancy and subsequent nursing of young
- milk is secreted via the nipples

Monotremes

type of mammal:

- ex. platypus
- LACK nipples
- secrete milk onto the fur of the mother’ belly

musculoskeletal system

made up of the muscular and skeletal systems

3 Types of Muscle

Smooth, Cardiac, and Skeletal Muscles

Smooth Muscle

type of muscle:

- LACKS striations
- cells are much smaller, tapering strands, with a single, centrally-located nucleus
- responsible for peristalsis, propelling, and regulating movement of substance
- contractions are involuntary and unconscious

Cardiac Muscle

type of muscle:

- striated involuntary muscle
- found in the heart
- with presence of intercalated discs

intercalated discs

part that supports synchronized contractions of the cardiac muscle cells

Skeletal Muscle

type of muscle:

- striated muscle
- voluntary contractions
- attached to and interacts with skeletal elements
- makes up most of musculoskeletal system

tendon

fibrous tissue that attaches the muscles to the bones

3 Connective Tissues surrounding the skeletal muscle

Epimysium, Perimysium, and Endomysium

Epimysium

type of connective tissue surrounding the skeletal muscle:

- outer layer
- surrounds the whole muscle tissue
- contains fascicle

fascicle

bundles of muscle fibers

Perimysium

type of connective tissue surrounding the skeletal muscle:

surrounds each fascicle

Endomysium

type of connective tissue surrounding the skeletal muscle:

covers every muscle fiber in each fascicle

Sarcomere

- functional unit of muscle
- bordered by Z lines
- made up of myofibril

myofibril

part in sarcomere that contains actin & myosin filaments

actin filaments

filaments that are connected to the Z lines in the sarcomere

myosin filaments

filaments found in the middle of sarcomere

A band

band where myosin filaments are found

I Band

band where actin filaments & Z lines are found

Sliding Filament Theory

theory that states that:

- actin & myosin filaments slide past each other longitudinally
- “head” of myosin binds to an actin filament, forming a cross-bridge and pulls the thin filament towards the center of the sarcomere
- works using ATP

Tropomyosin and troponin complex

regulatory proteins that:
- bind to actin strands when a muscle fiber is at rest
- prevents the actin and myosin from interacting

Calcium ions

ions that attach to the troponin complex & acts as a key to expose actin and contract the muscle

motor unit

made up of single motor neuron and all the muscle fibers that it controls

Skeletal System

organ system whose functions are:

- provides supporting framework
- surfaces for muscle attachment
- protection for vulnerable organs
- production of blood cells (hematopoiesis)
- storage of minerals

2 Types of Skeletons

Hydrostatic & Rigid skeletons

Hydrostatic Skeletons

type of skeleton:

- “fluid-filled sac”
- earthworms
- alternate contractions of circular and longitudinal muscles in the body wall

Exoskeleton

type of rigid skeleton:

- skeleton located outside the body
- ranges from very soft (shrimp) to very stiff (crab)
- typical of mollusks, arthropods, and many invertebrates

Endoskeleton

type of rigid skeleton:

- skeleton inside the animal
- vertebrate animals, echinoderms, and some cnidarians
- made up of bone and cartilages

Bone

- major component of the skeleton
- well-vascularized tissue capable of responding to its environment
- categorized according to location and shape

2 Types of Bone Location

Axial & Appendicular

Axial

bone location:

- in the middle of the body
- skull, vertebral column, ribs, & sternum

Appendicular

bone location:

bones of the limbs, shoulders, and pelvis

5 Types of Bone Shape

Long, Short, Flat, Irregular, & Sesamoid bones

Long Bones

bone shape:

- found in limbs
- provide attachment site for limb muscles & levers for movement
- the ends are enlarged and smooth to avoid risk of dislocation

2 Main Parts of Long Bones

Epiphysis & Diaphysis

epiphysis

part of long bone:

- both ends of bone
- spongy
- smooth
- contains epiphyseal line/growth plate

epiphyseal line

- aka growth plate
- line in the long bone that separates metaphysis and diaphysis of growing animals

diaphysis

part of long bone:

- middle
- contains marrow/medullar cavity
- contains Periosteum, Endosteum, & Nutrient Foramen

medullar cavity

cavity in the long bone that is surrounded by compact bone and produces RBCs

Periosteum

layer in the diaphysis:

- increase of diameter of bone
- aids in healing fractures
- made up outer fibrous layer and inner cell-rich layer (osteoblasts)

Endosteum

layer in the diaphysis:

- lining tissue of the bone surfaces that faces the medullar cavity
- can also be found in spongy bone

Nutrient Foramen

natural holes in bones in the diaphysis where nutrients go in

short bones

bone shape:

- found in carpus and tarsus
- highly irregular in size and shape relatively small
- ex. hands

flat bones

bone shape:

- “squamous bones”
- found in most regions of the skull and ribs
- serve a protective or reinforcing function
- ex. ribs and skull

irregular bones

bone shape:

- has jutting processes
- most from muscular & ligamentous attachments & some are for articulation
- bones of the vertebral column, pelvis, and skull that are not flat

sesamoid bones

bone shape:

- formed in between tendons near the freely mobile joints
- with one articular surface that glides on a flat or convex surface of one or more long bones
- protects tendons from stress & reduces friction between tendons
- ex. kneecap aka patella

2 Types of Bone Development

Intramembranous Ossification & Endochondral Ossification

Intramembranous Ossification

Type of Bone Development:

- fibrous membrane of some parts of the fetal skeleton are converted to bones
- skull and mandible

Endochondral Ossification

Type of Bone Development:

- conversion of (hyaline) cartilage to bone
- vertebrae, axial and appendicular bones, ribs, sternum

2 Types of Bone Structure

Compact & Spongy Bone

compact bone

Type of Bone Structure:

dense, appearing solid to the unaided eye

spongy bone

Type of Bone Structure:

- made up of open, interlacing framework of bony tissue, oriented to give maximum strength under normal stresses and strains that the bone receive
- found in epiphysis
- has adipose tissues or yellow bone marrow

3 types of animals

herbivores, carnivores, omnivores

herbivores

type of animal that only eat plants and algae

carnivores

type of animal that eat meat / other animals

omnivores

type of animal that consume animals and plants/algae

Animal's Diet

must provide:

- chemical energy for cellular processes
- organic building blocks for macromolecules
- essential nutrients

Essential Nutrients

Essential Amino Acids & Fatty Acids, Vitamins, and Minerals

Essential Amino Acid

type of essential nutrient:

- an amino acid that is required by animals but that they cannot synthesize
- 10 out of 20 must be supplied in the diet