Anatomy Flashcards
1
Q
Peritoneum and coverings of the testis
A
- tunica vaginalis
- skin
- superficial fascia (dartos in scrotum)
- flat muscles
- fascia transversalis
- parietal peritoneum
2
Q
What is the processus vaginalis?
A
Peritoneal tube dragged by the testis during descent and is obliterated in development (may leave a dimple)
3
Q
What is the spermatic fascia?
A
Extension of external oblique aponeurosis. It has a thin fibrous covering attached to the superficial inguinal ring
4
Q
What is the cremaster muscle?
A
Extension of external oblique muscle, bundles of skeletal muscle and is involved in lifting the testis.
Supplied by the genitofemoral nerve
5
Q
What is the internal spermatic fascia?
A
Extension of fascia transversalis, a thin fibrous tube that is attached to deep inguinal ring
6
Q
Blood supply of the testis
A
Testicular artery from the aorta
7
Q
Venous drainage of the testis
A
Pampiniform plexus - like tendrils
Form two veins or one in abdomen
Lead to IVC - the R testicular goes directly, left goes into renal vein then IVC
8
Q
Where is testicular pain referred to?
A
Visceral - lateral to umbilicus in T10 dermatome
9
Q
What is the epididymus?
A
Single highly coiled structure that is posterior to the testis and has a narrow tail continuing as ductus deferens
10
Q
Location of prostate gland
A
Surrounds prostatic urethra
Single median lobe
Posterior, lateral and anterior lobes
11
Q
Commonest site of fertilisation
A
Ampulla
12
Q
What are the angles of version and flexion?
A
Version: vagina cervix angle
Flexion: cervix body angle
13
Q
What is the fornix
A
Circular groove between cervix and vaginal wall, deeper posteriorly
14
Q
Describe the peritoneum of the uterus
A
- Uterovesical pouch (UV)
- Rectovaginal pouch (RV)
Broad ligament
o Mesometrium
o Mesosalpinx
o Mesovarium
15
Q
What supports the uterus?
A
Pelvic diaphragm
- transverse cervical ligament
- uterosacral ligament
- pubocervical ligament
- round ligament
- broad ligament
16
Q
Blood supply of female reproductive organs
A
- Uterine – internal iliac
- Ovarian – aorta
- Anastomoses tube
- Vaginal – independent and from uterine
- Uterine artery in pregnancy – supports extra musculature and foetus
17
Q
Relations of the cervix:
Anterior
Posterior
Lateral
A
Posterior: rectum Anterior: bladder Lateral: • Uterine artery • Ureter • Cross in a narrow region • Dangerously close – cancer of cervix/surgery
18
Q
Where do the uterine artery and ureter cross each other?
A
Very close to the cervix - lateral
19
Q
Location of the pregnant uterus at 12, 24, 36 and 40 weeks
A
- Above symphysis at 12 weeks
- 24 weeks – umbilicus
- 36 weeks – xiphersternum
- 36-40 weeks – engagement and descent
20
Q
What are the ‘3 set of kidneys’ at the beginning of development?
A
o Pronephros, mesonephros and metanephros
21
Q
Where is the pronephros located?
A
In the neck and thorax of the embryo
22
Q
What does the mesonephric duct open into?
A
Cloaca - common exit chamber for GIT and UG
23
Q
Describe the development of the metanephros
A
- Metanephros develops in sacral pelvic region
- Duct for metanephros – offshoot of mesonephric duct
- New duct (ureteric bud) ureter, calyces, collecting ducts
Metanephros nephrons
• As it develops, metanephros migrates cranially (ascent of kidney)
24
Q
What develops from the ureteric bud?
A
It dilates as the renal pelvis and then further branches into major and minor calyces, finer branches into the collecting duct
25
What develops from the metanephros?
• Form nephron parts up to DCTs
26
What does the gonadal ridge develop from?
Intermediate mesoderm
27
Ducts which male and female reproductive organs develop from:
Male: mesonephric duct ductus deferens
Female: paramesonephric duct
• Cranial parts uterine tubes
• Fused caudal part uterus, part of vagina
28
The ureteric bud is an offshoot of which duct?
Mesonephric
29
Describe the decent of the ovaries
Ovary in pelvis: Gubernaculum elongates
• From ovary to labium majus
•
Interrupted by the uteris two parts
o Ovary to uterus: ligament of ovary
o Uterus to labium: round ligament of uterus (via inguinal canal)
30
Chromosomes in somatic cells
- 23 pairs
- each pair homologous, maternal and paternal
- chromatids not seen in a non-dividing cell
- visible once they have already replicated
31
The goal of meiosis
Cell with haploid number - 23 chromosomes
32
When does crossing over occur?
Meiosis 1
33
End product of meiosis 1
2 cells, haploid replicated chromosomes but with mixed genes
34
End of meiosis 2
Chromatids separate and so 4 haploid cells are left
35
What proportion of the ovary is covered by peritoneum?
Entire ovary
36
What makes up a follicle in an ovary?
Oogenic cell + supporting cells
37
Oogenesis
- begins in fatal life
- meiosis is not completed
- suspended until puberty
38
Follicular maturation and terminology
- primordial follicle (oocyte + 1 layer flat cells)
- primary follicle (flat cells become cuboidal)
- granulose cells multiply and develop a cavity called a follicular antrum
- filled with fluid = liquor follicle
- egg placed on cumulus oophorus
- zone pellucide clearly visible
Mature follicle = graafian follicle about 1cm in diameter
Ovulation: oocyte released into peritoneal cavity and surrounded by 1 or 2 layers of cells = corona radiata
39
Theca
Theca interna: immediately surrounds follicle
| Theca externa: surrounding fibrous layer
40
Corpus luteum
Granulosa + theca interna
| Yellow body = temporary endocrine structure
41
Why are both meiotic divisions unequal in oogenesis?
* At the end of meiosis 1: one large secondary oocyte + one tiny polar body
* At the end of meiosis 2: secondary oocyte fertilizable egg + second polar body
42
When is meiosis 2 in females completed?
After entry of sperm
43
Uterine tube epithelium
* Pseudostratified columnar
* Ciliated cells
* NO GOBLET CELLS – the columnar cells secrete a watery fluid
* Cilia create a current in the fluid
44
Endometrial phases
1. Menstrual – bases of glands, stumps of blood vessels
2. Proliferative – epithelium continues, later glands develop
3. Secretory: coiled glands, glycogen, spiral arteries
45
Start and end product of meiosis 1 in males
Primary spermatocyte becomes a secondary spermatocyte
46
Changes undergone from spermatids to spermatozoa
```
• Spermatids lose a lot of cytoplasm
• Develop a tail
• Head: almost entirely occupied by nucleus
o Acrosomal cap – enzymes
• Neck – spiral mitochondrion
```
47
Sertoli cells
- Columnar cells
- spermatogenic cells fit into depressions
- blood testis barrier
- phagocytose XS cytoplasm
- produce androgen binding protein
48
What are the interstitial cells in the seminiferous tubules and what do they produce?
Lydia - testosterone
49
Epithelium of epididymus
• Pseudostratified columnar epithelium: with stereocilia – long microvilli
50
Anterior, lateral and posterior boundaries of the perineum
Anterior
o Pubic symphysis
o Ischiopubic rami
Lateral
o Ischial tuberosities
Posterior
o Sacrotuberous ligaments
o Coccyx
51
How does the urogenital tract differ between males and females?
o Male: long penile urethra (common U-G passage)
| o Female: short urethra (vagina is a separate opening)
52
Inferior and superior limit of the perineal pouches (vertical extent of perineum)
Inferior: scrotal + perineal skin with fascia
Superior: pelvic diaphragm and fascia
53
What does the perineal membrane separate?
Superficial and deep pouches
54
Structure of the penis
• 2 long cylindrical bodies
• Corpus cavernosum x2
o Large blood filled spaces (caverns)
• Single corpus spongiosum, contains urethra
• All 3 made of highly vascular dense fibrous tissue (especially cavernosa) = erectile tissue
• All 3 begin in the superficial pouch
• Each one associated with a muscle
55
Corpus cavernosa
* Begins as crura
* Attached to ischiopubic ramus
* Each crus covered by a muscle – ischiocavernosus (ischium to corpus cavernosum)
56
Corpus spongiosum
Begins as the bulb of the penis and contains urethra
| At the tip of the penis the spongiosum expands --> conical glans penis
57
Regions of the urethra
* Prostatic in the pelvis
* Membranous
* Bulbar
* Penile
58
Skin over the glans and its layer
Prepuce: 3 layers
- innermost is attached to glans
- two outer layers slide to retract
59
Which muscle makes the anorectal junction?
Puborectalis
60
Sphincters in the perineum of the anal triangle
Internal: thickening of circular smooth muscle
External: skeletal muscle below levator ani
61
What does the pudendal nerve supply? (S2,3,4)
- All of the perineum
- exits through greater sciatic foramen
- enters perineum through lesser sciatic foramen
62
Chromosomes in mitosis in somatic cells
* 23 pairs of chromosomes
* Each pair (homologous chromosomes) – one maternal and one paternal
* Chromosomes not seen in a non-dividing cell
* When visible – already replicated
* Here shown in metaphase of mitosis
* Chromatids identical – each chromatid = a chromosome in a resting cell
63
What is the goal of meiosis?
Cell with haploid number - 23 chromosomes
64
Meiosis 1 and 2
1: replication of chromosomes and crossing over resulting in two haploid cells with replicated chromosomes and mixed genes
2. chromatids separate, at the end there are 4 haploid cells
65
Peritoneal epithelium surrounding the ovary
Cuboidal cells but with each ovulation, the damage is repaired with squamous cells
66
What is the follicle in an ovary comprised of?
Oogenic cell and supporting cells = follicle
67
Oogenesis in the ovary
• Begins in fetal life – primordial germ cells
• Meiosis 1 begins but not completed
• Remains suspended for many years
• Resumed at puberty, however:
o Cyclical, few cells puruse the path to maturity in a cycle
o Generally only one is released for fertilization
• Thus:
o Some cells are in suspended division for 12 years +-
o Some may remain suspended for as many as 45 years+
68
Cells surrounding the oocyte through maturation ?
Granulosa cells
69
Primordial follicle
Oocyte + 1 layer of flat cells
70
What is the first sign go course to maturation (from primordial follicle to primary follicle)?
Flat granulosa cells become cuboidal
71
What is the cavity that the granulosa cells develop and what is it filled with?
Follicular antrum - filled with liquor folliculi
72
Mound of cells that the oocyte is placed on?
Cumulus oopohorus
73
4 facts on the mature follicle
o Graafian follicle – about 1cm in diameter
o Protrudes on the surface
o Pale spot on the stretched wall = stigma
o Oocyte with few layers of cumulus separate before ovulation
74
What surround the oocyte when it ruptures and is released into the peritoneal cavity?
Corona radiata
75
How is stroma involved in the follicle?
• Compressed by enlarging follicle
• Forms a container around the follicle = theca
• Two parts:
o Immediately around the follicle – theca interna (temporary endocrine organ)
o Surrounding fibrous layer: theca externa
76
After ovulation
* Large empty follicle collapses
* Granulosa + theca interna = corpus luteum
*
Persists for a few weeks if oocyte fertilized
• If not, it degenerates within 2 weeks – corpus luteum of menstruation
77
Cell populations of the corpus luteum
o Granulosa lutein cells
| o Theca lutein cells
78
Oogenesis:
At the end of meiosis 1:
At the end of meiosis 2:
* At the end of meiosis 1: one large secondary oocyte + one tiny polar body
* At the end of meiosis 2: secondary oocyte fertilizable egg + second polar body
79
Epithelium of uterine tube
* Pseudostratified columnar
* Ciliated cells
* NO GOBLET CELLS – the columnar cells secrete a watery fluid
* Cilia create a current in the fluid
80
Epithelium of the endometrium
• Columnar epithelium + glands
81
Endometrial phases
1. Menstrual – bases of glands, stumps of blood vessels
2. Proliferative – epithelium continues, later glands develop
3. Secretory: coiled glands, glycogen, spiral arteries
82
Cervix epithelium
o Columnar in canal
| o Stratified squamous from external os
83
Epithelium of vagina
Stratified squamous
84
Fibrous coat surrounding testes
Tunica albuginea
85
Spermatogenesis
```
Spermatogonia
• Small, round and peripheral
• Divide mitotically – some reserve, some mature
Spermatogonia primary spermatocyte
• Primary spermatocyte undergoes meiosis 1 secondary spermatocyte
Secondary spermatocyte: short lived
• Meiosis 2 spermatid
Meiosis produces four spermatids
```
86
Changes when spermatids become spermatozoa
```
• Spermatids lose a lot of cytoplasm
• Develop a tail
• Head: almost entirely occupied by nucleus
o Acrosomal cap – enzymes
• Neck – spiral mitochondrion
```
87
Structure and function of sertoli cells
```
• Supporting cells
• Columnar
• Spermatogenic cells fit into depressions
• Form tight junctions
o Isolate ‘genetically different’ cells
o Blood-testis carrier
• Phagocytose XS cytoplasm
• Produce androgen binding protein
```
88
Epithelium of epididymis
• Pseudostratified columnar epithelium: with stereocilia – long microvilli
89
Anterior, lateral and posterior boundaries of the perineum
Anterior
o Pubic symphysis (1)
o Ischiopubic rami (2)
Lateral : ischial tuberosities (3)
Posterior:
o Sacrotuberous ligaments (4)
o Coccyx (5)
90
What is contained in the deep perineal pouch?
Bulbourethral glands - ducts pass through perineal membrane --> urethra in superficial pouch
Blood vessels - internal pudendal, from internal iliac
91
Structure of the penis
2 x corpus cavernosum
| single corpus spongiosum containing urethra
92
Development of the corpus cavernosa
* Begins as crura
* Attached to ischiopubic ramus
* Each crus covered by a muscle – ischiocavernosus (ischium to corpus cavernosum)
* Corpus and muscle attachment
93
Corpus spongiosum
Begins as the bulb of the penis
• Contains urethra
• Muscle – bulbospongiosus
• Muscle fibres:
o Begin at the perineal membrane
o Go around the bulb
o Meet at a raphe on the inferior surface
• At the tip of the penis: spongiosum expands conical glans penis
• Three structures converge under the pubis – enclosed in fascia and skin
94
Prepuce
o 3 layers
o innermost attached to the glans
o two outer layers slide to retract
o Small fold on the ventral side (Y) – frenulum
95
What encloses the reproductive vestibule in females?
Labia minora
96
Ischiorectal fossa
Angular space between ischium and pelvic diaphragm
97
Sphincters in the perineum
Internal: thickening of the circular muscle
External: skeletal muscle, below levator ani
98
Nerve and blood supply of perineum
Pudendal nerve (S2, 3, 4) supplies all of perineum except root of penis
- exits greater sciatic foramen
- enters perineum through lesser sciatic foramen
Internal pudendal blood vessels (internal iliac system)
99
Which structures do not drain to the inguinal lymph nodes
Testis - para-aortic
Proximal anal canal - pre-aortic
100
What is breast composed of?
Glandular tissue, fibrous supports, fat
101
Female breast size and extent
Size determined by fat (except during lactation)
Vertical extent: 2nd to 6th rib
Horizontal: lateral border of sternum to midaxillary line
102
What does the female breast rest on?
Adjacent parts of:
♣ Pectoralis major.
♣ Serratus anterior.
♣ External oblique.
103
Internal anatomy of the breast
```
♣ Masses (lobes) of glandular tissue.
♣ Fat distributed amongst
and within these.
♣ Fibrous tissue between skin
and deep surface.
• Cooper’s ligaments
(“suspensory” ligaments).
• Not fixed to muscles!
```
104
Arterial supply of the breasts
Internal thoracic artery (branch of subclavian)
o Perforating cutaneous branches.
o Larger in spaces 2 – 4 / 5. : Main supply to the breast.
o Branches from axillary – More to superficial parts.
105
Venous drainage of the breasts
* More towards axillary.
* Superficial veins often visible, especially in pregnancy and lactation
* Subclavian (internal thoracic).
106
Lymphatics and lymph nodes of the breast
♣ Most lymphatics plexus deep to areola.
♣ Lateral part of plexus axillary nodes.
• Mainly nodes under pect. major.
• Other nodes : infra- and supraclavicular.
♣ Medial part nodes along the internal thoracic vessels (parasternal).
• May cross midline.
107
Age related changes of the breasts: prepubertal and pubertal
Prepubertal.
• Ducts, no secretory units.
• Little branching, growth of fibrous + adipose tissue.
Puberty.
• Ducts branch, new adipocytes form.
• Projection of nipple, enlargement of areola, smooth contour.
• Changes during menstrual cycle. Some cell proliferation, blood supply, stromal water content.
108
Post menopausal breast changes
Involution of glandular tissue but some ducts may remain
109
Histology of nipple
* Thin skin, no hair.
* Smooth muscle.
* Sebaceous glands (Seb).
* Lactiferous ducts.
110
Histology of areola
Glands : modified glands.
Enlarge during pregnancy : Montgomery’s tubercles (M).
111
Melanocytes in nipple and areolar
Pigmentation after puberty, darkening after pregnancy
112
Activity of the breasts: prepubertal and post-pubertal
Prepubertal:
• Rudimentary ducts
• Very little fat
```
Post-pubertal, non-lactating
• Fat increases
• Plenty of connective tissue
• Longer ducts
• No secretory units
```
113
Activity of the breasts during pregnancy
```
• Ducts proliferate in early pregnancy
(number and branching).
• Secretory units (alveoli) develop at tips.
• Lobules in each gland.
• Myoepithelial cells grow larger.
(Flat epithelial cells, contractile like smooth muscle. Surround secretory units.)
• CT: Lymphocytes, plasma cells.
• In late pregnancy :
♣ Secretory activity increases.
```
114
Activity of the breasts during lactation
• Large secretory units (alveoli) filled with secretion.
• Columnar cells, flattened somewhat by secretions.
♣ Contain membrane bound protein and lipid droplets.
• Secretory cells also take in IgA from plasma cells.
• Myoepithelial cell contraction pushes secretions into ducts.
• Vasculature and smooth muscle causes swelling of areola and erection of nipple.
♣ Also during sexual arousal.
115
Male breast anatomy
* Smaller nipple and areola
* Small ducts or solid cords of cells
* Slight enlargement in the neonate and at puberty
* Gynaecomastia
* Cancer can occur in the male breast, though rare
116
Gynacomastia
Benign growth of the male breast with possible hormonal cause or drug cause
117
What is in the spermatic cord?
```
Testicular artery
Testicular veins
Ductus deferens
Lymphatics
Nerves
```
118
What is in the inguinal canal?
In men, the spermatic cord passes through the inguinal canal, to supply and drain the testes. In women, the round ligament of uterus traverses through the canal
119
What forms the superficial and deep rings of the inguinal canal
Superficial: external oblique (marks the end of the inguinal canal, and lies just superior to the pubic tubercle)
Deep: Trasversalis fascia (above the midpoint of the inguinal ligament)
120
4 Features marking the differences between male and female pelvis
Male:
v shaped suprapubic angle
heart shaped pelvic inlet
Female
u shaped suprapubic angle
Round pelvic inlet
Acetabular distance from pubis symphysis > acet diameter
Greater sciatic notch much wider in female
121
Features of ischiopubic rami in males and females
In the male the edges
are thick and everted due to the attachments of the bigger and stronger ischiocavernosi muscles. In the female the edges are not so prominent.
122
Ischial spines in males and females
In a typical male pelvis they point inwards, in the female they are vertical or point outwards.
123
Oblique diameter of the pelvic inlet
The oblique diameter is measured from one sacroiliac joint to the opposite iliopubic eminence.
124
Anterior posterior diameter of the pelvic inlet
The anteroposterior diameter is measured from the centre of the sacral promontory and the anterior end of the pubic symphysis.
125
Pelvic outlet measurements
The anteroposterior diameter is from the posterior edge of the pubic symphysis to the tip of the coccyx. There is a joint between the sacrum and the coccyx, which is slightly movable, so during childbirth this diameter can be increased slightly.
The transverse diameter is between the ischial tuberosities.
The oblique diameter is from the middle of one ischiopubic ramus to the middle of the opposite
Sacrotuberous ligament.
126
Which measurements are greatest in the female pelvis at the inlet and outlet
In a typical female pelvis, transverse diameter is the greatest diameter at the inlet; at the outlet the anteroposterior diameter is the greatest.
