Exam 4 - Zoology (dr.hall)

Coelom

Tube within body cavity

Four levels of organization

Cells, Tissues, Organs, and Organ Systems

Tissues

Groups of cells similar in structure and function

Endoderm

give rise to epithelium that lines internal structures

Mesoderm

give rise to muscle, bone, and other connective tissue

Ectoderm

give rise to outer epithelium and to nerve tissue

Four principle tissue

Epithelial, Connective, Muscle and Nerve

Epithelial

Provides a barrier, passage to substance, and cover body surface

Connective

Blood, Bone

Muscle

Smooth (respiratory or digestive), Skeletal (lets us move), and Cardiac (protect, contract, and expand)

Nerve

Neurons, different cells make up nerve system

Organs

Body structures composed of different tissues that form a unit.

Organ System

Group of organs that function together to carry our major activities

Exocrine Gland

Releases secretion to external environment

Endocrine Gland

Secrete hormones throughout body

Simple epithelial membrane

one cell layer thick

Stratified epithelial membrane

several cell layers

Squamous cells

Flat, pancake like

Cubiodal cells

Cube like, Kidney

Columnar cells

intestinal tract

Special Connective Tissues

Cartilage, bone, and blood

Cartilage

A firm, flexible tissue that has great tensile strength

Lacunae

Cells of cartilage, Chondrocytes

Bones

“molded” in cartilage then calcify

Osteocytes

Bone cells

Erythrocytes

Red blood cells, carrier of oxygen

Leukocytes

White blood cells

Platelets

Thrombocytes (good for blood clotting)

Plasma

contains proteins

Homeostasis

The dynamic constancy of the internal environment

Antagonistic Effectors

The increasing activity of one effector is accompanied by decreasing activity of an antagonistic effector.

Positive Feedback Loops

Perturbations cause the effector to drive the value of the variable even farther from the set point

Herbivores

eat only plants

Carnivores

only eat meat

Omnivores

eat both meant and plants

Vertebrate Digestive Systems

A tubular gastrointestinal tract and accessory

Cecum

Break down cellulose in a blind pouch

Peristalsis

Rhythmic waves of muscular contractions

Stomach

a sac-like organ with an inner surface that enables it to fold up or expand

Parietal cells

Secrete hydrochloric acid

Chief cells

Secrete pepsiongen

Chyme

Mixture of partially digested food and gastric juice

Pancreas

large gland that contribute secretions to the digestive tract

Basal Metabolic Rate (BMR)

lowest level of energy consumption of body

Astrocytes

Support endothelial cells that make up the Brain Blood Barrier. Carry signals from the blood stream to the neurons.

Microglia

Serve as the phagocytic leukocytes of the CNS. Serve as the immune system on the CNS.

Sodium-Potassium Pump

Brings two K+ into cell for every three Na+ it pumps out

Ion leakage channels

Allow more K+ to diffuse out than Na+ to diffuse in.

Neuromuscular junction

Junction between motor neuron and muscle fiber

Acetylcholine

binds to ligand-gated receptor in the postsynaptic membrane

Excitatory postsynaptic potential (EPSP)

Stimulates muscle contraction

Acetylcholinesterase (AChE)

Causes muscle relaxation

Glutamate

major excitatory neurotransmitter in the vertebrate CNS

Epinephrine and Norepinephrine

Responsible for “fight or flight” response

Dopamine

controls body movement

Serotonin

regulation of sleep

Nitric Oxide (NO)

causes smooth muscle relaxation

Habituation

Cells decreases the number of receptors because there is an abundance of neurotransmitters

Spinal Cord

body’s information highway, relays message between body and brain

Monosynaptic

knee-jerk reflex

Nerves

bundles of axons bound by connective tissues

Ganglia

aggregates of neuron cell bodies

Somatic motor neurons

stimulate the skeletal muscles to contract

Hydrostatic Skeleton

fluid-filled cavity encircled by muscle fibers

Exoskeleton

rigid hard case surrounding body

Endoskeleton

a rigid internal skeleton to which muscles are attached

Axial Bones

form axis of body

Appendicular Bones

bones of limbs, and pectoral and pelvic girdles

Bone

Connective tissue in which collagen fibers are impregnated with hydroxyapatite crystals.

Osteoblasts

new bone formed

Haversian Canals

Bone is in layers laid around channels

Immovable Joints

Sutures that join bones

Slightly Movable Joints

Bones bridged by cartilage

Freely Movable Joints

ends of bones are within a synovial capsule filled with lubricating fluid

Stapedius Muscle

Smallest muscle in the human body

Gluteus Maximus

Largest muscle in the the buttock

Synergists

Muscles that cause the same action at a joint

Antagonists

Muscles that produce opposing actions

Isotonic

Muscle shortens and movement occurs

Isometric

Muscle does NOT shorten but tension increases

Sliding Filament Mechanism of Contraction

Each muscle contains muscle fibers, which encloses myofibrils, which are composed of myofiliments, myofiliments slides deeper into the A bands.

Actin

Thin filaments

Myosin

Thick Filaments

Motor Unit

set of muscle fibers stimulated by a given motor neuron

Slow Twitch (Energy used: Fatty acids)

Produces: CO2 + Water, Aerobic Level

Fast Twitch 1 (Energy used: Glycogen)

Produces: Lactate, Anaerobic Level

Fast Twitch 2 (Energy used: Creatine Phosphate)

Produces: Creatine, Beyond Anaerobic Level

Skeletal Muscle

Fibers: Striated, tubular, and multinucleated

Voluntary

Usually attached to skeleton

Smooth Muscle

Fibers: non-striated, spindle-shaped, and uninucleated

Involuntary

Usually covering walls of internal organs

Cardiac Muscle

Fibers: striated, branched and uninucleated

Involuntary

Only covering walls of the heart

Endocrine System

all the organs and tissues that produce hormones

Endocrine Glands

Specialized to secrete hormones

Exocrine Glands

Secrete their products, such as milk or saliva, into a duct for transport to the outside, not hormones

Lipophilic (nonpolar)

Fat-soluble, steroid hormones and thyroid hormones \*Binds to intracellular receptors

Hydrophilic (Polar)

Water-soluble, All other hormones \*Binds to extracellular receptors

Anterior Pituitary

Forward, Appears glandular, produces insulin-like growth factors

Posterior Pituitary

Backwards, Appears Fibrous

Thyroid-simulating hormone (TSH)

a hormone that your pituitary gland releases to trigger your thyroid to produce and release its own hormones, important when it comes to metabolism

Luteinizing hormone (LH)

Hormone that triggers ovulation

Follicle-Stimulating hormone (FSH)

Hormone your pituitary gland makes and releases that plays a role in sexual development and reproduction. Releases egg into fallopian tube.