quiz 1

Question 1

explain: difference between anatomy and physiology

Answer 1

• anat.: investigates body’s structure
• physio.: investigates processes and func. of living things

Question 2

list + define: organizational levels from smallest to largest (6)

Answer 2

1. chemical lvl (atoms)
2. cell lvl
3. tissue lvl (groups of cells)
4. organ lvl (2+ tissues working together)
5. organ sys. (groups of organs working together)
6. organism lvl (any living thing)

Question 3

name + explain: body positions (3)

Answer 3

1. anat. pos.
   - body erect
   - feet together
   - palms forward
2. supine
   - lying facing up
3. prone
   - lying facing down

Question 4

explain: superior vs inferior

Answer 4

• superior/cephalic: toward head
• inferior/caudal: away from head

Question 5

explain: medial vs lateral

Answer 5

• medial: middle
• lateral: sides

Question 6

explain: proximal vs distal

Answer 6

• used for linear struc.
• proximal: closer to attachment point to torso
• distal: father from attachment point to torso

Question 7

explain: superficial vs deep

Answer 7

• superficial: shallow
• deep: deep
• relative to surface of body

Question 8

explain: anterior vs posterior

Answer 8

• anterior/ventral: front
• posterior/dorsal: back

Question 9

name + explain: body planes (3.5)

Answer 9

1. sagittal
   - vertical
   - separates R and L of body
2. frontal/coronal
   - vertical
   - separates anterior and posterior
3. transverse/cross
   - horizontal
   - separates superior and inferior
4. oblique: not 90 degrees

Question 10

name + explain: planes through organs (2.5)

Answer 10

1. longitudinal
   - down the length of organ
2. cross/transverse
   - cuts at a right angle to organ
   - perpendicular to length
3. oblique: not 90 degrees

Question 11

name + explain: body cavities (3) and location of diaphragm

Answer 11

1. thorasic cav.
   - heart + lungs
   - mediastinum: contains all struc. of thorasic cav. except for lungs
2. abdomonial cav.
   - stomach, intestines, liver, splee, pancreas, kidneys
3. pelvic cav.
   - urinary bladder, some large intestine, rep organs

• diaphragm divides body cav. into thorasic vs ab.pelv.

Question 12

define: serous mem. (inner and outer walls)

Answer 12

• mem. covering organs of trunk cavity
• also lines cav.
• inner wall = visceral
• outer wall = parietal
• cavity between mem. walls filled with serious fluid to reduce friction and prevent damage

Question 13

name + explain: types of serous mem. (3)

Answer 13

1. pericardium
   - SM around hear
2. pleura
   - SM around lungs
3. peritoneum
   - SM around organs of ab. cav.
   - retroperitoneum org. = organs in ab. pev. cav. outside of SM

Question 14

define: homeostasis

Answer 14

• maintenance of constant envrt. w/in body
• ability to maintain internal equil. by adjusting physio. processes

Question 15

define: set point

Answer 15

• ideal normal value of var.
• can still fluctuate depending on sit. body is in
• ex. BP during exercise
  ⤷ body has greater demands ∴ normal range for BP increases
  ⤷ decreases back to normal set point after exercise

Question 16

define: components of feedback systems (3)

Answer 16

1. receptor
   - monitors value of the var.
   - detects change/stim.
2. control center
   - establishes set point
   - usually in CNS (brain)
3. effector
   - can change value of var.
   - prod. resp. to stim.
   - usually a target organ in body that can change

Question 17

explain: process of a feedback system

Answer 17

• stim. causes disruption to homeo.
• receptors detect the change from stim. + sends impulse/sig. to control center
• control center receives sig. and sends to effectors
• effectors make a resp. to alter the conditions
• body returns to homeo. when resp. brings conditions back to normal

Question 18

explain: -ive feedback sys. w/ ex.

Answer 18

• makes deviation from set point SMALLER
• resists change to try and maintain homeo.
• ex. body temp.
  ⤷ stim. = temp. increases
  ⤷ recep. on skin and blood vessels notice change
  ⤷ control center in brain sends resp. to sweat glands
  ⤷ effectors (sweat glands) produce sweat to cool body down
  ⤷ temp. decreases = homeo. restored

Question 19

explain: +ive feedback sys. w/ ex. (harmful and normal)

Answer 19

• makes deviation from set point even GREATER
• leads body away from homeo.
• unusual in healthy ppl
• harmful ex. hemorrhage
  ⤷ severe bleeding decreases blood pressure bc less blood circulating
  ⤷ less blood decreases heart’s ability to pump
  ⤷ decreases bp even more making heart worse
• normal ex. child birth
  ⤷ stim. = contractions
  ⤷ receptors notice stretch in cervix
  ⤷ sig. sent to brain (control center) releases hormone (effector)
  ⤷ makes body contract more forcefully
  ⤷ even more stretching = more hormones = more stretching etc.
  ⤷ baby delivered = breaks cycle and body can work on returning to homeo.

Question 20

explain: timeline of pre-natal dev.

Answer 20

1. germinal period
   - first 2 weeks
   - formation of primitive germ layers
2. embyronic period
   - weeks 3 - 8
   - organs sys. dev.
3. fetal period
   - week 8 - birth (38 weeks)
   - organ sys. dev. more and mature

Question 21

explain: ovulation and sperm swimming

Answer 21

• 14 days into menstrual cycle
• each menstrual cycle, ovary releases 1 gamete cell (secondary oocyte)
• 20 million sperm reach vagina -> 1% reach uterus -> 100 - 200 reach oocyte
• muscular contractions help push sperm up uterine tube towards ampulla region for fertilization

Question 22

explain: diff. between clinical age and post-ovulatory age

Answer 22

• clinical = based on clinical events
  ⤷ starts on date since last period
  ⤷ full term clinically = 40 weeks
• post-ovulatory = starts after ovulation/at fertilization
  ⤷ ovulation = around 14 days after first day of last menstrual cycle
  ⤷ so post-ovulatory date = 14 days later than clinical

Question 23

explain: initial steps of fertilization

Answer 23

1. sperm meets egg
   - sperm pushes through corona radiata of secondary oocyte
   - reaches zona pellucida which has ZP3 glycoprotein (sperm receptor)
2. acrosomal reaction
   - acrosome of sperm binds to ZP3 receptor
   - causes acrosomal reac.
   - acrosomes of sperm have digestive enz. that activate when binding to ZP3
   ⤷ many sperm needed to digest zona pellucida
3. sperm enters ooctye
   - 1 sperm binds to integrin α6β1 on oocyte plasma mem.
   - causes depolarization (fast block for polyspermy)
   - single sperm enters ooctye

Question 24

explain: blocks to polyspermy (fast vs slow) and why

Answer 24

• prevents multiple sperm from fertilizing oocyte
• fast = depolarization
  ⤷ elec. change to mem. shocks any other sperm trying to enter
• slow = intracellular release of Ca causing exocytosis of H2O
  ⤷ Ca moving out of cell brings water with it making oocyte shrink
  ⤷ zona pellucida degrades when cell shrinks and ZP3 inactivates
  ⤷ no more sperm can attach to ZP3 so sperm can’t reach oocyte nucleus

Question 25

explain: final stages of fertilization

Answer 25

4. female nucleus splits
   - second meiotic division
   - results in ovum and second polar body
5. female pronucleus and male pronucleus form
   - female = ovum and nucleus
   - male = sperm head
6. fuse to become zygote
   - haploids fuse and become single nucleus zygote (diploid)

Question 26

question: morula vs blastocyst

Answer 26

• morula: 12+ cells in solid ball
  ⤷ 5 days
  ⤷ totipotent: can diff. into anything
• blastocyst: new cell after hatching
  ⤷ 6 days
  ⤷ morula breaks free from ZP and secretes fluid
  ⤷ trophoblast layer on outside
  ⤷ has cells for embryo proper
  ⤷ cavity = blastocele (fluid filled)
  ⤷ pluripotent: only diff. into some cell types

Question 27

define + explain: implantation (days 8 - 12)

Answer 27

• implantation: burrowing of blastocyst into uterine wall
• technically 7 days after fertilization
• trophoblast = 2 types

1. syncytiotrophoblast
   - multinucleated cell invading endometrium
   - digests blood (maternal arterioles)
   - makes blood connection to embryo
   - release human chorionic gonadotropin into maternal blood
2. cytotrophoblast
   - remains close to embryo proper
   ⤷ separates embryo from mat. blood

Question 28

define: lacunae and placenta
explain: implantation (days 14 - 20)

Answer 28

• lacunae: pools of blood from maternal arterioles after syncytiotrophoblasts digest
  ⤷ becomes supply of nutrients and O2 for embryo
• placenta: exchange of nutrients + waste between mother and embryo
• connecting stalk -> umbilical cord

Question 29

explain: implantation (1 month)

Answer 29

• finger-like cytotrophoblasts become cytotrophoblast chords
• embryo begins building it’s own blood vessels (circulatory system)
• cytotrophoblasts act as protective barrier between mat. and embryo blood

Question 30

explain: mature placenta + fetus
define + explain: role of chorion

Answer 30

• cytotrophoblast chords become chorionic villi
  ⤷ fill w/ fetal arteriole and venules
  ⤷ connects to fetus via umbilical chord
• chorionic villi surrounded by large lacuna
• umbilical chord has 2 types of blood vessels:

1. umb. arteries: carries blood away from heart
2. umb. veins: carries blood towards heart

• mat. blood supply supplies oxygenated blood
  ⤷ arteries carry blood to chorionic villi -> umb. veins -> heart -> organs
• chorion: remaining syncytiotrophoblasts + basement mem.
  ⤷ separates mat. and fetus blood

**no more cytotrophoblasts

Question 31

name + define: parts of embyronic disk and corresponding cavities

Answer 31

• disk = 2 layers

1. epiblast: 3 germ layers (becomes embryo)
2. hypoblast: contributes to extraembryonic mems.
   ⤷ syncytiotrophoblasts and am. sac. also contribute to extraembryonic tissues

• amniotic cavity: forms inside inner cell mass
  ⤷ surrounded amniotic sac
• yolk sac: forms inside blastocele from hypoblast
• am. cav. surrounds embryo
  ⤷ forms protective fluid bag

Question 32

explain: formation of germ layers of epiblast

Answer 32

• process = gastrulation
  ⤷ day 13 - 14
• epiblast elongates and cells multiply
• region of cells thicken forming primitive streak
• cells move down to make 3 layered disk (embryonic disk)

Question 33

name + explain: germ layers of epiblast (from deep -> superficial)

Answer 33

1. endoderm: inner layer
   ⤷ forms lining of digestive tract + derivatives
2. mesoderm: middle layer
   ⤷ forms tissues (bone, muscle, blood vessels)
   ⤷ forms notochord
3. ectoderm: outer later
   ⤷ forms skin + nerv. sys.

• endoderm cells move down the most, ectoderm cells don’t move

Question 34

question: what is notochord?

Answer 34

• solid cylinder of cells under ectoderm made of mesoderm cells
  ⤷ like a core
• (for humans) involved in induction
  ⤷ sig. ectoderm to form neural plate
• has oropharyngeal and cloacal mem.
  ⤷ to determine anus vs mouth
• becomes vertebral column

Question 35

explain: formation of notochord

Answer 35

• day 16
• mesoderm cells form solid cylinder of cells
• forms under ectoderm

Question 36

define: oropharyngeal vs cloacal mem.

Answer 36

• during formation of notochord
• oropharyngeal: becomes mouth = cephalic
• cloacal: becomes anus = caudal

Question 37

question: how to differentiate between cephalic and caudal ends of embryo during notochord formation?

Answer 37

• caudal end = closer to primitive streak
• caudal = cloacal mem.
• cephalic end = further from primitive streak
  ⤷ looks wider? (in that one image from module)
• cephalic = oropharyngeal mem.

Question 38

question: what is neural tube?

Answer 38

• formed from from thickened part of ectoderm (neural plate)
• plate forms tube and closes
• becomes CNS (brain and spinal cord)

Question 39

explain: formation of neural tube

Answer 39

• days 18 - 26
• thickened part of ectoderm starts folding into midline
  ⤷ cephalic and caudal ends wrap around
• neural plate folds -> folds get deeper forming neural groove
• crests of neural folds get closer to form tube

Question 40

question: what are the neural crests?

Answer 40

• general connective tissue of head
  ⤷ sensory and post ganglionic autonomic portions of PNS
• help form neural tube by moving closer together
• some neural crest cells break off when folding into tube to become other things

Question 41

explain: formation of somites

Answer 41

• formed from mesoderm adjacent to neural tube
• becomes vertebral column, ribs and skeletal muscle

Question 42

recap: steps of fertilization (8)

Answer 42

1. sperm pushes through corona radiata
2. sperm binds to ZP3
3. acrosomal reaction + penetrates zona pellucida
4. sperm binds to integrin α6β1 receptor -> depolarization of mem. to prevent polyspermy
5. oocyte’s second meiotic division (form ovum and 2nd polar body)
6. female and male pronuclei form
7. pronuclei fuse to become zygote

Question 43

recap: steps of implantation and other formations w/ dates

Answer 43

1. day 5 - morula forms
   - inner cell mass form
2. days 8 - 12 (technically 7) - implantation happens
   - syncytiotrophoblast and cytotrophoblast
3. days 14 - 20 - connecting stalk -> umbilical, lacunae and placenta form
4. 1 month - cyto. -> cyto. chords + separating mat. and embryo blood, embryo making own circulatory sys.
5. mature fetus - cyto. chords -> chorionic villi, mom O2s blood
   - chorion: remaining syncytio. + basement mem. separate mat. vs fet. blood
6. days 13 - 14 - embryonic disk forms
   a) epiblast, hypoblast, yolk sac, am. sac
   b) primitive streak
   - gastrulation
   c) ectoderm
   d) endoderm
   e) mesoderm
7. day 16 - notochord forms
8. neural plate forms
   - notochord signals ectoderm to form plate
9. days 18 - 26 - neural tube forms
10. somites
    - formed from mesoderm cells