Anatomy Med Flashcards
Human anatomy
science that provides the foundation for understanding physical performance and body health.
Gross anatomy
structures that can be observed with naked eye.
Surface anatomy
Surface examination of the body observed \ palpated (felt firmly).
Microscopic anatomy
study of structures w\microscope.
- cytology (study of cells).
- histology (study of tissues).
cell \ tissues stained by (vital stains)
Radiological anatomy
study of structures by X-rays, ultrasound, or CT/MRI. scans performed on living body.
- radiopaque substances can be ingested or injected for visualizing internal organs.
Angiography
involves making a radiograph after injecting a dye into the blood stream.
Surgical anatomy
Precise incision
Developmental anatomy (embryology)
study of prenatal stages (266/280 days).
Anatomical Position
• Supine position ( نايم على ظهره)
• prone position ( نايم على بطنه)
• Lithotomy position ( وضعيه الولاده)
Anatomical Planes
maginary planes (lines) that cut through the body when it is in anatomical position.
Median Plane (mid sagittal)
the plane is dividing the human body into two equal parts ( left and right )
Sagittal Planes (lateral)
the plane is dividing the human body into two parts ( not equal ) ( left and right ). sagittal plane are parallel to the median plane
Coronal Planes (frontal)
the plane is dividing the human body into two parts ( not equal ) ( front and back )
( anterior and posterior). it is perpendicular to the median plane
Horizontal Planes (transverse/axial)
cross section plane dividing the body into upper part and lower part , you can take plenty of horizontal sections .. not exactly the middle of the body
Oblique Planes
not in any of the coronal, sagittal, median or horizontal planes.
Anatomical terms-Terms of Relationship
Superior (cranial) – Nearer to the head
Inferior (caudal) – Nearer to the feet
Anatomical terms-Terms of Relationship
Anterior (ventral) – Nearer to the front Posterior (dorsal) – Nearer to the back
Anatomical terms-Terms of Relationship
Medial – Nearer to the median plane
Lateral – Farther from the median plane
Anatomical terms-Terms of Relationship
Intermediate – means between
Anatomical terms-Terms of Relationship
Palmar describes the palm side of the hand
Plantar describes the bottom of the foot
Anatomical terms-Terms of Comparison
Proximal – Nearer to the trunk/point of origin
Distal – Away from the trunk/point of origin
Anatomical terms-Terms of Comparison
Superficial – Nearer to/on the surface
Deep – Farther from the surface
Anatomical terms-Terms of Comparison
External – Towards/on the exterior
Internal – Towards/in the interior
Anatomical terms-Terms of Comparison
Central – Nearer to/towards the center
Peripheral – Away from the center
Anatomical terms-Terms of Comparison
Parietal – External wall of a body cavity
Visceral – Pertaining to covering of an organ
Anatomical terms-Terms of Comparison
Ipsilateral – On the same side of the body
Contralateral – On the opposite side of the body
Anatomical terms-Terms of Comparison
Evagination – Outward bulging of the wall of a cavity
Invagination – Inward bulging of the wall of a cavity
Molecular Organization of Human Body
H2 > O > C > N
Major Classes of Compound
Water > protein > lipids > carbohydrates
Gametogenesis
process in which gametes are formed Gametes are sex cells (Oocyte and sperms)
Characterized in 4 stages (1st stage is same in male and female)
1st stage of gametogenesis
The extraembryonic origin of the germ cells and their migration into the gonads
What happen if the primordial germ cells fail to migrate into the gonad?
Teratomas occur
2nd stage of gametogenesis
An increase in the number of germ cells by mitosis / proliferation by mitosis.
Why is Proliferation by Mitosis important?
To insure that we pass on and become fertile
Proliferation by Mitosis
• Before entering mitosis each chromosome replicates its DNA.
• Each daughter cell complete complement of 46 chromosomes- diploid progeny.
• The pattern of mitotic divisions differs from male and female germ cells.
3rd stage of gametogenesis
A reduction in chromosomal number by meiosis.
Why reduction in chromosomal number by meiosis is important?
Because if I have two sex cells and they are going to fuse together I would need half of that in order to restore the diploid progeny / In order to have a haploid (23 chromosomes) progeny
Reduction by meiosis
• generate male and female gametes.
• Requires two cell divisions to reduce the number of chromosomes to the haploid number of 23.
• Homologous chromosomes pair (each 2 chromatids), separate into two daughter cells reducing to haploid.
• Meiosis ll separates sister chromatids, each gamete then contains 23 chromosomes(1 chromatid).
Crossover
• Crossover are critical events in meiosis I (interchange of chromatid segments between paired homologous chromosome).
• Genetic variability is enhanced through crossover and through random distribution.
Reduction by Meiosis
→ For oocytes: one primary gives rise to four daughter cells (each 22+X) only one develops into a mature gamete the other 3 (polar bodies) degenerate.
→ For spermatocyte: similar to oocyte gives two (22+X) and two (22+Y) all are mature gametes!
Ooginia and Spermatogonia (premature germ cells)
Ooginia: Peaks from second to fifth month of pregnancy. undergo programmed degeneration until menopause called atresia*.
Spermatogonia: maintain the ability to divide throughout postnatal life.
→ Spermatozoas are generated continuously
But females generate all their potential gametes before birth
Meiosis in Females
• oogonia → mitotic divisions → arranged in clusters surrounded by a layer of flat epithelium.
• Primary oocytes together+its surrounding flat epithelial cells → a primordial follicle.
• At birth, all primary oocytes have started prophase of meiosis I, but do not enter metaphase- *they enter diplotene stage until puberty.
why late pregnancies are often considered high risk of chromosomal abnormalities?
• Oocytes that reach maturity late in life have
been dormant for 40 years or more before
ovulation
Meiosis in Males
• Begins after puberty, not all spermatogonia enter meiosis at the same time.
• When spermatogonium enter meiotic phase as primary spermatocyte they spend several weeks dividing.
• The result is two secondary spermatocytes, which enter the second meiotic divisions and result in four haploid spermatids ~64 days
Does spermiogenesis happen before puberty? Why?
No, Because anything before the haploid Will not occur before puberty.
4th stage of gametogenesis
maturation
- Structural and functional maturation of the eggs and spermatozoa.
Maturation pertaining to the follicles
• Each month 15 to 20 follicles selected from the pool begin to mature and pass through 3 stages:
1) Primary (preantral)
2) Secondary(antral)
3) Preovulatory(Graafianfollicle)
• primary oocyte begins to grow, surrounding follicular cells change from flat → cuboidal → stratified epithelium of granulosa cells
• Theca folliculi
• Zona pellucida
Maturation pertaining to the Spermatozoa
• Formation of the acrosome, which covers half of the nuclear surface and contains enzymes to assist in fertilization
• Condensation of the nucleus
• Formation of the neck, middle piece, and tail
• Shedding of most of the cytoplasm as residual bodies
Chromosomal Abnormalities
- nondisjunction: Chromosomes fail to separate during meiosis.
- one haploid gamete has 24chromosomes, other haploid gamete has only 22chromosomes.
→ When these gametes combine with normal (23 chromosomal) the result is: - 47 chromosomal embryo (trisomy)
- 45 chromosomal embryo (monosomy)
• General term for abnormal number of chromosomes in an embryo is termed aneuploidy*.
Trisomy 21
• Down Syndrome
• delayed growth distinct facial characteristics and intellectual disability
• The risk increases with maternal age
• Premature aging, thyroid dysfunction, infections
Trisomy 18
• Trisomy 18 patients show mental retardation, congenital heart defects, low-set ears, flexion of fingers and hand
• Incidence rate is 1:5000, and usually all die by 2 months of age
Trisomy 13
• show cleft lip and palate, eye defects, deafness, mental retardation
• Trisomy 13 patients 1:20,000 . More than 90% die in their first month after birth
How to identify abnormalities
Fluorescence in situ Hybridization (FISH)
