ATI TEAS Science Portion-- STUDY GUIDE AMANDA KHATAB

All cells contain:

DNA and RNA that can synthesize proteins

Each cell consists of:

- nucleic acids

- cytoplasm

- cell membrane

cells--> tissues--> organs --> organ systems --> organism

Ribosomes

involved in synthesizing proteins from amino acids

- some mobile, some embedded in rough ER

Golgi Complex (Golgi Apparatus)

involved in synthesizing materials such as proteins

- located near nucleus// contains layers of membranes

Vacuoles

saces used for storage, digestion and waste removal

- plant cells: one large vacuole

- animal cells: numerous small vacuoles

Vesicle

moves materials within a cell

- small organelle within a cell

Cytoskeleton

consists of microtubules that help shape and support the cell

Microtubules

part of the cytoskeleton and helps support the cell

- made of protein

Cytosol

liquid material in the cell

- mostly water

Cytoplasm

general term that refers to cytosol and organelles found within the plasma membrane, but not within the nucleus

Cell membrane (plasma membrane)

acts as a barrier to the cell

- helps keep cytoplasm in and substances located outside the cell out

- determines what is allowed in/out of the cell

Endoplasmic Reticulum

- rough ER: has ribosomes on the surface

- Smooth ER: does not have ribosomes on the surface

Mitochondria

generates ATP, involved in cell growth and death

- contains its own DNA that is seperate from that contained in the nucleus

- aerobic respiration occurs here

- inner membrane of mitochondria encloses matrix, which contains mitochondrial DNA (mtDNA) and ribosomes

- between inner and outer membranes are folds (cristae)// chemical reactions occur here

Four functions of Mitochondria

1. production of cell energy

2. cell signaling

3. cellular differentiation (process where a nondifferentiated cell becomes transformed into a cell with a more specialized purpose)

4. cell cycle and growth regulation

Animal cell structure

- Centrosome: compromised of the pair of centrioles and surrounded by protein. Involved in mitosis and cell cycle

- Centrioles: involved in cellular division// contains microtubules

- Lysosomes: digests proteins, lipids, carbohydrates. Transports undigested substance to the cell membrane so they can be removed

- Cilia: causes the cell to move

- Flagella: tail like structures on cell that use whip-like movements to help the cell move

Nuclear Parts of a Cell

- Nucleus: contains chromosomes and regulates DNA of a cell. is the defining structure of eukaryotic cells. contains nuclear envelope, nucleoplasm, nucleolus, nuclear pores, chromatin and ribosomes

- Chromosome: threadlike rods of DNA. dna is the genetic material that stores info about the plant or animal

- Chromatin: consists of the DNA and protein that makes up chromosomes

- Nucleolus: involved in protein synthesis and synthesizes and stores RNA

- Nuclear Envelope: encloses the structures of the nucleus. consists of inner and outer membranes made of lipids

- Nuclear Pores: involved in the exchange of material between the nucleus and cytoplasm

- Nucleoplasm: liquid within the nucleus (similar to cytoplasm)

Cell Membranes:

- thin, semipermeable membrane of lipids and proteins. isolates the cell from its external environment

- consists of phospholipid bilayer (hydrophilic ends face external environment and inner layer facing inside of cell. Hydrophobic ends face each other.

- Cholesterol in cell membrane adds stiffness and flexibility.

- Glycolipids help cell recognize other cells of the organisms.

- proteins in cell membrane help give the cell shape.

Selective Permeability

- cell membrane only allows small molecules to diffuse through (o2, h2o)

- molecules that are soluble in phospholipids can usually pass through cell membrane

Cell cycle

- Mitosis: daughter cell is EXACT replica of parent cell

- Meiosis: daughter cells have different genetic coding than parent cell. only happens in gametes

Cell Differentiation

- controlled by genes of each cell among a group of cells known as zygote.

- Example: gastrulation: an early phase in the embryonic development of most animals. during this process, cells are organized into 3 germ layers (Ectoderm, mesoderm, endoderm). nervous system develops from ectoderm, muscular system develops from mesoderm, digestive system develops from endoderm.

Mitosis

1. Interphase: cell prepares for division by replicating its genetic and cytoplasmic material. divided into G1, S, G2

2. Prophase: chromatin thickens into chromosomes and nuclear membrane begins to disintegrate. Pairs of centrioles move to opposite sides of the cell and spindle fibers form. mitotic spindle moves chromosomes around within the cell

3. Metaphase: spindle moves to center of cell and chromosome pairs align along the center of spindle structure.

4. Anaphase: sister chromosomes pull apart. when they are seperated, they are called daughter chromosomes.

5. Telophase: spindle disintegrates, nuclear membrane reforms, chromosomes revert to chromatin.

6. Cytokinesis: physical splitting of the cell into two cells.

Meiosis

1. interphase 1, prophase 1, metaphase 1, anaphase 1, telophase 1, cytokinesis 1; chromosomes cross over, genetic material is exchanged, tetrads of four chromatids are formed. One cell division occurs that results in TWO CELLS.

2. second division occurs including prophase 2, metaphase 2, anaphase 2, telophase 2 and cytokinesis 2. results in FOUR daughter cells with different sets of chromosomes. Daughter cells are HAPLOID (half genetic material of the parent cell.

--- Meiosis encourages genetic diversity

Animal Tissues

- Epithelial: cells are joined together tightly (ex. Skin)

- Connective: may be dense, loose or fatty. protects and binds body parts. (ex: bone tissue, cartilage, tendons, ligaments, fat, blood, lymph)

- Cartilage: cushions and provides structural support for body parts. jelly like base and fibrous

- Blood: transports oxygen to cells and removes wastes; carries hormones and defends against disease.

- Bone: hard tissue that supports and protects softer tissues and organs. bone marrow produces red blood cells

- Muscle: helps support and move body (ex. cardiac, smooth, skeletal)

- Nervous: cells called neurons form a network through the body that control responses to changes in external and internal environment (located in brain, spinal cord and nerves.

11 major organ sytems

1. integumentary

2. respiratory

3. cardiovascular

4. endocrine

5. nervous

6. immune

7. digestive

8. excretory

9. muscular

10. skeletal

11. reproductive

Terms of direction (anatomy)

- Medial: near the midline of the body (ex. pinky is medial to thumb)

- Lateral: further away from body's midline (ex. thumb is lateral to pinky)

- Proximal: closer to the center of th body (ex. hip is proximal to knee)

- Distal: further away from center of the body (ex. knee is distal to hip)

- Anterior: front

- Posterior: behind

- Cephalad/Cephalic: toward the head

- Caudad: towards the tail or posterior

- Superior: above, closer to head

- Inferior: below, closer to fet

Three body planes

1. Transverse (horizontal): divides body into superior (upper) and inferior (lower) halves

2. Sagittal: divides body vertically into right and left sections. runs parallel to midline of body

3. Coronal (frontal): divides body into front and back sections.

Respiratory System

-Upper Respiratory System: nose, nasal cavity, mouth, pharynx, larynx

- Lower Respiratory System: trachea, lungs, bronchial tree

Respiratory System cont'd

- airway is lined with cilia that traps microbes/debris

-lungs house bronchi and bronchial network, which extends into the lungs and terminate in millions of alveoli (air sacs)

- right lung has THREE LOBES; left lung has TWO LOBES (space for the heart)

-lungs surrounded by pleural membrane, which reduces friction btwn surfaces when breathing

-respiratory muscles include diaphragm and intercostal muscles.

Functions of respiratory system

- supply body with oxygen and rid body of CO2 (exchange occurs in alveoli surrounded by blood capillaries)

- Filters air (warm, moist before it reaches lungs)

- responsible for speech; as air passes through throat, it moves thru larynx (voice box) which vibrates and produces sound before it enters trachea (windpipe)

- Cough production

- sense of smell; chemoreceptors in nasal cavity respond to airborne chemicals.

- helps body maintain acid-base homeostasis

Breathing process

- hyperventilation increases blood pH during acidosis (low pH).

- Slow breathing during alkalosis (high pH) helps lower blood pH

- diaphragm and intercostal muscles contract to expand lungs

- during INSPIRATION: diaphragm contracts and moves down, increasing size of chest cavity. as volume of chest cavity increases, pressure inside chest cavity decreases and air rushes into lungs

- during EXPIRATION: diaphragm and intercostal muscles relax and size of chest cavity decreases, forcing air out of the lungs).

- breathing process is controlled by medulla oblongata: monitors the level of CO2 in blood and signals breathing rate to increase when these levels are too high.

Circulatory system

- responsible for internal transport of substances to and from cells

- includes blood, blood vessels, heart

- can either be open or closed; most animal have closed systems, where heart and blood vessels are continually connected.

- flow of blood in capillary beds is slow

- lymph vascular system: cleans up excess fluids and proteins and returns them to circulatory system

Three components of circulatory system

1. blood: composed of water, solutes, and other elements in fluid connective tissue

2. blood vessels: tubules of different sizes that transport blood

3. heart: muscular pump providing pressure necessary to keep blood flowing

three layers of blood vessels (except capillaries)

1. tunica intima (innermost layer)

2. tunica media (consists of smooth muscle cells and elastic fibers)

3. tunica adventitia (outermost layer)

Elastic Arteries

- Structure: includes aorta and major branches tunica media has more elastin than any other vessel; largest vessels in arterial system

- Function: stretch when blood is forced out of the heart and recoil under low pressure

Muscular Arteries

- Structure: inclued arteries that branch off of the elastic arteries. Tunica media has a higher proportion of smooth muscle cells, and fewer elastic fiber compared to elastic arteries

- Function: Regulates blood flow by vasoconstriction/ vasodilation

Arterioles

- Structure: tiny vessels that lead to the capillary beds. Tunica media is thin but composed mostly of smooth muscle cells

- Function: primary vessels involved in vasoconstriction/vasodilation. Controls blood flow to capillaries

Venules

- Structure: tiny vessels that exit capillary beds. Thin porous walls; few muscle cells and elastic fibers

- Function: empties blood into larger veins

Veins

- Structure: thin tunica media and tunica intima. wide lumen. valves prevent backflow of blood

- Function: carries blood back to heart

Blood

- helps maintain healthy internal environment by carrying raw materials to cells and removing waste products

- helps stabilize internal pH

- an adult has about 5 quarts of blood.

- Composed of rbcs, wbcs, platelets, and plasm

- Plasma: mostly water; serves as solvent; contains plasma proteins, ions, glucose, amino acids, hormones and dissolved gases

- RBCS: transport oxygen to cells. form in bone marrow and can live for 4 months.

- WBCS: defend body against infection and remove waste. different types include lympcytes, neutrophils, 6

Heart

- muscular pump made of cardiac muscle tissue

- four chambers: right atrium, right ventricle, left atrium, right ventricle

- each halve of the heart is seperated by AV Valve (located between vetnricle and artery leading away from the heart.

- valves keep blood moving in a single direction and prevent any backwash into the chambers

- Atrial contraction: fills ventricles

- Ventricular contraction: empties ventricles, forcing circulation

- self exciting: muscles that do not need external stimuli.

Types of circulation

- Coronary circulation: flow of blood to the heart tissue. blood enters the coronary arteries, which branch off the aorta, supplying major arteries, which enter the heart with oxygenated bllod. deoxygenated blood returns to the right atrium through cardiac veins which empty into the coronary sinus.

- Pulmonary circulation: flow of blood between the heart and lungs. deoxygenated blood flows from the right ventricle to the lungs through pulmonary arteries. oxygenated blood flows back to the left atrium through th pulmonary veins

- Systemic circulation: flow of blood to the entire body with the exception of coronary circulation and pulmonary circulation. blood exits the left ventricle through the aorta, which branches into the carotid arteries, subclavian arteries, common iliac arteries and the renal artery. blood returns to the heart through the jugular veins, subclavian veins, common iliac veins, and renal veins, which empty into the superior and inferior venae cavae.

- portal circulation: included in systemic circulation; flow of blood from the digestive system to the liver and then to the heart

- renal circulation: flow of blood between the heart and kidneys

Blood Pressure

- Arterial blood pressure: transports oxygen-poor blood into the lungs and oxygen rich blood to the body tissues.

- arteries branch into smaller arterioles which contract and expand based on signals from the body

- arterioles are where adjustments are made in blood delivery to specific areas based on complex communication from body systems

- capillary beds: diffusion sites for exchangs between blood and interstitial fluid.

lymphatic system

main function: return excess tissue fluid to the bloodstream.

- consists of transport vessels and lymphoid organs.

- lymph vascular system consists of lymph capillaries, lymph vessels, lymph ducts.

-lymphoid organs include: lymph nodes, spleen, appendix, adnoids, thymus, tonsils and small patches of tissue in the small intestine

- each lymph node contains lymphocytes and plasma cells.

- spleen: filters blood stores of rbcs and macrophages.

-thymus: secretes hormones and is the major site of lympocyte production

Major functions of lymph vascular system

- return of excess fluid to the blood

- the return of protein from the capillaries

-transport of fats from the digestive tract

- disposal of debris and cellular waste

Spleen

- made up of lymphoid tissue.

- blood vessels connected to spleen by splenic sinuses.

- main function: filter unwanted materials from the blood// fight infections

- includes 3 peritoneal ligaments that support the spleen:

1. gastrolienal ligament: connects stomach to spleen

2. lienorenal ligament: connects kidney to the spleen

3. phrenicocolic ligament: connects left colic flexure to the thoracic diaphragm

Gastrointestinal system

- four functions: movement, secretion, digestion, absorption

Stomach functions

1. mixing and storing food

2. dissolving and degrading food via secretions

3. controlling passage of food into the small intestine

peristalsis:

contracting and relaxing of smooth muscle to move nutrients along

Liver

- 4 lobes: right, left, quadrate, cuadate

- 5 ligaments that secure liver: falciform, coronary, right triangular, left triangular, round

- hepatic portal vein: nutrient rich blood supplied to liver

- hepatic artery: supplies oxygen-rich blood

- hepatic veins: blood leabes liver through these veins

- lobules: liver's functional units

- sinusoids: blood flows through these

Function of the liver:

- produces bile

- produces blood plasma proteins

- produces cholesterol

- storage of excess glucose in form of glycogen

- regulates amino acids

- processes hemoglobin

- converts ammonia to urea

- purifies blood

-regulates blood clotting

Pancreas

- exocrine tissue: secretes digestive enzymes from a series of ducts that form the main pancreatic duct

- endocrine tissue: secretes hormones into the blood stream

- blood supplied to pancreas from splenic artery, gastroduodenal artery and superior mesenteric artery

digestive role of pancreas

- secretes enzymes to small intestine to help break down many foods, especially fats and proteins

- secretes large amounts of sodium bicarbonate to neutralize stomach acid that reaches small intestine

Small intestine

- most nutrients are absorbed in small intestine

- bile is secretion of liver and stored in gall bladder between meals

- lining of small intestine is covered with villi that increases the surface area for interaction with chyme

- microvilli increases the ability of small intestine to serve as main absorption organ of digestive tract

Large Intestine (colon)

- concentrates, mixes, and stores waste material

- attaches to rectum

- muscle sphincter at end of anus is stimulated to expell waste matter

Nervous system

- senses, interprets, and issues commands as a response to conditions in the body's environment

- messages sent across the plasma membrane of neurons through process call action potential

- at point of contact (chemical synapse), substance is released that stimulates or inhibits the action of adjoining cell

Sensory neurons

- transmit signals to the central nervous system (CNS) from the sensory receptors associated with touch, pain, temperature, hearing, sight, smell and taste

Motor neurons

- transmits stignals from the CNS to the rest of the body such as by signaling muscles or glands to respond

Interneurons

- transmits signals between neurons

- recieve transmitted signals between sensory neurons and motor neurons

Parts of a neuron

- Dendrites: receives impulses from sensory receptors or interneurons and transmit them toward cell body

- cell body (soma): contains nucleus of neuron

- axon: transmits impulses away from the cell body; insulated by oligodendrocytes and myelin sheath; axon terminates at synapse

Central nervous system (CNS)

- brain and spinal cord

- integrative and control centers

Peripheral nervous system (PNS)

- cranial nerves and spinal nerves

- communication lines between CNS and rest of body

Motor (efferent) division

- motor nerve fibers

- conducts impulses from CNS to effectors (muscles and glands)

Somatic nervous system

- somatic motor (voluntary)

- conducts impulses from CNS to skeletal muscles

Autonomic nervous system

- visceral motor (involuntary)

- conducts impulses from the CNS to cardiac muscles, smooth muscles and glands

parasympathetic division

- conserves energy

- promotes "housekeeping" functions during rest

sympathetic division

- mobilizes body systems during activity (fight or flight)

Sensory (afferent) division

- somatic and visceral sensory nerve fibers

- conducts impulses from receptors to CNS

Brain

- consists of hindbrain, midbrain, forebrain

- hindbrain: includes medulla oblongata, cerebellum and pons

- midbrain: integrates sensory signals and orchstrates responses to signals

- forebrain: includes cerebrum,thalamus, and hypothalamus

- cerebral cortex: thin layer of gray matter covering cerebrum

- 4 main lobes: frontal lobe, parietal lobe, occipital lobe, temporal lobe

Frontal lobe

- located in front of brain

- responsible for short term and working memory and information processing as well as decision making, planning and judgement

Parietal lobe

- located slightly toward back of brain and top of head

- responsible for sensory output and spatial positioning of the body

Occipital lobe

- located at back of head above brain stem

- responsible for visual input, processing and output

temporal lobe

- located at left and right sides of brain

- responsible for all auditory input, processing and output

Cerebellum

- plays role in processing and storing of implicit memories

Brain stem

- consists of midbrain, pons and medulla oblongata

- posterior area of the brain that is connected to spinal cord

- important part of respiratory, digestive and circulatory functions

midbrain

- lies above pons and medulla oblongata

- includes tectum, tegmentum and ventral tegmentum

- important part of vision and hearing

pons

- between midbrain and medulla oblongata

- information sent across pons from the cerebrum to medulla and cerebellum

Medulla oblongata

- beneath midbrain and pons

- piece of brainstem that connects spinal cord to the brain

- important role with ANS in circulatory and respiratory system

Autonomic nervous system

- maintains homeostasis within the body; regulates heart rate, breathing rate, temp and blood pH

- controls functions of internal organs, blood vessels, smooth muscle tissues and glands

- accomplished through direction of hypothalamus (above midbrain)

- divided into sympathetic nervous system and parasympathetic nervous system

sympathetic nervous system

the division of the autonomic nervous system that controls bodys reaction to extreme stressful and emergency situations

- increases heart rate, signals adrenal glands to secrete adrenaline, triggers dilation of pupils, slows digestion

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

- decreases heart rate, signals adrenal glands to stop secreting adrenaline, constricts pupils and returns digestion process to normal

Somatic nervous system(SNS)

- controls five senses and voluntary movement of skeletal muscle

- efferent (motor) and afferent (sensory) nerves help SNS operate senses and movement of skeletal muscles

efferent nerves

bring signals from central nervous system to sensory organs and muscles

afferent nerves

brings signals from sensory organs and muscles to the central nervous system

reflex

automatic response to a stimulus without any conscious though

- reflex arc: simplest nerve pathway which bypasses brain and is controlled by spinal cord

Three types of muscle tissue

- skeletal

- cardiac

- smooth

Three properties of all muscles

- excitability: all muscle tissues have an electric gradient which can reverse when stimulated

- contraction: all muscle tissues have the ability to contract or shorten

- elongate: all muscle tissues can elongate or relax

Skeletal muscle

- voluntary muscles

- composed of muscle fibers (cells) bound together in parallel bundles

- also known as striated muscle (due to striped appearance

Smooth muscle (visceral tissue)

- involuntary muscles

- found in internal organs (stomach, intestines, blood vessels)

- nonstriated

- shorter and wider than skeletal muscle fibers

Cardiac muscle

- involuntary

- only found in heart

- striated

Skeletal muscle contraction

- consists of numerous muscle fibers

- each muscle fiber contains bundle of myofibrils which are composed of sarcomeres

- when an action potential (electrical signal) reaches muscle fiber, CALCIUM ions are released

-calcium ions bind to myosin and actin which helps bind myosin heads (of thick filaments) to actin molecules (of thin filaments)

- Adenosine triphosphate that is released from glucose provides energy necessary for contraction

Myofibrils

- protein structures that make up muscle fibers

- contains two protein microfilaments: thick filament and thin filament

- thick filament composed of: myosin

- thin filament composed of: actin

Male reproductive system function

to produce, maintain and transfer sperm into female reproductive tract and to produce and secrete male hormones

external structure of male reproductive system

- penis: contains the urethra; can fill with blood and become erect, enabling deposition of semen and sperm

- Scrotum: sac of skin & smooth muscle that houses the testes and keeps it at proper temperature for spermatogenesis

- Testes/testicles: male gonads which produce sperm and testosterone

Internal structure of male reproductive system

- Epididymis: stores sperm as it matures

- Vas deferens: mature sperm moves from epididymis through vas deferens to ejaculatory duct

- ejaculatory duct: where mature sperm lies

- Seminal Vesicles: secretes alkaline fluids with proteins and mucus into ejaculatory duct

- Prostate gland: secretes milky white fluid with proteins and enzymes as part of the semen

- Bulbourethral (Cowper's glands): secrete fluid into urethra to neutralize acidity in the urethra

hormones of male reproductive system

- Follicle- stimulating hormone: stimulates speratogensis

- luteinizing hormone: stimulates testoterone production

- testosterone: responsible for male sex characteristics

Functions of female reproductive system

- produce ova (oocytes/egg cells)

- transfer ova to fallopian tubes for fertilization

- receive sperm from the male

- provide protective environment for developing embryo

External structures of female reproductive system

- labia majora and labia minora: enclose and protect vagina

- Bartholin's glands: secrete lubricating fluid

- Clitoris: contains erectile tissue and nerve endings for sensual pleasure

internal structures of female reproductive system

- ovaries: female gonads; produce the ova and secrete estrogen and progesterone

- fallopian tubes: carry mature egg towards uterus; fertilization occurs here

- uterus: when egg is fertilized, it travels here and it implants in uterine wall; protects and nourishes developing embryo until birth

- vagina: muscular tube that extends from the cervix of the uterus to outside of the body; receives semen and sperm during sex and provides birth canal when needed

female reproductive cycle (3 phases)

1. follicular phase: FSH stimulates maturation of follicle that secretes estrogen. estrogen helps regerate uterine lining that is shed during menstruation

2. Ovulation: release of a secondary oocyte from ovary; induced by surge in LH

3. Luteal phase: begins with formation of corpus luteum from remnants of follice. corpus luteum secretes progesterone and estrogen, which inhibits FSH and LH.