Midterm review

A & P 1

Vertebral Column

Humerus

Radius

Ulna

Pelvic Bone

Femur

MAJOR BONES OF THE HUMAN BODY

Clavicle

Sternum

Ribs

ANTERIOR THORACIC WALL

LungHeart

THORACIC CAVITY

Liver

Stomach

Gallbladder

Colon (Large Intestine)

Small Intestine

ABDOMINAL CAVITY(OR ABDMINOPELVIC CAVITY)

Spleen

Pancreas

Kidney

DEEP ABDOMINAL CAVITY(OR ABDOMINAL CAVITY)

Kidneys

Adrenal Gland

POSTERIOR ABDOMINAL CAVITY

(OR THE ABDOMINOPELVIC CAVITY)

Femur

Patella

Tibia

Fibula

Calcaneus

RIGHT LOWER EXTREMITY

Body Cavities

Body Planes and Sections•Sagittal / Midsagittal/Parasagittal•Transverse / Horizontal•Coronal/Frontal•Oblique

1. Transverse plane

2. Parasagittal plane

3. Mid-sagittal plane

BODY PLANESBODY PLANES

4 Abdominal Quadrants:

L. Hypochondriac Region

Epigastric Region

9 Regions of the Abdominopelvic Cavity:R. Hypochondriac Region

R. Lumbar Region L. Lumbar Region

Umbillical Region

L. Iliac (Inguinal) Region R. Iliac (Inguinal) Region

Hypogastric Region

Anatomy and Physiology

Anatomy – the science of body structures and the relationship among those structure

Physiology – the science of body functions; how body parts work.

Cavities of the Human Body

Body cavities are spaces within the body that help support, protect and separate internal organs

• Cranial Cavity: formed by the cranial bones; contains brain

• Vertebral Canal: formed by the vertebral column; contains spinal cord and the beginnings of the spinal nerves

• Thoracic Cavity: chest cavity; contains pleural and pericardial cavities and mediastinum

• Abdominopelvic cavity – superior abdominal cavity & inferior pelvic cavity.

Body Cavities

Anatomical Terminology

Anatomical Position – body standing erect, facing forward, upper limbs at the sides, palms facing forward.

In anatomical position, the body is upright; however, there are terms to describe the body in a reclining position

- Supine: term used to describe the body lying face up - Prone: term used to describe the body lying face down

Anatomical Position – standing erect, face is forward, and the upper limbs are at the sides with the palms facing forward.

Directional Terms:

Terms given to describe the position body parts relative to another body part

• Superficial: toward or on the surface of the body

• Deep: away from the surface of the body

• Superior: toward the head or upper part of a structure

• Inferior: away from the head or the lower part of a structure.

• Contralateral: on the opposite side of the body

• Ipsilateral: on the same side of the body

Medial: Towards the midline of the body

Lateral: Away from the midline of the body

Anterior: (Ventral) near to or at the front of the body

Posterior: (Dorsal) near to or at the back of the body

Proximal: near to the attachment of a limb of trunk; near the origination of the structure

Distal: farther from the attachment of the limb or trunk; farther from the origination of the structure

Pectoral Girdle

• clavicles• scapulae• supports upper limbs

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Upper Limb

• Humerus• Radius• Ulna• Carpals• Metacarpals• Phalanges

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Two Types of Cells

All organisms are comprised of either prokaryotic or eukaryotic cells

Prokaryotic Cells

Have no definitive nuclear membrane; DNA is free floating within the cytoplasm

The DNA is on the form of a single strand

Contains Ribosomes

Examples of prokaryotic cells include bacteria and some blue-green algae.

Eukaryotic Cells

Have a definitive nuclear membrane (can be many shapes).

•The nuclear membrane:

Has a double membraned structure- there are 2 membranes surrounding the nuclear material

•separates the DNA from the rest of the cell (cytoplasm).

•This, in turn, forms a nuclear compartment and a cytoplasmic compartment.

Is porous – the nuclear membrane has fenestrations or “holes” in it (nuclear pores)

Allows for communication between the nuclear and cytoplasmic compartments.

Eukaryotic cells can be anucleated, mononucleated, or poly-nucleated

Examples of eukaryotic cells include higher plant cells, protista (protozoans), and all animal cells.

The cell membrane consists of:

A phospholipid double layer with proteins inserted in it (integral proteins) or bound to the cytoplasmic surface (peripheral proteins)

Integral membrane proteins:

Firmly embedded in the lipid layers. The dotted line in the integral membrane protein is the region where hydrophobic amino acids interact with the hydrophobic portions of the membrane..

Transmembrane Proteins:

Completely span the bilayer

Peripheral Proteins - Many of the proteins and lipids have externally exposed oligosaccharide chains or phosopholipid groups.

Eukaryotic Cell Showing Some Organelles:

THE SINGER-NICOLSON MODEL OFMEMBRANE STRUCTURE

PHOSPHOLIPIDS

WATER SOLUBLE HEADS

WATER INSOLUBLE TAILS

(HYDROPHILIC)

(HYDROPHOBIC)

The Structure of Eukaryotic Cells

Cytoplasmic Organelles

Endoplasmic Reticulum (ER):1. Connected, membrane-bound sacs, canals, and vesicles.2. Transport system.3. Rough ER (rER).

• Studded with ribosomes.• Protein and lipid synthesis.• Smooth ER (sER).

• Lipid synthesis.• Breakdown of drugs.

Ribosomes:• Free floating or connected to ER• Site of protein synthesis 3-8

RERSER

Mitochondrion (sing.); Mitochondria (pl.)

Like the nuclear membrane, mitochondria have two membranes.

They function in the production of energy in the form of adenosine tri-phosphate (ATP). This is done by oxidative phosphorylation.

They also function in cytosolic cation buffering (especially for calcium, Ca++).

They also regulate the pH of the cytoplasm.

MITOCHONDRION STRUCTURE

CELL

ISOLATEDMTOCHONDRIA

THE MITOCHONDRION.THE CELL’S “POWER PLANT”.

Mitochondrion Structure

Cytoplasmic Organelles

Lysosomes:1. Enzyme-containing sacs.2. Digest worn out cell parts or unwanted

substances.

Peroxisomes: 1. Enzyme-containing

sacs (oxidases). 2. Break down organic molecules (lipids).

Centrosomes or Centrioles:1. Two rod-like centrioles.2. Used to produce cilia.3. Distributes chromosomes during cell division.

3-10CENTRIOLES

Smooth Endoplasmic Reticulum (sER)

Functions in steroid and lipid formation, detoxification reactions and others.

Lacks the ribosomes and therefore its rough appearance.

Ly

Ly

Ly

Ly = LYSOSOMESSER

SER

SER = SMOOTH ENDOPLASMIC RETICULUM

Vesicles:• membranous sacs• store substances

Microfilaments and Microtubules:• thin rods and tubules• support cytoplasm• allows for movement of organelles

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Cytoplasmic Organelles

MICROTUBULES

MICROFILAMENTS

MT + MF = CELL CYTOSKELETON

THE NUCLEUS (“THE BRAIN OF THE CELL”)Is surrounded by two membranes with many pores:

Nuclear Membranes:

•Separate the DNA from the rest of the cell (cytoplasm).

•This forms a nuclear 2 compartments: a cytoplasmic compartment and a nuclear compartment.

Nuclear pores:

Fenestrations “holes” in the nuclear membrane allow for communication between the nuclear and cytoplasmic

compartments

The nucleus contains the Genetic Information (DNA):

Heterochromatin- inactive DNA (dark staining)

Euchromatin- active DNA (light staining)

The Nucleolus

• Where RNA metabolism and ribosome formation occur.

• It is a dark, electron dense area within the nucleus.

Movements Into and Out of the Cell

Passive (Physical) Processes:1. Require no cellular energy.2. Simple diffusion.3. Facilitated diffusion.4. Osmosis.5. Filtration.

Active (Physiological) Processes:1. Require cellular energy.2. Active transport.3. Endocytosis.4. Exocytosis.5. Transcytosis.

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Enzymes

Enzymes are proteins or protein complexes that catalyze a chemical reaction

* Lower activation energy and thereby speed up the reaction time

* Contains an Active Site – which is defines as the portion of the enzyme that specifically combines with the substrate

* Substrate – material or substance with which the enzyme reacts

DNA

• DNA (Deoxyribonucleic Acid) is the building block of matter. It is responsible for coding our genetic instructions.

• DNA is: - Made up of Nucleotides - Exist in the form of a Double Helix - Found in the nucleus and mitochondria - Nitrogenous Base pairs (complementary pairs)

Nucleotides are made from phosphate, a sugar and nitrogenous base.

Structure Of DNA: General Rules

• Two polypeptide Chains• Hydrogen Bonds• Nitrogenous Bases are located together• Bases pair specifically (A-T, G-C)• Forms Double Helix• DNA is wrapped around histones to form

chromosomes

Nucleotide Bases – Purines & Pyramidines

• Purines – Adenine (A) , Guanine (G)• Pyramidines – Cytosine (C), Thymine (T), Uracil –

RNA (U)• One purine and One Pyramidine pair to join the DNA

strand: Adenine + Thymine A-T or T-A Guanine + Cytosine G-C or C-G

(Complementary Base Pairs)

Types of RNA Molecules

• RNA comes in three forms: 1. Messenger RNA (mRNA) – used for transcription

2. Transfer RNA (tRNA) – transfers an amino acid to a growing peptide chain by “reading” the codon of mRNA

binds amino acid at one end and anticodon on the tRNA binds the codon the mRNA on the other end

codon-sequence of 3 nucleotides found in the mRNA that endoes a specific amino acid

3. Ribosomal RNA (rRNA) – provides structure and enzyme activity for ribosomes

mRNA

• Messenger RNA (mRNA): - Delivers genetic information from the nucleus to the cytoplasm - Single nucleotide chain - Formed beside a strand of DNA - Complementary to DNA (except uracil, no thymine)

Protein Synthesis

• Transcription – occurs in the nucleus; mRNA is transcribed from a double strand of DNA to a single strand of RNA

• mRNA exits the nucleus and enters the cytoplasm to direct Translation (protein synthesis)

• Proteins are made of: - Amino Acids - Different sequences and arrangements of AA’s make up various proteins - mRNA specifies the order of the AA in the protein

Transcription (DNA to RNA)

• In the nucleus, DNA synthesizes mRNA which enters the cytoplasm

• In the nucleolus, DNA synthesizes rRNA which enters the cytoplasm

• In the nucleolus, DNA synthesizes tRNA which enters the cytoplasm

Translation - Inititation

• Translation is controlled by substances calls Initiation Factors (IF’s) – causes mRNA to bind to small subunits of ribosomes

• Always begins with Methionine (start codon)• tRNA for methionine secures the AA in the cytoplasm and

returns it to the ribosome. The methionine anticodon on the tRNA binds to the methionine codon on the mRNA

Translation - Elongation

• Ribosomes move along the mRNA strand• At the beginning, the methionine is located in the p-site, The

next AA in the sequence binds at the a-site.• Peptide bond is formed between the AA in the p-site and the

AA in the a-site (joined together)• tRNA is released from the p-site• Ribosomes move over one codon onto the mRNA strand• Processes repeats until all codons have been coded into AA’s

Chromosomes

• Chromosomes are divided into 22 pairs of autosomes and one pair of sex chromosomes (either XX – females and XY for males)

• Females have 23 pairs of homologous chromosomes and males only have 22 pairs

Karyotyping: Picture of Chromosomes

• Karyotyping is the process for analyzing chromosome morphology and number

• Used in mitotic active cells because they are condensed and can be easily viewed

• Result is a mix of all 46 chromosomes• They are divided into: 1. Autosomes vs. Sex Chromosomes 2. Groups – There are 7 groups of autosomes Human cells

have 44 autosomes (22 pairs)

The Cell Cycle

• The Cell Cycle is divided into 2 major stages: 1. Interphase 2. Mitosis

Interphase• During interphase, the cell grows and maintains its

routine functions• Cell replicates its genetic material to prepare for

nuclear division (karyokinesis) • The cell synthesizes new organelles to prepare for

cytoplasmic division• 3 sub-phases: 1. G1 (Gap 1) - growth phase 2. S (Synthesis) – replication/duplication of DNA 3. G2 (Gap 2) - growth phase

G1 – (Gap 1)

• Occurs after mitotic division and before DNA synthesis

• Cell grows and prepares for chromosomal replication; cell increases in size, produces RNA and synthesizes proteins

• Checks DNA damage (Checkpoint) before S-phase

S Phase - Synthesis

• DNA synthesis occurs (DNA replication)• This preceded mitosis and is necessary so that

each daughter cell will have a complete copy of the genetic information

G2 (Gap 2)

• Occurs after DNA synthesis and before the beginning of mitosis

• Cell produces new proteins• Cell begins to prepare for mitosis• Checks DNA duplication and damage before

entering Mitosis

Mitosis – Somatic Cell Division• Cell division that involves non-sex cells (somatic cells)

and produces two daughter cells form the original cell • New cells are genetically identical – each containing a

full complement of 46 chromosomes• During mitosis, the nuclear contents divide in an event

called karyokinesis• Cytoplasm is distributed to the two daughter cells in a

process called cytokinesis (during telophase)• Divided into 4 stages

Prophase – Phase 1• Chromatin condenses to form individual chromosomes• Each chromosome consists of two chromatids, joined

together at the centromere• Nuclear membrane and the nucleolus disappear• Centrioles begin to migrate to opposite poles (each

pair moves to one pole)• Centrioles function to produce microtubules• Other centriole fibers anchor the centrioles to the cell

membrane and hold it in place

Metaphase – Phase Two

• Chromosome fibers migrate to the middle of the cell and line up. This is know as the metaphase plate

• Chromosomes attach to the chromosomal fibers (microtubules) at the centromere

Anaphase – Phase 3

• Centrioles pull toward the poles, seperating the chromatids pairs into individual 1C chromosomes.

• The movement is the result of microtubule activity

Telophase – Phase 4• Final stage of mitosis• Begins when the chromosomes complete their migration toward

the centrioles• Contractile rings of microfilaments encircle the cell and the

metaphase plate• Fibers contract and split cytoplasm (cytokinesis), creating two

daughter cells• Nuclear membrane reforms around daughter cells and nucleoli

becomes visable.• Microtubules disassemble into free tubulin molecules.

Meiosis Overview• Meiosis is the process by which sex cells (gametes)

divide• Takes place during gametogenesis as egg and sperm

cells are formed from germ cells of the ovaries and the testes

• In human cells, the diploid number (2n) is 46. Thus, the haploid number is 23.

• During meiosis, the chromosome number is reduced from 46 to 23 so as cells enter this process they are diploid and as they complete the process they are haploid.

Meiosis Overview Continued

• At fertilization, two haploid cells unite to form a diploid zygote

• Therefore, the zygote inherits 23 chromosomes from the paternal side and 23 from the maternal side.

Meiosis: The Phases

• Meiosis involves two sequential cells divisions known as the meiotic or maturation divisions:

1. M-I Phase: reduction division during which chromosome number is reduced from diploid to haploid

2. M – II Phase: Precedes Mitosis*** The sequence of events is similar to mitosis

(prophase, metaphase, anaphase, telophase) ***

M-I: First Maturation Stage• Synapsis (pairing) of homologous chromosomes takes place• Complementary chromosomes align, side by side, during

metaphase. This is a very precise alignment does not occur in mitosis.

• Because each chromosome consists of two chromatids and synapsis involves the formation of structures know as tetrads (between 4 chromatids)

• During anaphase of M-I, one complete two chromatid chromosome from each pair, migrates to form daughters.

- One tetrad is split into dyads (two chromatids) - Each dyad represents one 2-chromatid (2C) chromosome of the homologous pair

First Division of Meiosis – M - I• Prophase I – each chromosome duplicates. These are called sister

chromatids. Crossing over (mixing of traits) can occur at the later part of this stage. One homologous chromosome comes from the individual’s father and one form the mother.– Crossing over – results in genetic variation; occurs when the tetrad is formed

during meiosis; occurs as a result of chiasma formation• Metaphase I – Homologous chromosomes align at the equatorial plate• Anaphase I – Homologous pairs separate with sister chromatids remaining

together• Telophase I – Two daughter cells are formed with each daughter

containing only one chromosome of the homologous pair• The resulting cells are haploid and contain 23, 2C chromosomes

The M – II Division of Meiosis

• This division is similar to mitosis• The splitting of two chromatids (2C)

chromosomes (dyads) into single chromosomes (1C) chromosomes – During anaphase II of meiosis

• This occurs because unlike no DNA synthesis or duplication occurs

• As an end result, each normal human gamete contains 23, 1C chromosomes.

Second Division of Meiosis (MII) – Gamete Formation

• Prophase II – DNA does not replicate• Metaphase II – Chromosomes align at the

equatorial plate but there is no synapsis• Anaphase II – Centromers divide and sister

chromatids migrate separatley to each pole• Telophase II – Cell division is complete. Four

haploid daughter cells are formed