Bio II Exam 3

Two types of symmetry

Radial and bilateral

Radial Symmetry

• Body parts arranged around central axis

• Can be bisected into 2 equal halves at any 2D plane

Bilateral Symmetry

• Body has right and left halves that are mirror images

• Only the sagittal plane bisects the animal into 2 equal halves

Sagittal Plane

Divides the body into right and left portions

Midsagittal Plane

Divides the body into EQUAL right and left portions

Frontal Plane (AKA Coronal Plane)

Separates the front from the back

Transverse plane (horizontal plane)

Divides into upper and lower portions

AKA cross-section

Called oblique plane if cut at an angle

Basal Metabolic Rate

• Average amount of energy used by an organism in a non-active state

• Smaller animals have a higher BMR to compensate for heat lost from a higher surface-area-to-volume ratio

4 types of animal tissue

Epithelia

Connective Tissue

Muscles

Neurons

Epithelial Tissue

Lines cavities, open spaces and surfaces

Secretion

Classified by number of layer and shape of the cell

Types of Epithelial Tissue

Squamous, cuboidal, columnar, transitional

Connective Tissue

Connects tissue together, provides support

Arises from the mesoderm

Consists of cells (fibroblasts) embedded in a non-cellular matrix

Matrix usually composed of a ground substance

Ground Substance

Composed of collagen, elastic, and reticular fibers

Cartilage

Connective Tissue

Chondrocytes and chondroblasts

Makes up fetal bones, intervertebral discs, joint spaces

Bone

Connective Tissue

Osteoblasts, osteocytes, osteoclasts

Makes up vertebrates’ skeletons

Adipose

Connective Tissue

Adipocytes

Energy storage and insulation

Blood

Connective Tissue

red blood cells (erythrocytes) and white blood cells (leukocytes) and platelets (thrombocytes)

Immune response and oxygen transport

Muscle Tissue

Generates movement

Types of Muscle Tissue

Smooth, skeletal, cardiac

Incomplete digestive tract

Single opening = gastrovascular cavity

Food enters through mouth and muscular pharynx

Waste exits through mouth and muscular pharynx

Lacks specialized parts

Complete digestive tract

Two openings = alimentary canal

Food enters through mouth

Wastes exit through anus

Monogastric Digestive Systems

• Humans and herbivores

• Rabbits have a distended cecum

Ruminant digestive system

• Four stomachs

• Rumen, reticulum, omasum, and abomasum

Rumen and reticulum

• Two of four stomachs of ruminants

• Contains prokaryotes and protists to digest cellulose fiber

Omasum

Third ruminant stomach

Cud is regurgitated, chewed and swallowed

Removes water

Abomasum

Stomach where enzymes are produced by animal (most like monogastric stomachs)

Bird digestive system

• Crop to store food

• Two stomachs:

  • Proventriculus (enzymes)

  • Gizzard (grinding)

• One opening (cloaca) to excrete urine and feces

Human Digestive Tract

• complete (alimentary canal)

• tube-within-a-tube body plan

• digestion is entirely extracellular

• digestive enzymes secreted by walls of digestive tract and nearby glands

Mouth

• Three major pairs of salivary glands

• Salivary amylase initiates starch digestion

• Tongue mixes chewed food with saliva and forms bolus

Pharynx

• Where digestive and respiratory passages come together

• Epiglottis covers opening into trachea and keeps food from air passages

Esophagus

• Takes food to stomach by peristalsis

• Peristalsis is rhythmical contraction to move contents in tubular organs

Human Stomach

• Stomach wall has deep folds called rugae

• Gastric pits drain gastric glands

• Gastric glands produce pepsin, a hydrolytic enzyme that acts on protein to produce peptides

• Junction between stomach and small intestine controlled by pyloric sphincter

Chyme

Food (bolus) mixing with gastric juices

Small intestine

• First segment is duodenum which chemically breaks down food (chyme) from the stomach

Liver

• Produces bile which is stored in gallbladder

• bile contains bile salts which break up fat into droplets via emulsification

• helps maintain glucose concentration in blood by converting excess into glycogen

Pancreas

• Exocrine gland

• Produces pancreatic juice and digestive enzymes into the duodenum

  • Pancreatic amylase digests starch to maltose

  • Trypsin digests protein to peptides

  • Lipase digests fat droplets to glycerol and fatty acids

Large Intestine

• Includes cecum, colon, rectum and anal canal

• Larger in diameter but shorter in length than small intestine

• Absorbs water, salts and some vitamins to dehydrate chyme

Essential amino acids for adults

Methionine, valine, threonine, phenylalanine, leucine, isoleucine, tryptophan, lysine

Fat-soluble vitamins

A, D, E, K

Vitamin A

• Fat soluble

• promotes eye health, helps form and maintain healthy skin, teeth and bones

Vitamin D

• Fat soluble

• Helps the body absorb calcium, maintains strong bones

Vitamin E

• fat soluble

• Antioxidant, boosts immune function

Vitamin K

• fat soluble

• aids in blood clotting

B vitamins

• Water soluble

• help the body produce energy, influence growth/development

Vitamin C

• water soluble

• boosts immune function, fights skin aging, antioxidant

Osmoregulation

Process of maintenance of salt and water balance across membranes within the body’s fluids

Kidneys

Located on either side of vertebral column, each connected to a ureter which connects urine from the kidney to the bladder

Tubular nephrons

Functional unit of the kidney

Composed of glomerular capsule, glomerulus, proximal convoluted tubule, loop of the nephron/Henle, distal convoluted tube, and collecting duct

Renal cortex

Outer region of the kidney, granular appearance

Renal medulla

Cone-shaped renal pyramids of kidney

Renal pelvis

Hollow-chambered innermost part of the kidney, receptive for collecting ducts

Processes of Urine Production

Glomerular filtration in glomerular capsule, tubular reabsorption (water) in proximal convoluted tubule, tubular secretion (and removal of sodium and chloride) at distal convoluted tube.

Excretion of hypertonic urine

Dependent on reabsorption of water from the loop of nephron and collecting duct

Antidiuretic hormone

Plays a role in water reabsorption, and released by posterior lobe of the pituitary gland in the brain

Contraction of EXTERNAL INTERCOSTAL MUSCLES

Expands the rib cage

Contraction of DIAPHRAGM

Expands the volume of thorax and lungs

Diaphragm is primary muscle of inspiration

Vital capacity

Maximum amount of air that can be expired after a forceful inspiration (you’ll almost always have a little left over)

Hemoglobin

Consists of four polypeptide chains, two alpha and two beta

Each chain is associated with a heme group that has a central iron atom that can bind a molecule of O2, forming oxyhemoglobin

Bohr shift

• Increased CO2 in blood increases H2, lowering pH and reducing hemoglobin’s affinity for O2

• High levels of CO2 mean oxygen is needed so the hemoglobin lets go of the oxygen

Central Nervous System

• Includes the brain and spinal cord

• Lies in the midline of the body

Peripheral Nervous System

• Contains cranial nerves and spinal nerves that gather info from sensors and conduct decisions to effectors

• Lies outside the CNS

Functions of the Nervous System

Receiving sensory input, performing integration, and generating motor output

Neurons

Cell body contains nucleus

Dendrites receive signals from sensory receptors

Axon conducts nerve impulses and is covered by myelin sheath that assists with action potential

Motor Neurons

Accept nerve impulses from the CNS (primary motor cortex in the frontal lobe) and transmits them to muscles or glands

Efferent (starts in brain and leaves through nervous system)

Sensory Neurons

Accepts impulses from sensory receptors and transmits them to the CNS

Afferent (starts in PNS and travels toward CNS then brain)

Four types of neurons

Unipolar neurons, bipolar neurons, multipolar neurons, and pseudounipolar neurons

Glial Cells

Support, protect, and nourish neurons

Outnumber neurons 10 to 1 in the brain

Fulfills immunity, making myelin sheaths, and nutritional support

Most brain tumors are caused by mutations in glia

Oligodendrocytes

CNS
Form myelin sheaths around axons

Astrocytes

CNS
Provides nutrients and structural support

Ependymal cells

CNS
Produce cerebrospinal fluid that cushions the neurons

Microglia

CNS
Scavenge pathogens and dead cells and immune support

Schwann cells

PNS

Forms the myelin sheath

Satellite cells

PNS
Provides nutrients and structural support to neurons