anatomy term 2 year 1 complex mcc

what is the organisation of the body

cell - tissue - organ - organ system- organism

define superior/ inferior

towards/ away from the head

define anterior/ posterior

nearer to the from/ back of the body

define medial/lateral/ intermediate

nearer/ further from the midline/ between two structures

define ipsilateral/contralateral

on the same/ opposite side as another structure

define proximal/ distal

nearer/ further to the attachment of a limb to the trunk

define superficial/ deep

towards/ away from the surface of the body

define flexion/ extension

decreasing/ increasing angle of a joint

define abduction/ adduction

moving limb away/ towards midline of the body

define dorsiflexion/ plantar flexion

pointing foot up/ down

define myofibril

long thread like structures inside muscle fibres made up of repeating units (sarcomeres) responsible for muscle contractions

define sarcomere

basic unit of a myofibril extending from one Z line to the next

what are sarcomeres made up of

thick filaments (myosin) and thin filaments (actin), along with regulatory proteins like troponin and tropomyosin.

What are the major bands and lines seen in a sarcomere?

• Z-line: boundary of each sarcomere

• A-band: dark band, contains thick filaments

• I-band: light band, contains thin filaments

• H-zone: center of A-band, only thick filaments

• M-line: center of the H-zone, holds thick filaments together

How do sarcomeres change during muscle contractions

During contraction, the sarcomere shortens as actin filaments slide over myosin filaments. The I-band and H-zone decrease in width, but the A-band remains the same.

label

What causes the membrane potential to begin rising toward threshold?

A stimulus causes a graded potential and opens ligand-gated cation channels.

What happens when the membrane potential reaches the threshold?

Voltage-gated Na⁺ channels open and Na⁺ rushes into the cell (depolarization begins).

what happens during depolarisation

Voltage-gated Na⁺ channels are closed, K⁺ channels are open, and K⁺ rushes out of the cell.

what causes hyper polarisation

V-gated K⁺ channels are slow to close, and K⁺ continues to leave the cell, making the membrane potential more negative than the resting level.

When does the membrane potential return to resting state?

When all voltage-gated K⁺ channels are closed, and only K⁺ leak channels are open.

What is the correct order of events in the generation of an action potential?

Resting potential (–70 mV), Stimulus causes graded potential, Threshold reached (~–55 mV), Depolarization – Na⁺ channels open, Na⁺ rushes in, Peak of action potential (~+30 mV) – Na⁺ channels close, K⁺ channels open, Repolarization – K⁺ rushes out, Hyperpolarization – K⁺ channels slow to close, Return to resting potential – all channels reset

define hyperpolarisation

the membrane potential becomes more negative than the resting level due to continued k+ leaving the cell

define action potential

rapid temporary change in a cells membrane potential that allows negative signals to travel

define depolarisation

the membrane potential becomes less negative as Na+ ions enter the cell

define repolarisation

the membrane potential returns to a negative value as k+ ions exit the cell

define refractory period

a short time after an action potential when a neutron can’t fire another one or is less likely to

define resting tidal volume

amount of air breathed in or out during a normal breath

what is inspiratory reserve volume

the extra air you can breathe out after a normal inhalation

define expiratory reserve volume

extra air you can breathe out after a normal exhalation

define residual volume

the air that stays in your lungs after full exhale - cannot be voluntarily breathed out

define inspiratory capacity

total air you can breathe In after a normal exhale (TV + IRV)

define functional residual capacity

air left in lungs after normal exhale (ERV +RV)

define vital capacity

total amount of air you can forcefully exhale after a full inhale (IRV + TV +ERV)

Define total lung capacity

the total volume of air your lungs can hold (VC + RV)

what is the pathway of the cardiac conduction system

Sinoatrial node, atrioventricular node, bundle of his, purkinje fibres

function of the SA

the pacemaker; starts the impulse

function of the AV

delays the impulse for 0.1 seconds to allow the atria to fully contract

function of bundle of his

carries the impulse to the ventricles

function of purkinje fibres

spread the impulse through the ventricles causing contraction

effects of adrenaline on the heart

interacts with beta-adrenergic receptors to accelerate heart rate and increase force of myocardial contraction

effects of adrenaline on blood vessels

vasoconstriction in skin and gastrointestinal tract, vasodilation in the musculature, coronary and hepatic circulation

effects of adrenaline on respiratory tract

increased respiratory rate and bronchodilation

effects of adrenaline on gastrointestinal tract and liver

reduced gut motility, reduced blood flow to gastrointestinal tract, reduced digestion, increased breakdown of glycogen to glucose in liver

effects of adrenaline on central nervous system

activation of the sympathetic branch of the autonomic nervous system

what is the first step of ATP yield

glycolysis

• glucose is broken down into pyruvate

• 2 ATP are made

• 2 NAD produced (via electron transport chain)

what is the second step of ATP yield

link reaction

• pyruvate converted into Acetyl coA

• 2 NAD produced

what is the third step of ATP yield

Krebs cycle

• Acetyl coA enters the Krebs cycle

• produces 6 NAD, 2 FAD, 2 ATP

what is the total ATP yield

32

define rate limiting enzymes

an enzyme in the metabolic pathway that determines the speed and direction of a reaction and often catalyses the metabolically irreversible step

example of rate limiting enzymes in cellular respiration

glycolysis (glucose - pyruvate)

body mass index calc (kg.m2)

• normal value for male and female

mass (kg) / [height (m)]2

fat mass

(% body fat / 100) x body mass

Fat free mass

(% non-body fat / 100) x body mass

waist to hip ratio

waist circumference / hip circumference

mean arterial pressure (mmHg)

(systolic bp + (diastolic bp x2))/3

cardiac output (L.min-1)

HR (bpm) X SV (ml)

FEV1/ FVC ratio (%)

(FEV1/ FVC) X100

minute ventilation (L.min-1)

respiratory rate x tidal volume

absolute haemltocrit from blood volume (ml)

(relative haematocrit / 100) x blood volume

daily resting metabolic rate (kcal.min-1)

resting metabolic rate (per min) x 60min x 24hrs