ANA 204 Heart and Genital Organs Flashcards
Describe Macrovasculature
vessels that are more than 0.1 mm in diameter (large arterioles, muscular and elastic arteries, and muscular veins). These vessels are seen grossly.
Describe Microvasculature
(arterioles, capillaries and postcapillary venules) These vessels are visible only with a microscope .
Function of microvasculature
the site of interchanges between blood and the surrounding tissues both under normal conditions and during inflammatory processes
Functions of BVS
transports oxygen and nutrients to tissues, carries carbon dioxide and waste products from the tissues,
•circulates hormones from the site of synthesis to their target cells.
Describe the heart
The heart is a muscular, highly specialized portion of the vascular system.
•it consists of 4 chambers:
•Right and Left Ventricle (RT< ventricles)
• Right and Left atria (RT< atria)
•The right and left ventricles pump blood to the lungs and the rest of the body respectively;
•right and left atria receive blood from the body and the pulmonary veins respectively.
Layers of the heart chambers
The internal endocardium
•The middle myocardium
•The external epicardium.
Describe the endocardium
•The Endocardium lines the lumen of the heart and is composed of simple squamous epithelium (endothelium) and a thin layer of loose connective tissue.
Describe the subendocardium
•Subendocardium :a connective tissue layer that contains veins, nerves, and Purkinje fibers, underlies it.
Describe the myocardium
The myocardium is the thickest of the tunics and consists of cardiac muscle cells arranged in layers that surround the heart chambers in a complex spiral.
Note: The myocardium is much thicker in the ventricles than in the atria.
Describe the epicardium
Epicardium, the outermost layer of the heart, constitutes the visceral layer of the pericardium.
•It is composed of simple squamous epithelium (mesothelium) on the external surface.
the epicardium is the site of the coronary vessels and contains considerable adipose tissue.
What is the fibrous skeleton of the heart?
•consists of thick bundles of collagen fibers oriented in various directions.
•It also contains occasional foci of fibrocartilage.
•It is the fibrous central region of the heart.
Function of fibrous skeleton
It serves as
•base of the valves.
•site of origin and insertion of cardiac muscle cells.
•Histologically, it is composed of dense irregular connective tissue, with separated nodules of fibrocartilage
What are the heart valves?
•Atrioventricular Valves
•Semilunar Valves
Describe the atrioventricular valve
Atrioventricular (AV) valves are composed of a skeleton of fibrous connective tissue arranged like an aponeurosis and lined on
both sides by endothelium.
• They are attached to the annuli fibrosi of the fibrous skeleton.
• The right AV valve is formed of three interlocking cusps (tricuspid valve) whereas the left AV valve is formed of two interlocking cusps (bicuspid or mitral valve).
Function of the atrioventricular valve
These valves prevent regurgitation of ventricular blood into the atria.
Describe the semilunar valve
Semilunar valves in the pulmonary and aortic trunks are composed of three cusps that approximate each other as
they fill with arterial blood.
• They are lined with endothelium on both sides separated by sparse strands of connective tissue.
Function of semilunar valves
These valves prevent regurgitation of pulmonary and aortic blood into the respective ventricles.
What is the cardiac cycle?
Cardiac cycle. The cardiac cycle describes the complete movement of the heart or heartbeat and includes the period from the beginning of one heartbeat to the beginning of the next one.
The Cardiac cycle consists of which processes?
• diastole (ventricular relaxation and filling)
• systole (ventricular contraction and emptying).
The right heart is the pump for the__________
pulmonary circuit
the left heart is the pump for the__________________
systemic circuit
Features of the male reproductive system
Gonad (testes)
Epididymis
Vas deferens
Male urethra
Prostate
Bulbourethral glands
External genitalia
The sperm cell is the only cell that can move from one point to another without external help T/F
TRUE
Characteristics and histology of the testes
Testes are the place of sperm production. Each testis is divided into lobules, each containing one to four semi-niferous tubules.
•The seminiferous tubules are tightly coiled, which adds to their length, and have a hollow center.
•Inside the seminiferous tubules are germ cells, called spermatocytes, in different stages of development and supporting cells called sustentacular cells or Sertoli cells.
•Germ cells are in close contact with Sertoli cells, an arrangement similar to marbles (germ cells) pushed into playdough (Sertoli cell).
•Sertoli cells secrete molecules that promote sperm production and control germ cell survival.
Histology
- Surrounded by a capsule: a visceral layer of tunica vaginalis, tunica albuginea and tunica vasculosa (from outer to inner)
Characteristics and histology of the seminiferous tubules
- A tightly convoluted hollow structure present in each lobule of the testis
- contains spermatocytes, sustentacular or Sertoli cells that secrete molecules that promote sperm production
- Site for spermatogenesis
- surrounded by interstitial loose CT (made of Leydig cells that secrete TESTOSTERONE)
Characteristics and histology of the rete testi
A network of small tubes in the testicle that helps move sperm cells from the testicle to the epididymis.
Labyrinth of straight tubules lined by cuboidal or low columnar epithelium, each cell has one cilium
Characteristics and histology of the epididymis
A highly convoluted tubule/duct which nourishes sperm for about 20 days before ejaculation
lined with pseudostratified epithelium with stereocilia
Function
Phagocytosis of defective spermatozoa and residual bodies eliminated during spermatogenesis
Absorption of excess fluid
Secretion of substances (sialic acid, glycerylphosphorylcholine) that plays a role in the maturation of sperm
Characteristics and histology of the seminal vesicle
Sac-like highly tortous mass in the posterior wall of the prostate gland and secretes a viscous fluid which makes up 70% of the ejaculate
Wall consists of:
1. Mucous membrane (lumen lined by pseudostratified columnar epithelium with microvilli and goblet cells and low columnar cells)
2. Muscular layer (thin layer of smooth muscle)
3. Connective tissue (outer covering of loose connective tissue forms the adventitial layer containing blood vessels and nerve)
Characteristics and histology of the ductus deferens
Long straight duct (muscular tube) lined by pseudostratified epithelium
Wall consists of:
1. Mucous membrane (lined by simple columnar throughout and pseudostratified columnar with stereocilia at the distal end, the epithelium is supported by lamina propria consisting of many elastic fibres) - similar to epididymis but shorter principal cells
2. Muscular layer (thick 3-layered of smooth muscle)
internal layer-longitudinal
Middle -circular
External - longitudinal
3. Connective tissue (fibroelastic connective tissue forms the adventitial layer containing blood vessels and nerves)
The ampulla is the dilated portion of the ductus deferens with tall principle cells and smaller basal cells
Thick muscle layer for peristalsis
Characteristics and histology of the urethra
A passage lined by stratified columnar or stratified cuboidal epithelium, moderately thick muscularis
Function of accessory male reproductive glands
- nourish and protect sperm in transport
- activate sperm before ejaculation
- clean the urethral tract before ejaculation
- produce secretions that assist in passage to the female reproductive tract
3 major accessory reproductive glands
Seminal vesicle
prostate
bulbourethral
Characteristics and histology of the prostate gland
- Largest reproductive gland
- straddles the urethra below the urinary bladder
- composed of secretory acini arranged in large irregular tubuloalveolar structures made of low columnar to cuboidal cells
- lined by Pseudostratified columnar epithelium
-covered by a capsule - peripheral zone is where prostrate cancer occurs
Secretes fluid pH 7.3
Function of Leydig cells in the testis
to secrete testosterone
What are the layers of the testes
Tunica vaginalis
Tunic albuginea
Tunica vasculosa
Characteristics and histology of the ejaculatory duct
Narrower part of the ductus deferens that runs through the prostate gland
Had characteristics of ductus deferens
Lined by Pseudostratified columnar epithelium with no muscular layer
Pathway of male reproductive sperm
- Seminiferous tubules
- Rete testis
- Efferent ductules
- Epididymis
- Vas deferens
- Spermatic cord abs seminal vesicles: empty into urethra
- Penis
The female reproductive system consists of
Gonads called ovaries
Fallopian tube
Accessory gland bulbourethral gland
Uterus
Vagina
External genitalia
Ovary
Characteristics and histology of the ovary
Divided into the cortex and medulla
Cortex contains ovarian follicles containing an oocyte
Medulla contains large arteries, veins, lymphatics and nerves in a loose collagenous matrix
Ovary is covered by cuboidal epithelium that converts to simple squamous epithelium later in life
Site of follicular development
Characteristics and histology of the ovarian duct
3 layers
Inner mucosa (highly convoluted covered in ciliated columnar epithelium with non-ciliated mucus secreting cells)
Middle muscular layer (smooth muscle)
Outer serosa
Characteristics and histology of the cervix
Part of the uterus that expands into the vagina
Runs from vaginal opening (external os) to the body of the uterus
Outer vaginal layer of the cervix is lined by stratified squamous epithelium of the Vagina
Epithelium abruptly transitions to (uterine cervix) simple columnar in the cervical canal that leads to the inside of the uterus
Characteristics and histology of the vagina
Layers:
Mucosa (stratified squamous epithelium with lamina propria without glands)
Muscularis: inner circular and outer longitudinal layer
Adventitia (dense fibroelastic CT)
Characteristics and histology of the penis
3 cylindrical masses of erectile tissue
and penile urethra surrounded by ski
Corpora cavernosa are placed dorsally
Corpus sponginosum are ventral and surround the urethra
Tunica albuginea (dense fibroblastic tissue) surrounds the 3 structures
Penile urethra is lined by pseudostratified columnar epithelium and contains a mucus gland
What part of the cervix is cervical cancer most common?
Cervical-epithelial junction
