Principles Anatomy Flashcards
What are the outer and inner bits of a bone called and what is the difference in them?
Outer cortex - dense, strong, heavy - compact, cortical bone
Inner medulla - more porous, weaker, lighter - spongy, trabecular bone. The medulla may contain marrow in some bones
What occurs in bone marrow?
Red and white blood cell production
What are the types of joint?
Fibrous
Cartilaginous
Synovial
Describe and give examples of fibrous joints
Fibrous joints - limited mobility, suture highly stable
a) Sutures - between skull bones
b) Fibrous sheet - interosseous membrane of forearm
Describe and give examples of cartilaginous joints
Cartilaginous joints - fairly limited mobility, relatively stable, can “slip”, connected entirely by cartilage
a) Primary - “synchondroses”. Bones are connected by hyaline cartilage and sometimes occur between ossification centres. This cartilage may ossify with age.
b) Secondary -v”symphyses”. Fibrocartilaginous and hyaline joints, usually occurring in the midline. eg between vertebrae are intervertebral discs of fibrocartilage
Sub - types of synovial joints
- Ball and socket joint - reasonable (hip) to good (shoulder) ranges of multi-axial movement
- Hinge joint - elbow
- Pivot joint
- Plane joint
- Biaxial joint - eg hands and feet
What makes up the TMJ (temporomandibular joint)?
The TMJ is the articulation between the MANDIBULAR FOSSA and the ARTICULAR TUBERCLE OF THE TEMPORAL BONE SUPERIORLY and the HEAD OF THE CONDYLAR PROCESS OF THE MANDLE INFERIORLY
Describe dislocation of the TMJ
Head of the condylar process of the mandible becomes stuck anterior to the articular tubercle of the temporal bone.
Mouth is wide open and cant be closed. Bilteral dislocation and chin remains in midline
How many cranial nerves are there?
12
Cranial Nerve 1…
The olfactory nerve - SMELL
Cranial Nerve 2…
The optic nerve - VISION
Cranial Nerve 3…
The oculomotor nerve - EYELID AND EYEBALL MOVEMENT
Cranial Nerve 4…
The trochlear nerve - INNERVATES SUPERIOR OBLIQUE AND TURNS EYE DOWN AND LATERAL
Cranial Nerve 5…
The trigeminal nerve - CHEWING. FACE AND MOUTH TOUCH AND PAIN
Cranial Nerve 6..
The abducent nerve - TURNS EYE LATERALLY
Cranial Nerve 7..
The facial nerve - EXPRESSION, SECRETION OF TEARS AND SALIVA, TASTE
Cranial Nerve 8..
The vestibulocochlear nerve - HEARING AND EQUILIBRIUM SENSATION
Cranial Nerve 9..
The glossopharyngeal nerve - TASTE, PHARYNX CONTRACTION, SALIVA
Cranial Nerve 10..
The vagus nerve - HEART, LUNG, VISCERA
Cranial Nerve 11..
The spinal accessory nerve - CONTRACTS NECK AND SHOULDER MUSCLES
Cranial Nerve 12..
The hypoglossal nerve - CONTROLS TONGUE MOVEMENTS
What is the anatomical position?
Standing Facing anterior;y Face and eyes facing anteriorly Upper limbs by side Palms of hands facing anteriorly Feet together Toes pointing anteriorly
Describe the sagittal plane
Longitudinal section - median sagittal plane is through body midline
Describe the coronal plane
Vertically running plane - divides body into front and back
Describe the axial/transverse plane
Horizontally running - divides body into upper and lower
Describe the oblique plane
Runs at diagonal across body
Name and give examples of three times of muscle
- Cardiac muscle - involuntary and striated - heart
- Smooth muscle - involuntary and non-striated - walls of blood vessels, walls of air passages, ducts eg ureter, walls of hollow organs eg stomach
- Skeletal muscle - voluntary and striated - biceps brachii etc.
Describe a skeletal muscle using the terms: Muscle belly; fascicle; muscle fibre (myocyte); myofibril, the sarcomere & myofilaments (actin & myosin)
The Muscle Belly…
made of many FASCICLES….
each are made of many MYOCYTES…
which are made of many BUNDLES OF MYOFIBRILS (which are repeating sections of SARCOMERES)..
each of which is made from many ACTIN AND MYOSIN MICROFILAMENTS
List the types of skeletal muscle
Flat muscle with aponeurosis Pennate muscles Fusiform muscle Quadrate muscle Circular or sphincteral muscle
What is the difference between a tendon and an aponeurosis
An aponeurosis is a flattened tendon. Aponeuroses attach from muscle to soft tissue as opposed to bone
Which area of attachments move most and least in skeletal muscle contraction?
The origin - moves least
The insertion - moves most
Describe muscle paralysis and muscle spasticity
Paralysis - muscle w/o functioning motor nerve supply, cant contract, reduced tone on exam
Spasticity - intact and functioning motor nerve, descending controls from brain not working, muscle allowed to over contract continuously, muscle would have increased tone
What structures are contained within the spermatic cord?
Vas deferens - transporting sperm Testicular artery - blood Pampiniform plexus of veins - join to form one testicular vein Lymphatics Nerves
What happens in a vasectomy
Vas deferens is cut to prevent sperm reaching penis
Sperm route from formation to ejaculation…
Sperm are formed in the seminiferous tubules of the testes
Testes are located in the scrotum
Sperm is pushed into the epididymis which becomes the vas deferens to the urethra in the penis from where they must be ejaculated
Semen is the liquid in which sperm are transported
The seminal vesicles & prostate gland provide secretions which contribute to semen
The testes are the reproductive organs
The vas deferens, seminal vesicles, prostate and penis are all accessory reproductive organs
Anatomy of the testis - what is the tunica vaginalis made up of?
Parietal layer
Visceral layer
Route of the vas deferens?
The vas deferens passes superiorly into the groin (within the spermatic cord) to a point called the deep inguinal ring.
At the deep inguinal ring, the vas deferens turns medially into the pelvis
What does the seminal vesicle do?
Adds secretions to the semen within the vas deferens. It secretes prostaglandins (help transport of sperm) and fructose (an energy source) into the semen
What does the prostate gland do?
secretes an alkaline fluid which contains clotting enzymes (to “clot” the sperm in the vagina) and Prostate Specific Antigen (PSA) (to “unclot” the sperm and allow them to ascend into and through the uterus)
What does the prostatic urethra become?
The prostatic urethra becomes the penile urethra and semen is ejaculated from the external urethral orifice at the tip of the penile urethra
What is the anatomy of erection and ejaculation? Describe..
ERECTION
The penis consists of 3 columns of erectile tissue
These engorge with blood as a result of vasodilation (dilation of the arteries) mediated by the nervous system. This causes the penis to become erect.
EJACULATION
Nerves stimulate the smooth muscle within the walls of the vas deferens, seminal vesicles, prostate and urethra. This assists in propulsion of the semen along these tubes and then out of the external urethral orifice on ejaculation. In addition, the columns of erectile tissue in the penis are surrounded by skeletal muscles which are reflexively stimulated by nerves to contract and assist in pushing the semen from the external urethral orifice on ejaculation
Overview of female reproductive cycle…
Oocytes (eggs) are formed in the ovaries
Ovaries are located in the lateral wall of the pelvis
The oocyte is released from the surface of the ovary (approx. every 28 days in a post pubertal female) and is picked up by the fimbriae of the uterine tube
The oocyte passes down the uterine tube. If it is to be fertilised, the ampulla is the usual site of fertilisation. The fertilised oocyte will then continue to the body of the uterus for implantation
If not fertilised, the oocyte continues down the uterine tube to the uterus where it degrades and as a result of hormonal changes, it passes through the vagina along with the inner layer of the uterus during menstruation
Where does fertilisation usually occur?
In the ampulla of the uterine tube
What is an ectopic pregnancy?
The fertilised oocyte implants outside the uterine cavity
What are the female reproductive organs and accessory reproductive organs?
Reproductive organs - ovaries
Accessory reproductive organs - the uterine tubes, uterus, vagina
What are the three layers that form the wall of the body of the uterus?
Inner to outer….
- Endometrium - sloughed off in menstruation
- Myometrium - contraction of smooth muscle here helps sloughing and gives cramps
- Perimetrium
Which muscle forms the majority of the pelvic floor?
Levator ani
What is an endocrine gland?
each gland is responsible for manufacturing, storing & releasing at least 1 specific molecule called a “hormone” which is secreted in the blood stream to act at target sites on cells with the correct receptor
Where are the main endocrine glands?
HEAD
Hypothalmus
Pituitary gland
NECK
4 parathyroid glands
the thyroid gland
ABDOMEN
2 adrenal glands
pancreas
PELVIS - females
2 ovaries
PERINEUM - males
2 testes
In homeostasis what are the normal values for... Temp Pulse BP pH arterial PO2 blood glucose
temperature (36.8oC) pulse (70 bpm) arterial blood pressure (120/80 mmHg) pH (7.4) arterial PO2 (>95%) blood glucose (4-8 mmol/L)
What is the diencephalon?
Thalamus and hypothalalmus
It forms the central core of the cerebrum with connections to the right and left cerebral hemispheres and the midbrain
Where is the pituitary gland?
midline structure in the pituitary fossa of the sphenoid bone
What is the infundibulum?
Connects pituitary gland and hypothalamus anatomically and functionally
What is a portal system?
when a capillary bed lies between 2 sets of veins
What is an exocrine gland?
An exocrine gland is one that secretes its products via ducts (i.e. not directly into the bloodstream)
What makes up the CNS and PNS?
CNS
- brain
- spinal cord
PNS
- cranial nerves
- spinal nerves
- autonomic nerves
What is a ganglion?
A group of nerve cell bodies in the PNS
What is a peripheral nerve?
Bundles of axons travelling together in the PNS.
More detail…a bundle of axons (nerve fibres), wrapped up in connective tissue, travelling together to/from the same region of the body or structure
en route, bundles of axons can leave the peripheral nerve as named “branches”
many peripheral nerves and their branches are large enough to find in dissection (contain thousands of axons)
many of these large/important peripheral nerves are given names (i.e. they are “named nerves”)
the musculocutaneous nerve (supplies the biceps brachii muscle)
What is an axon?
An axon or nerve fibre is an electrical cable conveying action potentials
What is a synapse?
a synapse: one neurone communicates with another neurone in a ganglion in the PNS or in a nucleus in the CNS electrical signal (AP) becomes a chemical signal (neurotransmitter) then an electrical signal again
Where are the spinal nerves in relation to vertebrae?
the “spinal nerve” is the part that is located within the intervertebral foramen BELOW* the vertebra of the same number (*except cervical region)
How many body plexuses are there and what are they?
Cervical, brachial and lumbar & sacral (the latter 2 often described together as the lumbosacral plexus), and that these plexuses are bilateral (ie we have right and left cervical plexuses etc.)
What is the somatic nervous system?
The Somatic Nervous System senses and responds to the external environment
What is the autonomic nervous system?
The Autonomic Nervous System (also called the visceral motor system) senses and responds to the internal environment.
Visceral afferent nerve fibres - sensory
Sympathetic and Parasympathetic nerve fibres - motor
What does the sympathetic part of the autonomic nervous system do?
“Fight or Flight”
Heart……….increases heart rate
Arterioles…dilates (skeletal muscle) or constricts (skin feels cold)
Skin…………makes hair stand on end/produces sweat
Lungs………dilates bronchioles
Gut………….reduces motility/closes sphincters
Pupils………dilates
Liver………..releases glucose
What does the parasympathetic part of the autonomic nervous system do?
Supplies the same organs (except the skin and arterioles)
Opposes (compliments) the sympathetic system
How many spinal nerves are there?
31 pairs
What makes up the urinary tract?
Kidney - formation of urine
Ureter - transport of urine
Bladder - storage of urine
Urethra - transport of urine our of body
What is the difference between an orifice and a sphincter?
An orifice is an opening, e.g. the ureteric orifice is the opening of the ureter into the bladder
A sphincter is a mechanism which controls the width of an opening. A sphincter is usually formed by muscle (skeletal or smooth muscle). We looked previously at examples of sphincters in the GI tract
Where will lymph from the urinary tract drain?
Ultimately through the para-aortic nodes and then into the thoracic duct
What are calculi?
Kidney stones, tend to be composed of calcium salts. Once formed they can remain in the kidney or travel inferiorly down the ureter, and have the potential to obstruct the urinary tract, leading to pain.
more detail…
pain from a calculus within the kidney tends to be felt in the lumbar/flank region (also referred to as the loin)
pain from a stone being forced down the ureter is classically described as being “colicky” in nature (“ureteric colic”) as waves of ureteric smooth muscle contraction try and force the stone inferiorly through the ureter
What is micturition?
Micturition is the clinical term for passing urine
How do we control micturition?
- As the bladder fills, this is sensed by stretch receptors at the end of visceral afferent nerve fibres
- This information is then relayed to the CNS
- There is a natural reflex at this point to empty the bladder by stimulation of the detrusor muscle and inhibition of the sphincter muscles
- However in those infants who have been “potty trained” along with children and adults, the brain learns to override this reflex and inhibits it until it is suitable for us to micturate
When suitable to micturate what does the body do?
Once it is suitable to micturate
The inhibition of this reflex is lifted and there is a co-ordinated contraction/relaxation of various muscles:
The pelvic splanchnic nerves containing parasympathetic nerve fibres stimulate the detrusor muscle to contract
The external urethral sphincter, levator ani (and internal urethral sphincter) muscles are relaxed so that urine flows through the urethra
The anterolateral abdominal wall muscles (i.e. rectus abdominis, the obliques and the transversus abdominis) contract to help increase intra-abdominal pressure and force urine out of the external urethral orifice
What is vasoconstriction?
Contraction of smooth muscle within the walls of arteries/arterioles which results in a narrower lumen.
It is sympathetic nerve fibres which innervate the smooth muscle. APs travelling down sympathetic nerve fibres will cause it to contract
What is vasodilation
Relaxation of smooth muscle within the walls of arteries/arterioles which results in a wider lumen
